diff -r 000000000000 -r 08ec8eefde2f persistentstorage/sql/SQLite/mutex.c
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/persistentstorage/sql/SQLite/mutex.c	Fri Jan 22 11:06:30 2010 +0200
@@ -0,0 +1,273 @@
+/*
+** 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.
+**
+** The implementation in this file does not provide any mutual
+** 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.
+*/
+int sqlite3MutexInit(void){ 
+  int rc = SQLITE_OK;
+  if( sqlite3Config.bCoreMutex ){
+    if( !sqlite3Config.mutex.xMutexAlloc ){
+      /* If the xMutexAlloc method has not been set, then the user did not
+      ** install a mutex implementation via sqlite3_config() prior to 
+      ** sqlite3_initialize() being called. This block copies pointers to
+      ** the default implementation into the sqlite3Config structure.
+      **
+      ** The danger is that although sqlite3_config() is not a threadsafe
+      ** API, sqlite3_initialize() is, and so multiple threads may be
+      ** attempting to run this function simultaneously. To guard write
+      ** access to the sqlite3Config structure, the 'MASTER' static mutex
+      ** is obtained before modifying it.
+      */
+      sqlite3_mutex_methods *p = sqlite3DefaultMutex();
+      sqlite3_mutex *pMaster = 0;
+  
+      rc = p->xMutexInit();
+      if( rc==SQLITE_OK ){
+        pMaster = p->xMutexAlloc(SQLITE_MUTEX_STATIC_MASTER);
+        assert(pMaster);
+        p->xMutexEnter(pMaster);
+        assert( sqlite3Config.mutex.xMutexAlloc==0 
+             || sqlite3Config.mutex.xMutexAlloc==p->xMutexAlloc
+        );
+        if( !sqlite3Config.mutex.xMutexAlloc ){
+          sqlite3Config.mutex = *p;
+        }
+        p->xMutexLeave(pMaster);
+      }
+    }else{
+      rc = sqlite3Config.mutex.xMutexInit();
+    }
+  }
+
+  return rc;
+}
+
+/*
+** Shutdown the mutex system. This call frees resources allocated by
+** sqlite3MutexInit().
+*/
+int sqlite3MutexEnd(void){
+  int rc = SQLITE_OK;
+  rc = sqlite3Config.mutex.xMutexEnd();
+  return rc;
+}
+
+/*
+** Retrieve a pointer to a static mutex or allocate a new dynamic one.
+*/
+sqlite3_mutex *sqlite3_mutex_alloc(int id){
+#ifndef SQLITE_OMIT_AUTOINIT
+  if( sqlite3_initialize() ) return 0;
+#endif
+  return sqlite3Config.mutex.xMutexAlloc(id);
+}
+
+sqlite3_mutex *sqlite3MutexAlloc(int id){
+  if( !sqlite3Config.bCoreMutex ){
+    return 0;
+  }
+  return sqlite3Config.mutex.xMutexAlloc(id);
+}
+
+/*
+** Free a dynamic mutex.
+*/
+void sqlite3_mutex_free(sqlite3_mutex *p){
+  if( p ){
+    sqlite3Config.mutex.xMutexFree(p);
+  }
+}
+
+/*
+** Obtain the mutex p. If some other thread already has the mutex, block
+** until it can be obtained.
+*/
+void sqlite3_mutex_enter(sqlite3_mutex *p){
+  if( p ){
+    sqlite3Config.mutex.xMutexEnter(p);
+  }
+}
+
+/*
+** Obtain the mutex p. If successful, return SQLITE_OK. Otherwise, if another
+** thread holds the mutex and it cannot be obtained, return SQLITE_BUSY.
+*/
+int sqlite3_mutex_try(sqlite3_mutex *p){
+  int rc = SQLITE_OK;
+  if( p ){
+    return sqlite3Config.mutex.xMutexTry(p);
+  }
+  return rc;
+}
+
+/*
+** The sqlite3_mutex_leave() routine exits a mutex that was previously
+** entered by the same thread.  The behavior is undefined if the mutex 
+** is not currently entered. If a NULL pointer is passed as an argument
+** this function is a no-op.
+*/
+void sqlite3_mutex_leave(sqlite3_mutex *p){
+  if( p ){
+    sqlite3Config.mutex.xMutexLeave(p);
+  }
+}
+
+#ifndef NDEBUG
+/*
+** The sqlite3_mutex_held() and sqlite3_mutex_notheld() routine are
+** intended for use inside assert() statements.
