Remove configuration preprocessor symbols 'THREAD'

and 'THREAD_SAFE_CLIENT'.
  
As of MySQL 5.5, we no longer support non-threaded
builds.   This patch removes all references to the
obsolete THREAD and THREAD_SAFE_CLIENT preprocessor
symbols.  These were used to distinguish between
threaded and non-threaded builds.

67 files changed, 94 insertions, 816 deletions

diff --git a/client/mysqladmin.cc b/client/mysqladmin.cc
index 4c4747c25de..2c10fdbe853 100644
--- a/client/mysqladmin.cc
+++ b/client/mysqladmin.cc
@@ -1,4 +1,4 @@
-/* Copyright (c) 2000, 2010, Oracle and/or its affiliates. All rights reserved.
+/* Copyright (c) 2000, 2011, Oracle and/or its affiliates. All rights reserved.
 
    This program is free software; you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
@@ -17,9 +17,7 @@
 
 #include "client_priv.h"
 #include <signal.h>
-#ifdef THREAD
 #include <my_pthread.h>				/* because of signal()	*/
-#endif
 #include <sys/stat.h>
 #include <mysql.h>
 #include <sql_common.h>
diff --git a/cmd-line-utils/readline/CMakeLists.txt b/cmd-line-utils/readline/CMakeLists.txt
index ed6a6b902ea..be84f22f210 100644
--- a/cmd-line-utils/readline/CMakeLists.txt
+++ b/cmd-line-utils/readline/CMakeLists.txt
@@ -16,7 +16,7 @@
 INCLUDE_DIRECTORIES(${CMAKE_SOURCE_DIR}/include
                     ${CMAKE_SOURCE_DIR}/cmd-line-utils)
 
-ADD_DEFINITIONS(-DHAVE_CONFIG_H -DNO_KILL_INTR -DMYSQL_CLIENT_NO_THREADS)
+ADD_DEFINITIONS(-DHAVE_CONFIG_H -DNO_KILL_INTR)
 
 INCLUDE_DIRECTORIES(${CURSES_INCLUDE_PATH})
 
diff --git a/config.h.cmake b/config.h.cmake
index fc582da337f..204e1032410 100644
--- a/config.h.cmake
+++ b/config.h.cmake
@@ -1,5 +1,6 @@
-/* Copyright (C) 2009 Sun Microsystems, Inc
- 
+/* Copyright (C) 2009, 2011, Oracle and/or its affiliates. All rights
+   reserved
+
  This program is free software; you can redistribute it and/or modify
  it under the terms of the GNU General Public License as published by
  the Free Software Foundation; version 2 of the License.
@@ -470,9 +471,6 @@
 
 #cmakedefine STACK_DIRECTION @STACK_DIRECTION@
 
-#define THREAD 1
-#define THREAD_SAFE_CLIENT 1
-
 #define SYSTEM_TYPE "@SYSTEM_TYPE@"
 #define MACHINE_TYPE "@CMAKE_SYSTEM_PROCESSOR@"
 #cmakedefine HAVE_DTRACE 1
diff --git a/dbug/dbug.c b/dbug/dbug.c
index 74568f55fe0..2c06eeff95a 100644
--- a/dbug/dbug.c
+++ b/dbug/dbug.c
@@ -319,15 +319,6 @@ static void DbugExit(const char *why);
 static const char *DbugStrTok(const char *s);
 static void DbugVfprintf(FILE *stream, const char* format, va_list args);
 
-#ifndef THREAD
-        /* Open profile output stream */
-static FILE *OpenProfile(CODE_STATE *cs, const char *name);
-        /* Profile if asked for it */
-static BOOLEAN DoProfile(CODE_STATE *);
-        /* Return current user time (ms) */
-static unsigned long Clock(void);
-#endif
-
 /*
  *      Miscellaneous printf format strings.
  */
@@ -355,7 +346,6 @@ static unsigned long Clock(void);
 ** Macros to allow dbugging with threads
 */
 
-#ifdef THREAD
 #include <my_pthread.h>
 static pthread_mutex_t THR_LOCK_dbug;
 
@@ -394,30 +384,6 @@ static CODE_STATE *code_state(void)
   return cs;
 }
 
-#else /* !THREAD */
-
-static CODE_STATE static_code_state=
-{
-  "dbug", "?func", "?file", NULL, &init_settings,
-  NullS, NullS, 0,0,0,0,0,NullS
-};
-
-static CODE_STATE *code_state(void)
-{
-  if (!init_done)
-  {
-    bzero(&init_settings, sizeof(init_settings));
-    init_settings.out_file=stderr;
-    init_settings.flags=OPEN_APPEND;
-    init_done=TRUE;
-  }
-  return &static_code_state;
-}
-
-#define pthread_mutex_lock(A) {}
-#define pthread_mutex_unlock(A) {}
-#endif
-
 /*
  *      Translate some calls among different systems.
  */
@@ -601,15 +567,6 @@ int DbugParse(CODE_STATE *cs, const char *control)
       else
         stack->flags |= PID_ON;
       break;
-#ifndef THREAD
-    case 'g':
-      if (OpenProfile(cs, PROF_FILE))
-      {
-        stack->flags |= PROFILE_ON;
-        stack->p_functions= ListAdd(stack->p_functions, control, end);
-      }
-      break;
-#endif
     case 'L':
       if (sign < 0)
         stack->flags &= ~LINE_ON;
@@ -1154,23 +1111,7 @@ void _db_enter_(const char *_func_, const char *_file_,
   _stack_frame_->prev= cs->framep;
   _stack_frame_->level= ++cs->level | framep_trace_flag(cs, cs->framep);
   cs->framep= _stack_frame_;
-#ifndef THREAD
-  if (DoProfile(cs))
-  {
-    long stackused;
-    if (cs->framep->prev == NULL)
-      stackused= 0;
-    else
-    {
-      stackused= (char*)(cs->framep->prev) - (char*)(cs->framep);
-      stackused= stackused > 0 ? stackused : -stackused;
-    }
-    (void) fprintf(cs->stack->prof_file, PROF_EFMT , Clock(), cs->func);
-    (void) fprintf(cs->stack->prof_file, PROF_SFMT, (ulong) cs->framep, stackused,
-                   AUTOS_REVERSE ? _stack_frame_->func : cs->func);
-    (void) fflush(cs->stack->prof_file);
-  }
-#endif
+
   switch (DoTrace(cs)) {
   case ENABLE_TRACE:
     cs->framep->level|= TRACE_ON;
@@ -1229,10 +1170,7 @@ void _db_return_(uint _line_, struct _db_stack_frame_ *_stack_frame_)
     my_snprintf(buf, sizeof(buf), ERR_MISSING_RETURN, cs->func);
     DbugExit(buf);
   }
-#ifndef THREAD
-  if (DoProfile(cs))
-    (void) fprintf(cs->stack->prof_file, PROF_XFMT, Clock(), cs->func);
-#endif
+
   if (DoTrace(cs) & DO_TRACE)
   {
     if (TRACING)
@@ -1744,36 +1682,6 @@ static int DoTrace(CODE_STATE *cs)
   return DONT_TRACE;
 }
 
-
-/*
- *  FUNCTION
- *
- *      DoProfile    check to see if profiling is current enabled
- *
- *  SYNOPSIS
- *
- *      static BOOLEAN DoProfile()
- *
- *  DESCRIPTION
- *
- *      Checks to see if profiling is enabled based on whether the
- *      user has specified profiling, the maximum trace depth has
- *      not yet been reached, the current function is selected,
- *      and the current process is selected.  Returns TRUE if
- *      profiling is enabled, FALSE otherwise.
- *
- */
-
-#ifndef THREAD
-static BOOLEAN DoProfile(CODE_STATE *cs)
-{
-  return PROFILING &&
-         cs->level <= cs->stack->maxdepth &&
-         InList(cs->stack->p_functions, cs->func) & (INCLUDE|MATCHED) &&
-         InList(cs->stack->processes, cs->process) & (INCLUDE|MATCHED);
-}
-#endif
-
 FILE *_db_fp_(void)
 {
   CODE_STATE *cs;
@@ -1900,11 +1808,7 @@ static void DoPrefix(CODE_STATE *cs, uint _line_)
   cs->lineno++;
   if (cs->stack->flags & PID_ON)
   {
-#ifdef THREAD
     (void) fprintf(cs->stack->out_file, "%-7s: ", my_thread_name());
-#else
-    (void) fprintf(cs->stack->out_file, "%5d: ", (int) getpid());
-#endif
   }
   if (cs->stack->flags & NUMBER_ON)
     (void) fprintf(cs->stack->out_file, "%5d: ", cs->lineno);
@@ -2014,63 +1918,6 @@ static void DBUGOpenFile(CODE_STATE *cs,
   }
 }
 
-
-/*
- *  FUNCTION
- *
- *      OpenProfile    open new output stream for profiler output
- *
- *  SYNOPSIS
- *
- *      static FILE *OpenProfile(name)
- *      char *name;
- *
- *  DESCRIPTION
- *
- *      Given name of a new file, opens the file
- *      and sets the profiler output stream to the new file.
- *
- *      It is currently unclear whether the prefered behavior is
- *      to truncate any existing file, or simply append to it.
- *      The latter behavior would be desirable for collecting
- *      accumulated runtime history over a number of separate
- *      runs.  It might take some changes to the analyzer program
- *      though, and the notes that Binayak sent with the profiling
- *      diffs indicated that append was the normal mode, but this
- *      does not appear to agree with the actual code. I haven't
- *      investigated at this time [fnf; 24-Jul-87].
- */
-
-#ifndef THREAD
-static FILE *OpenProfile(CODE_STATE *cs, const char *name)
-{
-  REGISTER FILE *fp;
-  REGISTER BOOLEAN newfile;
-
-  fp=0;
-  if (!Writable(name))
-  {
-    (void) fprintf(cs->stack->out_file, ERR_OPEN, cs->process, name);
-    perror("");
-    (void) Delay(cs->stack->delay);
-  }
-  else
-  {
-    newfile= !EXISTS(name);
-    if (!(fp= fopen(name, "w")))
-    {
-      (void) fprintf(cs->stack->out_file, ERR_OPEN, cs->process, name);
-      perror("");
-    }
-    else
-    {
-      cs->stack->prof_file= fp;
-    }
-  }
-  return fp;
-}
-#endif
-
 /*
  *  FUNCTION
  *
@@ -2419,80 +2266,6 @@ const char* _db_get_func_(void)
   return cs->func;
 }
 
-/*
- * Here we need the definitions of the clock routine.  Add your
- * own for whatever system that you have.
- */
-
-#ifndef THREAD
-#if defined(HAVE_GETRUSAGE)
-
-#include <sys/param.h>
-#include <sys/resource.h>
-
-/* extern int getrusage(int, struct rusage *); */
-
-/*
- * Returns the user time in milliseconds used by this process so
- * far.
- */
-
-static unsigned long Clock()
-{
-    struct rusage ru;
-
-    (void) getrusage(RUSAGE_SELF, &ru);
-    return ru.ru_utime.tv_sec*1000 + ru.ru_utime.tv_usec/1000;
-}
-
-#elif defined(__WIN__)
-
-static ulong Clock()
-{
-  return clock()*(1000/CLOCKS_PER_SEC);
-}
-#elif defined(amiga)
-
-struct DateStamp {              /* Yes, this is a hack, but doing it right */
-        long ds_Days;           /* is incredibly ugly without splitting this */
-        long ds_Minute;         /* off into a separate file */
-        long ds_Tick;
-};
-
-static int first_clock= TRUE;
-static struct DateStamp begin;
-static struct DateStamp elapsed;
-
-static unsigned long Clock()
-{
-    register struct DateStamp *now;
-    register unsigned long millisec= 0;
-    extern VOID *AllocMem();
-
-    now= (struct DateStamp *) AllocMem((long) sizeof(struct DateStamp), 0L);
-    if (now != NULL)
-    {
-        if (first_clock == TRUE)
-        {
-            first_clock= FALSE;
-            (void) DateStamp(now);
-            begin= *now;
-        }
-        (void) DateStamp(now);
-        millisec= 24 * 3600 * (1000 / HZ) * (now->ds_Days - begin.ds_Days);
-        millisec += 60 * (1000 / HZ) * (now->ds_Minute - begin.ds_Minute);
-        millisec += (1000 / HZ) * (now->ds_Tick - begin.ds_Tick);
-        (void) FreeMem(now, (long) sizeof(struct DateStamp));
-    }
-    return millisec;
-}
-#else
-static unsigned long Clock()
-{
-    return 0;
-}
-#endif /* RUSAGE */
-#endif /* THREADS */
 
 #else
 
diff --git a/dbug/dbug_analyze.c b/dbug/dbug_analyze.c
index 1ebe8bfd77e..3d5713758ae 100644
--- a/dbug/dbug_analyze.c
+++ b/dbug/dbug_analyze.c
@@ -571,12 +571,10 @@ int main (int argc, char **argv)
     FILE *infile;
     FILE *outfile = {stdout};
 
