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Overview
Comment:Expand the header comment to clarify the purpose for the sqlite3MemoryBarrier() function.
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SHA1: b89495ae09aa0e9652475b2ba1943dfd87c73e07
User & Date: drh 2015-09-26 03:23:29.340
Context
2015-09-26
03:31
Fix the title of the documentation on sqlite3_value_subtype(). This is a comment change only. (check-in: b790235424 user: drh tags: trunk)
03:23
Expand the header comment to clarify the purpose for the sqlite3MemoryBarrier() function. (check-in: b89495ae09 user: drh tags: trunk)
01:28
Remove an assert in the windows worker-thread logic that can fail in a race condition. (check-in: d7bfb96092 user: drh tags: trunk)
Changes
Unified Diff Ignore Whitespace Patch
Changes to src/mutex_unix.c.
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}
static int pthreadMutexNotheld(sqlite3_mutex *p){
  return p->nRef==0 || pthread_equal(p->owner, pthread_self())==0;
}
#endif

/*
** Try to provide a memory barrier operation, needed for initialization only.


*/
void sqlite3MemoryBarrier(void){
#if defined(SQLITE_MEMORY_BARRIER)
  SQLITE_MEMORY_BARRIER;
#elif defined(__GNUC__) && GCC_VERSION>=4001000
  __sync_synchronize();
#endif








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}
static int pthreadMutexNotheld(sqlite3_mutex *p){
  return p->nRef==0 || pthread_equal(p->owner, pthread_self())==0;
}
#endif

/*
** Try to provide a memory barrier operation, needed for initialization
** and also for the implementation of xShmBarrier in the VFS in cases
** where SQLite is compiled without mutexes.
*/
void sqlite3MemoryBarrier(void){
#if defined(SQLITE_MEMORY_BARRIER)
  SQLITE_MEMORY_BARRIER;
#elif defined(__GNUC__) && GCC_VERSION>=4001000
  __sync_synchronize();
#endif
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Changes to src/mutex_w32.c.
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static int winMutexNotheld(sqlite3_mutex *p){
  DWORD tid = GetCurrentThreadId();
  return winMutexNotheld2(p, tid);
}
#endif

/*
** Try to provide a memory barrier operation, needed for initialization only.


*/
void sqlite3MemoryBarrier(void){
#if defined(SQLITE_MEMORY_BARRIER)
  SQLITE_MEMORY_BARRIER;
#elif defined(__GNUC__)
  __sync_synchronize();
#else








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static int winMutexNotheld(sqlite3_mutex *p){
  DWORD tid = GetCurrentThreadId();
  return winMutexNotheld2(p, tid);
}
#endif

/*
** Try to provide a memory barrier operation, needed for initialization
** and also for the xShmBarrier method of the VFS in cases when SQLite is
** compiled without mutexes (SQLITE_THREADSAFE=0).
*/
void sqlite3MemoryBarrier(void){
#if defined(SQLITE_MEMORY_BARRIER)
  SQLITE_MEMORY_BARRIER;
#elif defined(__GNUC__)
  __sync_synchronize();
#else
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