Backported my_atomic from 6.0-codebase and added support for 64-bit atomics to enable removal of LOCK_thread_count from every query, removed LOCK_thread_count from use in dispatch_command and close of query which is used in every query, now uses atomic increments/decrements instead

2 files changed, 49 insertions, 14 deletions

diff --git a/include/atomic/rwlock.h b/include/atomic/rwlock.h
index 18b77e93d80..29e22fcb3d5 100644
--- a/include/atomic/rwlock.h
+++ b/include/atomic/rwlock.h
@@ -1,3 +1,6 @@
+#ifndef ATOMIC_RWLOCK_INCLUDED
+#define ATOMIC_RWLOCK_INCLUDED
+
 /* Copyright (C) 2006 MySQL AB
 
    This program is free software; you can redistribute it and/or modify
@@ -13,7 +16,8 @@
    along with this program; if not, write to the Free Software
    Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA */
 
-typedef struct {pthread_rwlock_t rw;} my_atomic_rwlock_t;
+typedef struct {pthread_mutex_t rw;} my_atomic_rwlock_t;
+#define MY_ATOMIC_MODE_RWLOCKS 1
 
 #ifdef MY_ATOMIC_MODE_DUMMY
 /*
@@ -31,18 +35,27 @@ typedef struct {pthread_rwlock_t rw;} my_atomic_rwlock_t;
 #define my_atomic_rwlock_wrunlock(name)
 #define MY_ATOMIC_MODE "dummy (non-atomic)"
 #else
-#define my_atomic_rwlock_destroy(name)     pthread_rwlock_destroy(& (name)->rw)
-#define my_atomic_rwlock_init(name)        pthread_rwlock_init(& (name)->rw, 0)
-#define my_atomic_rwlock_rdlock(name)      pthread_rwlock_rdlock(& (name)->rw)
-#define my_atomic_rwlock_wrlock(name)      pthread_rwlock_wrlock(& (name)->rw)
-#define my_atomic_rwlock_rdunlock(name)    pthread_rwlock_unlock(& (name)->rw)
-#define my_atomic_rwlock_wrunlock(name)    pthread_rwlock_unlock(& (name)->rw)
-#define MY_ATOMIC_MODE "rwlocks"
+/*
+  we're using read-write lock macros but map them to mutex locks, and they're
+  faster. Still, having semantically rich API we can change the
+  underlying implementation, if necessary.
+*/
+#define my_atomic_rwlock_destroy(name)     pthread_mutex_destroy(& (name)->rw)
+#define my_atomic_rwlock_init(name)        pthread_mutex_init(& (name)->rw, 0)
+#define my_atomic_rwlock_rdlock(name)      pthread_mutex_lock(& (name)->rw)
+#define my_atomic_rwlock_wrlock(name)      pthread_mutex_lock(& (name)->rw)
+#define my_atomic_rwlock_rdunlock(name)    pthread_mutex_unlock(& (name)->rw)
+#define my_atomic_rwlock_wrunlock(name)    pthread_mutex_unlock(& (name)->rw)
+#define MY_ATOMIC_MODE "mutex"
+#ifndef MY_ATOMIC_MODE_RWLOCKS
+#define MY_ATOMIC_MODE_RWLOCKS 1
+#endif
 #endif
 
 #define make_atomic_add_body(S)     int ## S sav; sav= *a; *a+= v; v=sav;
-#define make_atomic_swap_body(S)    int ## S sav; sav= *a; *a= v; v=sav;
+#define make_atomic_fas_body(S)     int ## S sav; sav= *a; *a= v; v=sav;
 #define make_atomic_cas_body(S)     if ((ret= (*a == *cmp))) *a= set; else *cmp=*a;
 #define make_atomic_load_body(S)    ret= *a;
 #define make_atomic_store_body(S)   *a= v;
 
+#endif /* ATOMIC_RWLOCK_INCLUDED */
diff --git a/include/atomic/x86-gcc.h b/include/atomic/x86-gcc.h
index c11483b4083..ba7e7eb572f 100644
--- a/include/atomic/x86-gcc.h
+++ b/include/atomic/x86-gcc.h
@@ -42,15 +42,37 @@
 #endif
 
 #ifndef MY_ATOMIC_NO_XADD
-#define make_atomic_add_body(S)					\
-  asm volatile (LOCK_prefix "; xadd %0, %1;" : "+r" (v) , "+m" (*a))
+#define make_atomic_add_body(S)         make_atomic_add_body ## S
+#define make_atomic_cas_body(S)         make_atomic_cas_body ## S
 #endif
-#define make_atomic_fas_body(S)				\
-  asm volatile ("xchg %0, %1;" : "+q" (v) , "+m" (*a))
-#define make_atomic_cas_body(S)					\
+
+#define make_atomic_add_body32                                  \
+  asm volatile (LOCK_prefix "; xadd %0, %1;" : "+r" (v) , "+m" (*a))
+
+#define make_atomic_cas_body32                                  \
   asm volatile (LOCK_prefix "; cmpxchg %3, %0; setz %2;"	\
                : "+m" (*a), "+a" (*cmp), "=q" (ret): "r" (set))
 
+#define make_atomic_cas_bodyptr make_atomic_cas_body32
+
+#ifndef __x86_64__
+#define make_atomic_add_body64 make_atomic_add_body32
+#define make_atomic_cas_body64 make_atomic_cas_body32
+#else
+#define make_atomic_add_body64                                  \
+  int64 tmp=*a;                                                 \
+  while (!my_atomic_cas64(a, &tmp, tmp+v));                     \
+  v=tmp;
+#define make_atomic_cas_body64                                  \
+  int32 ebx=(set & 0xFFFFFFFF), ecx=(set >> 32);                \
+  asm volatile (LOCK_prefix "; cmpxchg8b %0; setz %2;"         \
+               : "+m" (*a), "+A" (*cmp), "=q" (ret)             \
+               :"b" (ebx), "c" (ecx))
+#endif
+
+#define make_atomic_fas_body(S)                                        \
+  asm volatile ("xchg %0, %1;" : "+r" (v) , "+m" (*a))
+
 #ifdef MY_ATOMIC_MODE_DUMMY
 #define make_atomic_load_body(S)   ret=*a
 #define make_atomic_store_body(S)  *a=v