WL#4903 Plugin Service API part I

(mysql-next-mr backport)

34 files changed, 764 insertions, 258 deletions

diff --git a/CMakeLists.txt b/CMakeLists.txt
index c6769eca72d..6e53ff30159 100755
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -311,6 +311,7 @@ ADD_SUBDIRECTORY(extra)
 ADD_SUBDIRECTORY(client)
 ADD_SUBDIRECTORY(sql)
 ADD_SUBDIRECTORY(libmysql)
+ADD_SUBDIRECTORY(libservices)
 ADD_SUBDIRECTORY(tests)
 IF(WITH_EMBEDDED_SERVER) 
   ADD_SUBDIRECTORY(libmysqld)
diff --git a/Makefile.am b/Makefile.am
index 53be49768de..79c98d9d4a9 100644
--- a/Makefile.am
+++ b/Makefile.am
@@ -23,7 +23,7 @@ EXTRA_DIST =		INSTALL-SOURCE INSTALL-WIN-SOURCE \
 
 SUBDIRS =		. include @docs_dirs@ @zlib_dir@ \
 			@readline_topdir@ sql-common scripts \
-			@pstack_dir@ \
+			@pstack_dir@ libservices \
 			@sql_union_dirs@ unittest \
 			@sql_server@ @man_dirs@ tests \
 			netware @libmysqld_dirs@ \
@@ -32,7 +32,7 @@ SUBDIRS =		. include @docs_dirs@ @zlib_dir@ \
 
 DIST_SUBDIRS =		. include Docs zlib \
 			cmd-line-utils sql-common scripts \
-			pstack \
+			pstack libservices \
 			strings mysys dbug extra regex libmysql libmysql_r client unittest storage plugin \
 			vio sql man tests \
 			netware libmysqld \
diff --git a/configure.in b/configure.in
index 1564033cf7a..47e195f92a3 100644
--- a/configure.in
+++ b/configure.in
@@ -2946,7 +2946,7 @@ AC_CONFIG_FILES(Makefile extra/Makefile mysys/Makefile dnl
  man/Makefile BUILD/Makefile vio/Makefile dnl
  libmysql/Makefile libmysql_r/Makefile client/Makefile dnl
  sql/Makefile sql/share/Makefile dnl
- sql/sql_builtin.cc sql-common/Makefile dnl
+ sql/sql_builtin.cc sql-common/Makefile libservices/Makefile dnl
  dbug/Makefile scripts/Makefile include/Makefile dnl
  tests/Makefile Docs/Makefile support-files/Makefile dnl
  support-files/MacOSX/Makefile support-files/RHEL4-SElinux/Makefile dnl
diff --git a/include/Makefile.am b/include/Makefile.am
index dd6f53f7ca2..0a7a35bd6fa 100644
--- a/include/Makefile.am
+++ b/include/Makefile.am
@@ -21,7 +21,8 @@ HEADERS_GEN_MAKE =		my_config.h
 HEADERS_ABI =		mysql.h mysql_com.h mysql_time.h \
 			my_list.h my_alloc.h typelib.h mysql/plugin.h
 pkginclude_HEADERS =	$(HEADERS_ABI) my_dbug.h m_string.h my_sys.h \
-			my_xml.h mysql_embed.h \
+			my_xml.h mysql_embed.h mysql/services.h \
+			mysql/service_my_snprintf.h mysql/service_thd_alloc.h \
 		  	my_pthread.h my_no_pthread.h \
 			decimal.h errmsg.h my_global.h my_net.h \
 			my_getopt.h sslopt-longopts.h my_dir.h \
@@ -36,7 +37,7 @@ noinst_HEADERS =	config-win.h config-netware.h my_bit.h \
 			my_nosys.h my_alarm.h queues.h rijndael.h sha1.h \
 			my_aes.h my_tree.h my_trie.h hash.h thr_alarm.h \
 			thr_lock.h t_ctype.h violite.h my_md5.h base64.h \
-			my_handler.h my_time.h \
+			my_handler.h my_time.h service_versions.h \
 			my_vle.h my_user.h my_atomic.h atomic/nolock.h \
 			atomic/rwlock.h atomic/x86-gcc.h atomic/x86-msvc.h \
                         atomic/solaris.h \
diff --git a/include/m_string.h b/include/m_string.h
index c24bfd7aa6c..3c4c6ea088a 100644
--- a/include/m_string.h
+++ b/include/m_string.h
@@ -250,16 +250,10 @@ extern size_t my_snprintf(char *to, size_t n, const char *fmt, ...)
 
 /*
   LEX_STRING -- a pair of a C-string and its length.
+  (it's part of the plugin API as a MYSQL_LEX_STRING)
 */
 
-#ifndef _my_plugin_h
-/* This definition must match the one given in mysql/plugin.h */
-struct st_mysql_lex_string
-{
-  char *str;
-  size_t length;
-};
-#endif
+#include <mysql/plugin.h>
 typedef struct st_mysql_lex_string LEX_STRING;
 
 #define STRING_WITH_LEN(X) (X), ((size_t) (sizeof(X) - 1))
diff --git a/include/my_sys.h b/include/my_sys.h
index b4366a4cd3d..9121f0f249e 100644
--- a/include/my_sys.h
+++ b/include/my_sys.h
@@ -683,6 +683,8 @@ extern void my_error _VARARGS((int nr,myf MyFlags, ...));
 extern void my_printf_error _VARARGS((uint my_err, const char *format,
                                      myf MyFlags, ...))
                                      ATTRIBUTE_FORMAT(printf, 2, 4);
+extern void my_printv_error(uint error, const char *format, myf MyFlags,
+                            va_list ap);
 extern int my_error_register(const char** (*get_errmsgs) (),
                              int first, int last);
 extern const char **my_error_unregister(int first, int last);
diff --git a/include/mysql/plugin.h b/include/mysql/plugin.h
index 45d0234cb67..f158dc20999 100644
--- a/include/mysql/plugin.h
+++ b/include/mysql/plugin.h
@@ -1,4 +1,4 @@
-/* Copyright (C) 2005 MySQL AB
+/* Copyright (C) 2005 MySQL AB, 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
@@ -16,12 +16,6 @@
 #ifndef _my_plugin_h
 #define _my_plugin_h
 
-/* size_t */
-#include <stdlib.h>
-
-typedef struct st_mysql MYSQL;
-
-
 /*
   On Windows, exports from DLL need to be declared
 */
@@ -39,15 +33,7 @@ class Item;
 #define MYSQL_THD void*
 #endif
 
-#ifndef _m_string_h
-/* This definition must match the one given in m_string.h */
-struct st_mysql_lex_string
-{
-  char *str;
-  unsigned int length;
-};
-#endif /* _m_string_h */
-typedef struct st_mysql_lex_string MYSQL_LEX_STRING;
+#include <mysql/services.h>
 
 #define MYSQL_XIDDATASIZE 128
 /**
@@ -70,7 +56,7 @@ typedef struct st_mysql_xid MYSQL_XID;
   Plugin API. Common for all plugin types.
 */
 
-#define MYSQL_PLUGIN_INTERFACE_VERSION 0x0100
+#define MYSQL_PLUGIN_INTERFACE_VERSION 0x0101
 
 /*
   The allowable types of plugins
@@ -126,7 +112,8 @@ enum enum_mysql_show_type
 {
   SHOW_UNDEF, SHOW_BOOL, SHOW_INT, SHOW_LONG,
   SHOW_LONGLONG, SHOW_CHAR, SHOW_CHAR_PTR,
-  SHOW_ARRAY, SHOW_FUNC, SHOW_DOUBLE
+  SHOW_ARRAY, SHOW_FUNC, SHOW_DOUBLE,
+  SHOW_always_last
 };
 
 struct st_mysql_show_var {
@@ -750,54 +737,6 @@ int thd_killed(const MYSQL_THD thd);
 */
 unsigned long thd_get_thread_id(const MYSQL_THD thd);
 
