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Code formatting changes to make trunk more like wal2.

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FossilOrigin-Name: 8f725472b0fe62359a4cd3237b43d7b834e042d8ce425abde06e3ed6c62dbafa
This commit is contained in:
drh
2024-12-16 18:04:39 +00:00
parent bd1a5932d9
commit 32dd04b41e
3 changed files with 139 additions and 137 deletions
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12
manifest
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@@ -1,5 +1,5 @@
C Changes\sfor\sbetter\salignment\swith\sthe\swal2\sbranch.
D 2024-12-16T13:25:49.902
C Code\sformatting\schanges\sto\smake\strunk\smore\slike\swal2.
D 2024-12-16T18:04:39.151
F .fossil-settings/empty-dirs dbb81e8fc0401ac46a1491ab34a7f2c7c0452f2f06b54ebb845d024ca8283ef1
F .fossil-settings/ignore-glob 35175cdfcf539b2318cb04a9901442804be81cd677d8b889fcc9149c21f239ea
F LICENSE.md e108e1e69ae8e8a59e93c455654b8ac9356a11720d3345df2a4743e9590fb20d
@@ -858,7 +858,7 @@ F src/vdbetrace.c fe0bc29ebd4e02c8bc5c1945f1d2e6be5927ec12c06d89b03ef2a4def34bf8
F src/vdbevtab.c fc46b9cbd759dc013f0b3724549cc0d71379183c667df3a5988f7e2f1bd485f3
F src/vtab.c 316cd48e9320660db3047cd306cd056e4361180cebb4d0f10a39244e10c11422
F src/vxworks.h d2988f4e5a61a4dfe82c6524dd3d6e4f2ce3cdb9
F src/wal.c fcbc36c31df200daa4ed398923ab55a02dbbed9ce22a8a31c5d9bf447a130126
F src/wal.c 4e6181d8780ab0af2e1388d0754cbe6f2f04593d2b1ab6c41699a89942fd8997
F src/wal.h ba252daaa94f889f4b2c17c027e823d9be47ce39da1d3799886bbd51f0490452
F src/walker.c d5006d6b005e4ea7302ad390957a8d41ed83faa177e412f89bc5600a7462a014
F src/where.c 9ad3dea8003a8913da6a4ca8322e2fe30773f46e88a0d4fbf9db13bdb999efa2
@@ -2202,8 +2202,8 @@ F tool/version-info.c 3b36468a90faf1bbd59c65fd0eb66522d9f941eedd364fabccd7227350
F tool/warnings-clang.sh bbf6a1e685e534c92ec2bfba5b1745f34fb6f0bc2a362850723a9ee87c1b31a7
F tool/warnings.sh 49a486c5069de041aedcbde4de178293e0463ae9918ecad7539eedf0ec77a139
