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-rw-r--r--src/btree.c3
-rw-r--r--src/main.c55
-rw-r--r--src/os_unix.c55
-rw-r--r--src/sqlite.h.in8
-rw-r--r--src/sqliteInt.h3
5 files changed, 108 insertions, 16 deletions
diff --git a/src/btree.c b/src/btree.c
index e4aff9aca..6bcf379d6 100644
--- a/src/btree.c
+++ b/src/btree.c
@@ -2231,7 +2231,8 @@ static int btreeInvokeBusyHandler(void *pArg){
BtShared *pBt = (BtShared*)pArg;
assert( pBt->db );
assert( sqlite3_mutex_held(pBt->db->mutex) );
- return sqlite3InvokeBusyHandler(&pBt->db->busyHandler);
+ return sqlite3InvokeBusyHandler(&pBt->db->busyHandler,
+ sqlite3PagerFile(pBt->pPager));
}
/*
diff --git a/src/main.c b/src/main.c
index 53c4d5dbd..998fcb9ef 100644
--- a/src/main.c
+++ b/src/main.c
@@ -1476,21 +1476,38 @@ const char *sqlite3ErrStr(int rc){
** 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 @@ static int sqliteDefaultBusyCallback(
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 @@ static int sqliteDefaultBusyCallback(
/*
** 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 @@ int sqlite3_busy_handler(
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 @@ int sqlite3_busy_timeout(sqlite3 *db, int ms){
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);
}
diff --git a/src/os_unix.c b/src/os_unix.c
index 5a1d396ce..ac4ec2f2f 100644
--- a/src/os_unix.c
+++ b/src/os_unix.c
@@ -229,6 +229,9 @@ struct unixFile {
#if SQLITE_ENABLE_LOCKING_STYLE || defined(__APPLE__)
unsigned fsFlags; /* cached details from statfs() */
#endif
+#ifdef SQLITE_ENABLE_SETLK_TIMEOUT
+ unsigned iBusyTimeout; /* Wait this many millisec on locks */
+#endif
#if OS_VXWORKS
struct vxworksFileId *pId; /* Unique file ID */
#endif
@@ -1466,6 +1469,46 @@ static int unixCheckReservedLock(sqlite3_file *id, int *pResOut){
}
/*
+** Set a posix-advisory-lock.
+**
+** There are two versions of this routine. If compiled with
+** SQLITE_ENABLE_SETLK_TIMEOUT then the routine has an extra parameter
+** which is a pointer to a unixFile. If the unixFile->iBusyTimeout
+** value is set, then it is the number of milliseconds to wait before
+** failing the lock. The iBusyTimeout value is always reset back to
+** zero on each call.
+**
+** If SQLITE_ENABLE_SETLK_TIMEOUT is not defined, then do a non-blocking
+** attempt to set the lock.
+*/
+#ifndef SQLITE_ENABLE_SETLK_TIMEOUT
+# define osSetPosixAdvisoryLock(h,x,t) osFcntl(h,F_SETLK,x)
+#else
+static int osSetPosixAdvisoryLock(
+ int h, /* The file descriptor on which to take the lock */
+ struct flock *pLock, /* The description of the lock */
+ unixFile *pFile /* Structure holding timeout value */
+){
+ int rc = osFcntl(h,F_SETLK,pLock);
+ if( rc<0 && pFile->iBusyTimeout>0 ){
+ /* On systems that support some kind of blocking file lock with a timeout,
+ ** make appropriate changes here to invoke that blocking file lock. On
+ ** generic posix, however, there is no such API. So we simply try the
+ ** lock once every millisecond until either the timeout expires, or until
+ ** the lock is obtained. */
+ do{
+ usleep(1000);
+ rc = osFcntl(h,F_SETLK,pLock);
+ pFile->iBusyTimeout--;
+ }while( rc<0 && pFile->iBusyTimeout>0 );
+ pFile->iBusyTimeout = 0;
+ }
+ return rc;
