Untested implementation of the shared-memory dead-man-switch.
FossilOrigin-Name: 706611283ea2575c2942543391026b36061cfc1c
This commit is contained in:
drh
parent
7b6944047e
commit
31cbbbad1c
18
manifest
18
manifest
@ -1,8 +1,8 @@
|
||||
-----BEGIN PGP SIGNED MESSAGE-----
|
||||
Hash: SHA1
|
||||
|
||||
C Progress\stowards\sa\sVFS\sthat\swill\ssupport\sWAL.\s\sLocking\scode\sis\sin\splace\nbut\sis\suntested.\s\sStill\sno\ssupport\sfor\sthe\sDMS.
|
||||
D 2010-04-29T15:17:48
|
||||
C Untested\simplementation\sof\sthe\sshared-memory\sdead-man-switch.
|
||||
D 2010-04-29T16:40:51
|
||||
F Makefile.arm-wince-mingw32ce-gcc fcd5e9cd67fe88836360bb4f9ef4cb7f8e2fb5a0
|
||||
F Makefile.in d83a0ffef3dcbfb08b410a6c6dd6c009ec9167fb
|
||||
F Makefile.linux-gcc d53183f4aa6a9192d249731c90dbdffbd2c68654
|
||||
@ -153,7 +153,7 @@ F src/os.c 8bc63cf91e9802e2b807198e54e50227fa889306
|
||||
F src/os.h 534b082c3cb349ad05fa6fa0b06087e022af282c
|
||||
F src/os_common.h 0d6ee583b6ee3185eb9d951f890c6dd03021a08d
|
||||
F src/os_os2.c 8ad77a418630d7dee91d1bb04f79c2096301d3a0
|
||||
F src/os_unix.c 340c503705cdb447753a55771911a92aa41d27c8
|
||||
F src/os_unix.c f0e002e74108c8a3f70c63dd91419ab6bcafd095
|
||||
F src/os_win.c a8fc01d8483be472e495793c01064fd87e56a5c1
|
||||
F src/pager.c b4a41030860229e80295fa1f37addab24d21799c
|
||||
F src/pager.h cee4487ab4f0911dd9f22a40e3cd55afdb7ef444
|
||||
@ -811,14 +811,14 @@ F tool/speedtest2.tcl ee2149167303ba8e95af97873c575c3e0fab58ff
|
||||
F tool/speedtest8.c 2902c46588c40b55661e471d7a86e4dd71a18224
|
||||
F tool/speedtest8inst1.c 293327bc76823f473684d589a8160bde1f52c14e
|
||||
F tool/vdbe-compress.tcl d70ea6d8a19e3571d7ab8c9b75cba86d1173ff0f
|
||||
P 3cc55a7568daa3796483f632e33478969e381cf5
|
||||
R 1f2ad602233779dda1e35a2877201d1f
|
||||
P 1bde41cf081570ad257f927b641e752dff4ed014
|
||||
R a7ee89d9d5eb7d4f4fd9d69824beab31
|
||||
U drh
|
||||
Z 5bb08c68390b552fdeb1ef93301ae98c
|
||||
Z 15bd57757c5a0ce16c3065e9d45dae67
|
||||
-----BEGIN PGP SIGNATURE-----
|
||||
Version: GnuPG v1.4.6 (GNU/Linux)