+*/
+int sqlite3_mutex_held(sqlite3_mutex *p){
+  return p==0 || sqlite3Config.mutex.xMutexHeld(p);
+}
+int sqlite3_mutex_notheld(sqlite3_mutex *p){
+  return p==0 || sqlite3Config.mutex.xMutexNotheld(p);
+}
+#endif
+
+#endif
+
+#ifdef SQLITE_MUTEX_NOOP_DEBUG
+/*
+** In this implementation, mutexes do not provide any mutual exclusion.
+** But the error checking is provided.  This implementation is useful
+** for test purposes.
+*/
+
+/*
+** The mutex object
+*/
+struct sqlite3_mutex {
+  int id;     /* The mutex type */
+  int cnt;    /* Number of entries without a matching leave */
+};
+
+/*
+** The sqlite3_mutex_held() and sqlite3_mutex_notheld() routine are
+** intended for use inside assert() statements.
+*/
+static int noopMutexHeld(sqlite3_mutex *p){
+  return p==0 || p->cnt>0;
+}
+static int noopMutexNotheld(sqlite3_mutex *p){
+  return p==0 || p->cnt==0;
+}
+
+/*
+** Initialize and deinitialize the mutex subsystem.
+*/
+static int noopMutexInit(void){ return SQLITE_OK; }
+static int noopMutexEnd(void){ return SQLITE_OK; }
+
+/*
+** The sqlite3_mutex_alloc() routine allocates a new
+** mutex and returns a pointer to it.  If it returns NULL
+** that means that a mutex could not be allocated. 
+*/
+static sqlite3_mutex *noopMutexAlloc(int id){
+  static sqlite3_mutex aStatic[6];
+  sqlite3_mutex *pNew = 0;
+  switch( id ){
+    case SQLITE_MUTEX_FAST:
+    case SQLITE_MUTEX_RECURSIVE: {
+      pNew = sqlite3Malloc(sizeof(*pNew));
+      if( pNew ){
+        pNew->id = id;
+        pNew->cnt = 0;
+      }
+      break;
+    }
+    default: {
+      assert( id-2 >= 0 );
+      assert( id-2 < sizeof(aStatic)/sizeof(aStatic[0]) );
+      pNew = &aStatic[id-2];
+      pNew->id = id;
+      break;
+    }
+  }
+  return pNew;
+}
+
+/*
+** This routine deallocates a previously allocated mutex.
+*/
+static void noopMutexFree(sqlite3_mutex *p){
+  assert( p->cnt==0 );
+  assert( p->id==SQLITE_MUTEX_FAST || p->id==SQLITE_MUTEX_RECURSIVE );
+  sqlite3_free(p);
+}
+
+/*
+** The sqlite3_mutex_enter() and sqlite3_mutex_try() routines attempt
+** to enter a mutex.  If another thread is already within the mutex,
+** sqlite3_mutex_enter() will block and sqlite3_mutex_try() will return
+** SQLITE_BUSY.  The sqlite3_mutex_try() interface returns SQLITE_OK
+** upon successful entry.  Mutexes created using SQLITE_MUTEX_RECURSIVE can
+** be entered multiple times by the same thread.  In such cases the,
+** mutex must be exited an equal number of times before another thread
+** can enter.  If the same thread tries to enter any other kind of mutex
+** more than once, the behavior is undefined.
+*/
+static void noopMutexEnter(sqlite3_mutex *p){
+  assert( p->id==SQLITE_MUTEX_RECURSIVE || noopMutexNotheld(p) );
+  p->cnt++;
+}
+static int noopMutexTry(sqlite3_mutex *p){
+  assert( p->id==SQLITE_MUTEX_RECURSIVE || noopMutexNotheld(p) );
+  p->cnt++;
+  return SQLITE_OK;
+}
+
+/*
+** The sqlite3_mutex_leave() routine exits a mutex that was
+** previously entered by the same thread.  The behavior
+** is undefined if the mutex is not currently entered or
+** is not currently allocated.  SQLite will never do either.
+*/
+static void noopMutexLeave(sqlite3_mutex *p){
+  assert( noopMutexHeld(p) );
+  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 */