-#ifdef THREAD
 #if defined(HAVE_PTHREAD_INIT)
   pthread_init();                       /* Must be called before DBUG_ENTER */
 #endif
-  my_thread_global_init();
-#endif /* THREAD */
+  my_thread_global_init(); 
   {
     DBUG_ENTER ("main");
     DBUG_PROCESS (argv[0]);
diff --git a/dbug/my_main.c b/dbug/my_main.c
index 31c15aa67aa..48d092ca10a 100644
--- a/dbug/my_main.c
+++ b/dbug/my_main.c
@@ -16,12 +16,11 @@ char *argv[];
 {
   register int result, ix;
   extern int factorial(int);
-#if defined(HAVE_PTHREAD_INIT) && defined(THREAD)
+#if defined(HAVE_PTHREAD_INIT)
   pthread_init();			/* Must be called before DBUG_ENTER */
 #endif
-#ifdef THREAD
   my_thread_global_init();
-#endif
+
   {
     DBUG_ENTER ("main");
     DBUG_PROCESS (argv[0]);
diff --git a/dbug/tests.c b/dbug/tests.c
index d76266d34a3..837a477aef3 100644
--- a/dbug/tests.c
+++ b/dbug/tests.c
@@ -44,12 +44,11 @@ int main (int argc, char *argv[])
   if (argc == 1)
     return 0;
 
-#if defined(HAVE_PTHREAD_INIT) && defined(THREAD)
+#if defined(HAVE_PTHREAD_INIT)
   pthread_init();                       /* Must be called before DBUG_ENTER */
 #endif
-#ifdef THREAD
   my_thread_global_init();
-#endif
+
   dup2(1, 2);
   for (i = 1; i < argc; i++)
   {
diff --git a/include/CMakeLists.txt b/include/CMakeLists.txt
index e89929d159d..d8bac7532cc 100644
--- a/include/CMakeLists.txt
+++ b/include/CMakeLists.txt
@@ -40,7 +40,6 @@ SET(HEADERS
   my_xml.h
   mysql_embed.h
   my_pthread.h
-  my_no_pthread.h 
   decimal.h
   errmsg.h
   my_global.h
diff --git a/include/heap.h b/include/heap.h
index a585371e18f..755a1aa3fed 100644
--- a/include/heap.h
+++ b/include/heap.h
@@ -1,4 +1,5 @@
-/* Copyright (C) 2000-2004 MySQL AB, 2009 Sun Microsystems, Inc
+/* Copyright (C) 2000, 2011, Oracle and/or its affiliates. All rights 
+   reserved
 
    This program is free software; you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
@@ -25,10 +26,9 @@ extern "C" {
 #ifndef _my_base_h
 #include <my_base.h>
 #endif
-#ifdef THREAD
+
 #include <my_pthread.h>
 #include <thr_lock.h>
-#endif
 
 #include "my_handler.h"
 #include "my_tree.h"
@@ -146,10 +146,8 @@ typedef struct st_heap_share
   uint open_count;
   uchar *del_link;			/* Link to next block with del. rec */
   char * name;			/* Name of "memory-file" */
-#ifdef THREAD
   THR_LOCK lock;
   mysql_mutex_t intern_lock;            /* Locking for use with _locking */
-#endif
   my_bool delete_on_close;
   LIST open_list;
   uint auto_key;
@@ -175,9 +173,7 @@ typedef struct st_heap_info
   TREE_ELEMENT **last_pos;
   uint lastkey_len;
   my_bool implicit_emptied;
-#ifdef THREAD
   THR_LOCK_DATA lock;
-#endif
   LIST open_list;
 } HP_INFO;
 
diff --git a/include/my_base.h b/include/my_base.h
index 83b02bfd833..347bda01bef 100644
--- a/include/my_base.h
+++ b/include/my_base.h
@@ -1,4 +1,5 @@
-/* Copyright (C) 2000 MySQL AB
+/* Copyright (C) 2000, 2011, Oracle and/or its affiliates. All rights 
+   reserved
 
    This program is free software; you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
@@ -30,9 +31,6 @@
 #define EOVERFLOW 84
 #endif
 
-#if !defined(USE_MY_FUNC) && !defined(THREAD)
-#include <my_nosys.h>			/* For faster code, after test */
-#endif	/* USE_MY_FUNC */
 #endif	/* stdin */
 #include <my_list.h>
 
diff --git a/include/my_bitmap.h b/include/my_bitmap.h
index 548eec14d6e..78b33b09a51 100644
--- a/include/my_bitmap.h
+++ b/include/my_bitmap.h
@@ -33,9 +33,7 @@ typedef struct st_bitmap
      thread_safe flag in bitmap_init was set.  Otherwise, we optimize by not
      acquiring the mutex
    */
-#ifdef THREAD
   mysql_mutex_t *mutex;
-#endif
 } MY_BITMAP;
 
 #ifdef	__cplusplus
diff --git a/include/my_global.h b/include/my_global.h
index a411ab8a118..c1ae8a6d6bc 100644
--- a/include/my_global.h
+++ b/include/my_global.h
@@ -212,13 +212,6 @@
 #include <sys/types.h>
 #endif
 
-/* The client defines this to avoid all thread code */
-#if defined(MYSQL_CLIENT_NO_THREADS) || defined(UNDEF_THREADS_HACK)
-#undef THREAD
-#undef HAVE_LINUXTHREADS
-#undef HAVE_NPTL
-#endif
-
 #ifdef HAVE_THREADS_WITHOUT_SOCKETS
 /* MIT pthreads does not work with unix sockets */
 #undef HAVE_SYS_UN_H
@@ -261,7 +254,7 @@
 #endif
 #endif
 
-#if defined(THREAD) && !defined(__WIN__)
+#if !defined(__WIN__)
 #ifndef _POSIX_PTHREAD_SEMANTICS
 #define _POSIX_PTHREAD_SEMANTICS /* We want posix threads */
 #endif
@@ -282,7 +275,7 @@ C_MODE_END
 #if !defined(SCO) && !defined(_REENTRANT)
 #define _REENTRANT	1	/* Threads requires reentrant code */
 #endif
-#endif /* THREAD */
+#endif /* !defined(__WIN__) */
 
 /* Go around some bugs in different OS and compilers */
 #ifdef _AIX			/* By soren@t.dk */
@@ -415,7 +408,7 @@ C_MODE_END
 #include <sys/stream.h>		/* HPUX 10.20 defines ulong here. UGLY !!! */
 #define HAVE_ULONG
 #endif
-#if defined(HPUX10) && defined(_LARGEFILE64_SOURCE) && defined(THREAD)
+#if defined(HPUX10) && defined(_LARGEFILE64_SOURCE)
 /* Fix bug in setrlimit */
 #undef setrlimit
 #define setrlimit cma_setrlimit64
@@ -1342,17 +1335,6 @@ do { doubleget_union _tmp; \
 
 #endif /* WORDS_BIGENDIAN */
 
-#ifndef THREAD
-#define thread_safe_increment(V,L) (V)++
-#define thread_safe_decrement(V,L) (V)--
-#define thread_safe_add(V,C,L)     (V)+=(C)
-#define thread_safe_sub(V,C,L)     (V)-=(C)
-#define statistic_increment(V,L)   (V)++
-#define statistic_decrement(V,L)   (V)--
-#define statistic_add(V,C,L)       (V)+=(C)
-#define statistic_sub(V,C,L)       (V)-=(C)
-#endif
-
 #ifdef HAVE_CHARSET_utf8
 #define MYSQL_UNIVERSAL_CLIENT_CHARSET "utf8"
 #else
diff --git a/include/my_no_pthread.h b/include/my_no_pthread.h
deleted file mode 100644
index 633a5b94a6c..00000000000
--- a/include/my_no_pthread.h
+++ /dev/null
@@ -1,72 +0,0 @@
-#ifndef MY_NO_PTHREAD_INCLUDED
-#define MY_NO_PTHREAD_INCLUDED
-
-/* Copyright (C) 2000 MySQL AB, 2008-2009 Sun Microsystems, Inc
-
-   This program is free software; you can redistribute it and/or modify
-   it under the terms of the GNU General Public License as published by
-   the Free Software Foundation; version 2 of the License.
-
-   This program is distributed in the hope that it will be useful,
-   but WITHOUT ANY WARRANTY; without even the implied warranty of
-   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
-   GNU General Public License for more details.
-
-   You should have received a copy of the GNU General Public License
-   along with this program; if not, write to the Free Software
-   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA */
-
-
-#ifndef THREAD
-
-/*
-  This block is to access some thread-related type definitions
-  even in builds which do not need thread functions,
-  as some variables (based on these types) are declared
-  even in non-threaded builds.
-  Case in point: 'mf_keycache.c'
-*/
-#if defined(__WIN__)
-#else /* Normal threads */
-#include <pthread.h>
-
-#endif /* defined(__WIN__) */
-
-
-/*
-  This undefs some pthread mutex locks when one isn't using threads
-  to make thread safe code, that should also work in single thread
-  environment, easier to use.
-*/
-#define pthread_mutex_init(A,B)
-#define pthread_mutex_lock(A)
-#define pthread_mutex_unlock(A)
-#define pthread_mutex_destroy(A)
-#define my_rwlock_init(A,B)
-#define rw_rdlock(A)
-#define rw_wrlock(A)
-#define rw_unlock(A)
-#define rwlock_destroy(A)
-#define safe_mutex_assert_owner(mp)
-
-#define mysql_mutex_init(A, B, C) do {} while (0)
-#define mysql_mutex_lock(A) do {} while (0)
-#define mysql_mutex_unlock(A) do {} while (0)
-#define mysql_mutex_destroy(A) do {} while (0)
-
-#define mysql_rwlock_init(A, B, C) do {} while (0)
-#define mysql_rwlock_rdlock(A) do {} while (0)
-#define mysql_rwlock_wrlock(A) do {} while (0)
-#define mysql_rwlock_unlock(A) do {} while (0)
-#define mysql_rwlock_destroy(A) do {} while (0)
-
-typedef int my_pthread_once_t;
-#define MY_PTHREAD_ONCE_INIT 0
-#define MY_PTHREAD_ONCE_DONE 1
-
-#define my_pthread_once(C,F) do { \
-    if (*(C) != MY_PTHREAD_ONCE_DONE) { F(); *(C)= MY_PTHREAD_ONCE_DONE; } \
-  } while(0)
-
-#endif
-#endif /* MY_NO_PTHREAD_INCLUDED */
diff --git a/include/my_pthread.h b/include/my_pthread.h
index c71ad9bf321..f1636cad136 100644
--- a/include/my_pthread.h
+++ b/include/my_pthread.h
@@ -881,12 +881,6 @@ extern uint thd_lib_detected;
   to use my_atomic operations instead.
 */
 
-/*
-  Warning:
-  When compiling without threads, this file is not included.
-  See the *other* declarations of thread_safe_xxx in include/my_global.h
-*/
-#ifdef THREAD
 #ifndef thread_safe_increment
 #ifdef _WIN32
 #define thread_safe_increment(V,L) InterlockedIncrement((long*) &(V))
@@ -910,7 +904,7 @@ extern uint thd_lib_detected;
         (mysql_mutex_lock((L)), (V)-=(C), mysql_mutex_unlock((L)))
 #endif
 #endif
-#endif
+
 
 /*
   statistics_xxx functions are for non critical statistic,
diff --git a/include/my_sys.h b/include/my_sys.h
index 8f7d5b0925d..96b40415c56 100644
--- a/include/my_sys.h
+++ b/include/my_sys.h
@@ -41,11 +41,7 @@ typedef struct my_aio_result {
 # define MEM_CHECK_DEFINED(a,len) ((void) 0)
 #endif /* HAVE_VALGRIND */
 
-#ifndef THREAD
-extern int my_errno;  /* Last error in mysys */
-#else
 #include <my_pthread.h>
-#endif
 
 #include <m_ctype.h>                    /* for CHARSET_INFO */
 #include <stdarg.h>
@@ -314,7 +310,7 @@ struct st_my_file_info
   int    oflag;     /* open flags, e.g O_APPEND */
 #endif
   enum   file_type	type;
-#if defined(THREAD) && !defined(HAVE_PREAD) && !defined(_WIN32)
+#if !defined(HAVE_PREAD) && !defined(_WIN32)
   mysql_mutex_t mutex;
 #endif
 };
@@ -334,9 +330,7 @@ typedef struct st_my_tmpdir
   DYNAMIC_ARRAY full_list;
   char **list;
   uint cur, max;
-#ifdef THREAD
   mysql_mutex_t mutex;
-#endif
 } MY_TMPDIR;
 
 typedef struct st_dynamic_string
@@ -348,7 +342,6 @@ typedef struct st_dynamic_string
 struct st_io_cache;
 typedef int (*IO_CACHE_CALLBACK)(struct st_io_cache*);
 
-#ifdef THREAD
 typedef struct st_io_cache_share
 {
   mysql_mutex_t       mutex;           /* To sync on reads into buffer. */
@@ -368,7 +361,6 @@ typedef struct st_io_cache_share
   my_bool alloced;
 #endif
 } IO_CACHE_SHARE;
-#endif
 
 typedef struct st_io_cache		/* Used when cacheing files */
 {
@@ -409,7 +401,7 @@ typedef struct st_io_cache		/* Used when cacheing files */
     WRITE_CACHE, and &read_pos and &read_end respectively otherwise
   */
   uchar  **current_pos, **current_end;
-#ifdef THREAD
+
   /*
     The lock is for append buffer used in SEQ_READ_APPEND cache
     need mutex copying from append buffer to read buffer.
@@ -423,7 +415,7 @@ typedef struct st_io_cache		/* Used when cacheing files */
     READ_CACHE mode is supported.
   */
   IO_CACHE_SHARE *share;
-#endif
+
   /*
     A caller will use my_b_read() macro to read from the cache
     if the data is already in cache, it will be simply copied with
@@ -656,14 +648,6 @@ extern int my_redel(const char *from, const char *to, int MyFlags);
 extern int my_copystat(const char *from, const char *to, int MyFlags);
 extern char * my_filename(File fd);
 