|
||||
|
||||
iD8DBQFL2aMhoxKgR168RlERAntLAKCNwNXdF9LrZZqkEN8f3gsvrSxoXACaA2Ku
|
||||
SvIawhrGV2wraxrir5MNan8=
|
||||
=Vfpz
|
||||
iD4DBQFL2baVoxKgR168RlERArO2AJ9g8Vnb6XlVDltcg68idEyJzFPcYwCYh7Xs
|
||||
0Mdctk0jP1xbHiTJhHLX+A==
|
||||
=minX
|
||||
-----END PGP SIGNATURE-----
|
||||
|
||||
@ -1 +1 @@
|
||||
1bde41cf081570ad257f927b641e752dff4ed014
|
||||
706611283ea2575c2942543391026b36061cfc1c
|
||||
@ -4698,7 +4698,7 @@ static const char *unixShmLockString(u8 mask){
|
||||
** Locks block if the UNIX_SHM_MUTEX bit is set and are non-blocking
|
||||
** otherwise.
|
||||
*/
|
||||
static int unixShmSystemLocks(
|
||||
static int unixShmSystemLock(
|
||||
unixShmFile *pFile, /* Apply locks to this open shared-memory segment */
|
||||
int lockType, /* F_UNLCK, F_RDLCK, or F_WRLCK */
|
||||
u8 lockMask /* Which bytes to lock or unlock */
|
||||
@ -4709,6 +4709,9 @@ static int unixShmSystemLocks(
|
||||
int rc; /* Result code form fcntl() */
|
||||
u8 mask; /* Mask of bits in lockMask */
|
||||
|
||||
/* Access to the unixShmFile object is serialized by the caller */
|
||||
assert( sqlite3_mutex_held(pFile->mutex) );
|
||||
|
||||
/* Initialize the locking parameters */
|
||||
memset(&f, 0, sizeof(f));
|
||||
f.l_type = lockType;
|
||||
@ -4787,6 +4790,9 @@ static int unixShmUnlock(
|
||||
unixShm *pX; /* For looping over all sibling connections */
|
||||
u8 allMask; /* Union of locks held by connections other than "p" */
|
||||
|
||||
/* Access to the unixShmFile object is serialized by the caller */
|
||||
assert( sqlite3_mutex_held(pFile->mutex) );
|
||||
|
||||
/* We never try to unlock locks that we do not hold */
|
||||
assert( ((p->exclMask|p->sharedMask) & unlockMask)==unlockMask );
|
||||
|
||||
@ -4799,7 +4805,7 @@ static int unixShmUnlock(
|
||||
|
||||
/* Unlock the system-level locks */
|
||||
if( (unlockMask & allMask)!=unlockMask ){
|
||||
rc = unixShmSystemLocks(pFile, F_UNLCK, unlockMask & ~allMask);
|
||||
rc = unixShmSystemLock(pFile, F_UNLCK, unlockMask & ~allMask);
|
||||
}else{
|
||||
rc = SQLITE_OK;
|
||||
}
|
||||
@ -4824,6 +4830,9 @@ static int unixShmSharedLock(
|
||||
unixShm *pX; /* For looping over all sibling connections */
|
||||
u8 allShared; /* Union of locks held by connections other than "p" */
|
||||
|
||||
/* Access to the unixShmFile object is serialized by the caller */
|
||||
assert( sqlite3_mutex_held(pFile->mutex) );
|
||||
|
||||
/* Find out which shared locks are already held by sibling connections.
|
||||
** If any sibling already holds an exclusive lock, go ahead and return
|
||||
** SQLITE_BUSY.
|
||||
@ -4836,7 +4845,7 @@ static int unixShmSharedLock(
|
||||
|
||||
/* Get shared locks at the system level, if necessary */
|
||||
if( (~allShared) & readMask ){
|
||||
rc = unixShmSystemLocks(pFile, F_RDLCK, readMask);
|
||||
rc = unixShmSystemLock(pFile, F_RDLCK, readMask);
|
||||
}else{
|
||||
rc = SQLITE_OK;
|
||||
}
|
||||
@ -4860,6 +4869,9 @@ static int unixShmExclusiveLock(
|
||||
int rc; /* Result code */
|
||||
unixShm *pX; /* For looping over all sibling connections */
|
||||
|
||||
/* Access to the unixShmFile object is serialized by the caller */
|
||||
assert( sqlite3_mutex_held(pFile->mutex) );