-
-/**
-  Allocate memory in the connection's local memory pool
-
-  @details
-  When properly used in place of @c my_malloc(), this can significantly
-  improve concurrency. Don't use this or related functions to allocate
-  large chunks of memory. Use for temporary storage only. The memory
-  will be freed automatically at the end of the statement; no explicit
-  code is required to prevent memory leaks.
-
-  @see alloc_root()
-*/
-void *thd_alloc(MYSQL_THD thd, unsigned int size);
-/**
-  @see thd_alloc()
-*/
-void *thd_calloc(MYSQL_THD thd, unsigned int size);
-/**
-  @see thd_alloc()
-*/
-char *thd_strdup(MYSQL_THD thd, const char *str);
-/**
-  @see thd_alloc()
-*/
-char *thd_strmake(MYSQL_THD thd, const char *str, unsigned int size);
-/**
-  @see thd_alloc()
-*/
-void *thd_memdup(MYSQL_THD thd, const void* str, unsigned int size);
-
-/**
-  Create a LEX_STRING in this connection's local memory pool
-
-  @param thd      user thread connection handle
-  @param lex_str  pointer to LEX_STRING object to be initialized
-  @param str      initializer to be copied into lex_str
-  @param size     length of str, in bytes
-  @param allocate_lex_string  flag: if TRUE, allocate new LEX_STRING object,
-                              instead of using lex_str value
-  @return  NULL on failure, or pointer to the LEX_STRING object
-
-  @see thd_alloc()
-*/
-MYSQL_LEX_STRING *thd_make_lex_string(MYSQL_THD thd, MYSQL_LEX_STRING *lex_str,
-                                      const char *str, unsigned int size,
-                                      int allocate_lex_string);
-
 /**
   Get the XID for this connection's transaction
 
@@ -818,64 +757,6 @@ void mysql_query_cache_invalidate4(MYSQL_THD thd,
                                    const char *key, unsigned int key_length,
                                    int using_trx);
 
