sl@0: /*
sl@0: ** 2007 August 28
sl@0: **
sl@0: ** The author disclaims copyright to this source code.  In place of
sl@0: ** a legal notice, here is a blessing:
sl@0: **
sl@0: **    May you do good and not evil.
sl@0: **    May you find forgiveness for yourself and forgive others.
sl@0: **    May you share freely, never taking more than you give.
sl@0: **
sl@0: *************************************************************************
sl@0: **
sl@0: ** This file contains the common header for all mutex implementations.
sl@0: ** The sqliteInt.h header #includes this file so that it is available
sl@0: ** to all source files.  We break it out in an effort to keep the code
sl@0: ** better organized.
sl@0: **
sl@0: ** NOTE:  source files should *not* #include this header file directly.
sl@0: ** Source files should #include the sqliteInt.h file and let that file
sl@0: ** include this one indirectly.
sl@0: **
sl@0: ** $Id: mutex.h,v 1.9 2008/10/07 15:25:48 drh Exp $
sl@0: */
sl@0: 
sl@0: 
sl@0: /*
sl@0: ** Figure out what version of the code to use.  The choices are
sl@0: **
sl@0: **   SQLITE_MUTEX_OMIT         No mutex logic.  Not even stubs.  The
sl@0: **                             mutexes implemention cannot be overridden
sl@0: **                             at start-time.
sl@0: **
sl@0: **   SQLITE_MUTEX_NOOP         For single-threaded applications.  No
sl@0: **                             mutual exclusion is provided.  But this
sl@0: **                             implementation can be overridden at
sl@0: **                             start-time.
sl@0: **
sl@0: **   SQLITE_MUTEX_PTHREADS     For multi-threaded applications on Unix.
sl@0: **
sl@0: **   SQLITE_MUTEX_W32          For multi-threaded applications on Win32.
sl@0: **
sl@0: **   SQLITE_MUTEX_OS2          For multi-threaded applications on OS/2.
sl@0: */
sl@0: #if !SQLITE_THREADSAFE
sl@0: # define SQLITE_MUTEX_OMIT
sl@0: #endif
sl@0: #if SQLITE_THREADSAFE && !defined(SQLITE_MUTEX_NOOP)
sl@0: #  if SQLITE_OS_UNIX
sl@0: #    define SQLITE_MUTEX_PTHREADS
sl@0: #  elif SQLITE_OS_WIN
sl@0: #    define SQLITE_MUTEX_W32
sl@0: #  elif SQLITE_OS_OS2
sl@0: #    define SQLITE_MUTEX_OS2
sl@0: #  else
sl@0: #    define SQLITE_MUTEX_NOOP
sl@0: #  endif
sl@0: #endif
sl@0: 
sl@0: #ifdef SQLITE_MUTEX_OMIT
sl@0: /*
sl@0: ** If this is a no-op implementation, implement everything as macros.
sl@0: */
sl@0: #define sqlite3_mutex_alloc(X)    ((sqlite3_mutex*)8)
sl@0: #define sqlite3_mutex_free(X)
sl@0: #define sqlite3_mutex_enter(X)
sl@0: #define sqlite3_mutex_try(X)      SQLITE_OK
sl@0: #define sqlite3_mutex_leave(X)
sl@0: #define sqlite3_mutex_held(X)     1
sl@0: #define sqlite3_mutex_notheld(X)  1
sl@0: #define sqlite3MutexAlloc(X)      ((sqlite3_mutex*)8)
sl@0: #define sqlite3MutexInit()        SQLITE_OK
sl@0: #define sqlite3MutexEnd()
sl@0: #endif /* defined(SQLITE_OMIT_MUTEX) */