/*
** 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.
*/


/*
** Figure out what version of the code to use. The choices are
**
** SQLITE_MUTEX_OMIT No mutex logic. Not even stubs. The
** mutexes implementation cannot be overridden
** at start-time.
**
** SQLITE_MUTEX_NOOP For single-threaded applications. No
** mutual exclusion is provided. But this
** implementation can be overridden at
** start-time.
**
** SQLITE_MUTEX_PTHREADS For multi-threaded applications on Unix.
**
** SQLITE_MUTEX_W32 For multi-threaded applications on Win32.
*/
#if !SQLITE_THREADSAFE
# define SQLITE_MUTEX_OMIT
#endif
#if SQLITE_THREADSAFE && !defined(SQLITE_MUTEX_NOOP)
# if SQLITE_OS_UNIX
# define SQLITE_MUTEX_PTHREADS
# elif SQLITE_OS_WIN
# define SQLITE_MUTEX_W32
# else
# define SQLITE_MUTEX_NOOP
# endif
#endif

#ifdef SQLITE_MUTEX_OMIT
/*
** 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) ((void)(X),1)
#define sqlite3_mutex_notheld(X) ((void)(X),1)
#define sqlite3MutexAlloc(X) ((sqlite3_mutex*)8)
#define sqlite3MutexInit() SQLITE_OK
#define sqlite3MutexEnd()
#define MUTEX_LOGIC(X)
#else
#define MUTEX_LOGIC(X) X
int sqlite3_mutex_held(sqlite3_mutex*);
#endif /* defined(SQLITE_MUTEX_OMIT) */