-#ifndef THREAD
-extern void dont_break(void);
-extern void allow_break(void);
-#else
-#define dont_break()
-#define allow_break()
-#endif
-
 #ifdef EXTRA_DEBUG
 void my_print_open_files(void);
 #else
@@ -736,12 +720,10 @@ extern my_bool reinit_io_cache(IO_CACHE *info,enum cache_type type,
 			       pbool clear_cache);
 extern void setup_io_cache(IO_CACHE* info);
 extern int _my_b_read(IO_CACHE *info,uchar *Buffer,size_t Count);
-#ifdef THREAD
 extern int _my_b_read_r(IO_CACHE *info,uchar *Buffer,size_t Count);
 extern void init_io_cache_share(IO_CACHE *read_cache, IO_CACHE_SHARE *cshare,
                                 IO_CACHE *write_cache, uint num_threads);
 extern void remove_io_thread(IO_CACHE *info);
-#endif
 extern int _my_b_seq_read(IO_CACHE *info,uchar *Buffer,size_t Count);
 extern int _my_b_net_read(IO_CACHE *info,uchar *Buffer,size_t Count);
 extern int _my_b_get(IO_CACHE *info);
diff --git a/include/myisam.h b/include/myisam.h
index c4076ead403..cb641e12e8e 100644
--- a/include/myisam.h
+++ b/include/myisam.h
@@ -433,10 +433,8 @@ typedef struct st_mi_check_param
   const char *db_name, *table_name;
   const char *op_name;
   enum_mi_stats_method stats_method;
-#ifdef THREAD
   mysql_mutex_t print_msg_mutex;
   my_bool need_print_msg_lock;
-#endif
 } MI_CHECK;
 
 typedef struct st_sort_ft_buf
@@ -460,10 +458,8 @@ typedef struct st_sort_info
   SORT_FT_BUF *ft_buf;
   /* sync things */
   uint got_error, threads_running;
-#ifdef THREAD
   mysql_mutex_t mutex;
   mysql_cond_t  cond;
-#endif
 } SORT_INFO;
 
 /* functions in mi_check */
diff --git a/include/thr_alarm.h b/include/thr_alarm.h
index 8d7f5bcdee0..8c91fc0b899 100644
--- a/include/thr_alarm.h
+++ b/include/thr_alarm.h
@@ -41,7 +41,7 @@ typedef struct st_alarm_info
 
 void thr_alarm_info(ALARM_INFO *info);
 
-#if defined(DONT_USE_THR_ALARM) || !defined(THREAD)
+#if defined(DONT_USE_THR_ALARM)
 
 #define USE_ALARM_THREAD
 #undef USE_ONE_SIGNAL_HAND
diff --git a/libmysql/client_settings.h b/libmysql/client_settings.h
index 5204d03e5af..c5a08ce1fcc 100644
--- a/libmysql/client_settings.h
+++ b/libmysql/client_settings.h
@@ -35,21 +35,6 @@ sig_handler my_pipe_sig_handler(int sig);
 void read_user_name(char *name);
 my_bool handle_local_infile(MYSQL *mysql, const char *net_filename);
 
-/*
-  Let the user specify that we don't want SIGPIPE;  This doesn't however work
-  with threaded applications as we can have multiple read in progress.
-*/
-
-#if !defined(__WIN__) && defined(SIGPIPE) && !defined(THREAD)
-#define init_sigpipe_variables  sig_return old_signal_handler=(sig_return) 0;
-#define set_sigpipe(mysql)     if ((mysql)->client_flag & CLIENT_IGNORE_SIGPIPE) old_signal_handler=signal(SIGPIPE, my_pipe_sig_handler)
-#define reset_sigpipe(mysql) if ((mysql)->client_flag & CLIENT_IGNORE_SIGPIPE) signal(SIGPIPE,old_signal_handler);
-#else
-#define init_sigpipe_variables
-#define set_sigpipe(mysql)
-#define reset_sigpipe(mysql)
-#endif
-
 void mysql_read_default_options(struct st_mysql_options *options,
 				const char *filename,const char *group);
 void mysql_detach_stmt_list(LIST **stmt_list, const char *func_name);
diff --git a/libmysql/libmysql.c b/libmysql/libmysql.c
index c498ed0f089..f802387cf9a 100644
--- a/libmysql/libmysql.c
+++ b/libmysql/libmysql.c
@@ -51,7 +51,7 @@
 #ifdef HAVE_SYS_UN_H
 #include <sys/un.h>
 #endif
-#if defined(THREAD) && !defined(__WIN__)
+#if !defined(__WIN__)
 #include <my_pthread.h>				/* because of signal()	*/
 #endif
 #ifndef INADDR_NONE
@@ -172,10 +172,8 @@ int STDCALL mysql_server_init(int argc __attribute__((unused)),
        result= init_embedded_server(argc, argv, groups);
 #endif
   }
-#ifdef THREAD
   else
     result= (int)my_thread_init();         /* Init if new thread */
-#endif
   return result;
 }
 
@@ -229,18 +227,12 @@ MYSQL_PARAMETERS *STDCALL mysql_get_parameters(void)
 
 my_bool STDCALL mysql_thread_init()
 {
-#ifdef THREAD
   return my_thread_init();
-#else
-  return 0;
-#endif
 }
 
 void STDCALL mysql_thread_end()
 {
-#ifdef THREAD
   my_thread_end();
-#endif
 }
 
 
@@ -1092,11 +1084,7 @@ void STDCALL mysql_get_character_set_info(MYSQL *mysql, MY_CHARSET_INFO *csinfo)
 
 uint STDCALL mysql_thread_safe(void)
 {
-#ifdef THREAD
   return 1;
-#else
-  return 0;
-#endif
 }
 
 
diff --git a/mysys/mf_brkhant.c b/mysys/mf_brkhant.c
deleted file mode 100644
index 3573b9973b2..00000000000
--- a/mysys/mf_brkhant.c
+++ /dev/null
@@ -1,72 +0,0 @@
-/* Copyright (C) 2000 MySQL AB
-
-   This program is free software; you can redistribute it and/or modify
-   it under the terms of the GNU General Public License as published by
-   the Free Software Foundation; version 2 of the License.
-
-   This program is distributed in the hope that it will be useful,
-   but WITHOUT ANY WARRANTY; without even the implied warranty of
-   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
-   GNU General Public License for more details.
-
-   You should have received a copy of the GNU General Public License
-   along with this program; if not, write to the Free Software
-   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA */
-
-/* Dont let the user break when you are doing something important */
-/* Remembers if it got 'SIGINT' and executes it on allow_break */
-/* A static buffer is used; don't call dont_break() twice in a row */
-
-#include "mysys_priv.h"
-#include "my_static.h"
-
-	/* Set variable that we can't break */
-
-#if !defined(THREAD)
-void dont_break(void)
-{
-  my_dont_interrupt=1;
-  return;
-} /* dont_break */
-
-void allow_break(void)
-{
-  {
-    reg1 int index;
-
-    my_dont_interrupt=0;
-    if (_my_signals)
-    {
-      if (_my_signals > MAX_SIGNALS)
-	_my_signals=MAX_SIGNALS;
-      for (index=0 ; index < _my_signals ; index++)
-      {
-	if (_my_sig_remember[index].func)			/* Safequard */
-	{
-	  (*_my_sig_remember[index].func)(_my_sig_remember[index].number);
-	  _my_sig_remember[index].func=0;
-	}
-      }
-      _my_signals=0;
-    }
-  }
-} /* dont_break */
-#endif
-
-	/* Set old status */
-
-#if !defined(THREAD)
-void my_remember_signal(int signal_number, sig_handler (*func) (int))
-{
-#ifndef __WIN__
-  reg1 int index;
-
-  index=_my_signals++;			/* Nobody can break a ++ ? */
-  if (index < MAX_SIGNALS)
-  {
-    _my_sig_remember[index].number=signal_number;
-    _my_sig_remember[index].func=func;
-  }
-#endif /* __WIN__ */
-} /* my_remember_signal */
-#endif /* THREAD */
diff --git a/mysys/mf_iocache.c b/mysys/mf_iocache.c
index 575581712d4..62e51ffb629 100644
--- a/mysys/mf_iocache.c
+++ b/mysys/mf_iocache.c
@@ -55,15 +55,10 @@ static void my_aiowait(my_aio_result *result);
 #endif
 #include <errno.h>
 
-#ifdef THREAD
 #define lock_append_buffer(info) \
   mysql_mutex_lock(&(info)->append_buffer_lock)
 #define unlock_append_buffer(info) \
   mysql_mutex_unlock(&(info)->append_buffer_lock)
-#else
-#define lock_append_buffer(info)
-#define unlock_append_buffer(info)
-#endif
 
 #define IO_ROUND_UP(X) (((X)+IO_SIZE-1) & ~(IO_SIZE-1))
 #define IO_ROUND_DN(X) ( (X)            & ~(IO_SIZE-1))
@@ -116,11 +111,7 @@ init_functions(IO_CACHE* info)
     info->write_function = 0;			/* Force a core if used */
     break;
   default:
-    info->read_function =
-#ifdef THREAD
-                          info->share ? _my_b_read_r :
-#endif
-                                        _my_b_read;
+    info->read_function = info->share ? _my_b_read_r : _my_b_read;
     info->write_function = _my_b_write;
   }
 
@@ -193,9 +184,7 @@ int init_io_cache(IO_CACHE *info, File file, size_t cachesize,
   }
 
   info->disk_writes= 0;
-#ifdef THREAD
   info->share=0;
-#endif
 
   if (!cachesize && !(cachesize= my_default_record_cache_size))
     DBUG_RETURN(1);				/* No cache requested */
@@ -263,12 +252,10 @@ int init_io_cache(IO_CACHE *info, File file, size_t cachesize,
   {
     info->append_read_pos = info->write_pos = info->write_buffer;
     info->write_end = info->write_buffer + info->buffer_length;
-#ifdef THREAD
     mysql_mutex_init(key_IO_CACHE_append_buffer_lock,
                      &info->append_buffer_lock, MY_MUTEX_INIT_FAST);
-#endif
   }
-#if defined(SAFE_MUTEX) && defined(THREAD)
+#if defined(SAFE_MUTEX)
   else
   {
     /* Clear mutex so that safe_mutex will notice that it's not initialized */
@@ -601,7 +588,6 @@ int _my_b_read(register IO_CACHE *info, uchar *Buffer, size_t Count)
 }
 
 
-#ifdef THREAD
 /*
   Prepare IO_CACHE for shared use.
 
@@ -1162,7 +1148,6 @@ static void copy_to_read_buffer(IO_CACHE *write_cache,
     write_length-= copy_length;
   }
 }
-#endif /*THREAD*/
 
 
 /*
@@ -1579,7 +1564,6 @@ int _my_b_write(register IO_CACHE *info, const uchar *Buffer, size_t Count)
     if (mysql_file_write(info->file, Buffer, length, info->myflags | MY_NABP))
       return info->error= -1;
 
-#ifdef THREAD
     /*
       In case of a shared I/O cache with a writer we normally do direct
       write cache to read cache copy. Simulate this here by direct
@@ -1593,7 +1577,6 @@ int _my_b_write(register IO_CACHE *info, const uchar *Buffer, size_t Count)
     */
     if (info->share)
       copy_to_read_buffer(info, Buffer, length);
-#endif
 
     Count-=length;
     Buffer+=length;
@@ -1615,13 +1598,11 @@ int my_b_append(register IO_CACHE *info, const uchar *Buffer, size_t Count)
 {
   size_t rest_length,length;
 
-#ifdef THREAD
   /*
     Assert that we cannot come here with a shared cache. If we do one
     day, we might need to add a call to copy_to_read_buffer().
   */
   DBUG_ASSERT(!info->share);
-#endif
 
   lock_append_buffer(info);
   rest_length= (size_t) (info->write_end - info->write_pos);
@@ -1683,13 +1664,11 @@ int my_block_write(register IO_CACHE *info, const uchar *Buffer, size_t Count,
   size_t length;
   int error=0;
 
-#ifdef THREAD
   /*
     Assert that we cannot come here with a shared cache. If we do one
     day, we might need to add a call to copy_to_read_buffer().
   */
   DBUG_ASSERT(!info->share);
-#endif
 
   if (pos < info->pos_in_file)
   {
@@ -1735,16 +1714,10 @@ int my_block_write(register IO_CACHE *info, const uchar *Buffer, size_t Count,
 
 	/* Flush write cache */
 
-#ifdef THREAD
 #define LOCK_APPEND_BUFFER if (need_append_buffer_lock) \
   lock_append_buffer(info);
 #define UNLOCK_APPEND_BUFFER if (need_append_buffer_lock) \
   unlock_append_buffer(info);
-#else
-#define LOCK_APPEND_BUFFER
-#define UNLOCK_APPEND_BUFFER
-#endif
-
 
 int my_b_flush_io_cache(IO_CACHE *info,
                         int need_append_buffer_lock __attribute__((unused)))
@@ -1755,10 +1728,8 @@ int my_b_flush_io_cache(IO_CACHE *info,
   DBUG_ENTER("my_b_flush_io_cache");
   DBUG_PRINT("enter", ("cache: 0x%lx", (long) info));
 
