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-rw-r--r--src/backup.c10
-rw-r--r--src/main.c83
-rw-r--r--src/sqlite.h.in49
-rw-r--r--src/sqliteInt.h2
-rw-r--r--src/vdbeapi.c11
-rw-r--r--src/vdbeaux.c1
6 files changed, 111 insertions, 45 deletions
diff --git a/src/backup.c b/src/backup.c
index 0ada33c3b..527ecb574 100644
--- a/src/backup.c
+++ b/src/backup.c
@@ -543,14 +543,14 @@ int sqlite3_backup_step(sqlite3_backup *p, int nPage){
*/
int sqlite3_backup_finish(sqlite3_backup *p){
sqlite3_backup **pp; /* Ptr to head of pagers backup list */
- MUTEX_LOGIC( sqlite3_mutex *mutex; ) /* Mutex to protect source database */
+ sqlite3 *pSrcDb; /* Source database connection */
int rc; /* Value to return */
/* Enter the mutexes */
if( p==0 ) return SQLITE_OK;
- sqlite3_mutex_enter(p->pSrcDb->mutex);
+ pSrcDb = p->pSrcDb;
+ sqlite3_mutex_enter(pSrcDb->mutex);
sqlite3BtreeEnter(p->pSrc);
- MUTEX_LOGIC( mutex = p->pSrcDb->mutex; )
if( p->pDestDb ){
sqlite3_mutex_enter(p->pDestDb->mutex);
}
@@ -576,7 +576,7 @@ int sqlite3_backup_finish(sqlite3_backup *p){
/* Exit the mutexes and free the backup context structure. */
if( p->pDestDb ){
- sqlite3_mutex_leave(p->pDestDb->mutex);
+ sqlite3LeaveMutexAndCloseZombie(p->pDestDb);
}
sqlite3BtreeLeave(p->pSrc);
if( p->pDestDb ){
@@ -585,7 +585,7 @@ int sqlite3_backup_finish(sqlite3_backup *p){
** sqlite3_backup_finish(). */
sqlite3_free(p);
}
- sqlite3_mutex_leave(mutex);
+ sqlite3LeaveMutexAndCloseZombie(pSrcDb);
return rc;
}
diff --git a/src/main.c b/src/main.c
index 7ecb4f261..16294a619 100644
--- a/src/main.c
+++ b/src/main.c
@@ -766,12 +766,24 @@ static void disconnectAllVtab(sqlite3 *db){
}
/*
-** Close an existing SQLite database
+** Return TRUE if database connection db has unfinalized prepared
+** statements or unfinished sqlite3_backup objects.
*/
-int sqlite3_close(sqlite3 *db){
- HashElem *i; /* Hash table iterator */
+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
+*/
+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;
}
/*
diff --git a/src/sqlite.h.in b/src/sqlite.h.in
index ea36673ad..69ea6d15d 100644
--- a/src/sqlite.h.in
+++ b/src/sqlite.h.in
@@ -214,7 +214,8 @@ int sqlite3_threadsafe(void);
** the opaque structure named "sqlite3". It is useful to think of an sqlite3
** pointer as an object. The [sqlite3_open()], [sqlite3_open16()], and
** [sqlite3_open_v2()] interfaces are its constructors, and [sqlite3_close()]
-** is its destructor. There are many other interfaces (such as
+** and [sqlite3_close_v2()] are its destructors. There are many other
+** interfaces (such as
** [sqlite3_prepare_v2()], [sqlite3_create_function()], and
** [sqlite3_busy_timeout()] to name but three) that are methods on an
** sqlite3 object.
@@ -261,28 +262,46 @@ typedef sqlite_uint64 sqlite3_uint64;
/*
** CAPI3REF: Closing A Database Connection
**
-** ^The sqlite3_close() routine is the destructor for the [sqlite3] object.
-** ^Calls to sqlite3_close() return SQLITE_OK if the [sqlite3] object is
-** successfully destroyed and all associated resources are deallocated.
-**
-** Applications must [sqlite3_finalize | finalize] all [prepared statements]
-** and [sqlite3_blob_close | close] all [BLOB handles] associated with
-** the [sqlite3] object prior to attempting to close the object. ^If
+** ^The sqlite3_close() and sqlite3_close_v2() routines are destructors
+** for the [sqlite3] object.
+** ^Calls to sqlite3_close() and sqlite3_close_v2() return SQLITE_OK if
+** the [sqlite3] object is successfully destroyed and all associated
+** resources are deallocated.
+**
+** ^If the database connection is associated with unfinalized prepared
+** statements or unfinished sqlite3_backup objects then sqlite3_close()
+** will leave the database connection open and return [SQLITE_BUSY].
