Experimental changes to put sqlite3_temp_directory behind a mutex.

FossilOrigin-Name: 5ee3515fbb88bf1ae5f8b507844f82dcc429380b6ebeab9b09b52b25ee60a60d

1 files changed, 31 insertions, 4 deletions

diff --git a/src/os_win.c b/src/os_win.c
index 8832c8012..591f57ee5 100644
--- a/src/os_win.c
+++ b/src/os_win.c
@@ -1922,6 +1922,7 @@ int sqlite3_win32_set_directory8(
   int rc = sqlite3_initialize();
   if( rc ) return rc;
 #endif
+  sqlite3_mutex_enter(sqlite3MutexAlloc(SQLITE_MUTEX_STATIC_TEMPDIR));
   if( type==SQLITE_WIN32_DATA_DIRECTORY_TYPE ){
     ppDirectory = &sqlite3_data_directory;
   }else if( type==SQLITE_WIN32_TEMP_DIRECTORY_TYPE ){
@@ -1936,14 +1937,19 @@ int sqlite3_win32_set_directory8(
     if( zValue && zValue[0] ){
       zCopy = sqlite3_mprintf("%s", zValue);
       if ( zCopy==0 ){
-        return SQLITE_NOMEM_BKPT;
+        rc = SQLITE_NOMEM_BKPT;
+        goto set_directory8_done;
       }
     }
     sqlite3_free(*ppDirectory);
     *ppDirectory = zCopy;
-    return SQLITE_OK;
+    rc = SQLITE_OK;
+  }else{
+    rc = SQLITE_ERROR;
   }
-  return SQLITE_ERROR;
+set_directory8_done:
+  sqlite3_mutex_leave(sqlite3MutexAlloc(SQLITE_MUTEX_STATIC_TEMPDIR));
+  return rc;
 }
 
 /*
@@ -4718,6 +4724,18 @@ static int winMakeEndInDirSep(int nBuf, char *zBuf){
 }
 
 /*
+** If sqlite3_temp_directory is not, take the mutex and return true.
+**
+** If sqlite3_temp_directory is NULL, omit the mutex and return false.
+*/
+static int winTempDirDefined(void){
+  sqlite3_mutex_enter(sqlite3MutexAlloc(SQLITE_MUTEX_STATIC_TEMPDIR));
+  if( sqlite3_temp_directory!=0 ) return 1;
+  sqlite3_mutex_leave(sqlite3MutexAlloc(SQLITE_MUTEX_STATIC_TEMPDIR));
+  return 0;
+}
+
+/*
 ** Create a temporary file name and store the resulting pointer into pzBuf.
 ** The pointer returned in pzBuf must be freed via sqlite3_free().
 */
@@ -4753,20 +4771,23 @@ static int winGetTempname(sqlite3_vfs *pVfs, char **pzBuf){
   */
   nDir = nMax - (nPre + 15);
   assert( nDir>0 );
-  if( sqlite3_temp_directory ){
+  if( winTempDirDefined() ){
     int nDirLen = sqlite3Strlen30(sqlite3_temp_directory);
     if( nDirLen>0 ){
       if( !winIsDirSep(sqlite3_temp_directory[nDirLen-1]) ){
         nDirLen++;
       }
       if( nDirLen>nDir ){
+        sqlite3_mutex_leave(sqlite3MutexAlloc(SQLITE_MUTEX_STATIC_TEMPDIR));
         sqlite3_free(zBuf);
         OSTRACE(("TEMP-FILENAME rc=SQLITE_ERROR\n"));
         return winLogError(SQLITE_ERROR, 0, "winGetTempname1", 0);
       }
       sqlite3_snprintf(nMax, zBuf, "%s", sqlite3_temp_directory);
     }
+    sqlite3_mutex_leave(sqlite3MutexAlloc(SQLITE_MUTEX_STATIC_TEMPDIR));
   }
+
 #if defined(__CYGWIN__)
   else{
     static const char *azDirs[] = {
@@ -5579,6 +5600,7 @@ static int winFullPathname(
   SimulateIOError( return SQLITE_ERROR );
   UNUSED_PARAMETER(nFull);
   assert( nFull>=pVfs->mxPathname );
+  sqlite3_mutex_enter(sqlite3MutexAlloc(SQLITE_MUTEX_STATIC_TEMPDIR));
   if ( sqlite3_data_directory && !winIsVerbatimPathname(zRelative) ){
     /*
     ** NOTE: We are dealing with a relative path name and the data
@@ -5629,6 +5651,7 @@ static int winFullPathname(
       sqlite3_free(zOut);
     }
   }
+  sqlite3_mutex_leave(sqlite3MutexAlloc(SQLITE_MUTEX_STATIC_TEMPDIR));
   return SQLITE_OK;
 #endif
 
@@ -5636,6 +5659,7 @@ static int winFullPathname(
   SimulateIOError( return SQLITE_ERROR );
   /* WinCE has no concept of a relative pathname, or so I am told. */
   /* WinRT has no way to convert a relative path to an absolute one. */
+  sqlite3_mutex_enter(sqlite3MutexAlloc(SQLITE_MUTEX_STATIC_TEMPDIR));
   if ( sqlite3_data_directory && !winIsVerbatimPathname(zRelative) ){
     /*
     ** NOTE: We are dealing with a relative path name and the data
@@ -5648,6 +5672,7 @@ static int winFullPathname(
   }else{
     sqlite3_snprintf(MIN(nFull, pVfs->mxPathname), zFull, "%s", zRelative);
   }
+  sqlite3_mutex_leave(sqlite3MutexAlloc(SQLITE_MUTEX_STATIC_TEMPDIR));
   return SQLITE_OK;
 #endif
 
@@ -5658,6 +5683,7 @@ static int winFullPathname(
   ** current working directory has been unlinked.
   */
   SimulateIOError( return SQLITE_ERROR );
+  sqlite3_mutex_enter(sqlite3MutexAlloc(SQLITE_MUTEX_STATIC_TEMPDIR));
   if ( sqlite3_data_directory && !winIsVerbatimPathname(zRelative) ){
     /*
     ** NOTE: We are dealing with a relative path name and the data
@@ -5667,6 +5693,7 @@ static int winFullPathname(
     */
     sqlite3_snprintf(MIN(nFull, pVfs->mxPathname), zFull, "%s%c%s",
                      sqlite3_data_directory, winGetDirSep(), zRelative);
+    sqlite3_mutex_leave(sqlite3MutexAlloc(SQLITE_MUTEX_STATIC_TEMPDIR));
     return SQLITE_OK;
   }
   zConverted = winConvertFromUtf8Filename(zRelative);