-#ifdef THREAD
   if (!append_cache)
     need_append_buffer_lock= 0;
-#endif
 
   if (info->type == WRITE_CACHE || append_cache)
   {
@@ -1771,7 +1742,6 @@ int my_b_flush_io_cache(IO_CACHE *info,
 
     if ((length=(size_t) (info->write_pos - info->write_buffer)))
     {
-#ifdef THREAD
       /*
         In case of a shared I/O cache with a writer we do direct write
         cache to read cache copy. Do it before the write here so that
@@ -1780,7 +1750,6 @@ int my_b_flush_io_cache(IO_CACHE *info,
       */
       if (info->share)
         copy_to_read_buffer(info, info->write_buffer, length);
-#endif
 
       pos_in_file=info->pos_in_file;
       /*
@@ -1859,13 +1828,11 @@ int end_io_cache(IO_CACHE *info)
   DBUG_ENTER("end_io_cache");
   DBUG_PRINT("enter",("cache: 0x%lx", (ulong) info));
 
-#ifdef THREAD
   /*
     Every thread must call remove_io_thread(). The last one destroys
     the share elements.
   */
   DBUG_ASSERT(!info->share || !info->share->total_threads);
-#endif
 
   if ((pre_close=info->pre_close))
   {
@@ -1884,9 +1851,7 @@ int end_io_cache(IO_CACHE *info)
   {
     /* Destroy allocated mutex */
     info->type= TYPE_NOT_SET;
-#ifdef THREAD
     mysql_mutex_destroy(&info->append_buffer_lock);
-#endif
   }
   DBUG_RETURN(error);
 } /* end_io_cache */
diff --git a/mysys/mf_iocache2.c b/mysys/mf_iocache2.c
index 7a40ea8a86f..8962a037da0 100644
--- a/mysys/mf_iocache2.c
+++ b/mysys/mf_iocache2.c
@@ -90,9 +90,8 @@ my_off_t my_b_append_tell(IO_CACHE* info)
     from messing with the variables that we need in order to provide the
     answer to the question.
   */
-#ifdef THREAD
   mysql_mutex_lock(&info->append_buffer_lock);
-#endif
+
 #ifndef DBUG_OFF
   /*
     Make sure EOF is where we think it is. Note that we cannot just use
@@ -112,9 +111,7 @@ my_off_t my_b_append_tell(IO_CACHE* info)
   }
 #endif  
   res = info->end_of_file + (info->write_pos-info->append_read_pos);
-#ifdef THREAD
   mysql_mutex_unlock(&info->append_buffer_lock);
-#endif
   return res;
 }
 
diff --git a/mysys/mf_keycache.c b/mysys/mf_keycache.c
index 9993c636fb1..42cdea65f34 100644
--- a/mysys/mf_keycache.c
+++ b/mysys/mf_keycache.c
@@ -225,14 +225,11 @@ KEY_CACHE *dflt_key_cache= &dflt_key_cache_var;
 #define FLUSH_CACHE         2000            /* sort this many blocks at once */
 
 static int flush_all_key_blocks(KEY_CACHE *keycache);
-#ifdef THREAD
+
 static void wait_on_queue(KEYCACHE_WQUEUE *wqueue,
                           mysql_mutex_t *mutex);
 static void release_whole_queue(KEYCACHE_WQUEUE *wqueue);
-#else
-#define wait_on_queue(wqueue, mutex)    do {} while (0)
-#define release_whole_queue(wqueue)     do {} while (0)
-#endif
+
 static void free_block(KEY_CACHE *keycache, BLOCK_LINK *block);
 #if !defined(DBUG_OFF)
 static void test_key_cache(KEY_CACHE *keycache,
@@ -285,7 +282,7 @@ static void keycache_debug_print(const char *fmt,...);
 #endif /* defined(KEYCACHE_DEBUG_LOG) && defined(KEYCACHE_DEBUG) */
 
 #if defined(KEYCACHE_DEBUG) || !defined(DBUG_OFF)
-#ifdef THREAD
+
 static long keycache_thread_id;
 #define KEYCACHE_THREAD_TRACE(l)                                              \
              KEYCACHE_DBUG_PRINT(l,("|thread %ld",keycache_thread_id))
@@ -297,11 +294,6 @@ static long keycache_thread_id;
 
 #define KEYCACHE_THREAD_TRACE_END(l)                                          \
             KEYCACHE_DBUG_PRINT(l,("]thread %ld",keycache_thread_id))
-#else /* THREAD */
-#define KEYCACHE_THREAD_TRACE(l)        KEYCACHE_DBUG_PRINT(l,(""))
-#define KEYCACHE_THREAD_TRACE_BEGIN(l)  KEYCACHE_DBUG_PRINT(l,(""))
-#define KEYCACHE_THREAD_TRACE_END(l)    KEYCACHE_DBUG_PRINT(l,(""))
-#endif /* THREAD */
 #else
 #define KEYCACHE_THREAD_TRACE_BEGIN(l)
 #define KEYCACHE_THREAD_TRACE_END(l)
@@ -583,7 +575,6 @@ int resize_key_cache(KEY_CACHE *keycache, uint key_cache_block_size,
 
   keycache_pthread_mutex_lock(&keycache->cache_lock);
 
-#ifdef THREAD
   /*
     We may need to wait for another thread which is doing a resize
     already. This cannot happen in the MySQL server though. It allows
@@ -596,7 +587,6 @@ int resize_key_cache(KEY_CACHE *keycache, uint key_cache_block_size,
     wait_on_queue(&keycache->resize_queue, &keycache->cache_lock);
     /* purecov: end */
   }
-#endif
 
   /*
     Mark the operation in progress. This blocks other threads from doing
@@ -625,7 +615,6 @@ int resize_key_cache(KEY_CACHE *keycache, uint key_cache_block_size,
     keycache->resize_in_flush= 0;
   }
 
-#ifdef THREAD
   /*
     Some direct read/write operations (bypassing the cache) may still be
     unfinished. Wait until they are done. If the key cache can be used,
@@ -639,9 +628,6 @@ int resize_key_cache(KEY_CACHE *keycache, uint key_cache_block_size,
   */
   while (keycache->cnt_for_resize_op)
     wait_on_queue(&keycache->waiting_for_resize_cnt, &keycache->cache_lock);
-#else
-  KEYCACHE_DBUG_ASSERT(keycache->cnt_for_resize_op == 0);
-#endif
 
   /*
     Free old cache structures, allocate new structures, and initialize
@@ -782,8 +768,6 @@ void end_key_cache(KEY_CACHE *keycache, my_bool cleanup)
 } /* end_key_cache */
 
 
-#ifdef THREAD
-
 /*
   Link a thread into double-linked queue of waiting threads.
 
@@ -963,8 +947,6 @@ static void release_whole_queue(KEYCACHE_WQUEUE *wqueue)
   wqueue->last_thread= NULL;
 }
 
-#endif /* THREAD */
-
 
 /*
   Unlink a block from the chain of dirty/clean blocks
@@ -1136,7 +1118,7 @@ static void link_block(KEY_CACHE *keycache, BLOCK_LINK *block, my_bool hot,
   DBUG_ASSERT(block->prev_changed && *block->prev_changed == block);
   DBUG_ASSERT(!block->next_used);
   DBUG_ASSERT(!block->prev_used);
-#ifdef THREAD
+
   if (!hot && keycache->waiting_for_block.last_thread)
   {
     /* Signal that in the LRU warm sub-chain an available block has appeared */
@@ -1196,10 +1178,7 @@ static void link_block(KEY_CACHE *keycache, BLOCK_LINK *block, my_bool hot,
 #endif
     return;
   }
-#else /* THREAD */
-  KEYCACHE_DBUG_ASSERT(! (!hot && keycache->waiting_for_block.last_thread));
-      /* Condition not transformed using DeMorgan, to keep the text identical */
-#endif /* THREAD */
+
   pins= hot ? &keycache->used_ins : &keycache->used_last;
   ins= *pins;
   if (ins)
@@ -1421,12 +1400,9 @@ static void remove_reader(BLOCK_LINK *block)
   DBUG_ASSERT(!block->next_used);
   DBUG_ASSERT(!block->prev_used);
   DBUG_ASSERT(block->hash_link->requests);
-#ifdef THREAD
+
   if (! --block->hash_link->requests && block->condvar)
     keycache_pthread_cond_signal(block->condvar);
-#else
-  --block->hash_link->requests;
-#endif
 }
 
 
@@ -1438,7 +1414,6 @@ static void remove_reader(BLOCK_LINK *block)
 static void wait_for_readers(KEY_CACHE *keycache,
                              BLOCK_LINK *block)
 {
-#ifdef THREAD
   struct st_my_thread_var *thread= my_thread_var;
   DBUG_ASSERT(block->status & (BLOCK_READ | BLOCK_IN_USE));
   DBUG_ASSERT(!(block->status & (BLOCK_IN_FLUSH | BLOCK_CHANGED)));
@@ -1460,9 +1435,6 @@ static void wait_for_readers(KEY_CACHE *keycache,
     keycache_pthread_cond_wait(&thread->suspend, &keycache->cache_lock);
     block->condvar= NULL;
   }
-#else
-  KEYCACHE_DBUG_ASSERT(block->hash_link->requests == 0);
-#endif
 }
 
 
@@ -1492,7 +1464,7 @@ static void unlink_hash(KEY_CACHE *keycache, HASH_LINK *hash_link)
   if ((*hash_link->prev= hash_link->next))
     hash_link->next->prev= hash_link->prev;
   hash_link->block= NULL;
-#ifdef THREAD
+
   if (keycache->waiting_for_hash_link.last_thread)
   {
     /* Signal that a free hash link has appeared */
@@ -1528,9 +1500,6 @@ static void unlink_hash(KEY_CACHE *keycache, HASH_LINK *hash_link)
               hash_link);
     return;
   }
-#else /* THREAD */
-  KEYCACHE_DBUG_ASSERT(! (keycache->waiting_for_hash_link.last_thread));
-#endif /* THREAD */
   hash_link->next= keycache->free_hash_list;
   keycache->free_hash_list= hash_link;
 }
@@ -1595,7 +1564,6 @@ restart:
     }
     else
     {
-#ifdef THREAD
       /* Wait for a free hash link */
       struct st_my_thread_var *thread= my_thread_var;
       KEYCACHE_PAGE page;
@@ -1609,9 +1577,6 @@ restart:
       keycache_pthread_cond_wait(&thread->suspend,
                                  &keycache->cache_lock);
       thread->opt_info= NULL;
-#else
-      KEYCACHE_DBUG_ASSERT(0);
-#endif
       goto restart;
     }
     hash_link->file= file;
@@ -1731,7 +1696,6 @@ restart:
       - block assigned but not yet read from file (invalid data).
   */
 
-#ifdef THREAD
   if (keycache->in_resize)
   {
     /* This is a request during a resize operation */
@@ -1973,9 +1937,6 @@ restart:
     }
     DBUG_RETURN(0);
   }
-#else /* THREAD */
-  DBUG_ASSERT(!keycache->in_resize);
-#endif
 
   if (page_status == PAGE_READ &&
       (block->status & (BLOCK_IN_EVICTION | BLOCK_IN_SWITCH |
@@ -2105,7 +2066,6 @@ restart:
           from the LRU ring.
         */
 
-#ifdef THREAD
         if (! keycache->used_last)
         {
           /*
@@ -2138,9 +2098,7 @@ restart:
           DBUG_ASSERT(!hash_link->block->next_used);
           DBUG_ASSERT(!hash_link->block->prev_used);
         }
-#else
-        KEYCACHE_DBUG_ASSERT(keycache->used_last);
-#endif
+
         /*
           If we waited above, hash_link->block has been assigned by
           link_block(). Otherwise it is still NULL. In the latter case
@@ -2610,10 +2568,8 @@ uchar *key_cache_read(KEY_CACHE *keycache,
       set_if_smaller(read_length, keycache->key_cache_block_size-offset);
       KEYCACHE_DBUG_ASSERT(read_length > 0);
 
-#ifndef THREAD
       if (block_length > keycache->key_cache_block_size || offset)
 	return_buffer=0;
-#endif
 
       /* Request the cache block that matches file/pos. */
       keycache->global_cache_r_requests++;
@@ -2673,9 +2629,6 @@ uchar *key_cache_read(KEY_CACHE *keycache,
       /* block status may have added BLOCK_ERROR in the above 'if'. */
       if (!(block->status & BLOCK_ERROR))
       {
-#ifndef THREAD
-        if (! return_buffer)
-#endif
         {
           DBUG_ASSERT(block->status & (BLOCK_READ | BLOCK_IN_USE));
 #if !defined(SERIALIZED_READ_FROM_CACHE)
@@ -2714,20 +2667,6 @@ uchar *key_cache_read(KEY_CACHE *keycache,
         break;
       }
 
-#ifndef THREAD
-      /* This is only true if we where able to read everything in one block */
-      if (return_buffer)
-      {
-        if (MYSQL_KEYCACHE_READ_DONE_ENABLED())
-        {
-          MYSQL_KEYCACHE_READ_DONE((ulong) (keycache->blocks_used *
-                                            keycache->key_cache_block_size),
-                                   (ulong) (keycache->blocks_unused *
-                                            keycache->key_cache_block_size));
-        }
-	DBUG_RETURN(block->buffer);
-      }
-#endif
     next_block:
       buff+= read_length;
       filepos+= read_length+offset;
diff --git a/mysys/mf_keycaches.c b/mysys/mf_keycaches.c
index ee4ad025b0b..93b7eab4561 100644
--- a/mysys/mf_keycaches.c
+++ b/mysys/mf_keycaches.c
@@ -53,9 +53,7 @@ typedef struct st_safe_hash_entry
 
 typedef struct st_safe_hash_with_default
 {
-#ifdef THREAD
   rw_lock_t mutex;
-#endif
   HASH hash;
   uchar *default_value;
   SAFE_HASH_ENTRY *root;
diff --git a/mysys/my_bitmap.c b/mysys/my_bitmap.c
index 3401c7301e9..dc15014121b 100644
--- a/mysys/my_bitmap.c
+++ b/mysys/my_bitmap.c
@@ -22,9 +22,6 @@
     * the internal size is a set of 32 bit words
     * the number of bits specified in creation can be any number > 0
     * there are THREAD safe versions of most calls called bitmap_lock_*
-      many of those are not used and not compiled normally but the code
-      already exist for them in an #ifdef:ed part. These can only be used
-      if THREAD was specified in bitmap_init
 
