Add infrastructure to support for using F_SETLKW with a timeout on system
that support that functionality. Requires SQLITE_ENABLE_SETLK_TIMEOUT.
FossilOrigin-Name: 2e54a7433ece4eb27e71bda6f2d121d5aa46ddd5a481357d8543d1432aaad689
diff --git a/src/main.c b/src/main.c
index 53c4d5d..998fcb9 100644
--- a/src/main.c
+++ b/src/main.c
@@ -1476,21 +1476,38 @@
** again until a timeout value is reached. The timeout value is
** an integer number of milliseconds passed in as the first
** argument.
+**
+** Return non-zero to retry the lock. Return zero to stop trying
+** and cause SQLite to return SQLITE_BUSY.
*/
static int sqliteDefaultBusyCallback(
- void *ptr, /* Database connection */
- int count /* Number of times table has been busy */
+ void *ptr, /* Database connection */
+ int count, /* Number of times table has been busy */
+ sqlite3_file *pFile /* The file on which the lock occurred */
){
#if SQLITE_OS_WIN || HAVE_USLEEP
+ /* This case is for systems that have support for sleeping for fractions of
+ ** a second. Examples: All windows systems, unix systems with usleep() */
static const u8 delays[] =
{ 1, 2, 5, 10, 15, 20, 25, 25, 25, 50, 50, 100 };
static const u8 totals[] =
{ 0, 1, 3, 8, 18, 33, 53, 78, 103, 128, 178, 228 };
# define NDELAY ArraySize(delays)
sqlite3 *db = (sqlite3 *)ptr;
- int timeout = db->busyTimeout;
+ int tmout = db->busyTimeout;
int delay, prior;
+#ifdef SQLITE_ENABLE_SETLK_TIMEOUT
+ if( sqlite3OsFileControl(pFile,SQLITE_FCNTL_LOCK_TIMEOUT,&tmout)==SQLITE_OK ){
+ if( count ){
+ tmout = 0;
+ sqlite3OsFileControl(pFile, SQLITE_FCNTL_LOCK_TIMEOUT, &tmout);
+ return 0;
+ }else{
+ return 1;
+ }
+ }
+#endif
assert( count>=0 );
if( count < NDELAY ){
delay = delays[count];
@@ -1499,16 +1516,18 @@
delay = delays[NDELAY-1];
prior = totals[NDELAY-1] + delay*(count-(NDELAY-1));
}
- if( prior + delay > timeout ){
- delay = timeout - prior;
+ if( prior + delay > tmout ){
+ delay = tmout - prior;
if( delay<=0 ) return 0;
}
sqlite3OsSleep(db->pVfs, delay*1000);
return 1;
#else
+ /* This case for unix systems that lack usleep() support. Sleeping
+ ** must be done in increments of whole seconds */
sqlite3 *db = (sqlite3 *)ptr;
- int timeout = ((sqlite3 *)ptr)->busyTimeout;
- if( (count+1)*1000 > timeout ){
+ int tmout = ((sqlite3 *)ptr)->busyTimeout;
+ if( (count+1)*1000 > tmout ){
return 0;
}
sqlite3OsSleep(db->pVfs, 1000000);
@@ -1519,14 +1538,25 @@
/*
** Invoke the given busy handler.
**
-** This routine is called when an operation failed with a lock.
+** This routine is called when an operation failed to acquire a
+** lock on VFS file pFile.
+**
** If this routine returns non-zero, the lock is retried. If it
** returns 0, the operation aborts with an SQLITE_BUSY error.
*/
-int sqlite3InvokeBusyHandler(BusyHandler *p){
+int sqlite3InvokeBusyHandler(BusyHandler *p, sqlite3_file *pFile){
int rc;
if( p->xBusyHandler==0 || p->nBusy<0 ) return 0;
- rc = p->xBusyHandler(p->pBusyArg, p->nBusy);
+ if( p->bExtraFileArg ){
+ /* Add an extra parameter with the pFile pointer to the end of the
+ ** callback argument list */
+ int (*xTra)(void*,int,sqlite3_file*);
+ xTra = (int(*)(void*,int,sqlite3_file*))p->xBusyHandler;
+ rc = xTra(p->pBusyArg, p->nBusy, pFile);
+ }else{
+ /* Legacy style busy handler callback */
+ rc = p->xBusyHandler(p->pBusyArg, p->nBusy);
+ }
if( rc==0 ){
p->nBusy = -1;
}else{
@@ -1551,6 +1581,7 @@
db->busyHandler.xBusyHandler = xBusy;
db->busyHandler.pBusyArg = pArg;
db->busyHandler.nBusy = 0;
+ db->busyHandler.bExtraFileArg = 0;
db->busyTimeout = 0;
sqlite3_mutex_leave(db->mutex);
return SQLITE_OK;
@@ -1598,8 +1629,10 @@
if( !sqlite3SafetyCheckOk(db) ) return SQLITE_MISUSE_BKPT;
#endif
if( ms>0 ){
- sqlite3_busy_handler(db, sqliteDefaultBusyCallback, (void*)db);
+ sqlite3_busy_handler(db, (int(*)(void*,int))sqliteDefaultBusyCallback,
+ (void*)db);
db->busyTimeout = ms;
+ db->busyHandler.bExtraFileArg = 1;
}else{
sqlite3_busy_handler(db, 0, 0);
}