-/**
-   Get the value of user variable as an integer.
-
-   This function will return the value of variable @a name as an
-   integer. If the original value of the variable is not an integer,
-   the value will be converted into an integer.
-
-   @param name     user variable name
-   @param value    pointer to return the value
-   @param null_value if not NULL, the function will set it to true if
-   the value of variable is null, set to false if not
-
-   @retval 0 Success
-   @retval 1 Variable not found
-*/
-int get_user_var_int(const char *name,
-                     long long int *value, int *null_value);
-
-/**
-   Get the value of user variable as a double precision float number.
-
-   This function will return the value of variable @a name as real
-   number. If the original value of the variable is not a real number,
-   the value will be converted into a real number.
-
-   @param name     user variable name
-   @param value    pointer to return the value
-   @param null_value if not NULL, the function will set it to true if
-   the value of variable is null, set to false if not
-
-   @retval 0 Success
-   @retval 1 Variable not found
-*/
-int get_user_var_real(const char *name,
-                      double *value, int *null_value);
-
-/**
-   Get the value of user variable as a string.
-
-   This function will return the value of variable @a name as
-   string. If the original value of the variable is not a string,
-   the value will be converted into a string.
-
-   @param name     user variable name
-   @param value    pointer to the value buffer
-   @param len      length of the value buffer
-   @param precision precision of the value if it is a float number
-   @param null_value if not NULL, the function will set it to true if
-   the value of variable is null, set to false if not
-
-   @retval 0 Success
-   @retval 1 Variable not found
-*/
-int get_user_var_str(const char *name,
-                     char *value, unsigned long len,
-                     unsigned int precision, int *null_value);
-
-  
 #ifdef __cplusplus
 }
 #endif
diff --git a/include/mysql/plugin.h.pp b/include/mysql/plugin.h.pp
index d864140333b..b7dd7bc0032 100644
--- a/include/mysql/plugin.h.pp
+++ b/include/mysql/plugin.h.pp
@@ -1,11 +1,38 @@
+#include <mysql/services.h>
+#include <mysql/service_my_snprintf.h>
+#include <stdarg.h>
+#include <stdlib.h>
+extern struct my_snprintf_service_st {
+  size_t (*my_snprintf_type)(char*, size_t, const char*, ...);
+  size_t (*my_vsnprintf_type)(char *, size_t, const char*, va_list);
+} *my_snprintf_service;
+size_t my_snprintf(char* to, size_t n, const char* fmt, ...);
+size_t my_vsnprintf(char *to, size_t n, const char* fmt, va_list ap);
+#include <mysql/service_thd_alloc.h>
 #include <stdlib.h>
-typedef struct st_mysql MYSQL;
 struct st_mysql_lex_string
 {
   char *str;
-  unsigned int length;
+  size_t length;
 };
 typedef struct st_mysql_lex_string MYSQL_LEX_STRING;
+extern struct thd_alloc_service_st {
+  void *(*thd_alloc_func)(void*, unsigned int);
+  void *(*thd_calloc_func)(void*, unsigned int);
+  char *(*thd_strdup_func)(void*, const char *);
+  char *(*thd_strmake_func)(void*, const char *, unsigned int);
+  void *(*thd_memdup_func)(void*, const void*, unsigned int);
+  MYSQL_LEX_STRING *(*thd_make_lex_string_func)(void*, MYSQL_LEX_STRING *,
+                                        const char *, unsigned int, int);
+} *thd_alloc_service;
+void *thd_alloc(void* thd, unsigned int size);
+void *thd_calloc(void* thd, unsigned int size);
+char *thd_strdup(void* thd, const char *str);
+char *thd_strmake(void* thd, const char *str, unsigned int size);
+void *thd_memdup(void* thd, const void* str, unsigned int size);
+MYSQL_LEX_STRING *thd_make_lex_string(void* thd, MYSQL_LEX_STRING *lex_str,
+                                      const char *str, unsigned int size,
+                                      int allocate_lex_string);
 struct st_mysql_xid {
   long formatID;
   long gtrid_length;
@@ -17,7 +44,8 @@ enum enum_mysql_show_type
 {
   SHOW_UNDEF, SHOW_BOOL, SHOW_INT, SHOW_LONG,
   SHOW_LONGLONG, SHOW_CHAR, SHOW_CHAR_PTR,
-  SHOW_ARRAY, SHOW_FUNC, SHOW_DOUBLE
+  SHOW_ARRAY, SHOW_FUNC, SHOW_DOUBLE,
+  SHOW_always_last
 };
 struct st_mysql_show_var {
   const char *name;
@@ -107,9 +135,9 @@ struct st_mysql_information_schema
 {
   int interface_version;
 };
-struct Mysql_replication {
-  int interface_version;
-};
+ struct Mysql_replication {
+   int interface_version;
+ };
 struct st_mysql_value
 {
   int (*value_type)(struct st_mysql_value *);
@@ -130,22 +158,7 @@ void thd_inc_row_count(void* thd);
 int mysql_tmpfile(const char *prefix);
 int thd_killed(const void* thd);
 unsigned long thd_get_thread_id(const void* thd);
-void *thd_alloc(void* thd, unsigned int size);
-void *thd_calloc(void* thd, unsigned int size);
-char *thd_strdup(void* thd, const char *str);
-char *thd_strmake(void* thd, const char *str, unsigned int size);
-void *thd_memdup(void* thd, const void* str, unsigned int size);
-MYSQL_LEX_STRING *thd_make_lex_string(void* thd, MYSQL_LEX_STRING *lex_str,
-                                      const char *str, unsigned int size,
-                                      int allocate_lex_string);
 void thd_get_xid(const void* thd, MYSQL_XID *xid);
 void mysql_query_cache_invalidate4(void* thd,
                                    const char *key, unsigned int key_length,
                                    int using_trx);
-int get_user_var_int(const char *name,
-                     long long int *value, int *null_value);
-int get_user_var_real(const char *name,
-                      double *value, int *null_value);
-int get_user_var_str(const char *name,
-                     char *value, unsigned long len,
-                     unsigned int precision, int *null_value);
diff --git a/include/mysql/service_my_snprintf.h b/include/mysql/service_my_snprintf.h
new file mode 100644
index 00000000000..a9f205fc4de
--- /dev/null
+++ b/include/mysql/service_my_snprintf.h
@@ -0,0 +1,98 @@
+#ifndef MYSQL_SERVICE_MY_SNPRINTF_INCLUDED
+/* Copyright (C) 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 */
+
+/**
+  @file
+  my_snprintf service
+
+  Portable and limited vsnprintf() implementation.
+
+  This is a portable, limited vsnprintf() implementation, with some
+  extra features. "Portable" means that it'll produce identical result
+  on all platforms (for example, on Windows and Linux system printf %e
+  formats the exponent differently, on different systems %p either
+  prints leading 0x or not, %s may accept null pointer or crash on
+  it). "Limited" means that it does not support all the C89 features.
+  But it supports few extensions, not in any standard.
+
+  my_vsnprintf(to, n, fmt, ap)
+
+  @param[out] to     A buffer to store the result in
+  @param[in]  n      Store up to n-1 characters, followed by an end 0
+  @param[in]  fmt    printf-like format string
+  @param[in]  ap     Arguments
+
+  @return a number of bytes written to a buffer *excluding* terminating '\0'
+
+  @post
+  The syntax of a format string is generally the same:
+  % <flag> <width> <precision> <length modifier> <format>
+  where everithing but the format is optional.
+
+  Three one-character flags are regognized:
+    '0' has the standard zero-padding semantics;
+    '-' is parsed, but silently ignored;
+    '`' (backtick) is only supported for strings (%s) and means that the
+        string will be quoted according to MySQL identifier quoting rules.
+
+  Both <width> and <precision> can be specified as numbers or '*'.
+
+  <length modifier> can be 'l', 'll', or 'z'.
+
+  Supported formats are 's' (null pointer is accepted, printed as
+  "(null)"), 'b' (extension, see below), 'c', 'd', 'u', 'x',
+  'X', 'p' (works as 0x%x).
+
+  Standard syntax for positional arguments $n is supported.
+
+  Extensions:
+
+  Flag '`' (backtick): see above.
+
+  Format 'b': binary buffer, prints exactly <precision> bytes from the
+  argument, without stopping at '\0'.
+*/
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+#include <stdarg.h>
+#include <stdlib.h>
+extern struct my_snprintf_service_st {
+  size_t (*my_snprintf_type)(char*, size_t, const char*, ...);
+  size_t (*my_vsnprintf_type)(char *, size_t, const char*, va_list);
+} *my_snprintf_service;
+
+#ifdef MYSQL_DYNAMIC_PLUGIN
+
+#define my_vsnprintf my_snprintf_service->my_vsnprintf_type
+#define my_snprintf my_snprintf_service->my_snprintf_type
+
+#else
+
+size_t my_snprintf(char* to, size_t n, const char* fmt, ...);
+size_t my_vsnprintf(char *to, size_t n, const char* fmt, va_list ap);
+
+#endif
+
+#ifdef __cplusplus
+}
+#endif
+
+#define MYSQL_SERVICE_MY_SNPRINTF_INCLUDED
+#endif
+
diff --git a/include/mysql/service_thd_alloc.h b/include/mysql/service_thd_alloc.h
new file mode 100644
index 00000000000..86158ba1359
--- /dev/null
+++ b/include/mysql/service_thd_alloc.h
@@ -0,0 +1,128 @@
+#ifndef MYSQL_SERVICE_THD_ALLOC_INCLUDED
+/* Copyright (C) 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 */
+
+/**
+  @file
+  This service provdes functions to allocate memory in a connection local
+  memory pool. The memory allocated there will be automatically freed at the
+  end of the statement, don't use it for allocations that should live longer
+  than that. For short living allocations this is more efficient than
+  using my_malloc and friends, and automatic "garbage collection" allows not
+  to think about memory leaks.
+
+  The pool is best for small to medium objects, don't use it for large
+  allocations - they are better served with my_malloc.
+*/
+
+#include <stdlib.h>
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+struct st_mysql_lex_string
+{
+  char *str;
+  size_t length;
+};
+typedef struct st_mysql_lex_string MYSQL_LEX_STRING;
+
+extern struct thd_alloc_service_st {
+  void *(*thd_alloc_func)(MYSQL_THD, unsigned int);
+  void *(*thd_calloc_func)(MYSQL_THD, unsigned int);