   TODO:
   Make assembler THREAD safe versions of these using test-and-set instructions
@@ -85,18 +82,14 @@ void create_last_word_mask(MY_BITMAP *map)
 
 static inline void bitmap_lock(MY_BITMAP *map __attribute__((unused)))
 {
-#ifdef THREAD
   if (map->mutex)
     mysql_mutex_lock(map->mutex);
-#endif
 }
 
 static inline void bitmap_unlock(MY_BITMAP *map __attribute__((unused)))
 {
-#ifdef THREAD
   if (map->mutex)
     mysql_mutex_unlock(map->mutex);
-#endif
 }
 
 
@@ -108,30 +101,30 @@ my_bool bitmap_init(MY_BITMAP *map, my_bitmap_map *buf, uint n_bits,
   {
     uint size_in_bytes= bitmap_buffer_size(n_bits);
     uint extra= 0;
-#ifdef THREAD
+
     if (thread_safe)
     {
       size_in_bytes= ALIGN_SIZE(size_in_bytes);
       extra= sizeof(mysql_mutex_t);
     }
     map->mutex= 0;
-#endif
+
     if (!(buf= (my_bitmap_map*) my_malloc(size_in_bytes+extra, MYF(MY_WME))))
       DBUG_RETURN(1);
-#ifdef THREAD
+
     if (thread_safe)
     {
       map->mutex= (mysql_mutex_t *) ((char*) buf + size_in_bytes);
       mysql_mutex_init(key_BITMAP_mutex, map->mutex, MY_MUTEX_INIT_FAST);
     }
-#endif
+
   }
-#ifdef THREAD
+
   else
   {
     DBUG_ASSERT(thread_safe == 0);
   }
-#endif
+
 
   map->bitmap= buf;
   map->n_bits= n_bits;
@@ -146,10 +139,9 @@ void bitmap_free(MY_BITMAP *map)
   DBUG_ENTER("bitmap_free");
   if (map->bitmap)
   {
-#ifdef THREAD
     if (map->mutex)
       mysql_mutex_destroy(map->mutex);
-#endif
+
     my_free(map->bitmap);
     map->bitmap=0;
   }
diff --git a/mysys/my_fstream.c b/mysys/my_fstream.c
index 0c7e4ef7aa3..83cb0d261c0 100644
--- a/mysys/my_fstream.c
+++ b/mysys/my_fstream.c
@@ -124,10 +124,9 @@ size_t my_fwrite(FILE *stream, const uchar *Buffer, size_t Count, myf MyFlags)
       }
 #endif
 #if !defined(NO_BACKGROUND) && defined(USE_MY_STREAM)
-#ifdef THREAD
       if (my_thread_var->abort)
 	MyFlags&= ~ MY_WAIT_IF_FULL;		/* End if aborted by user */
-#endif
+
       if ((errno == ENOSPC || errno == EDQUOT) &&
           (MyFlags & MY_WAIT_IF_FULL))
       {
diff --git a/mysys/my_gethostbyname.c b/mysys/my_gethostbyname.c
index 8a9c721c2fb..28ecec13ef2 100644
--- a/mysys/my_gethostbyname.c
+++ b/mysys/my_gethostbyname.c
@@ -78,9 +78,7 @@ struct hostent *my_gethostbyname_r(const char *name,
 
 #else /* !HAVE_GETHOSTBYNAME_R */
 
-#ifdef THREAD
 extern mysql_mutex_t LOCK_gethostbyname_r;
-#endif
 
 /*
   No gethostbyname_r() function exists.
diff --git a/mysys/my_init.c b/mysys/my_init.c
index ab6ffef7ac7..f5a2d9ac4bd 100644
--- a/mysys/my_init.c
+++ b/mysys/my_init.c
@@ -91,23 +91,22 @@ my_bool my_basic_init(void)
   instrumented_stdin.m_psi= NULL;       /* not yet instrumented */
   mysql_stdin= & instrumented_stdin;
 
-#if defined(THREAD)
   if (my_thread_global_init())
     return 1;
-#  if defined(SAFE_MUTEX)
+
+#if defined(SAFE_MUTEX)
   safe_mutex_global_init();		/* Must be called early */
-#  endif
 #endif
-#if defined(THREAD) && defined(MY_PTHREAD_FASTMUTEX) && !defined(SAFE_MUTEX)
+
+#if defined(MY_PTHREAD_FASTMUTEX) && !defined(SAFE_MUTEX)
   fastmutex_global_init();              /* Must be called early */
 #endif
-#ifdef THREAD
+
 #if defined(HAVE_PTHREAD_INIT)
   pthread_init();			/* Must be called before DBUG_ENTER */
 #endif
   if (my_thread_basic_global_init())
     return 1;
-#endif
 
   /* $HOME is needed early to parse configuration files located in ~/ */
   if ((home_dir= getenv("HOME")) != 0)
@@ -138,10 +137,9 @@ my_bool my_init(void)
   if (my_basic_init())
     return 1;
 
-#ifdef THREAD
   if (my_thread_global_init())
     return 1;
-#endif /* THREAD */
+
   {
     DBUG_ENTER("my_init");
     DBUG_PROCESS((char*) (my_progname ? my_progname : "unknown"));
@@ -240,7 +238,7 @@ Voluntary context switches %ld, Involuntary context switches %ld\n",
   {
     DBUG_END();                /* Must be done before my_thread_end */
   }
-#ifdef THREAD
+
   my_thread_end();
   my_thread_global_end();
 #if defined(SAFE_MUTEX)
@@ -251,7 +249,6 @@ Voluntary context switches %ld, Involuntary context switches %ld\n",
   safe_mutex_end((infoflag & (MY_GIVE_INFO | MY_CHECK_ERROR)) ? stderr :
                  (FILE *) 0);
 #endif /* defined(SAFE_MUTEX) */
-#endif /* THREAD */
 
 #ifdef __WIN__
   if (have_tcpip)
@@ -518,7 +515,7 @@ PSI_mutex_key key_BITMAP_mutex, key_IO_CACHE_append_buffer_lock,
 
 static PSI_mutex_info all_mysys_mutexes[]=
 {
-#if defined(THREAD) && !defined(HAVE_PREAD) && !defined(_WIN32)
+#if !defined(HAVE_PREAD) && !defined(_WIN32)
   { &key_my_file_info_mutex, "st_my_file_info:mutex", 0},
 #endif /* !defined(HAVE_PREAD) && !defined(_WIN32) */
 #if !defined(HAVE_LOCALTIME_R) || !defined(HAVE_GMTIME_R)
diff --git a/mysys/my_lib.c b/mysys/my_lib.c
index 890ff0b5dd1..06f9521a664 100644
--- a/mysys/my_lib.c
+++ b/mysys/my_lib.c
@@ -41,7 +41,7 @@
 # endif
 #endif
 
-#if defined(THREAD) && defined(HAVE_READDIR_R)
+#if defined(HAVE_READDIR_R)
 #define READDIR(A,B,C) ((errno=readdir_r(A,B,&C)) != 0 || !C)
 #else
 #define READDIR(A,B,C) (!(C=readdir(A)))
@@ -97,13 +97,12 @@ MY_DIR	*my_dir(const char *path, myf MyFlags)
   DIR		*dirp;
   struct dirent *dp;
   char		tmp_path[FN_REFLEN+1],*tmp_file;
-#ifdef THREAD
   char	dirent_tmp[sizeof(struct dirent)+_POSIX_PATH_MAX+1];
-#endif
+
   DBUG_ENTER("my_dir");
   DBUG_PRINT("my",("path: '%s' MyFlags: %d",path,MyFlags));
 
-#if defined(THREAD) && !defined(HAVE_READDIR_R)
+#if !defined(HAVE_READDIR_R)
   mysql_mutex_lock(&THR_LOCK_open);
 #endif
 
@@ -135,11 +134,7 @@ MY_DIR	*my_dir(const char *path, myf MyFlags)
 
   tmp_file=strend(tmp_path);
 
-#ifdef THREAD
   dp= (struct dirent*) dirent_tmp;
-#else
-  dp=0;
-#endif
   
   while (!(READDIR(dirp,(struct dirent*) dirent_tmp,dp)))
   {
@@ -166,7 +161,7 @@ MY_DIR	*my_dir(const char *path, myf MyFlags)
   }
 
   (void) closedir(dirp);
-#if defined(THREAD) && !defined(HAVE_READDIR_R)
+#if !defined(HAVE_READDIR_R)
   mysql_mutex_unlock(&THR_LOCK_open);
 #endif
   result->dir_entry= (FILEINFO *)dir_entries_storage->buffer;
@@ -178,7 +173,7 @@ MY_DIR	*my_dir(const char *path, myf MyFlags)
   DBUG_RETURN(result);
 
  error:
-#if defined(THREAD) && !defined(HAVE_READDIR_R)
+#if !defined(HAVE_READDIR_R)
   mysql_mutex_unlock(&THR_LOCK_open);
 #endif
   my_errno=errno;
diff --git a/mysys/my_open.c b/mysys/my_open.c
index 8f34ce1c6dc..2aef97b3e34 100644
--- a/mysys/my_open.c
+++ b/mysys/my_open.c
@@ -89,7 +89,7 @@ int my_close(File fd, myf MyFlags)
   if ((uint) fd < my_file_limit && my_file_info[fd].type != UNOPEN)
   {
     my_free(my_file_info[fd].name);
-#if defined(THREAD) && !defined(HAVE_PREAD) && !defined(_WIN32)
+#if !defined(HAVE_PREAD) && !defined(_WIN32)
     mysql_mutex_destroy(&my_file_info[fd].mutex);
 #endif
     my_file_info[fd].type = UNOPEN;
@@ -125,7 +125,7 @@ File my_register_filename(File fd, const char *FileName, enum file_type
   {
     if ((uint) fd >= my_file_limit)
     {
-#if defined(THREAD) && !defined(HAVE_PREAD) 
+#if !defined(HAVE_PREAD) 
       my_errno= EMFILE;
 #else
       thread_safe_increment(my_file_opened,&THR_LOCK_open);
@@ -140,7 +140,7 @@ File my_register_filename(File fd, const char *FileName, enum file_type
         my_file_opened++;
         my_file_total_opened++;
         my_file_info[fd].type = type_of_file;
-#if defined(THREAD) && !defined(HAVE_PREAD) && !defined(_WIN32)
+#if !defined(HAVE_PREAD) && !defined(_WIN32)
         mysql_mutex_init(key_my_file_info_mutex, &my_file_info[fd].mutex,
                          MY_MUTEX_INIT_FAST);
 #endif
diff --git a/mysys/my_pread.c b/mysys/my_pread.c
index d0a0ddaec66..e006360c11b 100644
--- a/mysys/my_pread.c
+++ b/mysys/my_pread.c
@@ -85,14 +85,14 @@ size_t my_pread(File Filedes, uchar *Buffer, size_t Count, my_off_t offset,
 
       DBUG_PRINT("warning",("Read only %d bytes off %u from %d, errno: %d",
                             (int) readbytes, (uint) Count,Filedes,my_errno));
-#ifdef THREAD
+
       if ((readbytes == 0 || readbytes == (size_t) -1) && errno == EINTR)
       {
         DBUG_PRINT("debug", ("my_pread() was interrupted and returned %d",
                              (int) readbytes));
         continue;                              /* Interrupted */
       }
-#endif
+
       if (MyFlags & (MY_WME | MY_FAE | MY_FNABP))
       {
         if (readbytes == (size_t) -1)
@@ -173,10 +173,10 @@ size_t my_pwrite(File Filedes, const uchar *Buffer, size_t Count,
     }
     DBUG_PRINT("error",("Write only %u bytes", (uint) writtenbytes));
 #ifndef NO_BACKGROUND
-#ifdef THREAD
+
     if (my_thread_var->abort)
       MyFlags&= ~ MY_WAIT_IF_FULL;		/* End if aborted by user */
-#endif
+
     if ((my_errno == ENOSPC || my_errno == EDQUOT) &&
         (MyFlags & MY_WAIT_IF_FULL))
     {
diff --git a/mysys/my_pthread.c b/mysys/my_pthread.c
index dee34d10b38..150bde3fb33 100644
--- a/mysys/my_pthread.c
+++ b/mysys/my_pthread.c
@@ -18,7 +18,6 @@
 #define DONT_REMAP_PTHREAD_FUNCTIONS
 