F tool/win/sqlite.vsix deb315d026cc8400325c5863eef847784a219a2f
P ae580443d210811c12209866112fc8b0b83281e24945504b748a17d93ad84062
R dc9095f065111bf3b125973079f69b6b
P 4fab85b3d0d1cad2d185f2456de7ddf281badf8561cc051e10e16655441dcc84
R 9aaaecad314aea90d45c80b60798b57a
U drh
Z 26e0562f544e2adce22ef893d4b0b579
Z 2a765bcb487b40c3fb2da87580a07616
# Remove this line to create a well-formed Fossil manifest.

2
manifest.uuid
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@@ -1 +1 @@
4fab85b3d0d1cad2d185f2456de7ddf281badf8561cc051e10e16655441dcc84
8f725472b0fe62359a4cd3237b43d7b834e042d8ce425abde06e3ed6c62dbafa

260
src/wal.c
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@@ -2986,11 +2986,7 @@ static int walBeginShmUnreliable(Wal *pWal, int *pChanged){
*/
static int walTryBeginRead(Wal *pWal, int *pChanged, int useWal, int *pCnt){
volatile WalCkptInfo *pInfo; /* Checkpoint information in wal-index */
u32 mxReadMark; /* Largest aReadMark[] value */
int mxI; /* Index of largest aReadMark[] value */
int i; /* Loop counter */
int rc = SQLITE_OK; /* Return code */
u32 mxFrame; /* Wal frame to lock to */
#ifdef SQLITE_ENABLE_SETLK_TIMEOUT
int nBlockTmout = 0;
#endif
@@ -3096,141 +3092,147 @@ static int walTryBeginRead(Wal *pWal, int *pChanged, int useWal, int *pCnt){
assert( pWal->apWiData[0]!=0 );
pInfo = walCkptInfo(pWal);
SEH_INJECT_FAULT;
if( !useWal && AtomicLoad(&pInfo->nBackfill)==pWal->hdr.mxFrame
{
u32 mxReadMark; /* Largest aReadMark[] value */
int mxI; /* Index of largest aReadMark[] value */
int i; /* Loop counter */
u32 mxFrame; /* Wal frame to lock to */
if( !useWal && AtomicLoad(&pInfo->nBackfill)==pWal->hdr.mxFrame
#ifdef SQLITE_ENABLE_SNAPSHOT
&& ((pWal->bGetSnapshot==0 && pWal->pSnapshot==0) || pWal->hdr.mxFrame==0)
&& ((pWal->bGetSnapshot==0 && pWal->pSnapshot==0) || pWal->hdr.mxFrame==0)
#endif
){
/* The WAL has been completely backfilled (or it is empty).
** and can be safely ignored.
*/
rc = walLockShared(pWal, WAL_READ_LOCK(0));
walShmBarrier(pWal);
if( rc==SQLITE_OK ){
if( memcmp((void *)walIndexHdr(pWal), &pWal->hdr, sizeof(WalIndexHdr)) ){
/* It is not safe to allow the reader to continue here if frames
** may have been appended to the log before READ_LOCK(0) was obtained.
** When holding READ_LOCK(0), the reader ignores the entire log file,
** which implies that the database file contains a trustworthy
** snapshot. Since holding READ_LOCK(0) prevents a checkpoint from
** happening, this is usually correct.
**
** However, if frames have been appended to the log (or if the log
** is wrapped and written for that matter) before the READ_LOCK(0)
** is obtained, that is not necessarily true. A checkpointer may
** have started to backfill the appended frames but crashed before
** it finished. Leaving a corrupt image in the database file.
*/
walUnlockShared(pWal, WAL_READ_LOCK(0));
return WAL_RETRY;
}
pWal->readLock = 0;
return SQLITE_OK;
}else if( rc!=SQLITE_BUSY ){
return rc;
}
}
/* If we get this far, it means that the reader will want to use
** the WAL to get at content from recent commits. The job now is
** to select one of the aReadMark[] entries that is closest to
** but not exceeding pWal->hdr.mxFrame and lock that entry.
*/
mxReadMark = 0;
mxI = 0;
mxFrame = pWal->hdr.mxFrame;
#ifdef SQLITE_ENABLE_SNAPSHOT
if( pWal->pSnapshot && pWal->pSnapshot->mxFrame<mxFrame ){
mxFrame = pWal->pSnapshot->mxFrame;
}
#endif
for(i=1; i<WAL_NREADER; i++){
u32 thisMark = AtomicLoad(pInfo->aReadMark+i); SEH_INJECT_FAULT;
if( mxReadMark<=thisMark && thisMark<=mxFrame ){
assert( thisMark!=READMARK_NOT_USED );
mxReadMark = thisMark;
mxI = i;
}
}
if( (pWal->readOnly & WAL_SHM_RDONLY)==0
&& (mxReadMark<mxFrame || mxI==0)
){
for(i=1; i<WAL_NREADER; i++){
rc = walLockExclusive(pWal, WAL_READ_LOCK(i), 1);
){
/* The WAL has been completely backfilled (or it is empty).
** and can be safely ignored.
*/
rc = walLockShared(pWal, WAL_READ_LOCK(0));
walShmBarrier(pWal);
if( rc==SQLITE_OK ){
AtomicStore(pInfo->aReadMark+i,mxFrame);
mxReadMark = mxFrame;
mxI = i;
walUnlockExclusive(pWal, WAL_READ_LOCK(i), 1);
break;
