diff options
Diffstat (limited to 'src/os_unix.c')
| -rw-r--r-- | src/os_unix.c | 18 |
1 files changed, 10 insertions, 8 deletions
diff --git a/src/os_unix.c b/src/os_unix.c index 56e53929e..e1ed575b0 100644 --- a/src/os_unix.c +++ b/src/os_unix.c @@ -4819,22 +4819,24 @@ static int unixShmLock( assert( pShmNode->hShm>=0 || pDbFd->pInode->bProcessLock==1 ); assert( pShmNode->hShm<0 || pDbFd->pInode->bProcessLock==0 ); - /* Check that, if this to be a blocking lock, that locks have been - ** obtained in the following order. + /* Check that, if this to be a blocking lock, no locks that occur later + ** in the following list than the lock being obtained are already held: ** ** 1. Checkpointer lock (ofst==1). - ** 2. Recover lock (ofst==2). + ** 2. Write lock (ofst==0). ** 3. Read locks (ofst>=3 && ofst<SQLITE_SHM_NLOCK). - ** 4. Write lock (ofst==0). ** ** In other words, if this is a blocking lock, none of the locks that ** occur later in the above list than the lock being obtained may be ** held. */ #ifdef SQLITE_ENABLE_SETLK_TIMEOUT - assert( pDbFd->iBusyTimeout==0 - || (flags & SQLITE_SHM_UNLOCK) || ofst==0 - || ((p->exclMask|p->sharedMask)&~((1<<ofst)-2))==0 - ); + assert( (flags & SQLITE_SHM_UNLOCK) || pDbFd->iBusyTimeout==0 || ( + (ofst!=2) /* not RECOVER */ + && (n==1) /* Single lock only */ + && (ofst!=1 || (p->exclMask|p->sharedMask)==0) + && (ofst!=0 || (p->exclMask|p->sharedMask)<3) + && (ofst<3 || (p->exclMask|p->sharedMask)<(1<<ofst)) + )); #endif mask = (1<<(ofst+n)) - (1<<ofst); |