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 23 24 /* 25 ** Figure out what version of the code to use. The choices are 26 ** 27 ** SQLITE_MUTEX_OMIT No mutex logic. Not even stubs. The 28 ** mutexes implementation cannot be overridden 29 ** at start-time. 30 ** 31 ** SQLITE_MUTEX_NOOP For single-threaded applications. No 32 ** mutual exclusion is provided. But this 33 ** implementation can be overridden at 34 ** start-time. 35 ** 36 ** SQLITE_MUTEX_PTHREADS For multi-threaded applications on Unix. 37 ** 38 ** SQLITE_MUTEX_W32 For multi-threaded applications on Win32. 39 */ 40 #if !SQLITE_THREADSAFE 41 # define SQLITE_MUTEX_OMIT 42 #endif 43 #if SQLITE_THREADSAFE && !defined(SQLITE_MUTEX_NOOP) 44 # if SQLITE_OS_UNIX 45 # define SQLITE_MUTEX_PTHREADS 46 # elif SQLITE_OS_WIN 47 # define SQLITE_MUTEX_W32 48 # else 49 # define SQLITE_MUTEX_NOOP 50 # endif 51 #endif 52 53 #ifdef SQLITE_MUTEX_OMIT 54 /* 55 ** If this is a no-op implementation, implement everything as macros. 56 */ 57 #define sqlite3_mutex_alloc(X) ((sqlite3_mutex*)8) 58 #define sqlite3_mutex_free(X) 59 #define sqlite3_mutex_enter(X) 60 #define sqlite3_mutex_try(X) SQLITE_OK 61 #define sqlite3_mutex_leave(X) 62 #define sqlite3_mutex_held(X) ((void)(X),1) 63 #define sqlite3_mutex_notheld(X) ((void)(X),1) 64 #define sqlite3MutexAlloc(X) ((sqlite3_mutex*)8) 65 #define sqlite3MutexInit() SQLITE_OK 66 #define sqlite3MutexEnd() 67 #define MUTEX_LOGIC(X) 68 #else 69 #define MUTEX_LOGIC(X) X 70 #endif /* defined(SQLITE_MUTEX_OMIT) */ 71