/*

** 2007 August 28

**

** The author disclaims copyright to this source code.  In place of

** a legal notice, here is a blessing:

**

**    May you do good and not evil.

**    May you find forgiveness for yourself and forgive others.

**    May you share freely, never taking more than you give.

**

*************************************************************************

**

** This file contains the common header for all mutex implementations.

** The sqliteInt.h header #includes this file so that it is available

** to all source files.  We break it out in an effort to keep the code

** better organized.

**

** NOTE:  source files should *not* #include this header file directly.

** Source files should #include the sqliteInt.h file and let that file

** include this one indirectly.

**

** $Id: mutex.h 1282 2008-11-13 09:31:33Z LarsPson $

*/

#ifdef SQLITE_MUTEX_APPDEF

/*

** If SQLITE_MUTEX_APPDEF is defined, then this whole module is

** omitted and equivalent functionality must be provided by the

** application that links against the SQLite library.

*/

#else

/*

** Figure out what version of the code to use.  The choices are

**

**   SQLITE_MUTEX_NOOP         For single-threaded applications that

**                             do not desire error checking.

**

**   SQLITE_MUTEX_NOOP_DEBUG   For single-threaded applications with

**                             error checking to help verify that mutexes

**                             are being used correctly even though they

**                             are not needed.  Used when SQLITE_DEBUG is

**                             defined on single-threaded builds.

**

**   SQLITE_MUTEX_PTHREADS     For multi-threaded applications on Unix.

**

**   SQLITE_MUTEX_W32          For multi-threaded applications on Win32.

**

**   SQLITE_MUTEX_OS2          For multi-threaded applications on OS/2.

*/

#define SQLITE_MUTEX_NOOP 1   /* The default */

#if defined(SQLITE_DEBUG) && !SQLITE_THREADSAFE

# undef SQLITE_MUTEX_NOOP

# define SQLITE_MUTEX_NOOP_DEBUG

#endif

#if defined(SQLITE_MUTEX_NOOP) && SQLITE_THREADSAFE && OS_UNIX

# undef SQLITE_MUTEX_NOOP

# define SQLITE_MUTEX_PTHREADS

#endif

#if defined(SQLITE_MUTEX_NOOP) && SQLITE_THREADSAFE && OS_WIN

# undef SQLITE_MUTEX_NOOP

# define SQLITE_MUTEX_W32

#endif

#if defined(SQLITE_MUTEX_NOOP) && SQLITE_THREADSAFE && OS_OS2

# undef SQLITE_MUTEX_NOOP

# define SQLITE_MUTEX_OS2

#endif

#ifdef SQLITE_MUTEX_NOOP

/*

** If this is a no-op implementation, implement everything as macros.

*/

#define sqlite3_mutex_alloc(X)    ((sqlite3_mutex*)8)

#define sqlite3_mutex_free(X)

#define sqlite3_mutex_enter(X)

#define sqlite3_mutex_try(X)      SQLITE_OK

#define sqlite3_mutex_leave(X)

#define sqlite3_mutex_held(X)     1

#define sqlite3_mutex_notheld(X)  1

#endif

#endif /* SQLITE_MUTEX_APPDEF */