 #include "mysys_priv.h"
-#ifdef THREAD
 #include <signal.h>
 #include <m_string.h>
 #include <thr_alarm.h>
@@ -468,4 +467,3 @@ int pthread_dummy(int ret)
 {
   return ret;
 }
-#endif /* THREAD */
diff --git a/mysys/my_read.c b/mysys/my_read.c
index 75f9dd64f1d..dbe9006a1d3 100644
--- a/mysys/my_read.c
+++ b/mysys/my_read.c
@@ -59,14 +59,14 @@ size_t my_read(File Filedes, uchar *Buffer, size_t Count, myf MyFlags)
       DBUG_PRINT("warning",("Read only %d bytes off %lu from %d, errno: %d",
                             (int) readbytes, (ulong) Count, Filedes,
                             my_errno));
-#ifdef THREAD
+
       if ((readbytes == 0 || (int) readbytes == -1) && errno == EINTR)
       {  
         DBUG_PRINT("debug", ("my_read() was interrupted and returned %ld",
                              (long) readbytes));
         continue;                              /* Interrupted */
       }
-#endif
+
       if (MyFlags & (MY_WME | MY_FAE | MY_FNABP))
       {
         if (readbytes == (size_t) -1)
diff --git a/mysys/my_static.c b/mysys/my_static.c
index d7354555f3d..ec8d66ab0cf 100644
--- a/mysys/my_static.c
+++ b/mysys/my_static.c
@@ -32,9 +32,7 @@ char		curr_dir[FN_REFLEN]= {0},
 ulong		my_stream_opened=0,my_file_opened=0, my_tmp_file_created=0;
 ulong           my_file_total_opened= 0;
 int		my_umask=0664, my_umask_dir=0777;
-#ifndef THREAD
-int		my_errno=0;
-#endif
+
 struct st_my_file_info my_file_info_default[MY_NFILE];
 uint   my_file_limit= MY_NFILE;
 struct st_my_file_info *my_file_info= my_file_info_default;
diff --git a/mysys/my_thr_init.c b/mysys/my_thr_init.c
index 045b56b11c2..c4b56cde850 100644
--- a/mysys/my_thr_init.c
+++ b/mysys/my_thr_init.c
@@ -22,7 +22,6 @@
 #include <m_string.h>
 #include <signal.h>
 
-#ifdef THREAD
 pthread_key(struct st_my_thread_var*, THR_KEY_mysys);
 mysql_mutex_t THR_LOCK_malloc, THR_LOCK_open,
               THR_LOCK_lock, THR_LOCK_isam, THR_LOCK_myisam, THR_LOCK_heap,
@@ -532,4 +531,3 @@ static void install_sigabrt_handler(void)
 }
 #endif
 
-#endif /* THREAD */
diff --git a/mysys/my_write.c b/mysys/my_write.c
index 3eac1364f46..64f7546620f 100644
--- a/mysys/my_write.c
+++ b/mysys/my_write.c
@@ -52,10 +52,9 @@ size_t my_write(File Filedes, const uchar *Buffer, size_t Count, myf MyFlags)
     DBUG_PRINT("error",("Write only %ld bytes, error: %d",
 			(long) writtenbytes, my_errno));
 #ifndef NO_BACKGROUND
-#ifdef THREAD
     if (my_thread_var->abort)
       MyFlags&= ~ MY_WAIT_IF_FULL;		/* End if aborted by user */
-#endif
+
     if ((my_errno == ENOSPC || my_errno == EDQUOT) &&
         (MyFlags & MY_WAIT_IF_FULL))
     {
diff --git a/mysys/mysys_priv.h b/mysys/mysys_priv.h
index 1ae6a9e3a99..4e642b7e3d3 100644
--- a/mysys/mysys_priv.h
+++ b/mysys/mysys_priv.h
@@ -24,7 +24,6 @@
 #include <sys/resource.h>
 #endif
 
-#ifdef THREAD
 #include <my_pthread.h>
 
 #ifdef HAVE_PSI_INTERFACE
@@ -62,9 +61,6 @@ extern PSI_thread_key key_thread_alarm;
 extern mysql_mutex_t THR_LOCK_malloc, THR_LOCK_open, THR_LOCK_keycache;
 extern mysql_mutex_t THR_LOCK_lock, THR_LOCK_isam, THR_LOCK_net;
 extern mysql_mutex_t THR_LOCK_charset, THR_LOCK_time;
-#else /* THREAD */
-#include <my_no_pthread.h>
-#endif /* THREAD */
 
 #include <mysql/psi/mysql_file.h>
 
diff --git a/mysys/thr_alarm.c b/mysys/thr_alarm.c
index 54eef693558..2e427f96bdd 100644
--- a/mysys/thr_alarm.c
+++ b/mysys/thr_alarm.c
@@ -18,7 +18,7 @@
 #include "mysys_priv.h"
 #include <my_global.h>
 
-#if defined(THREAD) && !defined(DONT_USE_THR_ALARM)
+#if !defined(DONT_USE_THR_ALARM)
 #include <errno.h>
 #include <my_pthread.h>
 #include <signal.h>
@@ -686,15 +686,14 @@ void resize_thr_alarm(uint max_alarms)
 
 #endif /* __WIN__ */
 
-#endif /* THREAD */
-
+#endif
 
 /****************************************************************************
   Handling of test case (when compiled with -DMAIN)
 ***************************************************************************/
 
 #ifdef MAIN
-#if defined(THREAD) && !defined(DONT_USE_THR_ALARM)
+#if !defined(DONT_USE_THR_ALARM)
 
 static mysql_cond_t COND_thread_count;
 static mysql_mutex_t LOCK_thread_count;
@@ -961,17 +960,13 @@ int main(int argc __attribute__((unused)),char **argv __attribute__((unused)))
   return 0;
 }
 
-#else /* THREAD */
+#else /* !defined(DONT_USE_ALARM_THREAD) */
 
 int main(int argc __attribute__((unused)),char **argv __attribute__((unused)))
 {
-#ifndef THREAD
-  printf("thr_alarm disabled because we are not using threads\n");
-#else
   printf("thr_alarm disabled with DONT_USE_THR_ALARM\n");
-#endif
   exit(1);
 }
 
-#endif /* THREAD */
+#endif /* !defined(DONT_USE_ALARM_THREAD) */
 #endif /* MAIN */
diff --git a/mysys/thr_lock.c b/mysys/thr_lock.c
index d96d08ea0c3..2ab283e068d 100644
--- a/mysys/thr_lock.c
+++ b/mysys/thr_lock.c
@@ -74,7 +74,6 @@ one TL_WRITE_DELAYED lock at the same time as multiple read locks.
 
 #include "mysys_priv.h"
 
-#ifdef THREAD
 #include "thr_lock.h"
 #include <m_string.h>
 #include <errno.h>
@@ -1451,7 +1450,6 @@ void thr_print_locks(void)
   mysql_mutex_unlock(&THR_LOCK_lock);
 }
 
-#endif /* THREAD */
 
 /*****************************************************************************
 ** Test of thread locks
@@ -1459,8 +1457,6 @@ void thr_print_locks(void)
 
 #ifdef MAIN
 
-#ifdef THREAD
-
 struct st_test {
   uint lock_nr;
   enum thr_lock_type lock_type;
@@ -1689,13 +1685,4 @@ int main(int argc __attribute__((unused)),char **argv __attribute__((unused)))
   return 0;
 }
 
-#else /* THREAD */
-
-int main(int argc __attribute__((unused)),char **argv __attribute__((unused)))
-{
-  printf("thr_lock disabled because we are not using threads\n");
-  exit(1);
-}
-
-#endif /* THREAD */
 #endif /* MAIN */
diff --git a/mysys/thr_mutex.c b/mysys/thr_mutex.c
index 00890bc0425..37ced4f7633 100644
--- a/mysys/thr_mutex.c
+++ b/mysys/thr_mutex.c
@@ -19,7 +19,7 @@
 #if defined(TARGET_OS_LINUX) && !defined (__USE_UNIX98)
 #define __USE_UNIX98			/* To get rw locks under Linux */
 #endif
-#if defined(THREAD) && defined(SAFE_MUTEX)
+#if defined(SAFE_MUTEX)
 #undef SAFE_MUTEX			/* Avoid safe_mutex redefinitions */
 #include "mysys_priv.h"
 #include "my_static.h"
@@ -395,9 +395,9 @@ void safe_mutex_end(FILE *file __attribute__((unused)))
 #endif /* SAFE_MUTEX_DETECT_DESTROY */
 }
 
-#endif /* THREAD && SAFE_MUTEX */
+#endif /* SAFE_MUTEX */
 
-#if defined(THREAD) && defined(MY_PTHREAD_FASTMUTEX) && !defined(SAFE_MUTEX)
+#if defined(MY_PTHREAD_FASTMUTEX) && !defined(SAFE_MUTEX)
 
 #include "mysys_priv.h"
 #include "my_static.h"
@@ -500,4 +500,4 @@ void fastmutex_global_init(void)
 #endif
 }
   
-#endif /* defined(THREAD) && defined(MY_PTHREAD_FASTMUTEX) && !defined(SAFE_MUTEX) */ 
+#endif /* defined(MY_PTHREAD_FASTMUTEX) && !defined(SAFE_MUTEX) */ 
diff --git a/mysys/thr_rwlock.c b/mysys/thr_rwlock.c
index 13651221d37..bad80b43eef 100644
--- a/mysys/thr_rwlock.c
+++ b/mysys/thr_rwlock.c
@@ -16,7 +16,6 @@
 /* Synchronization - readers / writer thread locks */
 
 #include "mysys_priv.h"
-#if defined(THREAD)
 #if defined(NEED_MY_RW_LOCK)
 #include <errno.h>
 
@@ -471,4 +470,3 @@ int rw_pr_unlock(rw_pr_lock_t *rwlock)
 }
 
 
-#endif /* defined(THREAD) */
diff --git a/sql-common/client.c b/sql-common/client.c
index 3bb626e824a..354c04b717b 100644
--- a/sql-common/client.c
+++ b/sql-common/client.c
@@ -24,7 +24,6 @@
     mysql_real_connect()
   - Support for reading local file with LOAD DATA LOCAL
   - SHARED memory handling
-  - Protection against sigpipe
   - Prepared statements
   
   - Things that only works for the server
@@ -70,9 +69,9 @@ my_bool	net_flush(NET *net);
 #include "mysqld_error.h"
 #include "errmsg.h"
 #include <violite.h>
-#if defined(THREAD) && !defined(__WIN__)
+#if !defined(__WIN__)
 #include <my_pthread.h>				/* because of signal()	*/
-#endif /* defined(THREAD) && !defined(__WIN__) */
+#endif /* !defined(__WIN__) */
 
 #include <sys/stat.h>
 #include <signal.h>
@@ -287,7 +286,7 @@ static int wait_for_data(my_socket fd, uint timeout)
   {
     tv.tv_sec = (long) timeout;
     tv.tv_usec = 0;
-#if defined(HPUX10) && defined(THREAD)
+#if defined(HPUX10)
     if ((res = select(fd+1, NULL, (int*) &sfds, NULL, &tv)) > 0)
       break;
 #else
@@ -731,13 +730,9 @@ cli_safe_read(MYSQL *mysql)
 {
   NET *net= &mysql->net;
   ulong len=0;
-  init_sigpipe_variables
 
-  /* Don't give sigpipe errors if the client doesn't want them */
-  set_sigpipe(mysql);
   if (net->vio != 0)
     len=my_net_read(net);
-  reset_sigpipe(mysql);
 
   if (len == packet_error || len == 0)
   {
@@ -817,13 +812,9 @@ cli_advanced_command(MYSQL *mysql, enum enum_server_command command,
 {
   NET *net= &mysql->net;
   my_bool result= 1;
-  init_sigpipe_variables
   my_bool stmt_skip= stmt ? stmt->state != MYSQL_STMT_INIT_DONE : FALSE;
   DBUG_ENTER("cli_advanced_command");
 
-  /* Don't give sigpipe errors if the client doesn't want them */
-  set_sigpipe(mysql);
-
   if (mysql->net.vio == 0)
   {						/* Do reconnect if possible */
     if (mysql_reconnect(mysql) || stmt_skip)
@@ -872,7 +863,6 @@ cli_advanced_command(MYSQL *mysql, enum enum_server_command command,
     result= ((mysql->packet_length=cli_safe_read(mysql)) == packet_error ?
 	     1 : 0);
 end:
-  reset_sigpipe(mysql);
   DBUG_PRINT("exit",("result: %d", result));
   DBUG_RETURN(result);
 }
@@ -1089,14 +1079,11 @@ void end_server(MYSQL *mysql)
   DBUG_ENTER("end_server");
   if (mysql->net.vio != 0)
   {
-    init_sigpipe_variables
     DBUG_PRINT("info",("Net: %s", vio_description(mysql->net.vio)));
 #ifdef MYSQL_SERVER
     slave_io_thread_detach_vio();
 #endif
-    set_sigpipe(mysql);
     vio_delete(mysql->net.vio);
-    reset_sigpipe(mysql);
     mysql->net.vio= 0;          /* Marker */
     mysql_prune_stmt_list(mysql);
   }
@@ -2939,7 +2926,6 @@ CLI_MYSQL_REAL_CONNECT(MYSQL *mysql,const char *host, const char *user,
 #ifdef HAVE_SYS_UN_H
   struct	sockaddr_un UNIXaddr;
 #endif
-  init_sigpipe_variables
   DBUG_ENTER("mysql_real_connect");
 
   DBUG_PRINT("enter",("host: %s  db: %s  user: %s (client)",
@@ -2954,8 +2940,6 @@ CLI_MYSQL_REAL_CONNECT(MYSQL *mysql,const char *host, const char *user,
     DBUG_RETURN(0);
   }
 