+  char *(*thd_strdup_func)(MYSQL_THD, const char *);
+  char *(*thd_strmake_func)(MYSQL_THD, const char *, unsigned int);
+  void *(*thd_memdup_func)(MYSQL_THD, const void*, unsigned int);
+  MYSQL_LEX_STRING *(*thd_make_lex_string_func)(MYSQL_THD, MYSQL_LEX_STRING *,
+                                        const char *, unsigned int, int);
+} *thd_alloc_service;
+
+#ifdef MYSQL_DYNAMIC_PLUGIN
+
+#define thd_alloc(thd,size) (thd_alloc_service->thd_alloc_func((thd), (size)))
+
+#define thd_calloc(thd,size) (thd_alloc_service->thd_calloc_func((thd), (size)))
+
+#define thd_strdup(thd,str) (thd_alloc_service->thd_strdup_func((thd), (str)))
+
+#define thd_strmake(thd,str,size) \
+  (thd_alloc_service->thd_strmake_func((thd), (str), (size)))
+
+#define thd_memdup(thd,str,size) \
+  (thd_alloc_service->thd_memdup_func((thd), (str), (size)))
+
+#define thd_make_lex_string(thd, lex_str, str, size, allocate_lex_string) \
+  (thd_alloc_service->thd_make_lex_string_func((thd), (lex_str), (str), \
+                                               (size), (allocate_lex_string)))
+
+#else
+
+/**
+  Allocate memory in the connection's local memory pool
+
+  @details
+  When properly used in place of @c my_malloc(), this can significantly
+  improve concurrency. Don't use this or related functions to allocate
+  large chunks of memory. Use for temporary storage only. The memory
+  will be freed automatically at the end of the statement; no explicit
+  code is required to prevent memory leaks.
+
+  @see alloc_root()
+*/
+void *thd_alloc(MYSQL_THD thd, unsigned int size);
+/**
+  @see thd_alloc()
+*/
+void *thd_calloc(MYSQL_THD thd, unsigned int size);
+/**
+  @see thd_alloc()
+*/
+char *thd_strdup(MYSQL_THD thd, const char *str);
+/**
+  @see thd_alloc()
+*/
+char *thd_strmake(MYSQL_THD thd, const char *str, unsigned int size);
+/**
+  @see thd_alloc()
+*/
+void *thd_memdup(MYSQL_THD thd, const void* str, unsigned int size);
+
+/**
+  Create a LEX_STRING in this connection's local memory pool
+
+  @param thd      user thread connection handle
+  @param lex_str  pointer to LEX_STRING object to be initialized
+  @param str      initializer to be copied into lex_str
+  @param size     length of str, in bytes
+  @param allocate_lex_string  flag: if TRUE, allocate new LEX_STRING object,
+                              instead of using lex_str value
+  @return  NULL on failure, or pointer to the LEX_STRING object
+
+  @see thd_alloc()
+*/
+MYSQL_LEX_STRING *thd_make_lex_string(MYSQL_THD thd, MYSQL_LEX_STRING *lex_str,
+                                      const char *str, unsigned int size,
+                                      int allocate_lex_string);
+
+#endif
+
+#ifdef __cplusplus
+}
+#endif
+
+#define MYSQL_SERVICE_THD_ALLOC_INCLUDED
+#endif
+
diff --git a/include/mysql/services.h b/include/mysql/services.h
new file mode 100644
index 00000000000..19003e66b96
--- /dev/null
+++ b/include/mysql/services.h
@@ -0,0 +1,30 @@
+#ifndef MYSQL_SERVICES_INCLUDED
+/* Copyright (C) 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 */
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+#include <mysql/service_my_snprintf.h>
+#include <mysql/service_thd_alloc.h>
+
+#ifdef __cplusplus
+}
+#endif
+
+#define MYSQL_SERVICES_INCLUDED
+#endif
+
diff --git a/include/service_versions.h b/include/service_versions.h
new file mode 100644
index 00000000000..114957cdd86
--- /dev/null
+++ b/include/service_versions.h
@@ -0,0 +1,24 @@
+/* Copyright (C) 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 */
+
+#ifdef _WIN32
+#define SERVICE_VERSION __declspec(dllexport) void *
+#else
+#define SERVICE_VERSION void *
+#endif
+
+#define VERSION_my_snprintf     0x0100
+#define VERSION_thd_alloc       0x0100
+
diff --git a/libservices/CMakeLists.txt b/libservices/CMakeLists.txt
new file mode 100644
index 00000000000..ddfa2495ade
--- /dev/null
+++ b/libservices/CMakeLists.txt
@@ -0,0 +1,20 @@
+# Copyright (C) 2006 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., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
+
+INCLUDE_DIRECTORIES(${CMAKE_SOURCE_DIR}/include)
+
+SET(MYSQLSERVICES_SOURCES my_snprintf_service.c thd_alloc_service.c)
+
+ADD_LIBRARY(mysqlservices ${MYSQLSERVICES_SOURCES})
diff --git a/libservices/HOWTO b/libservices/HOWTO
new file mode 100644
index 00000000000..b4960cb11dc
--- /dev/null
+++ b/libservices/HOWTO
@@ -0,0 +1,100 @@
+How to create a new service
+^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+A "service" is a set of C functions in a structure that a
+service dynamic linker uses when a dynamic plugin is loaded.
+
+If you want to export C++ class you need to provide an
+extern "C" function that will create a new instance of your class,
+and put it in a service.
+
+Data structures are not part of the service structure, but they are part
+of the API you create and usually need to be declared in the same
+service_*.h file.
+
+To turn a set of functions (foo_func1, foo_func2)
+into a service "foo" you need to
+
+1. create a new file include/mysql/service_foo.h
+
+2. the template is
+==================================================================
+  #ifndef MYSQL_SERVICE_FOO_INCLUDED
+  /* standard GPL header */
+
+  /**
+    @file
+    *exhaustive* description of the interface you provide.
+    This file is the main user documentation of the new service
+  */
+  #ifdef __cplusplus
+  extern "C" {
+  #endif
+
+  extern struct foo_service_st {
+    int (*foo_func1_type)(...);  /* fix the prototype as appropriate */
+    void (*foo_func2_type)(...); /* fix the prototype as appropriate */
+  } *foo_service;
+
+  #ifdef MYSQL_DYNAMIC_PLUGIN
+
+  #define foo_func1(...) foo_service->foo_func1_type(...)
+  #define foo_func2(...) foo_service->foo_func2_type(...)
+
+  #else
+
+  int foo_func1_type(...);  /* fix the prototype as appropriate */
+  void foo_func2_type(...); /* fix the prototype as appropriate */
+
+  #endif
+
+  #ifdef __cplusplus
+  }
+  #endif
+
+  #define MYSQL_SERVICE_FOO_INCLUDED
+  #endif
+==================================================================
+
+the service_foo.h file should be self-contained, if it needs system headers -
+include them in it, e.g. if you use size_t - #include <stdlib.h>
+
+it should also declare all the accompanying data structures, as necessary
+(e.g. thd_alloc_service declares MYSQL_LEX_STRING).
+
+3. add the new file to include/Makefile.am (pkginclude_HEADERS)
+4. add the new file to include/mysql/services.h
+5. increase the minor plugin ABI version in include/mysql/plugin.h
+   (MYSQL_PLUGIN_INTERFACE_VERSION = MYSQL_PLUGIN_INTERFACE_VERSION+1)
+6. add the version of your service to include/service_versions.h:
+==================================================================
+    #define VERSION_foo 0x0100
+==================================================================
+
+7. create a new file libservices/foo_service.h using the following template:
+==================================================================
+  /* GPL header */
+  #include <service_versions.h>
+  SERVICE_VERSION *foo_service= (void*)VERSION_foo;
+==================================================================
+
+8. add the new file to libservices/CMakeLists.txt (MYSQLSERVICES_SOURCES)
+9. add the new file to libservices/Makefile.am (libmysqlservices_a_SOURCES)
+10. and finally, register your service for dynamic linking in
+    sql/sql_plugin_services.h
+10.1 fill in the service structure:
+==================================================================
+  static struct foo_service_st foo_handler = {
+    foo_func1,
+    foo_func2
+  }
+==================================================================
+
+10.2 and add it to the list of services
+
+==================================================================
+    { "foo_service", VERSION_foo, &foo_handler }
+==================================================================
+
+that's all.
+
diff --git a/libservices/Makefile.am b/libservices/Makefile.am
new file mode 100644
index 00000000000..642081859c1
--- /dev/null
+++ b/libservices/Makefile.am
@@ -0,0 +1,19 @@
+# Copyright 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
+
+AM_CPPFLAGS =		-I$(top_srcdir)/include
+pkglib_LIBRARIES =	libmysqlservices.a
+libmysqlservices_a_SOURCES =  my_snprintf_service.c thd_alloc_service.c
+EXTRA_DIST = CMakeLists.txt
diff --git a/libservices/my_snprintf_service.c b/libservices/my_snprintf_service.c
new file mode 100644
index 00000000000..40d778e4b8d
--- /dev/null
+++ b/libservices/my_snprintf_service.c
@@ -0,0 +1,17 @@
+/* Copyright (C) 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 */
+
+#include <service_versions.h>
+SERVICE_VERSION my_snprintf_service= (void*)VERSION_my_snprintf;
diff --git a/libservices/thd_alloc_service.c b/libservices/thd_alloc_service.c
new file mode 100644
index 00000000000..5d4d496774c
--- /dev/null
+++ b/libservices/thd_alloc_service.c
@@ -0,0 +1,17 @@
+/* Copyright (C) 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 */
+
+#include <service_versions.h>
+SERVICE_VERSION *thd_alloc_service= (void*)VERSION_thd_alloc;
diff --git a/mysql-test/r/plugin.result b/mysql-test/r/plugin.result
index 782d2a5a9a4..85fbd1353cc 100644
--- a/mysql-test/r/plugin.result
+++ b/mysql-test/r/plugin.result
@@ -12,6 +12,15 @@ CREATE TABLE t1(a int) ENGINE=EXAMPLE;
 SELECT * FROM t1;
 a
 DROP TABLE t1;
+set global example_ulong_var=500;
+set global example_enum_var= e1;
+show status like 'example%';
+Variable_name	Value
+example_func_example	enum_var is 0, ulong_var is 500, really
+show variables like 'example%';
+Variable_name	Value
+example_enum_var	e1
+example_ulong_var	500
 UNINSTALL PLUGIN example;
 UNINSTALL PLUGIN EXAMPLE;
 ERROR 42000: PLUGIN EXAMPLE does not exist
diff --git a/mysql-test/t/plugin.test b/mysql-test/t/plugin.test
index 788a7b336ef..0bf86b47dd7 100644
--- a/mysql-test/t/plugin.test
+++ b/mysql-test/t/plugin.test
@@ -22,6 +22,12 @@ SELECT * FROM t1;
 
