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Fix a couple uninitialized variables in the xShmLock method of the unix VFS.

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Improved debugging logic for xShmLock.

FossilOrigin-Name: 69567c5fca9e30b7660e6f56350be929c3890d7e
This commit is contained in:
drh
2010-04-30 15:54:46 +00:00
parent a7ad518ef0
commit d749084ad0
3 changed files with 31 additions and 12 deletions
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17
src/os_unix.c
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@@ -4716,6 +4716,7 @@ static int unixShmSystemLock(
f.l_whence = SEEK_SET;
if( (lockMask & UNIX_SHM_MUTEX)!=0 && lockType!=F_UNLCK ){
lockOp = F_SETLKW;
OSTRACE(("SHM-LOCK requesting blocking lock\n"));
}else{
lockOp = F_SETLK;
}
@@ -4768,7 +4769,7 @@ static int unixShmSystemLock(
OSTRACE(("write-lock failed"));
}
}
OSTRACE((" - change requested %s - afterwards %s,%s\n",
OSTRACE((" - change requested %s - afterwards %s:%s\n",
unixShmLockString(lockMask),
unixShmLockString(pFile->sharedMask),
unixShmLockString(pFile->exclMask)));
@@ -4794,6 +4795,7 @@ static int unixShmUnlock(
assert( sqlite3_mutex_held(pFile->mutex) );
/* Compute locks held by sibling connections */
allMask = 0;
for(pX=pFile->pFirst; pX; pX=pX->pNext){
if( pX==p ) continue;
assert( (pX->exclMask & (p->exclMask|p->sharedMask))==0 );
@@ -4834,6 +4836,7 @@ static int unixShmSharedLock(
** If any sibling already holds an exclusive lock, go ahead and return
** SQLITE_BUSY.
*/
allShared = 0;
for(pX=pFile->pFirst; pX; pX=pX->pNext){
if( pX==p ) continue;
if( (pX->exclMask & readMask)!=0 ) return SQLITE_BUSY;
@@ -5004,12 +5007,13 @@ static int unixShmOpen(
if( unixShmSystemLock(pFile, F_WRLCK, UNIX_SHM_DMS)==SQLITE_OK ){
if( ftruncate(pFile->h, 0) ){
rc = SQLITE_IOERR;
goto shm_open_err;
}
}
rc = unixShmSystemLock(pFile, F_RDLCK, UNIX_SHM_DMS);
if( rc ) goto shm_open_err;
if( rc==SQLITE_OK ){
rc = unixShmSystemLock(pFile, F_RDLCK, UNIX_SHM_DMS);
}
unixShmSystemLock(pFile, F_UNLCK, UNIX_SHM_MUTEX);
if( rc ) goto shm_open_err;
}
/* Make the new connection a child of the unixShmFile */
@@ -5201,10 +5205,14 @@ static int unixShmLock(
|| desiredLock==p->lockState
|| (desiredLock==SQLITE_SHM_READ && p->lockState==SQLITE_SHM_READ_FULL)
){
OSTRACE(("SHM-LOCK shmid-%d, pid-%d request %d and got %d\n",
p->id, getpid(), desiredLock, p->lockState));
if( pGotLock ) *pGotLock = p->lockState;
return SQLITE_OK;
}
OSTRACE(("SHM-LOCK shmid-%d, pid-%d request %d->%d\n",
p->id, getpid(), p->lockState, desiredLock));
sqlite3_mutex_enter(pFile->mutex);
switch( desiredLock ){
case SQLITE_SHM_UNLOCK: {
@@ -5293,6 +5301,7 @@ static int unixShmLock(
}
}
sqlite3_mutex_leave(pFile->mutex);
OSTRACE(("SHM-LOCK shmid-%d, pid-%d got %d\n", p->id,getpid(),p->lockState));
if( pGotLock ) *pGotLock = p->lockState;
return rc;
}