SQLite

** exclusion and is thus suitable for use only in applications
** that use SQLite in a single thread.  But this implementation
** does do a lot of error checking on mutexes to make sure they
** are called correctly and at appropriate times.  Hence, this
** implementation is suitable for testing.
** debugging purposes
**
** $Id: mutex.c,v 1.27 2008/06/19 08:51:24 danielk1977 Exp $
*/
#include "sqliteInt.h"

#ifndef SQLITE_MUTEX_NOOP
/*
** Initialize the mutex system.
*/

  p->cnt--;
  assert( p->id==SQLITE_MUTEX_RECURSIVE || noopMutexNotheld(p) );
}

sqlite3_mutex_methods *sqlite3DefaultMutex(void){
  static sqlite3_mutex_methods sMutex = {
    noopMutexInit,
    noopMutexEnd,
    noopMutexAlloc,
    noopMutexFree,
    noopMutexEnter,
    noopMutexTry,
    noopMutexLeave,


    noopMutexHeld,
    noopMutexNotheld
  };

  return &sMutex;
}
#endif /* SQLITE_MUTEX_NOOP_DEBUG */

/*
** 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 C functions that implement mutexes for OS/2
**
** $Id: mutex_os2.c,v 1.9 2008/06/19 08:51:24 danielk1977 Exp $
*/
#include "sqliteInt.h"

/*
** The code in this file is only used if SQLITE_MUTEX_OS2 is defined.
** See the mutex.h file for details.
*/

  }
  return p==0 || p->nRef==0 || p->owner!=tid;
}

sqlite3_mutex_methods *sqlite3DefaultMutex(void){
  static sqlite3_mutex_methods sMutex = {
    os2MutexInit,
    os2MutexEnd,
    os2MutexAlloc,
    os2MutexFree,
    os2MutexEnter,
    os2MutexTry,
    os2MutexLeave,


    os2MutexHeld,
    os2MutexNotheld
  };

  return &sMutex;
}
#endif /* SQLITE_MUTEX_OS2 */

/*
** 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 C functions that implement mutexes for pthreads
**
** $Id: mutex_unix.c,v 1.11 2008/06/19 08:51:24 danielk1977 Exp $
*/
#include "sqliteInt.h"

/*
** The code in this file is only used if we are compiling threadsafe
** under unix with pthreads.
**

  }
#endif
}

sqlite3_mutex_methods *sqlite3DefaultMutex(void){
  static sqlite3_mutex_methods sMutex = {
    pthreadMutexInit,
    pthreadMutexEnd,
    pthreadMutexAlloc,
    pthreadMutexFree,
    pthreadMutexEnter,
    pthreadMutexTry,
    pthreadMutexLeave,


    pthreadMutexHeld,
    pthreadMutexNotheld
  };

  return &sMutex;
}

#endif /* SQLITE_MUTEX_PTHREAD */

/*
** 2007 August 14
**
** 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 C functions that implement mutexes for win32
**
** $Id: mutex_w32.c,v 1.9 2008/06/19 08:51:24 danielk1977 Exp $
*/
#include "sqliteInt.h"

/*
** The code in this file is only used if we are compiling multithreaded
** on a win32 system.
*/

  assert( p->nRef==0 || p->id==SQLITE_MUTEX_RECURSIVE );
  LeaveCriticalSection(&p->mutex);
}

sqlite3_mutex_methods *sqlite3DefaultMutex(void){
  static sqlite3_mutex_methods sMutex = {
    winMutexInit,
    winMutexEnd,
    winMutexAlloc,
    winMutexFree,
    winMutexEnter,
    winMutexTry,
    winMutexLeave,


    winMutexHeld,
    winMutexNotheld
  };

  return &sMutex;
}
#endif /* SQLITE_MUTEX_W32 */

** on how SQLite interfaces are suppose to operate.
**
** The name of this file under configuration management is "sqlite.h.in".
** The makefile makes some minor changes to this file (such as inserting
** the version number) and changes its name to "sqlite3.h" as
** part of the build process.
**
** @(#) $Id: sqlite.h.in,v 1.339 2008/06/19 08:51:24 danielk1977 Exp $
*/
#ifndef _SQLITE3_H_
#define _SQLITE3_H_
#include <stdarg.h>     /* Needed for the definition of va_list */

/*
** Make sure we can call this stuff from C++.

int sqlite3_vfs_register(sqlite3_vfs*, int makeDflt);
int sqlite3_vfs_unregister(sqlite3_vfs*);

/*
** CAPI3REF: Mutexes {F17000}
**
** The SQLite core uses these routines for thread
** synchronization. Though they are intended for internal
** use by SQLite, code that links against SQLite is
** permitted to use any of these routines.
**
** The SQLite source code contains multiple implementations 
** of these mutex routines.  An appropriate implementation
** is selected automatically at compile-time.  The following
** implementations are available in the SQLite core:

** that does no real locking and is appropriate for use in 
** a single-threaded application.  The SQLITE_MUTEX_OS2,
** SQLITE_MUTEX_PTHREAD, and SQLITE_MUTEX_W32 implementations
** are appropriate for use on OS/2, Unix, and Windows.
** 
** If SQLite is compiled with the SQLITE_MUTEX_APPDEF preprocessor
** macro defined (with "-DSQLITE_MUTEX_APPDEF=1"), then no mutex
** implementation is included with the library. In this case the



** application must supply a custom mutex implementation using the


** [SQLITE_CONFIG_MUTEX] option of the sqlite3_config() function
** before calling sqlite3_initialize() or any other public sqlite3_ 


** function that calls sqlite3_initialize().






**
** {F17011} The sqlite3_mutex_alloc() routine allocates a new
** mutex and returns a pointer to it. {F17012} If it returns NULL
** that means that a mutex could not be allocated. {F17013} SQLite
** will unwind its stack and return an error. {F17014} The argument
** to sqlite3_mutex_alloc() is one of these integer constants:
**

int sqlite3_mutex_try(sqlite3_mutex*);
void sqlite3_mutex_leave(sqlite3_mutex*);

/*
** CAPI3REF: Mutex Methods Object {F17120}
**
** An instance of this structure defines the low-level routines
** used to allocate and use mutexes.
**
** Usually, the default mutex implementations provided by SQLite are
** sufficient, however the user has the option of substituting a custom 
** implementation for specialized deployments or systems for which SQLite 
** does not provide a suitable implementation. In this case, the user
** creates and populates an instance of this structure to pass
** to sqlite3_config() along with the [SQLITE_CONFIG_MUTEX] option. 
** Additionally, an instance of this structure can be used as an
** output variable when querying the system for the current mutex
** implementation, using the [SQLITE_CONFIG_GETMUTEX] option.
**
** The xMutexInit method defined by this structure is invoked as
** part of system initialization by the sqlite3_initialize() function.
** {F17001} The xMutexInit routine shall be called by SQLite once for each
** effective call to [sqlite3_initialize()].  
**
** The xMutexEnd method defined by this structure is invoked as
** part of system shutdown by the sqlite3_shutdown() function. The
** implementation of this method is expected to release all outstanding
** resources obtained by the mutex methods implementation, especially
** those obtained by the xMutexInit method. {F17003} The xMutexEnd() 
** interface shall be invoked once for each call to [sqlite3_shutdown()]. 
**
** The remaining seven methods defined by this structure (xMutexAlloc,
** xMutexFree, xMutexEnter, xMutexTry, xMutexLeave, xMutexHeld and
** xMutexNotheld) implement the following interfaces (respectively):
**
** <ul>

**   <li>  [sqlite3_mutex_alloc()] </li>
**   <li>  [sqlite3_mutex_free()] </li>
**   <li>  [sqlite3_mutex_enter()] </li>
**   <li>  [sqlite3_mutex_try()] </li>
**   <li>  [sqlite3_mutex_leave()] </li>

**   <li>  [sqlite3_mutex_held()] </li>
**   <li>  [sqlite3_mutex_notheld()] </li>
** </ul>
**
** The only difference is that the public sqlite3_XXX functions enumerated
** above silently ignore any invocations that pass a NULL pointer instead
** of a valid mutex handle. The implementations of the methods defined
** by this structure are not required to handle this case, the results
** of passing a NULL pointer instead of a valid mutex handle are undefined
** (i.e. it is acceptable to provide an implementation that segfaults if
** it is passed a NULL pointer).
*/
typedef struct sqlite3_mutex_methods sqlite3_mutex_methods;
struct sqlite3_mutex_methods {
  int (*xMutexInit)(void);
  int (*xMutexEnd)(void);
  sqlite3_mutex *(*xMutexAlloc)(int);
  void (*xMutexFree)(sqlite3_mutex *);
  void (*xMutexEnter)(sqlite3_mutex *);
  int (*xMutexTry)(sqlite3_mutex *);
  void (*xMutexLeave)(sqlite3_mutex *);

  int (*xMutexHeld)(sqlite3_mutex *);
  int (*xMutexNotheld)(sqlite3_mutex *);
};


/*
** CAPI3REF: Mutex Verifcation Routines {F17080}

/*
** 2008 June 18
**
** 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.
**
*************************************************************************
** 
** $Id: test_mutex.c,v 1.3 2008/06/19 08:51:25 danielk1977 Exp $
*/

#include "tcl.h"
#include "sqlite3.h"
#include <stdlib.h>
#include <assert.h>
#include <string.h>

  Tcl_Obj *CONST objv[]
){
  int rc = SQLITE_OK;
  int isInstall;

  sqlite3_mutex_methods counter_methods = {
    counterMutexInit,
    counterMutexEnd,
    counterMutexAlloc,
    counterMutexFree,
    counterMutexEnter,
    counterMutexTry,
    counterMutexLeave,

    counterMutexHeld,
    counterMutexNotheld
  };

  if( objc!=2 ){
    Tcl_WrongNumArgs(interp, 1, objv, "BOOLEAN");
    return TCL_ERROR;