 DROP TABLE t1;
 
+# a couple of tests for variables
+set global example_ulong_var=500;
+set global example_enum_var= e1;
+show status like 'example%';
+show variables like 'example%';
+
 UNINSTALL PLUGIN example;
 --error 1305
 UNINSTALL PLUGIN EXAMPLE;
diff --git a/mysys/my_error.c b/mysys/my_error.c
index ff9156faf82..e2523a39d0b 100644
--- a/mysys/my_error.c
+++ b/mysys/my_error.c
@@ -126,6 +126,29 @@ void my_printf_error(uint error, const char *format, myf MyFlags, ...)
 }
 
 /*
+  Error with va_list
+
+  SYNOPSIS
+    my_printv_error()
+      error	Errno
+      format	Format string
+      MyFlags	Flags
+      ...	variable list
+*/
+
+void my_printv_error(uint error, const char *format, myf MyFlags, va_list ap)
+{
+  char ebuff[ERRMSGSIZE];
+  DBUG_ENTER("my_printv_error");
+  DBUG_PRINT("my", ("nr: %d  MyFlags: %d  errno: %d  format: %s",
+		    error, MyFlags, errno, format));
+
+  (void) my_vsnprintf(ebuff, sizeof(ebuff), format, ap);
+  (*error_handler_hook)(error, ebuff, MyFlags);
+  DBUG_VOID_RETURN;
+}
+
+/*
   Give message using error_handler_hook
 
   SYNOPSIS
diff --git a/plugin/daemon_example/Makefile.am b/plugin/daemon_example/Makefile.am
index c5414cd46c7..fce67285a5f 100644
--- a/plugin/daemon_example/Makefile.am
+++ b/plugin/daemon_example/Makefile.am
@@ -26,7 +26,8 @@ INCLUDES =              -I$(top_srcdir)/include -I$(top_builddir)/include \
 
 EXTRA_LTLIBRARIES =	libdaemon_example.la
 pkgplugin_LTLIBRARIES =	@plugin_daemon_example_shared_target@
-libdaemon_example_la_LDFLAGS =	-module -rpath $(pkgplugindir)
+libdaemon_example_la_LDFLAGS =	-module -rpath $(pkgplugindir) -L$(top_builddir)/libservices -lmysqlservices
+
 libdaemon_example_la_CXXFLAGS=	$(AM_CFLAGS) -DMYSQL_DYNAMIC_PLUGIN
 libdaemon_example_la_CFLAGS =	$(AM_CFLAGS) -DMYSQL_DYNAMIC_PLUGIN
 libdaemon_example_la_SOURCES =	daemon_example.cc
diff --git a/sql/CMakeLists.txt b/sql/CMakeLists.txt
index 3e350144f74..15c2d950ff9 100755
--- a/sql/CMakeLists.txt
+++ b/sql/CMakeLists.txt
@@ -45,7 +45,7 @@ SET (SQL_SOURCE
                discover.cc ../libmysql/errmsg.c field.cc  field_conv.cc 
                filesort.cc gstream.cc
                ha_partition.cc
-               handler.cc hash_filo.cc hash_filo.h 
+               handler.cc hash_filo.cc hash_filo.h sql_plugin_services.h
                hostname.cc init.cc item.cc item_buff.cc item_cmpfunc.cc 
                item_create.cc item_func.cc item_geofunc.cc item_row.cc 
                item_strfunc.cc item_subselect.cc item_sum.cc item_timefunc.cc 
diff --git a/sql/Makefile.am b/sql/Makefile.am
index 569bb70965e..5c3a1d3a8fe 100644
--- a/sql/Makefile.am
+++ b/sql/Makefile.am
@@ -82,7 +82,7 @@ mysqld_LDADD =		libndb.la \
 
 noinst_HEADERS =	item.h item_func.h item_sum.h item_cmpfunc.h \
 			item_strfunc.h item_timefunc.h \
-			item_xmlfunc.h \
+			item_xmlfunc.h sql_plugin_services.h \
 			item_create.h item_subselect.h item_row.h \
 			mysql_priv.h item_geofunc.h sql_bitmap.h \
 			procedure.h sql_class.h sql_lex.h sql_list.h \
diff --git a/sql/mysql_priv.h b/sql/mysql_priv.h
index 05a79957963..c9909298b63 100644
--- a/sql/mysql_priv.h
+++ b/sql/mysql_priv.h
@@ -28,6 +28,16 @@
 
 #ifndef MYSQL_CLIENT
 
+/*
+  the following #define adds server-only members to enum_mysql_show_type,
+  that is defined in mysql/plugin.h
+  it has to be before mysql/plugin.h is included.
+*/
+#define SHOW_always_last SHOW_KEY_CACHE_LONG, \
+            SHOW_KEY_CACHE_LONGLONG, SHOW_LONG_STATUS, SHOW_DOUBLE_STATUS, \
+            SHOW_HAVE, SHOW_MY_BOOL, SHOW_HA_ROWS, SHOW_SYS, \
+            SHOW_LONG_NOFLUSH, SHOW_LONGLONG_STATUS
+
 #include <my_global.h>
 #include <mysql_version.h>
 #include <mysql_embed.h>
diff --git a/sql/replication.h b/sql/replication.h
index 6b7be58a5b1..eea77ef9f8e 100644
--- a/sql/replication.h
+++ b/sql/replication.h
@@ -16,6 +16,8 @@
 #ifndef REPLICATION_H
 #define REPLICATION_H
 
+typedef struct st_mysql MYSQL;
+
 #ifdef __cplusplus
 extern "C" {
 #endif
@@ -483,6 +485,64 @@ const char* thd_enter_cond(MYSQL_THD thd, pthread_cond_t *cond,
 */
 void thd_exit_cond(MYSQL_THD thd, const char *old_msg);
 
+/**
+   Get the value of user variable as an integer.
+
+   This function will return the value of variable @a name as an
+   integer. If the original value of the variable is not an integer,
+   the value will be converted into an integer.
+
+   @param name     user variable name
+   @param value    pointer to return the value
+   @param null_value if not NULL, the function will set it to true if
+   the value of variable is null, set to false if not
+
+   @retval 0 Success
+   @retval 1 Variable not found
+*/
+int get_user_var_int(const char *name,
+                     long long int *value, int *null_value);
+
+/**
+   Get the value of user variable as a double precision float number.
+
+   This function will return the value of variable @a name as real
+   number. If the original value of the variable is not a real number,
+   the value will be converted into a real number.
+
+   @param name     user variable name
+   @param value    pointer to return the value
+   @param null_value if not NULL, the function will set it to true if
+   the value of variable is null, set to false if not
+
+   @retval 0 Success
+   @retval 1 Variable not found
+*/
+int get_user_var_real(const char *name,
+                      double *value, int *null_value);
+
+/**
+   Get the value of user variable as a string.
+
+   This function will return the value of variable @a name as
+   string. If the original value of the variable is not a string,
+   the value will be converted into a string.
+
+   @param name     user variable name
+   @param value    pointer to the value buffer
+   @param len      length of the value buffer
+   @param precision precision of the value if it is a float number
+   @param null_value if not NULL, the function will set it to true if
+   the value of variable is null, set to false if not
+
+   @retval 0 Success
+   @retval 1 Variable not found
+*/
+int get_user_var_str(const char *name,
+                     char *value, unsigned long len,
+                     unsigned int precision, int *null_value);
+
+  
 
