database/sqlite
1
0
Fork 0
mirror of https://github.com/sqlite/sqlite.git synced 2025-11-14 00:22:38 +03:00
Code Activity

Add the sqlite3_close_v2() interface (from the deferred-close branch) that

Browse Source 
allows close operations to happen out-of-order in bindings to
garbage-collected langauges.

FossilOrigin-Name: fb8893abeefabe9de44e34dcf4327764481189f5
This commit is contained in:
drh
2012-06-21 15:51:42 +00:00
parent 567520226a 4104337270
commit ed68801b20
9 changed files with 125 additions and 59 deletions
Download Patch File Download Diff File Expand all files Collapse all files

85
src/main.c
View File

@@ -765,13 +765,25 @@ static void disconnectAllVtab(sqlite3 *db){
#endif
}
/*
** Return TRUE if database connection db has unfinalized prepared
** statements or unfinished sqlite3_backup objects.
*/
static int connectionIsBusy(sqlite3 *db){
int j;
assert( sqlite3_mutex_held(db->mutex) );
if( db->pVdbe ) return 1;
for(j=0; j<db->nDb; j++){
Btree *pBt = db->aDb[j].pBt;
if( pBt && sqlite3BtreeIsInBackup(pBt) ) return 1;
}
return 0;
}
/*
** Close an existing SQLite database
*/
int sqlite3_close(sqlite3 *db){
HashElem *i; /* Hash table iterator */
int j;
static int sqlite3Close(sqlite3 *db, int forceZombie){
if( !db ){
return SQLITE_OK;
}
@@ -792,25 +804,63 @@ int sqlite3_close(sqlite3 *db){
*/
sqlite3VtabRollback(db);
/* If there are any outstanding VMs, return SQLITE_BUSY. */
if( db->pVdbe ){
sqlite3Error(db, SQLITE_BUSY,
"unable to close due to unfinalised statements");
/* Legacy behavior (sqlite3_close() behavior) is to return
** SQLITE_BUSY if the connection can not be closed immediately.
*/
if( !forceZombie && connectionIsBusy(db) ){
sqlite3Error(db, SQLITE_BUSY, "unable to close due to unfinalized "
"statements or unfinished backups");
sqlite3_mutex_leave(db->mutex);
return SQLITE_BUSY;
}
assert( sqlite3SafetyCheckSickOrOk(db) );
for(j=0; j<db->nDb; j++){
Btree *pBt = db->aDb[j].pBt;
if( pBt && sqlite3BtreeIsInBackup(pBt) ){
sqlite3Error(db, SQLITE_BUSY,
"unable to close due to unfinished backup operation");
sqlite3_mutex_leave(db->mutex);
return SQLITE_BUSY;
}
/* Convert the connection into a zombie and then close it.
*/
db->magic = SQLITE_MAGIC_ZOMBIE;
sqlite3LeaveMutexAndCloseZombie(db);
return SQLITE_OK;
}
/*
** Two variations on the public interface for closing a database
** connection. The sqlite3_close() version returns SQLITE_BUSY and
** leaves the connection option if there are unfinalized prepared
** statements or unfinished sqlite3_backups. The sqlite3_close_v2()
** version forces the connection to become a zombie if there are
** unclosed resources, and arranges for deallocation when the last
** prepare statement or sqlite3_backup closes.
*/
int sqlite3_close(sqlite3 *db){ return sqlite3Close(db,0); }
int sqlite3_close_v2(sqlite3 *db){ return sqlite3Close(db,1); }
/*
** Close the mutex on database connection db.
**
** Furthermore, if database connection db is a zombie (meaning that there
** has been a prior call to sqlite3_close(db) or sqlite3_close_v2(db)) and
** every sqlite3_stmt has now been finalized and every sqlite3_backup has
** finished, then free all resources.
*/
void sqlite3LeaveMutexAndCloseZombie(sqlite3 *db){
HashElem *i; /* Hash table iterator */
int j;
/* If there are outstanding sqlite3_stmt or sqlite3_backup objects
** or if the connection has not yet been closed by sqlite3_close_v2(),
** then just leave the mutex and return.
*/
if( db->magic!=SQLITE_MAGIC_ZOMBIE || connectionIsBusy(db) ){
sqlite3_mutex_leave(db->mutex);
return;
}
/* If we reach this point, it means that the database connection has
** closed all sqlite3_stmt and sqlite3_backup objects and has been
** pased to sqlite3_close (meaning that it is a zombie). Therefore,
** go ahead and free all resources.
*/
/* Free any outstanding Savepoint structures. */
sqlite3CloseSavepoints(db);
@@ -898,7 +948,6 @@ int sqlite3_close(sqlite3 *db){
sqlite3_free(db->lookaside.pStart);
}
sqlite3_free(db);
return SQLITE_OK;
}
/*