if( memcmp((void *)walIndexHdr(pWal), &pWal->hdr,sizeof(WalIndexHdr)) ){
/* It is not safe to allow the reader to continue here if frames
** may have been appended to the log before READ_LOCK(0) was obtained.
** When holding READ_LOCK(0), the reader ignores the entire log file,
** which implies that the database file contains a trustworthy
** snapshot. Since holding READ_LOCK(0) prevents a checkpoint from
** happening, this is usually correct.
**
** However, if frames have been appended to the log (or if the log
** is wrapped and written for that matter) before the READ_LOCK(0)
** is obtained, that is not necessarily true. A checkpointer may
** have started to backfill the appended frames but crashed before
** it finished. Leaving a corrupt image in the database file.
*/
walUnlockShared(pWal, WAL_READ_LOCK(0));
return WAL_RETRY;
}
pWal->readLock = 0;
return SQLITE_OK;
}else if( rc!=SQLITE_BUSY ){
return rc;
}
}
}
if( mxI==0 ){
assert( rc==SQLITE_BUSY || (pWal->readOnly & WAL_SHM_RDONLY)!=0 );
return rc==SQLITE_BUSY ? WAL_RETRY : SQLITE_READONLY_CANTINIT;
}
(void)walEnableBlockingMs(pWal, nBlockTmout);
rc = walLockShared(pWal, WAL_READ_LOCK(mxI));
walDisableBlocking(pWal);
if( rc ){
#ifdef SQLITE_ENABLE_SETLK_TIMEOUT
if( rc==SQLITE_BUSY_TIMEOUT ){
*pCnt |= WAL_RETRY_BLOCKED_MASK;
/* If we get this far, it means that the reader will want to use
** the WAL to get at content from recent commits. The job now is
** to select one of the aReadMark[] entries that is closest to
** but not exceeding pWal->hdr.mxFrame and lock that entry.
*/
mxReadMark = 0;
mxI = 0;
mxFrame = pWal->hdr.mxFrame;
#ifdef SQLITE_ENABLE_SNAPSHOT
if( pWal->pSnapshot && pWal->pSnapshot->mxFrame<mxFrame ){
mxFrame = pWal->pSnapshot->mxFrame;
}
#else
assert( rc!=SQLITE_BUSY_TIMEOUT );
#endif
assert( (rc&0xFF)!=SQLITE_BUSY||rc==SQLITE_BUSY||rc==SQLITE_BUSY_TIMEOUT );
return (rc&0xFF)==SQLITE_BUSY ? WAL_RETRY : rc;
