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-rw-r--r--src/backend/access/transam/xlog.c82
-rw-r--r--src/backend/storage/buffer/bufmgr.c6
-rw-r--r--src/backend/storage/buffer/s_lock.c52
3 files changed, 69 insertions, 71 deletions
diff --git a/src/backend/access/transam/xlog.c b/src/backend/access/transam/xlog.c
index 7294b97ff34..ff8916cd37b 100644
--- a/src/backend/access/transam/xlog.c
+++ b/src/backend/access/transam/xlog.c
@@ -6,7 +6,7 @@
* Portions Copyright (c) 1996-2000, PostgreSQL, Inc
* Portions Copyright (c) 1994, Regents of the University of California
*
- * $Header: /cvsroot/pgsql/src/backend/access/transam/xlog.c,v 1.45 2000/12/28 13:00:08 vadim Exp $
+ * $Header: /cvsroot/pgsql/src/backend/access/transam/xlog.c,v 1.46 2000/12/29 21:31:21 tgl Exp $
*
*-------------------------------------------------------------------------
*/
@@ -411,7 +411,7 @@ begin:;
}
}
}
- s_lock_sleep(i++);
+ S_LOCK_SLEEP(&(XLogCtl->insert_lck), i++);
if (!TAS(&(XLogCtl->insert_lck)))
break;
}
@@ -599,17 +599,10 @@ begin:;
if (updrqst)
{
- for (;;)
- {
- if (!TAS(&(XLogCtl->info_lck)))
- {
- if (XLByteLT(XLogCtl->LgwrRqst.Write, LgwrRqst.Write))
- XLogCtl->LgwrRqst.Write = LgwrRqst.Write;
- S_UNLOCK(&(XLogCtl->info_lck));
- break;
- }
- s_lock_sleep(i++);
- }
+ S_LOCK(&(XLogCtl->info_lck));
+ if (XLByteLT(XLogCtl->LgwrRqst.Write, LgwrRqst.Write))
+ XLogCtl->LgwrRqst.Write = LgwrRqst.Write;
+ S_UNLOCK(&(XLogCtl->info_lck));
}
END_CRIT_CODE;
@@ -622,7 +615,7 @@ XLogFlush(XLogRecPtr record)
XLogRecPtr WriteRqst;
char buffer[BLCKSZ];
char *usebuf = NULL;
- unsigned i = 0;
+ unsigned spins = 0;
bool force_lgwr = false;
if (XLOG_DEBUG)
@@ -715,7 +708,7 @@ XLogFlush(XLogRecPtr record)
break;
}
}
- s_lock_sleep(i++);
+ S_LOCK_SLEEP(&(XLogCtl->lgwr_lck), spins++);
}
if (logFile >= 0 && (LgwrResult.Write.xlogid != logId ||
@@ -740,18 +733,12 @@ XLogFlush(XLogRecPtr record)
logId, logSeg);
LgwrResult.Flush = LgwrResult.Write;
- for (i = 0;;)
- {
- if (!TAS(&(XLogCtl->info_lck)))
- {
- XLogCtl->LgwrResult = LgwrResult;
- if (XLByteLT(XLogCtl->LgwrRqst.Write, LgwrResult.Write))
- XLogCtl->LgwrRqst.Write = LgwrResult.Write;
- S_UNLOCK(&(XLogCtl->info_lck));
- break;
- }
- s_lock_sleep(i++);
- }
+ S_LOCK(&(XLogCtl->info_lck));
+ XLogCtl->LgwrResult = LgwrResult;
+ if (XLByteLT(XLogCtl->LgwrRqst.Write, LgwrResult.Write))
+ XLogCtl->LgwrRqst.Write = LgwrResult.Write;
+ S_UNLOCK(&(XLogCtl->info_lck));
+
XLogCtl->Write.LgwrResult = LgwrResult;
S_UNLOCK(&(XLogCtl->lgwr_lck));
@@ -767,6 +754,7 @@ GetFreeXLBuffer()
XLogCtlInsert *Insert = &XLogCtl->Insert;
XLogCtlWrite *Write = &XLogCtl->Write;
uint16 curridx = NextBufIdx(Insert->curridx);
+ unsigned spins = 0;
LgwrRqst.Write = XLogCtl->xlblocks[Insert->curridx];
for (;;)
@@ -809,9 +797,8 @@ GetFreeXLBuffer()
InitXLBuffer(curridx);
return;
}
+ S_LOCK_SLEEP(&(XLogCtl->lgwr_lck), spins++);
}
-
- return;
}
static void
@@ -820,7 +807,6 @@ XLogWrite(char *buffer)
XLogCtlWrite *Write = &XLogCtl->Write;
char *from;
uint32 wcnt = 0;
- int i = 0;
bool usexistent;
for (; XLByteLT(LgwrResult.Write, LgwrRqst.Write);)
@@ -919,18 +905,12 @@ XLogWrite(char *buffer)
LgwrResult.Flush = LgwrResult.Write;
}
- for (;;)
- {
- if (!TAS(&(XLogCtl->info_lck)))
- {
- XLogCtl->LgwrResult = LgwrResult;
- if (XLByteLT(XLogCtl->LgwrRqst.Write, LgwrResult.Write))
- XLogCtl->LgwrRqst.Write = LgwrResult.Write;
- S_UNLOCK(&(XLogCtl->info_lck));
- break;
- }
- s_lock_sleep(i++);
- }
+ S_LOCK(&(XLogCtl->info_lck));
+ XLogCtl->LgwrResult = LgwrResult;
+ if (XLByteLT(XLogCtl->LgwrRqst.Write, LgwrResult.Write))
+ XLogCtl->LgwrRqst.Write = LgwrResult.Write;
+ S_UNLOCK(&(XLogCtl->info_lck));
+
Write->LgwrResult = LgwrResult;
}
@@ -2062,18 +2042,17 @@ CreateCheckPoint(bool shutdown)
uint32 _logId;
uint32 _logSeg;
char archdir[MAXPGPATH];
+ unsigned spins = 0;