-  /* Don't give sigpipe errors if the client doesn't want them */
-  set_sigpipe(mysql);
   mysql->methods= &client_methods;
   net->vio = 0;				/* If something goes wrong */
   mysql->client_flag=0;			/* For handshake */
@@ -3465,11 +3449,9 @@ CLI_MYSQL_REAL_CONNECT(MYSQL *mysql,const char *host, const char *user,
 #endif
 
   DBUG_PRINT("exit", ("Mysql handler: 0x%lx", (long) mysql));
-  reset_sigpipe(mysql);
   DBUG_RETURN(mysql);
 
 error:
-  reset_sigpipe(mysql);
   DBUG_PRINT("error",("message: %u/%s (%s)",
                       net->last_errno,
                       net->sqlstate,
diff --git a/sql-common/client_plugin.c b/sql-common/client_plugin.c
index 6114d95cd73..6b4cca8aeea 100644
--- a/sql-common/client_plugin.c
+++ b/sql-common/client_plugin.c
@@ -31,11 +31,7 @@
 #include "mysql.h"
 #include <my_sys.h>
 #include <m_string.h>
-#ifdef THREAD
 #include <my_pthread.h>
-#else
-#include <my_no_pthread.h>
-#endif
 
 #include <sql_common.h>
 #include "errmsg.h"
@@ -67,9 +63,7 @@ static uint plugin_version[MYSQL_CLIENT_MAX_PLUGINS]=
   loading the same plugin twice in parallel.
 */
 struct st_client_plugin_int *plugin_list[MYSQL_CLIENT_MAX_PLUGINS];
-#ifdef THREAD
 static pthread_mutex_t LOCK_load_client_plugin;
-#endif
 
 static int is_not_initialized(MYSQL *mysql, const char *name)
 {
diff --git a/sql/client_settings.h b/sql/client_settings.h
index ff35cff2440..2f242519ef4 100644
--- a/sql/client_settings.h
+++ b/sql/client_settings.h
@@ -27,9 +27,6 @@
                              CLIENT_SECURE_CONNECTION | CLIENT_TRANSACTIONS | \
 			     CLIENT_PROTOCOL_41 | CLIENT_SECURE_CONNECTION)
 
-#define init_sigpipe_variables
-#define set_sigpipe(mysql)
-#define reset_sigpipe(mysql)
 #define read_user_name(A) {}
 #undef HAVE_SMEM
 #undef _CUSTOMCONFIG_
diff --git a/sql/filesort.cc b/sql/filesort.cc
index 419f18263cc..f888206f730 100644
--- a/sql/filesort.cc
+++ b/sql/filesort.cc
@@ -1,4 +1,4 @@
-/* Copyright (C) 2000-2006 MySQL AB, 2008-2009 Sun Microsystems, Inc
+/* Copyright (c) 2000, 2011, Oracle and/or its affiliates. All rights reserved.
 
    This program is free software; you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
@@ -33,10 +33,6 @@
 #include "sql_test.h"                           // TEST_filesort
 #include "opt_range.h"                          // SQL_SELECT
 
-#ifndef THREAD
-#define SKIP_DBUG_IN_FILESORT
-#endif
-
 /// How to write record_ref.
 #define WRITE_REF(file,from) \
 if (my_b_write((file),(uchar*) (from),param->ref_length)) \
diff --git a/storage/heap/heapdef.h b/storage/heap/heapdef.h
index bc3c6bf7239..87866678c2f 100644
--- a/storage/heap/heapdef.h
+++ b/storage/heap/heapdef.h
@@ -17,9 +17,7 @@
 
 #include <my_base.h>			/* This includes global */
 C_MODE_START
-#ifdef THREAD
 #include <my_pthread.h>
-#endif
 #include "heap.h"			/* Structs & some defines */
 #include "my_tree.h"
 
@@ -102,14 +100,11 @@ extern void hp_clear(HP_SHARE *info);
 extern void hp_clear_keys(HP_SHARE *info);
 extern uint hp_rb_pack_key(HP_KEYDEF *keydef, uchar *key, const uchar *old,
                            key_part_map keypart_map);
-#ifdef THREAD
+
 extern mysql_mutex_t THR_LOCK_heap;
-#endif
 
 #ifdef HAVE_PSI_INTERFACE
-#ifdef THREAD
 extern PSI_mutex_key hp_key_mutex_HP_SHARE_intern_lock;
-#endif /* THREAD */
 void init_heap_psi_keys();
 #endif /* HAVE_PSI_INTERFACE */
 
diff --git a/storage/heap/hp_block.c b/storage/heap/hp_block.c
index 7f6cc1ef90a..41391fba060 100644
--- a/storage/heap/hp_block.c
+++ b/storage/heap/hp_block.c
@@ -86,7 +86,6 @@ int hp_get_new_block(HP_BLOCK *block, size_t *alloc_length)
   }
   else
   {
-    dont_break();		/* Dont allow SIGHUP or SIGINT */
     if ((uint) i == block->levels)
     {
       /* Adding a new level on top of the existing ones. */
@@ -117,7 +116,6 @@ int hp_get_new_block(HP_BLOCK *block, size_t *alloc_length)
       allocated bytes. Use it as a leaf block.
     */
     block->level_info[0].last_blocks= root;
-    allow_break();		/* Allow SIGHUP & SIGINT */
   }
   return 0;
 }
diff --git a/storage/heap/hp_create.c b/storage/heap/hp_create.c
index bbf649c5e46..67fe0b3136f 100644
--- a/storage/heap/hp_create.c
+++ b/storage/heap/hp_create.c
@@ -192,11 +192,9 @@ int heap_create(const char *name, HP_CREATE_INFO *create_info,
       my_free(share);
       goto err;
     }
-#ifdef THREAD
     thr_lock_init(&share->lock);
     mysql_mutex_init(hp_key_mutex_HP_SHARE_intern_lock,
                      &share->intern_lock, MY_MUTEX_INIT_FAST);
-#endif
     if (!create_info->internal_table)
     {
       share->open_list.data= (void*) share;
@@ -301,10 +299,8 @@ void hp_free(HP_SHARE *share)
   if (share->open_list.data)                    /* If not internal table */
     heap_share_list= list_delete(heap_share_list, &share->open_list);
   hp_clear(share);			/* Remove blocks from memory */
-#ifdef THREAD
   thr_lock_delete(&share->lock);
   mysql_mutex_destroy(&share->intern_lock);
-#endif
   my_free(share->name);
   my_free(share);
   return;
diff --git a/storage/heap/hp_open.c b/storage/heap/hp_open.c
index 12d9bfe1ed3..5ac4da22e0a 100644
--- a/storage/heap/hp_open.c
+++ b/storage/heap/hp_open.c
@@ -37,9 +37,7 @@ HP_INFO *heap_open_from_share(HP_SHARE *share, int mode)
     DBUG_RETURN(0);
   }
   share->open_count++; 
-#ifdef THREAD
   thr_lock_data_init(&share->lock,&info->lock,NULL);
-#endif
   info->s= share;
   info->lastkey= (uchar*) (info + 1);
   info->recbuf= (uchar*) (info->lastkey + share->max_key_length);
diff --git a/storage/heap/hp_static.c b/storage/heap/hp_static.c
index e1ca7d1f445..a58ecb8b754 100644
--- a/storage/heap/hp_static.c
+++ b/storage/heap/hp_static.c
@@ -25,7 +25,6 @@
 LIST *heap_open_list=0,*heap_share_list=0;
 
 #ifdef HAVE_PSI_INTERFACE
-#ifdef THREAD
 PSI_mutex_key hp_key_mutex_HP_SHARE_intern_lock;
 
 static PSI_mutex_info all_heap_mutexes[]=
@@ -36,11 +35,9 @@ static PSI_mutex_info all_heap_mutexes[]=
     THR_LOCK_heap is part of mysys, not storage/heap.
   */
 };
-#endif /* THREAD */
 
 void init_heap_psi_keys()
 {
-#ifdef THREAD
   const char* category= "memory";
   int count;
 
@@ -49,7 +46,6 @@ void init_heap_psi_keys()
 
   count= array_elements(all_heap_mutexes);
   PSI_server->register_mutex(category, all_heap_mutexes, count);
-#endif /* THREAD */
 }
 #endif /* HAVE_PSI_INTERFACE */
 
diff --git a/storage/heap/hp_test2.c b/storage/heap/hp_test2.c
index 3ee903be7ed..af388867c3c 100644
--- a/storage/heap/hp_test2.c
+++ b/storage/heap/hp_test2.c
@@ -1,4 +1,5 @@
-/* Copyright (C) 2000-2003, 2006 MySQL AB
+/* Copyright (C) 2000, 2011, Oracle and/or its affiliates. All rights
+   reserved
 
    This program is free software; you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
@@ -656,11 +657,6 @@ static int rnd(int max_value)
 
 static sig_handler endprog(int sig_number __attribute__((unused)))
 {
-#ifndef THREAD
-  if (my_dont_interrupt)
-    my_remember_signal(sig_number,endprog);
-  else
-#endif
   {
     hp_panic(HA_PANIC_CLOSE);
     my_end(1);
diff --git a/storage/myisam/ha_myisam.cc b/storage/myisam/ha_myisam.cc
index c4bb6d7dbd4..c7b6b2239ce 100644
--- a/storage/myisam/ha_myisam.cc
+++ b/storage/myisam/ha_myisam.cc
@@ -168,10 +168,9 @@ static void mi_check_print_msg(MI_CHECK *param,	const char* msg_type,
     Also we likely need to lock mutex here (in both cases with protocol and
     push_warning).
   */
-#ifdef THREAD
   if (param->need_print_msg_lock)
     mysql_mutex_lock(&param->print_msg_mutex);
-#endif
+
   protocol->prepare_for_resend();
   protocol->store(name, length, system_charset_info);
   protocol->store(param->op_name, system_charset_info);
@@ -180,10 +179,10 @@ static void mi_check_print_msg(MI_CHECK *param,	const char* msg_type,
   if (protocol->write())
     sql_print_error("Failed on my_net_write, writing to stderr instead: %s\n",
 		    msgbuf);
-#ifdef THREAD
+
   if (param->need_print_msg_lock)
     mysql_mutex_unlock(&param->print_msg_mutex);
-#endif
+
   return;
 }
 
diff --git a/storage/myisam/mi_check.c b/storage/myisam/mi_check.c
index 79a8105f823..5d8a7c3daef 100644
--- a/storage/myisam/mi_check.c
+++ b/storage/myisam/mi_check.c
@@ -99,9 +99,7 @@ void myisamchk_init(MI_CHECK *param)
   param->max_record_length= LONGLONG_MAX;
   param->key_cache_block_size= KEY_CACHE_BLOCK_SIZE;
   param->stats_method= MI_STATS_METHOD_NULLS_NOT_EQUAL;
-#ifdef THREAD
   param->need_print_msg_lock= 0;
-#endif
 }
 
 	/* Check the status flags for the table */
@@ -2631,9 +2629,6 @@ err:
 int mi_repair_parallel(MI_CHECK *param, register MI_INFO *info,
 			const char * name, int rep_quick)
 {
-#ifndef THREAD
-  return mi_repair_by_sort(param, info, name, rep_quick);
-#else
   int got_error;
   uint i,key, total_key_length, istep;
   ulong rec_length;
@@ -3122,7 +3117,6 @@ err:
     share->pack.header_length=0;
   }
   DBUG_RETURN(got_error);
-#endif /* THREAD */
 }
 
 	/* Read next record and return next key */
diff --git a/storage/myisam/mi_close.c b/storage/myisam/mi_close.c
index 51408ab191c..105ee3810cd 100644
--- a/storage/myisam/mi_close.c
+++ b/storage/myisam/mi_close.c
@@ -91,7 +91,6 @@ int mi_close(register MI_INFO *info)
       my_free(share->decode_trees);
       my_free(share->decode_tables);
     }
-#ifdef THREAD
     thr_lock_delete(&share->lock);
     mysql_mutex_destroy(&share->intern_lock);
     {
@@ -102,7 +101,6 @@ int mi_close(register MI_INFO *info)
         mysql_rwlock_destroy(&share->key_root_lock[i]);
       }
     }
-#endif
     my_free(info->s);
   }
   mysql_mutex_unlock(&THR_LOCK_myisam);
diff --git a/storage/myisam/mi_delete.c b/storage/myisam/mi_delete.c
index 9314148cd8c..5fa7cba7d5e 100644
--- a/storage/myisam/mi_delete.c
+++ b/storage/myisam/mi_delete.c
@@ -102,7 +102,7 @@ int mi_delete(MI_INFO *info,const uchar *record)
   mi_sizestore(lastpos,info->lastpos);
   myisam_log_command(MI_LOG_DELETE,info,(uchar*) lastpos,sizeof(lastpos),0);
   (void) _mi_writeinfo(info,WRITEINFO_UPDATE_KEYFILE);
-  allow_break();			/* Allow SIGHUP & SIGINT */
+
   if (info->invalidator != 0)
   {
     DBUG_PRINT("info", ("invalidator... '%s' (delete)", info->filename));
@@ -122,7 +122,6 @@ err:
   }
   (void) _mi_writeinfo(info,WRITEINFO_UPDATE_KEYFILE);
   info->update|=HA_STATE_WRITTEN;	/* Buffer changed */
-  allow_break();			/* Allow SIGHUP & SIGINT */
   my_errno=save_errno;
   if (save_errno == HA_ERR_KEY_NOT_FOUND)
   {
diff --git a/storage/myisam/mi_delete_all.c b/storage/myisam/mi_delete_all.c
index 7a2e24189e6..cc610b73839 100644
--- a/storage/myisam/mi_delete_all.c
+++ b/storage/myisam/mi_delete_all.c
@@ -66,7 +66,6 @@ int mi_delete_all_rows(MI_INFO *info)
   if (share->file_map)
     mi_dynmap_file(info, (my_off_t) 0);
 #endif
-  allow_break();			/* Allow SIGHUP & SIGINT */
   DBUG_RETURN(0);
 
 err:
@@ -74,7 +73,6 @@ err:
     int save_errno=my_errno;
     (void) _mi_writeinfo(info,WRITEINFO_UPDATE_KEYFILE);
     info->update|=HA_STATE_WRITTEN;	/* Buffer changed */
-    allow_break();			/* Allow SIGHUP & SIGINT */
     DBUG_RETURN(my_errno=save_errno);
   }
 } /* mi_delete */
diff --git a/storage/myisam/mi_dynrec.c b/storage/myisam/mi_dynrec.c
index f429edd2759..8b407a36d6f 100644
--- a/storage/myisam/mi_dynrec.c
+++ b/storage/myisam/mi_dynrec.c
@@ -39,13 +39,11 @@ static int delete_dynamic_record(MI_INFO *info,my_off_t filepos,
 static int _mi_cmp_buffer(File file, const uchar *buff, my_off_t filepos,
 			  uint length);
 