+}
+#endif /* SQLITE_ENABLE_SETLK_TIMEOUT */
+
+
+/*
** Attempt to set a system-lock on the file pFile. The lock is
** described by pLock.
**
@@ -1497,7 +1540,7 @@ static int unixFileLock(unixFile *pFile, struct flock *pLock){
lock.l_start = SHARED_FIRST;
lock.l_len = SHARED_SIZE;
lock.l_type = F_WRLCK;
- rc = osFcntl(pFile->h, F_SETLK, &lock);
+ rc = osSetPosixAdvisoryLock(pFile->h, &lock, pFile);
if( rc<0 ) return rc;
pInode->bProcessLock = 1;
pInode->nLock++;
@@ -1505,7 +1548,7 @@ static int unixFileLock(unixFile *pFile, struct flock *pLock){
rc = 0;
}
}else{
- rc = osFcntl(pFile->h, F_SETLK, pLock);
+ rc = osSetPosixAdvisoryLock(pFile->h, pLock, pFile);
}
return rc;
}
@@ -3865,6 +3908,12 @@ static int unixFileControl(sqlite3_file *id, int op, void *pArg){
*(int*)pArg = fileHasMoved(pFile);
return SQLITE_OK;
}
+#ifdef SQLITE_ENABLE_SETLK_TIMEOUT
+ case SQLITE_FCNTL_LOCK_TIMEOUT: {
+ pFile->iBusyTimeout = *(int*)pArg;
+ return SQLITE_OK;
+ }
+#endif
#if SQLITE_MAX_MMAP_SIZE>0
case SQLITE_FCNTL_MMAP_SIZE: {
i64 newLimit = *(i64*)pArg;
@@ -4184,7 +4233,7 @@ static int unixShmSystemLock(
f.l_whence = SEEK_SET;
f.l_start = ofst;
f.l_len = n;
- rc = osFcntl(pShmNode->h, F_SETLK, &f);
+ rc = osSetPosixAdvisoryLock(pShmNode->h, &f, pFile);
rc = (rc!=(-1)) ? SQLITE_OK : SQLITE_BUSY;
}
diff --git a/src/sqlite.h.in b/src/sqlite.h.in
index b2402522d..bb4452390 100644
--- a/src/sqlite.h.in
+++ b/src/sqlite.h.in
@@ -1064,6 +1064,12 @@ struct sqlite3_io_methods {
** so that all subsequent write operations are independent.
** ^SQLite will never invoke SQLITE_FCNTL_ROLLBACK_ATOMIC_WRITE without
** a prior successful call to [SQLITE_FCNTL_BEGIN_ATOMIC_WRITE].
+**
+** <li>[[SQLITE_FCNTL_LOCK_TIMEOUT]]
+** The [SQLITE_FCNTL_LOCK_TIMEOUT] opcode causes attempts to obtain
+** a file lock using the xLock or xShmLock methods of the VFS to wait
+** for up to M milliseconds before failing, where M is the single
+** unsigned integer parameter.
** </ul>
*/
#define SQLITE_FCNTL_LOCKSTATE 1
@@ -1098,6 +1104,8 @@ struct sqlite3_io_methods {
#define SQLITE_FCNTL_BEGIN_ATOMIC_WRITE 31
#define SQLITE_FCNTL_COMMIT_ATOMIC_WRITE 32
#define SQLITE_FCNTL_ROLLBACK_ATOMIC_WRITE 33
+#define SQLITE_FCNTL_LOCK_TIMEOUT 34
+#define SQLITE_FCNTL_LAST 34 /* Last value */
/* deprecated names */
#define SQLITE_GET_LOCKPROXYFILE SQLITE_FCNTL_GET_LOCKPROXYFILE
diff --git a/src/sqliteInt.h b/src/sqliteInt.h
index b10fe9432..d932ae87d 100644
--- a/src/sqliteInt.h
+++ b/src/sqliteInt.h
@@ -964,6 +964,7 @@ struct BusyHandler {
int (*xBusyHandler)(void *,int); /* The busy callback */
void *pBusyArg; /* First arg to busy callback */
int nBusy; /* Incremented with each busy call */
+ u8 bExtraFileArg; /* Include sqlite3_file as callback arg */
};
/*
@@ -4103,7 +4104,7 @@ void sqlite3AlterBeginAddColumn(Parse *, SrcList *);
CollSeq *sqlite3GetCollSeq(Parse*, u8, CollSeq *, const char*);
char sqlite3AffinityType(const char*, u8*);
void sqlite3Analyze(Parse*, Token*, Token*);
-int sqlite3InvokeBusyHandler(BusyHandler*);
+int sqlite3InvokeBusyHandler(BusyHandler*, sqlite3_file*);
int sqlite3FindDb(sqlite3*, Token*);
int sqlite3FindDbName(sqlite3 *, const char *);
int sqlite3AnalysisLoad(sqlite3*,int iDB);
generated by cgit v1.2.3 (git 2.25.1) at 2025-07-19 05:43:52 +0000