}
/* Now that the read-lock has been obtained, check that neither the
** value in the aReadMark[] array or the contents of the wal-index
** header have changed.
**
** It is necessary to check that the wal-index header did not change
** between the time it was read and when the shared-lock was obtained
** on WAL_READ_LOCK(mxI) was obtained to account for the possibility
** that the log file may have been wrapped by a writer, or that frames
** that occur later in the log than pWal->hdr.mxFrame may have been
** copied into the database by a checkpointer. If either of these things
** happened, then reading the database with the current value of
** pWal->hdr.mxFrame risks reading a corrupted snapshot. So, retry
** instead.
**
** Before checking that the live wal-index header has not changed
** since it was read, set Wal.minFrame to the first frame in the wal
** file that has not yet been checkpointed. This client will not need
** to read any frames earlier than minFrame from the wal file - they
** can be safely read directly from the database file.
**
** Because a ShmBarrier() call is made between taking the copy of
** nBackfill and checking that the wal-header in shared-memory still
** matches the one cached in pWal->hdr, it is guaranteed that the
** checkpointer that set nBackfill was not working with a wal-index
** header newer than that cached in pWal->hdr. If it were, that could
** cause a problem. The checkpointer could omit to checkpoint
** a version of page X that lies before pWal->minFrame (call that version
** A) on the basis that there is a newer version (version B) of the same
** page later in the wal file. But if version B happens to like past
** frame pWal->hdr.mxFrame - then the client would incorrectly assume
** that it can read version A from the database file. However, since
** we can guarantee that the checkpointer that set nBackfill could not
** see any pages past pWal->hdr.mxFrame, this problem does not come up.
*/
pWal->minFrame = AtomicLoad(&pInfo->nBackfill)+1; SEH_INJECT_FAULT;
walShmBarrier(pWal);
if( AtomicLoad(pInfo->aReadMark+mxI)!=mxReadMark
|| memcmp((void *)walIndexHdr(pWal), &pWal->hdr, sizeof(WalIndexHdr))
){
walUnlockShared(pWal, WAL_READ_LOCK(mxI));
return WAL_RETRY;
}else{
assert( mxReadMark<=pWal->hdr.mxFrame );
pWal->readLock = (i16)mxI;
for(i=1; i<WAL_NREADER; i++){
u32 thisMark = AtomicLoad(pInfo->aReadMark+i); SEH_INJECT_FAULT;
if( mxReadMark<=thisMark && thisMark<=mxFrame ){
assert( thisMark!=READMARK_NOT_USED );
mxReadMark = thisMark;
mxI = i;
}
}
if( (pWal->readOnly & WAL_SHM_RDONLY)==0
&& (mxReadMark<mxFrame || mxI==0)
){
for(i=1; i<WAL_NREADER; i++){
rc = walLockExclusive(pWal, WAL_READ_LOCK(i), 1);
if( rc==SQLITE_OK ){
AtomicStore(pInfo->aReadMark+i,mxFrame);
mxReadMark = mxFrame;
mxI = i;
walUnlockExclusive(pWal, WAL_READ_LOCK(i), 1);
break;
}else if( rc!=SQLITE_BUSY ){
return rc;
}
}
}
if( mxI==0 ){
assert( rc==SQLITE_BUSY || (pWal->readOnly & WAL_SHM_RDONLY)!=0 );
return rc==SQLITE_BUSY ? WAL_RETRY : SQLITE_READONLY_CANTINIT;
}
(void)walEnableBlockingMs(pWal, nBlockTmout);
rc = walLockShared(pWal, WAL_READ_LOCK(mxI));
walDisableBlocking(pWal);
if( rc ){
#ifdef SQLITE_ENABLE_SETLK_TIMEOUT
if( rc==SQLITE_BUSY_TIMEOUT ){
*pCnt |= WAL_RETRY_BLOCKED_MASK;
}
#else
assert( rc!=SQLITE_BUSY_TIMEOUT );
#endif
assert((rc&0xFF)!=SQLITE_BUSY||rc==SQLITE_BUSY||rc==SQLITE_BUSY_TIMEOUT);
return (rc&0xFF)==SQLITE_BUSY ? WAL_RETRY : rc;
}
/* Now that the read-lock has been obtained, check that neither the
** value in the aReadMark[] array or the contents of the wal-index
** header have changed.
**
** It is necessary to check that the wal-index header did not change
** between the time it was read and when the shared-lock was obtained
** on WAL_READ_LOCK(mxI) was obtained to account for the possibility
** that the log file may have been wrapped by a writer, or that frames
** that occur later in the log than pWal->hdr.mxFrame may have been
** copied into the database by a checkpointer. If either of these things
** happened, then reading the database with the current value of
** pWal->hdr.mxFrame risks reading a corrupted snapshot. So, retry
** instead.
**
** Before checking that the live wal-index header has not changed
** since it was read, set Wal.minFrame to the first frame in the wal
** file that has not yet been checkpointed. This client will not need
** to read any frames earlier than minFrame from the wal file - they
** can be safely read directly from the database file.
**
** Because a ShmBarrier() call is made between taking the copy of
** nBackfill and checking that the wal-header in shared-memory still
** matches the one cached in pWal->hdr, it is guaranteed that the
** checkpointer that set nBackfill was not working with a wal-index
** header newer than that cached in pWal->hdr. If it were, that could
** cause a problem. The checkpointer could omit to checkpoint
** a version of page X that lies before pWal->minFrame (call that version
** A) on the basis that there is a newer version (version B) of the same
** page later in the wal file. But if version B happens to like past
** frame pWal->hdr.mxFrame - then the client would incorrectly assume
** that it can read version A from the database file. However, since
** we can guarantee that the checkpointer that set nBackfill could not
** see any pages past pWal->hdr.mxFrame, this problem does not come up.
*/
pWal->minFrame = AtomicLoad(&pInfo->nBackfill)+1; SEH_INJECT_FAULT;
walShmBarrier(pWal);
if( AtomicLoad(pInfo->aReadMark+mxI)!=mxReadMark
|| memcmp((void *)walIndexHdr(pWal), &pWal->hdr, sizeof(WalIndexHdr))
){
walUnlockShared(pWal, WAL_READ_LOCK(mxI));
return WAL_RETRY;
}else{
assert( mxReadMark<=pWal->hdr.mxFrame );
pWal->readLock = (i16)mxI;
}
}
return rc;
}