-#ifdef THREAD
 /* Play it safe; We have a small stack when using threads */
 #undef my_alloca
 #undef my_afree
 #define my_alloca(A) my_malloc((A),MYF(0))
 #define my_afree(A) my_free((A))
-#endif
 
 	/* Interface function from MI_INFO */
 
@@ -1579,9 +1577,6 @@ int _mi_cmp_dynamic_record(register MI_INFO *info, register const uchar *record)
   MI_BLOCK_INFO block_info;
   DBUG_ENTER("_mi_cmp_dynamic_record");
 
-	/* We are going to do changes; dont let anybody disturb */
-  dont_break();				/* Dont allow SIGHUP or SIGINT */
-
   if (info->opt_flag & WRITE_CACHE_USED)
   {
     info->update&= ~(HA_STATE_WRITE_AT_END | HA_STATE_EXTEND_BLOCK);
diff --git a/storage/myisam/mi_log.c b/storage/myisam/mi_log.c
index 5af4a057a95..4b207f48e1c 100644
--- a/storage/myisam/mi_log.c
+++ b/storage/myisam/mi_log.c
@@ -24,11 +24,7 @@
 #endif
 
 #undef GETPID					/* For HPUX */
-#ifdef THREAD
 #define GETPID() (log_type == 1 ? (long) myisam_pid : (long) my_thread_dbug_id())
-#else
-#define GETPID() myisam_pid
-#endif
 
 	/* Activate logging if flag is 1 and reset logging if flag is 0 */
 
diff --git a/storage/myisam/mi_open.c b/storage/myisam/mi_open.c
index e3c29909067..6efcfd8862f 100644
--- a/storage/myisam/mi_open.c
+++ b/storage/myisam/mi_open.c
@@ -286,9 +286,7 @@ MI_INFO *mi_open(const char *name, int mode, uint open_flags)
 			 &share->state.key_root,keys*sizeof(my_off_t),
 			 &share->state.key_del,
 			 (share->state.header.max_block_size_index*sizeof(my_off_t)),
-#ifdef THREAD
                          &share->key_root_lock, sizeof(mysql_rwlock_t)*keys,
-#endif
                          &share->mmap_lock, sizeof(mysql_rwlock_t),
 			 NullS))
       goto err;
@@ -498,7 +496,6 @@ MI_INFO *mi_open(const char *name, int mode, uint open_flags)
     my_afree(disk_cache);
     mi_setup_functions(share);
     share->is_log_table= FALSE;
-#ifdef THREAD
     thr_lock_init(&share->lock);
     mysql_mutex_init(mi_key_mutex_MYISAM_SHARE_intern_lock,
                      &share->intern_lock, MY_MUTEX_INIT_FAST);
@@ -528,7 +525,6 @@ MI_INFO *mi_open(const char *name, int mode, uint open_flags)
 	share->lock.check_status=mi_check_status;
       }
     }
-#endif
     /*
       Memory mapping can only be requested after initializing intern_lock.
     */
@@ -625,9 +621,7 @@ MI_INFO *mi_open(const char *name, int mode, uint open_flags)
   bzero(info.rec_buff, mi_get_rec_buff_len(&info, info.rec_buff));
 
   *m_info=info;
-#ifdef THREAD
   thr_lock_data_init(&share->lock,&m_info->lock,(void*) m_info);
-#endif
   m_info->open_list.data=(void*) m_info;
   myisam_open_list=list_add(myisam_open_list,&m_info->open_list);
 
diff --git a/storage/myisam/mi_static.c b/storage/myisam/mi_static.c
index 55967fc9001..711287ca16f 100644
--- a/storage/myisam/mi_static.c
+++ b/storage/myisam/mi_static.c
@@ -32,7 +32,7 @@ File	myisam_log_file= -1;
 uint	myisam_quick_table_bits=9;
 ulong	myisam_block_size= MI_KEY_BLOCK_LENGTH;		/* Best by test */
 my_bool myisam_flush=0, myisam_delay_key_write=0, myisam_single_user=0;
-#if defined(THREAD) && !defined(DONT_USE_RW_LOCKS)
+#if !defined(DONT_USE_RW_LOCKS)
 ulong myisam_concurrent_insert= 2;
 #else
 ulong myisam_concurrent_insert= 0;
diff --git a/storage/myisam/mi_statrec.c b/storage/myisam/mi_statrec.c
index f83afa3c886..bf791726aa9 100644
--- a/storage/myisam/mi_statrec.c
+++ b/storage/myisam/mi_statrec.c
@@ -114,9 +114,6 @@ int _mi_cmp_static_record(register MI_INFO *info, register const uchar *old)
 {
   DBUG_ENTER("_mi_cmp_static_record");
 
-  /* We are going to do changes; dont let anybody disturb */
-  dont_break();				/* Dont allow SIGHUP or SIGINT */
-
   if (info->opt_flag & WRITE_CACHE_USED)
   {
     if (flush_io_cache(&info->rec_cache))
diff --git a/storage/myisam/mi_update.c b/storage/myisam/mi_update.c
index b538bcd0bb1..a9aad421235 100644
--- a/storage/myisam/mi_update.c
+++ b/storage/myisam/mi_update.c
@@ -179,7 +179,6 @@ int mi_update(register MI_INFO *info, const uchar *oldrec, uchar *newrec)
     there is no index change there could be data change.
   */
   (void) _mi_writeinfo(info, WRITEINFO_UPDATE_KEYFILE);
-  allow_break();				/* Allow SIGHUP & SIGINT */
   if (info->invalidator != 0)
   {
     DBUG_PRINT("info", ("invalidator... '%s' (update)", info->filename));
@@ -230,7 +229,6 @@ err:
  err_end:
   myisam_log_record(MI_LOG_UPDATE,info,newrec,info->lastpos,my_errno);
   (void) _mi_writeinfo(info,WRITEINFO_UPDATE_KEYFILE);
-  allow_break();				/* Allow SIGHUP & SIGINT */
   if (save_errno == HA_ERR_KEY_NOT_FOUND)
   {
     mi_print_error(info->s, HA_ERR_CRASHED);
diff --git a/storage/myisam/mi_write.c b/storage/myisam/mi_write.c
index bd56bb04f65..f3fbb7206e2 100644
--- a/storage/myisam/mi_write.c
+++ b/storage/myisam/mi_write.c
@@ -60,7 +60,7 @@ int mi_write(MI_INFO *info, uchar *record)
   }
   if (_mi_readinfo(info,F_WRLCK,1))
     DBUG_RETURN(my_errno);
-  dont_break();				/* Dont allow SIGHUP or SIGINT */
+
   filepos= ((share->state.dellink != HA_OFFSET_ERROR &&
              !info->append_insert_at_end) ?
 	    share->state.dellink :
@@ -169,7 +169,6 @@ int mi_write(MI_INFO *info, uchar *record)
   if (share->is_log_table)
     mi_update_status((void*) info);
 
-  allow_break();				/* Allow SIGHUP & SIGINT */
   DBUG_RETURN(0);
 
 err:
@@ -228,7 +227,6 @@ err2:
   save_errno=my_errno;
   myisam_log_record(MI_LOG_WRITE,info,record,filepos,my_errno);
   (void) _mi_writeinfo(info,WRITEINFO_UPDATE_KEYFILE);
-  allow_break();			/* Allow SIGHUP & SIGINT */
   DBUG_RETURN(my_errno=save_errno);
 } /* mi_write */
 
diff --git a/storage/myisam/myisamdef.h b/storage/myisam/myisamdef.h
index c7f0cb27a40..133d0cec9eb 100644
--- a/storage/myisam/myisamdef.h
+++ b/storage/myisam/myisamdef.h
@@ -18,12 +18,8 @@
 #include "myisam.h"			/* Structs & some defines */
 #include "myisampack.h"			/* packing of keys */
 #include <my_tree.h>
-#ifdef THREAD
 #include <my_pthread.h>
 #include <thr_lock.h>
-#else
-#include <my_no_pthread.h>
-#endif
 #include <mysql/psi/mysql_file.h>
 
 /* undef map from my_nosys; We need test-if-disk full */
@@ -211,11 +207,10 @@ typedef struct st_mi_isam_share {	/* Shared between opens */
     not_flushed,
     temporary,delay_key_write,
     concurrent_insert;
-#ifdef THREAD
+
   THR_LOCK lock;
   mysql_mutex_t intern_lock;            /* Locking for use with _locking */
   mysql_rwlock_t *key_root_lock;
-#endif
   my_off_t mmaped_length;
   uint     nonmmaped_inserts;           /* counter of writing in non-mmaped
                                            area */
@@ -298,9 +293,7 @@ struct st_myisam_info {
 #ifdef __WIN__
   my_bool owned_by_merge;                       /* This MyISAM table is part of a merge union */
 #endif
-#ifdef THREAD
   THR_LOCK_DATA lock;
-#endif
   uchar  *rtree_recursion_state;	/* For RTREE */
   int     rtree_recursion_depth;
 };
@@ -461,10 +454,9 @@ typedef struct st_mi_sort_param
 #define MI_UNIQUE_HASH_TYPE	HA_KEYTYPE_ULONG_INT
 #define mi_unique_store(A,B)    mi_int4store((A),(B))
 
-#ifdef THREAD
 extern mysql_mutex_t THR_LOCK_myisam;
-#endif
-#if !defined(THREAD) || defined(DONT_USE_RW_LOCKS)
+
+#if defined(DONT_USE_RW_LOCKS)
 #define mysql_rwlock_wrlock(A) {}
 #define mysql_rwlock_rdlock(A) {}
 #define mysql_rwlock_unlock(A) {}
@@ -774,9 +766,7 @@ void mi_check_print_info(MI_CHECK *param, const char *fmt,...);
 int flush_pending_blocks(MI_SORT_PARAM *param);
 int sort_ft_buf_flush(MI_SORT_PARAM *sort_param);
 int thr_write_keys(MI_SORT_PARAM *sort_param);
-#ifdef THREAD
 pthread_handler_t thr_find_all_keys(void *arg);
-#endif
 int flush_blocks(MI_CHECK *param, KEY_CACHE *key_cache, File file);
 
 int sort_write_record(MI_SORT_PARAM *sort_param);
diff --git a/storage/myisam/sort.c b/storage/myisam/sort.c
index 9532b9f0474..6630b99dd9c 100644
--- a/storage/myisam/sort.c
+++ b/storage/myisam/sort.c
@@ -302,7 +302,6 @@ static ha_rows find_all_keys(MI_SORT_PARAM *info, uint keys,
 } /* find_all_keys */
 
 
-#ifdef THREAD
 /* Search after all keys and place them in a temp. file */
 
 pthread_handler_t thr_find_all_keys(void *arg)
@@ -637,7 +636,6 @@ int thr_write_keys(MI_SORT_PARAM *sort_param)
   my_free(mergebuf);
   DBUG_RETURN(got_error);
 }
-#endif /* THREAD */
 
         /* Write all keys in memory to file for later merge */
 
diff --git a/storage/myisammrg/myrg_def.h b/storage/myisammrg/myrg_def.h
index b916243be21..9bc0881b212 100644
--- a/storage/myisammrg/myrg_def.h
+++ b/storage/myisammrg/myrg_def.h
@@ -23,9 +23,7 @@
 
 extern LIST *myrg_open_list;
 
-#ifdef THREAD
 extern mysql_mutex_t THR_LOCK_open;
-#endif
 
 int _myrg_init_queue(MYRG_INFO *info,int inx,enum ha_rkey_function search_flag);
 int _myrg_mi_read_record(MI_INFO *info, uchar *buf);
diff --git a/tests/thread_test.c b/tests/thread_test.c
index c243a3a7321..4edfe59772c 100644
--- a/tests/thread_test.c
+++ b/tests/thread_test.c
@@ -15,15 +15,6 @@
 
 #include <my_global.h>
 
-#ifndef THREAD
-
-int main(int argc __attribute__((unused)), char **argv __attribute__((unused)))
-{
-  printf("This test must be compiled with multithread support to work\n");
-  exit(1);
-}
-#else
-
 #include <my_sys.h>
 #include <my_pthread.h>
 #include "mysql.h"
@@ -254,4 +245,3 @@ int main(int argc, char **argv)
   return 0;					/* Keep some compilers happy */
 }
 
-#endif /* THREAD */