+** ^If sqlite3_close_v2() is called with unfinalized prepared statements
+** and unfinished sqlite3_backups, then the database connection becomes
+** an unusable "zombie" which will automatically be deallocated when the
+** last prepared statement is finalized or the last sqlite3_backup is
+** finished. The sqlite3_close_v2() interface is intended for use with
+** host languages that are garbage collected, and where the order in which
+** destructors are called is arbitrary.
+**
+** Applications should [sqlite3_finalize | finalize] all [prepared statements],
+** [sqlite3_blob_close | close] all [BLOB handles], and
+** [sqlite3_backup_finish | finish] all [sqlite3_backup] objects associated
+** with the [sqlite3] object prior to attempting to close the object. ^If
** sqlite3_close() is called on a [database connection] that still has
-** outstanding [prepared statements] or [BLOB handles], then it returns
-** SQLITE_BUSY.
+** outstanding [prepared statements], [BLOB handles], and/or
+** [sqlite3_backup] objects then it returns SQLITE_OK but the deallocation
+** of resources is deferred until all [prepared statements], [BLOB handles],
+** and [sqlite3_backup] objects are also destroyed.
**
-** ^If [sqlite3_close()] is invoked while a transaction is open,
+** ^If an [sqlite3] object is destroyed while a transaction is open,
** the transaction is automatically rolled back.
**
-** The C parameter to [sqlite3_close(C)] must be either a NULL
+** The C parameter to [sqlite3_close(C)] and [sqlite3_close_v2(C)]
+** must be either a NULL
** pointer or an [sqlite3] object pointer obtained
** from [sqlite3_open()], [sqlite3_open16()], or
** [sqlite3_open_v2()], and not previously closed.
-** ^Calling sqlite3_close() with a NULL pointer argument is a
-** harmless no-op.
+** ^Calling sqlite3_close() or sqlite3_close_v2() with a NULL pointer
+** argument is a harmless no-op.
*/
-int sqlite3_close(sqlite3 *);
+int sqlite3_close(sqlite3*);
+int sqlite3_close_v2(sqlite3*);
/*
** The type for a callback function.
diff --git a/src/sqliteInt.h b/src/sqliteInt.h
index ca409670b..f7f5fd386 100644
--- a/src/sqliteInt.h
+++ b/src/sqliteInt.h
@@ -983,6 +983,7 @@ struct sqlite3 {
#define SQLITE_MAGIC_SICK 0x4b771290 /* Error and awaiting close */
#define SQLITE_MAGIC_BUSY 0xf03b7906 /* Database currently in use */
#define SQLITE_MAGIC_ERROR 0xb5357930 /* An SQLITE_MISUSE error occurred */
+#define SQLITE_MAGIC_ZOMBIE 0x64cffc7f /* Close with last statement close */
/*
** Each SQL function is defined by an instance of the following
@@ -2844,6 +2845,7 @@ void sqlite3CommitTransaction(Parse*);
void sqlite3RollbackTransaction(Parse*);
void sqlite3Savepoint(Parse*, int, Token*);
void sqlite3CloseSavepoints(sqlite3 *);
+void sqlite3LeaveMutexAndCloseZombie(sqlite3*);
int sqlite3ExprIsConstant(Expr*);
int sqlite3ExprIsConstantNotJoin(Expr*);
int sqlite3ExprIsConstantOrFunction(Expr*);
diff --git a/src/vdbeapi.c b/src/vdbeapi.c
index 94db205e1..e25acd944 100644
--- a/src/vdbeapi.c
+++ b/src/vdbeapi.c
@@ -71,17 +71,12 @@ int sqlite3_finalize(sqlite3_stmt *pStmt){
}else{
Vdbe *v = (Vdbe*)pStmt;
sqlite3 *db = v->db;
-#if SQLITE_THREADSAFE
- sqlite3_mutex *mutex;
-#endif
if( vdbeSafety(v) ) return SQLITE_MISUSE_BKPT;
-#if SQLITE_THREADSAFE
- mutex = v->db->mutex;
-#endif
- sqlite3_mutex_enter(mutex);
+ sqlite3_mutex_enter(db->mutex);
rc = sqlite3VdbeFinalize(v);
+ if( (rc&0xff)==SQLITE_MISUSE ) rc = SQLITE_OK;
rc = sqlite3ApiExit(db, rc);
- sqlite3_mutex_leave(mutex);
+ sqlite3LeaveMutexAndCloseZombie(db);
}
return rc;
}
diff --git a/src/vdbeaux.c b/src/vdbeaux.c
index caa2bf670..3ccf71161 100644
--- a/src/vdbeaux.c
+++ b/src/vdbeaux.c
@@ -2469,6 +2469,7 @@ void sqlite3VdbeDelete(Vdbe *p){
if( NEVER(p==0) ) return;
db = p->db;
+ assert( sqlite3_mutex_held(db->mutex) );
if( p->pPrev ){
p->pPrev->pNext = p->pNext;
}else{
generated by cgit v1.2.3 (git 2.25.1) at 2025-07-19 19:05:28 +0000