 #ifdef __cplusplus
 }
diff --git a/sql/sql_class.cc b/sql/sql_class.cc
index 757f6abb00b..1958bbe271c 100644
--- a/sql/sql_class.cc
+++ b/sql/sql_class.cc
@@ -272,12 +272,7 @@ const char* thd_enter_cond(MYSQL_THD thd, pthread_cond_t *cond,
   if (!thd)
     thd= current_thd;
 
-  const char* old_msg = thd->proc_info;
-  safe_mutex_assert_owner(mutex);
-  thd->mysys_var->current_mutex = mutex;
-  thd->mysys_var->current_cond = cond;
-  thd->proc_info = msg;
-  return old_msg;
+  return thd->enter_cond(cond, mutex, msg);
 }
 
 extern "C"
@@ -286,18 +281,7 @@ void thd_exit_cond(MYSQL_THD thd, const char *old_msg)
   if (!thd)
     thd= current_thd;
 
-  /*
-    Putting the mutex unlock in thd_exit_cond() ensures that
-    mysys_var->current_mutex is always unlocked _before_ mysys_var->mutex is
-    locked (if that would not be the case, you'll get a deadlock if someone
-    does a THD::awake() on you).
-  */
-  pthread_mutex_unlock(thd->mysys_var->current_mutex);
-  pthread_mutex_lock(&thd->mysys_var->mutex);
-  thd->mysys_var->current_mutex = 0;
-  thd->mysys_var->current_cond = 0;
-  thd->proc_info = old_msg;
-  pthread_mutex_unlock(&thd->mysys_var->mutex);
+  thd->exit_cond(old_msg);
   return;
 }
 
diff --git a/sql/sql_class.h b/sql/sql_class.h
index aaa959feae9..3f40195ba5b 100644
--- a/sql/sql_class.h
+++ b/sql/sql_class.h
@@ -25,7 +25,6 @@
 
 #include "log.h"
 #include "rpl_tblmap.h"
-#include "replication.h"
 
 /**
   An interface that is used to take an action when
@@ -1886,11 +1885,28 @@ public:
   inline const char* enter_cond(pthread_cond_t *cond, pthread_mutex_t* mutex,
 			  const char* msg)
   {
-    return thd_enter_cond(this, cond, mutex, msg);
+    const char* old_msg = proc_info;
+    safe_mutex_assert_owner(mutex);
+    mysys_var->current_mutex = mutex;
+    mysys_var->current_cond = cond;
+    proc_info = msg;
+    return old_msg;
   }
   inline void exit_cond(const char* old_msg)
   {
-    thd_exit_cond(this, old_msg);
+    /*
+      Putting the mutex unlock in thd->exit_cond() ensures that
+      mysys_var->current_mutex is always unlocked _before_ mysys_var->mutex is
+      locked (if that would not be the case, you'll get a deadlock if someone
+      does a THD::awake() on you).
+    */
+    pthread_mutex_unlock(mysys_var->current_mutex);
+    pthread_mutex_lock(&mysys_var->mutex);
+    mysys_var->current_mutex = 0;
+    mysys_var->current_cond = 0;
+    proc_info = old_msg;
+    pthread_mutex_unlock(&mysys_var->mutex);
+    return;
   }
   inline time_t query_start() { query_start_used=1; return start_time; }
   inline void set_time()
diff --git a/sql/sql_plugin.cc b/sql/sql_plugin.cc
index 1278eafce92..fb1da901f1b 100644
--- a/sql/sql_plugin.cc
+++ b/sql/sql_plugin.cc
@@ -1,4 +1,4 @@
-/* Copyright (C) 2005 MySQL AB
+/* Copyright (C) 2005 MySQL AB, 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
@@ -99,7 +99,9 @@ static int cur_plugin_info_interface_version[MYSQL_MAX_PLUGIN_TYPE_NUM]=
   MYSQL_REPLICATION_INTERFACE_VERSION,
 };
 
-static bool initialized= 0;
+/* support for Services */
+
+#include "sql_plugin_services.h"
 
 /*
   A mutex LOCK_plugin must be acquired before accessing the
@@ -113,6 +115,8 @@ static HASH plugin_hash[MYSQL_MAX_PLUGIN_TYPE_NUM];
 static bool reap_needed= false;
 static int plugin_array_version=0;
 
+static bool initialized= 0;
+
 /*
   write-lock on LOCK_system_variables_hash is required before modifying
   the following variables/structures
@@ -225,6 +229,22 @@ extern bool throw_bounds_warning(THD *thd, bool fixed, bool unsignd,
 extern bool check_if_table_exists(THD *thd, TABLE_LIST *table, bool *exists);
 #endif /* EMBEDDED_LIBRARY */
 
+static void report_error(int where_to, uint error, ...)
+{
+  va_list args;
+  if (where_to & REPORT_TO_USER)
+  {
+    va_start(args, error);
+    my_printv_error(error, ER(error), MYF(0), args);
+    va_end(args);
+  }
+  if (where_to & REPORT_TO_LOG)
+  {
+    va_start(args, error);
+    error_log_print(ERROR_LEVEL, ER(error), args);
+    va_end(args);
+  }
+}
 