|
||||
|
||||
/* Make sure no sibling connections hold locks that will block this
|
||||
** lock. If any do, return SQLITE_BUSY right away.
|
||||
*/
|
||||
@ -4872,7 +4884,7 @@ static int unixShmExclusiveLock(
|
||||
/* Get the exclusive locks at the system level. Then if successful
|
||||
** also mark the local connection as being locked.
|
||||
*/
|
||||
rc = unixShmSystemLocks(pFile, F_WRLCK, writeMask);
|
||||
rc = unixShmSystemLock(pFile, F_WRLCK, writeMask);
|
||||
if( rc==SQLITE_OK ){
|
||||
p->sharedMask &= ~writeMask;
|
||||
p->exclMask |= writeMask;
|
||||
@ -4917,16 +4929,20 @@ static int unixShmOpen(
|
||||
const char *zName, /* Name of file to mmap */
|
||||
sqlite3_shm **pShm /* Write the unixShm object created here */
|
||||
){
|
||||
struct unixShm *p = 0;
|
||||
struct unixShmFile *pFile = 0;
|
||||
int rc;
|
||||
struct unixFileId fid;
|
||||
struct stat sStat;
|
||||
struct unixShm *p = 0; /* The connection to be opened */
|
||||
struct unixShmFile *pFile = 0; /* The underlying mmapped file */
|
||||
int rc; /* Result code */
|
||||
struct unixFileId fid; /* Unix file identifier */
|
||||
struct stat sStat; /* Result from stat() an fstat() */
|
||||
|
||||
/* Allocate space for the new sqlite3_shm object */
|
||||
p = sqlite3_malloc( sizeof(*p) );
|
||||
if( p==0 ) return SQLITE_NOMEM;
|
||||
memset(p, 0, sizeof(*p));
|
||||
|
||||
/* Look to see if there is an existing unixShmFile that can be used.
|
||||
** If no matching unixShmFile currently exists, create a new one.
|
||||
*/
|
||||
unixEnterMutex();
|
||||
rc = stat(zName, &sStat);
|
||||
if( rc==0 ){
|
||||
@ -4982,16 +4998,27 @@ static int unixShmOpen(
|
||||
pFile->fid.ino = sStat.st_ino;
|
||||
pFile->size = (int)sStat.st_size;
|
||||
pFile->size = (pFile->size/SQLITE_UNIX_SHM_INCR)*SQLITE_UNIX_SHM_INCR;
|
||||
if( pFile->size==0 ){
|
||||
pFile->size = SQLITE_UNIX_SHM_INCR;
|
||||
rc = ftruncate(pFile->h, pFile->size);
|
||||
if( rc ){
|
||||
rc = SQLITE_FULL;
|
||||
|
||||
/* Check to see if another process is holding the dead-man switch.
|
||||
** If not, truncate the file to zero length.
|
||||
*/
|
||||
if( unixShmSystemLock(pFile, F_WRLCK, UNIX_SHM_MUTEX) ){
|
||||
rc = SQLITE_IOERR_LOCK;
|
||||
goto shm_open_err;
|
||||
}
|
||||
if( unixShmSystemLock(pFile, F_WRLCK, UNIX_SHM_DMS)==SQLITE_OK ){
|
||||
if( ftruncate(pFile->h, 0) ){
|
||||
rc = SQLITE_IOERR;
|
||||
goto shm_open_err;
|
||||
}
|
||||
pFile->size = 0;
|
||||
}
|
||||
rc = unixShmSystemLock(pFile, F_RDLCK, UNIX_SHM_DMS);
|
||||
if( rc ) goto shm_open_err;
|
||||
unixShmSystemLock(pFile, F_UNLCK, UNIX_SHM_MUTEX);
|
||||
}
|
||||
|
||||
/* Make the new connection a child of the unixShmFile */
|
||||
p->pFile = pFile;
|
||||
p->pNext = pFile->pFirst;
|
||||
#ifdef SQLITE_DEBUG
|
||||
@ -5003,6 +5030,7 @@ static int unixShmOpen(
|
||||
unixLeaveMutex();
|
||||
return SQLITE_OK;
|
||||
|
||||
/* Jump here on any error */
|
||||
shm_open_err:
|
||||
unixShmPurge();
|
||||
sqlite3_free(p);
|
||||
|
||||
Loading…
x
Reference in New Issue
Block a user