1 /* 2 ** 2007 August 28 3 ** 4 ** The author disclaims copyright to this source code. In place of 5 ** a legal notice, here is a blessing: 6 ** 7 ** May you do good and not evil. 8 ** May you find forgiveness for yourself and forgive others. 9 ** May you share freely, never taking more than you give. 10 ** 11 ************************************************************************* 12 ** 13 ** This file contains the common header for all mutex implementations. 14 ** The sqliteInt.h header #includes this file so that it is available 15 ** to all source files. We break it out in an effort to keep the code 16 ** better organized. 17 ** 18 ** NOTE: source files should *not* #include this header file directly. 19 ** Source files should #include the sqliteInt.h file and let that file 20 ** include this one indirectly. 21 ** 22 ** $Id: mutex.h,v 1.9 2008/10/07 15:25:48 drh Exp $ 23 */ 24 25 26 /* 27 ** Figure out what version of the code to use. The choices are 28 ** 29 ** SQLITE_MUTEX_OMIT No mutex logic. Not even stubs. The 30 ** mutexes implemention cannot be overridden 31 ** at start-time. 32 ** 33 ** SQLITE_MUTEX_NOOP For single-threaded applications. No 34 ** mutual exclusion is provided. But this 35 ** implementation can be overridden at 36 ** start-time. 37 ** 38 ** SQLITE_MUTEX_PTHREADS For multi-threaded applications on Unix. 39 ** 40 ** SQLITE_MUTEX_W32 For multi-threaded applications on Win32. 41 ** 42 ** SQLITE_MUTEX_OS2 For multi-threaded applications on OS/2. 43 */ 44 #if !SQLITE_THREADSAFE 45 # define SQLITE_MUTEX_OMIT 46 #endif 47 #if SQLITE_THREADSAFE && !defined(SQLITE_MUTEX_NOOP) 48 # if SQLITE_OS_UNIX 49 # define SQLITE_MUTEX_PTHREADS 50 # elif SQLITE_OS_WIN 51 # define SQLITE_MUTEX_W32 52 # elif SQLITE_OS_OS2 53 # define SQLITE_MUTEX_OS2 54 # else 55 # define SQLITE_MUTEX_NOOP 56 # endif 57 #endif 58 59 #ifdef SQLITE_MUTEX_OMIT 60 /* 61 ** If this is a no-op implementation, implement everything as macros. 62 */ 63 #define sqlite3_mutex_alloc(X) ((sqlite3_mutex*)8) 64 #define sqlite3_mutex_free(X) 65 #define sqlite3_mutex_enter(X) 66 #define sqlite3_mutex_try(X) SQLITE_OK 67 #define sqlite3_mutex_leave(X) 68 #define sqlite3_mutex_held(X) 1 69 #define sqlite3_mutex_notheld(X) 1 70 #define sqlite3MutexAlloc(X) ((sqlite3_mutex*)8) 71 #define sqlite3MutexInit() SQLITE_OK 72 #define sqlite3MutexEnd() 73 #endif /* defined(SQLITE_OMIT_MUTEX) */ 74