 /****************************************************************************
   Value type thunks, allows the C world to play in the C++ world
@@ -345,7 +365,7 @@ static st_plugin_dl *plugin_dl_add(const LEX_STRING *dl, int report)
 {
 #ifdef HAVE_DLOPEN
   char dlpath[FN_REFLEN];
-  uint plugin_dir_len, dummy_errors, dlpathlen;
+  uint plugin_dir_len, dummy_errors, dlpathlen, i;
   struct st_plugin_dl *tmp, plugin_dl;
   void *sym;
   DBUG_ENTER("plugin_dl_add");
@@ -360,10 +380,7 @@ static st_plugin_dl *plugin_dl_add(const LEX_STRING *dl, int report)
                                system_charset_info, 1) ||
       plugin_dir_len + dl->length + 1 >= FN_REFLEN)
   {
-    if (report & REPORT_TO_USER)
-      my_error(ER_UDF_NO_PATHS, MYF(0));
-    if (report & REPORT_TO_LOG)
-      sql_print_error("%s", ER_DEFAULT(ER_UDF_NO_PATHS));
+    report_error(report, ER_UDF_NO_PATHS);
     DBUG_RETURN(0);
   }
   /* If this dll is already loaded just increase ref_count. */
@@ -388,21 +405,14 @@ static st_plugin_dl *plugin_dl_add(const LEX_STRING *dl, int report)
       if (*errmsg == ':') errmsg++;
       if (*errmsg == ' ') errmsg++;
     }
-    if (report & REPORT_TO_USER)
-      my_error(ER_CANT_OPEN_LIBRARY, MYF(0), dlpath, errno, errmsg);
-    if (report & REPORT_TO_LOG)
-      sql_print_error(ER_DEFAULT(ER_CANT_OPEN_LIBRARY), dlpath, errno, errmsg);
+    report_error(report, ER_CANT_OPEN_LIBRARY, dlpath, errno, errmsg);
     DBUG_RETURN(0);
   }
   /* Determine interface version */
   if (!(sym= dlsym(plugin_dl.handle, plugin_interface_version_sym)))
   {
     free_plugin_mem(&plugin_dl);
-    if (report & REPORT_TO_USER)
-      my_error(ER_CANT_FIND_DL_ENTRY, MYF(0), plugin_interface_version_sym);
-    if (report & REPORT_TO_LOG)
-      sql_print_error(ER_DEFAULT(ER_CANT_FIND_DL_ENTRY),
-                      plugin_interface_version_sym);
+    report_error(report, ER_CANT_FIND_DL_ENTRY, plugin_interface_version_sym);
     DBUG_RETURN(0);
   }
   plugin_dl.version= *(int *)sym;
@@ -411,29 +421,42 @@ static st_plugin_dl *plugin_dl_add(const LEX_STRING *dl, int report)
       (plugin_dl.version >> 8) > (MYSQL_PLUGIN_INTERFACE_VERSION >> 8))
   {
     free_plugin_mem(&plugin_dl);
-    if (report & REPORT_TO_USER)
-      my_error(ER_CANT_OPEN_LIBRARY, MYF(0), dlpath, 0,
-               "plugin interface version mismatch");
-    if (report & REPORT_TO_LOG)
-      sql_print_error(ER_DEFAULT(ER_CANT_OPEN_LIBRARY), dlpath, 0,
-                      "plugin interface version mismatch");
+    report_error(report, ER_CANT_OPEN_LIBRARY, MYF(0), dlpath, 0,
+                 "plugin interface version mismatch");
     DBUG_RETURN(0);
   }
+
+  /* link the services in */
+  for (i= 0; i < array_elements(list_of_services); i++)
+  {
+    if ((sym= dlsym(plugin_dl.handle, list_of_services[i].name)))
+    {
+      uint ver= (uint)(intptr)*(void**)sym;
+      if (ver > list_of_services[i].version ||
+        (ver >> 8) < (list_of_services[i].version >> 8))
+      {
+        char buf[MYSQL_ERRMSG_SIZE];
+        my_snprintf(buf, sizeof(buf),
+                    "service '%s' interface version mismatch",
+                    list_of_services[i].name);
+        report_error(report, ER_CANT_OPEN_LIBRARY, dlpath, 0, buf);
+        DBUG_RETURN(0);
+      }
+      *(void**)sym= list_of_services[i].service;
+    }
+  }
+
   /* Find plugin declarations */
   if (!(sym= dlsym(plugin_dl.handle, plugin_declarations_sym)))
   {
     free_plugin_mem(&plugin_dl);
-    if (report & REPORT_TO_USER)
-      my_error(ER_CANT_FIND_DL_ENTRY, MYF(0), plugin_declarations_sym);
-    if (report & REPORT_TO_LOG)
-      sql_print_error(ER_DEFAULT(ER_CANT_FIND_DL_ENTRY),
-                      plugin_declarations_sym);
+    report_error(report, ER_CANT_FIND_DL_ENTRY, MYF(0),
+                 plugin_declarations_sym);
     DBUG_RETURN(0);
   }
 
   if (plugin_dl.version != MYSQL_PLUGIN_INTERFACE_VERSION)
   {
-    int i;
     uint sizeof_st_plugin;
     struct st_mysql_plugin *old, *cur;
     char *ptr= (char *)sym;
@@ -443,11 +466,7 @@ static st_plugin_dl *plugin_dl_add(const LEX_STRING *dl, int report)
     else
     {
 #ifdef ERROR_ON_NO_SIZEOF_PLUGIN_SYMBOL
-      free_plugin_mem(&plugin_dl);
-      if (report & REPORT_TO_USER)
-        my_error(ER_CANT_FIND_DL_ENTRY, MYF(0), sizeof_st_plugin_sym);
-      if (report & REPORT_TO_LOG)
-        sql_print_error(ER_DEFAULT(ER_CANT_FIND_DL_ENTRY), sizeof_st_plugin_sym);
+      report_error(report, ER_CANT_FIND_DL_ENTRY, sizeof_st_plugin_sym);
       DBUG_RETURN(0);
 #else
       /*
@@ -469,10 +488,7 @@ static st_plugin_dl *plugin_dl_add(const LEX_STRING *dl, int report)
     if (!cur)
     {
       free_plugin_mem(&plugin_dl);
-      if (report & REPORT_TO_USER)
-        my_error(ER_OUTOFMEMORY, MYF(0), plugin_dl.dl.length);
-      if (report & REPORT_TO_LOG)
-        sql_print_error(ER_DEFAULT(ER_OUTOFMEMORY), plugin_dl.dl.length);
+      report_error(report, ER_OUTOFMEMORY, plugin_dl.dl.length);
       DBUG_RETURN(0);
     }
     /*
@@ -494,10 +510,7 @@ static st_plugin_dl *plugin_dl_add(const LEX_STRING *dl, int report)
   if (! (plugin_dl.dl.str= (char*) my_malloc(plugin_dl.dl.length, MYF(0))))
   {
     free_plugin_mem(&plugin_dl);
-    if (report & REPORT_TO_USER)
-      my_error(ER_OUTOFMEMORY, MYF(0), plugin_dl.dl.length);
-    if (report & REPORT_TO_LOG)
-      sql_print_error(ER_DEFAULT(ER_OUTOFMEMORY), plugin_dl.dl.length);
+    report_error(report, ER_OUTOFMEMORY, plugin_dl.dl.length);
     DBUG_RETURN(0);
   }
   plugin_dl.dl.length= copy_and_convert(plugin_dl.dl.str, plugin_dl.dl.length,
@@ -508,19 +521,13 @@ static st_plugin_dl *plugin_dl_add(const LEX_STRING *dl, int report)
   if (! (tmp= plugin_dl_insert_or_reuse(&plugin_dl)))
   {
     free_plugin_mem(&plugin_dl);
-    if (report & REPORT_TO_USER)
-      my_error(ER_OUTOFMEMORY, MYF(0), sizeof(struct st_plugin_dl));
-    if (report & REPORT_TO_LOG)
-      sql_print_error(ER_DEFAULT(ER_OUTOFMEMORY), sizeof(struct st_plugin_dl));
+    report_error(report, ER_OUTOFMEMORY, sizeof(struct st_plugin_dl));
     DBUG_RETURN(0);
   }
   DBUG_RETURN(tmp);
 #else
   DBUG_ENTER("plugin_dl_add");
-  if (report & REPORT_TO_USER)
-    my_error(ER_FEATURE_DISABLED, MYF(0), "plugin", "HAVE_DLOPEN");
-  if (report & REPORT_TO_LOG)
-    sql_print_error(ER_DEFAULT(ER_FEATURE_DISABLED), "plugin", "HAVE_DLOPEN");
+  report_error(report, ER_FEATURE_DISABLED, "plugin", "HAVE_DLOPEN");
   DBUG_RETURN(0);
 #endif
 }
@@ -636,7 +643,7 @@ static plugin_ref intern_plugin_lock(LEX *lex, plugin_ref rc CALLER_INFO_PROTO)
     /*
       For debugging, we do an additional malloc which allows the
       memory manager and/or valgrind to track locked references and
-      double unlocks to aid resolving reference counting.problems.
+      double unlocks to aid resolving reference counting problems.
     */
     if (!(plugin= (plugin_ref) my_malloc_ci(sizeof(pi), MYF(MY_WME))))
       DBUG_RETURN(NULL);
@@ -719,10 +726,7 @@ static bool plugin_add(MEM_ROOT *tmp_root,
   DBUG_ENTER("plugin_add");
   if (plugin_find_internal(name, MYSQL_ANY_PLUGIN))
   {
-    if (report & REPORT_TO_USER)
-      my_error(ER_UDF_EXISTS, MYF(0), name->str);
-    if (report & REPORT_TO_LOG)
-      sql_print_error(ER_DEFAULT(ER_UDF_EXISTS), name->str);
+    report_error(report, ER_UDF_EXISTS, name->str);
     DBUG_RETURN(TRUE);
   }
   /* Clear the whole struct to catch future extensions. */
@@ -749,10 +753,7 @@ static bool plugin_add(MEM_ROOT *tmp_root,
         strxnmov(buf, sizeof(buf) - 1, "API version for ",
                  plugin_type_names[plugin->type].str,
                  " plugin is too different", NullS);
-        if (report & REPORT_TO_USER)
-          my_error(ER_CANT_OPEN_LIBRARY, MYF(0), dl->str, 0, buf);
-        if (report & REPORT_TO_LOG)
-          sql_print_error(ER_DEFAULT(ER_CANT_OPEN_LIBRARY), dl->str, 0, buf);
+        report_error(report, ER_CANT_OPEN_LIBRARY, dl->str, 0, buf);
         goto err;
       }
       tmp.plugin= plugin;
@@ -781,10 +782,7 @@ static bool plugin_add(MEM_ROOT *tmp_root,
       DBUG_RETURN(FALSE);
     }
   }
-  if (report & REPORT_TO_USER)
-    my_error(ER_CANT_FIND_DL_ENTRY, MYF(0), name->str);
-  if (report & REPORT_TO_LOG)
-    sql_print_error(ER_DEFAULT(ER_CANT_FIND_DL_ENTRY), name->str);
+  report_error(report, ER_CANT_FIND_DL_ENTRY, name->str);
 err:
   plugin_dl_del(dl);
   DBUG_RETURN(TRUE);
diff --git a/sql/sql_plugin.h b/sql/sql_plugin.h
index c6ad846943c..23ce85c994b 100644
--- a/sql/sql_plugin.h
+++ b/sql/sql_plugin.h
@@ -35,16 +35,6 @@ class sys_var;
 
