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
70int sqlite3_mutex_held(sqlite3_mutex*);
71#endif /* defined(SQLITE_MUTEX_OMIT) */
72