 #define INITIAL_LEX_PLUGIN_LIST_SIZE    16
 
-/*
-  the following #define adds server-only members to enum_mysql_show_type,
-  that is defined in plugin.h
-*/
-#define SHOW_FUNC    SHOW_FUNC, SHOW_KEY_CACHE_LONG, SHOW_KEY_CACHE_LONGLONG, \
-                     SHOW_LONG_STATUS, SHOW_DOUBLE_STATUS, SHOW_HAVE,   \
-                     SHOW_MY_BOOL, SHOW_HA_ROWS, SHOW_SYS, SHOW_LONG_NOFLUSH, \
-                     SHOW_LONGLONG_STATUS
-#include <mysql/plugin.h>
-#undef SHOW_FUNC
 typedef enum enum_mysql_show_type SHOW_TYPE;
 typedef struct st_mysql_show_var SHOW_VAR;
 
diff --git a/sql/sql_plugin_services.h b/sql/sql_plugin_services.h
new file mode 100644
index 00000000000..7491ddab79d
--- /dev/null
+++ b/sql/sql_plugin_services.h
@@ -0,0 +1,44 @@
+/* Copyright (C) 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 */
+
+/* support for Services */
+#include <service_versions.h>
+
+struct st_service_ref {
+  const char *name;
+  uint version;
+  void *service;
+};
+
+static struct my_snprintf_service_st my_snprintf_handler = {
+  my_snprintf,
+  my_vsnprintf
+};
+
+static struct thd_alloc_service_st thd_alloc_handler= {
+  thd_alloc,
+  thd_calloc,
+  thd_strdup,
+  thd_strmake,
+  thd_memdup,
+  thd_make_lex_string
+};
+
+static struct st_service_ref list_of_services[]=
+{
+  { "my_snprintf_service", VERSION_my_snprintf, &my_snprintf_handler },
+  { "thd_alloc_service",   VERSION_thd_alloc,   &thd_alloc_handler }
+};
+
diff --git a/storage/example/Makefile.am b/storage/example/Makefile.am
index ce269aee59b..1179a338ee2 100644
--- a/storage/example/Makefile.am
+++ b/storage/example/Makefile.am
@@ -34,7 +34,7 @@ noinst_HEADERS =	ha_example.h
 
 EXTRA_LTLIBRARIES =	ha_example.la
 pkgplugin_LTLIBRARIES =	@plugin_example_shared_target@
-ha_example_la_LDFLAGS =	-module -rpath $(pkgplugindir)
+ha_example_la_LDFLAGS =	-module -rpath $(pkgplugindir) -L$(top_builddir)/libservices -lmysqlservices
 ha_example_la_CXXFLAGS=	$(AM_CFLAGS) -DMYSQL_DYNAMIC_PLUGIN
 ha_example_la_CFLAGS =	$(AM_CFLAGS) -DMYSQL_DYNAMIC_PLUGIN
 ha_example_la_SOURCES =	ha_example.cc
diff --git a/storage/example/ha_example.cc b/storage/example/ha_example.cc
index 30fc82c82d2..4b982f2943f 100644
--- a/storage/example/ha_example.cc
+++ b/storage/example/ha_example.cc
@@ -1,4 +1,4 @@
-/* Copyright (C) 2003 MySQL AB
+/* Copyright (C) 2003 MySQL AB, 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
@@ -921,6 +921,24 @@ static struct st_mysql_sys_var* example_system_variables[]= {
   NULL
 };
 
+// this is an example of SHOW_FUNC and of my_snprintf() service
+static int show_func_example(MYSQL_THD thd, struct st_mysql_show_var *var,
+                             char *buf)
+{
+  var->type= SHOW_CHAR;
+  var->value= buf; // it's of SHOW_VAR_FUNC_BUFF_SIZE bytes
+  my_snprintf(buf, SHOW_VAR_FUNC_BUFF_SIZE,
+              "enum_var is %u, ulong_var is %lu, %.6b", // %b is MySQL extension
+              srv_enum_var, srv_ulong_var, "really");
+  return 0;
+}
+
+static struct st_mysql_show_var func_status[]=
+{
+  {"example_func_example",  (char *)show_func_example, SHOW_FUNC},
+  {0,0,SHOW_UNDEF}
+};
+
 mysql_declare_plugin(example)
 {
   MYSQL_STORAGE_ENGINE_PLUGIN,
@@ -932,7 +950,7 @@ mysql_declare_plugin(example)
   example_init_func,                            /* Plugin Init */
   example_done_func,                            /* Plugin Deinit */
   0x0001 /* 0.1 */,
-  NULL,                                         /* status variables */
+  func_status,                                  /* status variables */
   example_system_variables,                     /* system variables */
   NULL                                          /* config options */
 }
diff --git a/storage/mysql_storage_engine.cmake b/storage/mysql_storage_engine.cmake
index af8c3a85cd1..b920f16452b 100644
--- a/storage/mysql_storage_engine.cmake
+++ b/storage/mysql_storage_engine.cmake
@@ -34,7 +34,7 @@ IF(NOT SOURCE_SUBLIBS)
     #The dll is linked to the mysqld executable
     SET(dyn_libname ha_${libname})
     ADD_LIBRARY(${dyn_libname} SHARED ${${engine}_SOURCES})
-    TARGET_LINK_LIBRARIES (${dyn_libname}  mysqld)
+    TARGET_LINK_LIBRARIES (${dyn_libname} mysqlservices mysqld)
     IF(${engine}_LIBS)
       TARGET_LINK_LIBRARIES(${dyn_libname} ${${engine}_LIBS})
     ENDIF(${engine}_LIBS)
diff --git a/strings/my_vsnprintf.c b/strings/my_vsnprintf.c
index 3362559972a..46961058eea 100644
--- a/strings/my_vsnprintf.c
+++ b/strings/my_vsnprintf.c
@@ -472,6 +472,8 @@ start:
 /**
   Produces output string according to a format string
 
+  See the detailed documentation around my_snprintf_service_st
+
   @param cs         string charset
   @param to         buffer where processed string will be place
   @param n          size of buffer