if (MyLastRecPtr.xrecoff != 0)
elog(ERROR, "CreateCheckPoint: cannot be called inside transaction block");
START_CRIT_CODE;
+
+ /* Grab lock, using larger than normal sleep between tries (1 sec) */
while (TAS(&(XLogCtl->chkp_lck)))
{
- struct timeval delay = {2, 0};
-
- if (shutdown)
- elog(STOP, "Checkpoint lock is busy while data base is shutting down");
- (void) select(0, NULL, NULL, NULL, &delay);
+ S_LOCK_SLEEP_INTERVAL(&(XLogCtl->chkp_lck), spins++, 1000000);
}
memset(&checkPoint, 0, sizeof(checkPoint));
@@ -2087,14 +2066,7 @@ CreateCheckPoint(bool shutdown)
checkPoint.Shutdown = shutdown;
/* Get REDO record ptr */
- while (TAS(&(XLogCtl->insert_lck)))
- {
- struct timeval delay = {1, 0};
-
- if (shutdown)
- elog(STOP, "XLog insert lock is busy while data base is shutting down");
- (void) select(0, NULL, NULL, NULL, &delay);
- }
+ S_LOCK(&(XLogCtl->insert_lck));
freespace = ((char *) Insert->currpage) + BLCKSZ - Insert->currpos;
if (freespace < SizeOfXLogRecord)
{
diff --git a/src/backend/storage/buffer/bufmgr.c b/src/backend/storage/buffer/bufmgr.c
index 2adea99e82c..d97ddfdbff4 100644
--- a/src/backend/storage/buffer/bufmgr.c
+++ b/src/backend/storage/buffer/bufmgr.c
@@ -8,7 +8,7 @@
*
*
* IDENTIFICATION
- * $Header: /cvsroot/pgsql/src/backend/storage/buffer/bufmgr.c,v 1.100 2000/12/28 13:00:21 vadim Exp $
+ * $Header: /cvsroot/pgsql/src/backend/storage/buffer/bufmgr.c,v 1.101 2000/12/29 21:31:21 tgl Exp $
*
*-------------------------------------------------------------------------
*/
@@ -1987,7 +1987,7 @@ LockBuffer(Buffer buffer, int mode)
while (buf->ri_lock || buf->w_lock)
{
S_UNLOCK(&(buf->cntx_lock));
- s_lock_sleep(i++);
+ S_LOCK_SLEEP(&(buf->cntx_lock), i++);
S_LOCK(&(buf->cntx_lock));
}
(buf->r_locks)++;
@@ -2013,7 +2013,7 @@ LockBuffer(Buffer buffer, int mode)
buf->ri_lock = true;
}
S_UNLOCK(&(buf->cntx_lock));
- s_lock_sleep(i++);
+ S_LOCK_SLEEP(&(buf->cntx_lock), i++);
S_LOCK(&(buf->cntx_lock));
}
buf->w_lock = true;
diff --git a/src/backend/storage/buffer/s_lock.c b/src/backend/storage/buffer/s_lock.c
index 7f658ad26a8..932e5b0049b 100644
--- a/src/backend/storage/buffer/s_lock.c
+++ b/src/backend/storage/buffer/s_lock.c
@@ -8,7 +8,7 @@
*
*
* IDENTIFICATION
- * $Header: /cvsroot/pgsql/src/backend/storage/buffer/Attic/s_lock.c,v 1.27 2000/12/11 00:49:51 tgl Exp $
+ * $Header: /cvsroot/pgsql/src/backend/storage/buffer/Attic/s_lock.c,v 1.28 2000/12/29 21:31:20 tgl Exp $
*
*-------------------------------------------------------------------------
*/
@@ -25,19 +25,21 @@
* number of microseconds to wait. This accomplishes pseudo random back-off.
* Values are not critical but 10 milliseconds is a common platform
* granularity.
- * note: total time to cycle through all 16 entries might be about .07 sec.
+ *
+ * Total time to cycle through all 20 entries might be about .07 sec,
+ * so the given value of S_MAX_BUSY results in timeout after ~70 sec.
*/
#define S_NSPINCYCLE 20
#define S_MAX_BUSY 1000 * S_NSPINCYCLE
int s_spincycle[S_NSPINCYCLE] =
-{0, 0, 0, 0, 10000, 0, 0, 0, 10000, 0,
+{ 0, 0, 0, 0, 10000, 0, 0, 0, 10000, 0,
0, 10000, 0, 0, 10000, 0, 10000, 0, 10000, 10000
};
/*
- * s_lock_stuck(lock) - complain about a stuck spinlock
+ * s_lock_stuck() - complain about a stuck spinlock
*/
static void
s_lock_stuck(volatile slock_t *lock, const char *file, const int line)
@@ -52,13 +54,38 @@ s_lock_stuck(volatile slock_t *lock, const char *file, const int line)
}
+/*
+ * s_lock_sleep() - sleep a pseudo-random amount of time, check for timeout
+ *
+ * Normally 'microsec' is 0, specifying to use the next s_spincycle[] value.
+ * Some callers may pass a nonzero interval, specifying to use exactly that
+ * delay value rather than a pseudo-random delay.
+ */
void
-s_lock_sleep(unsigned spin)
+s_lock_sleep(unsigned spins, int microsec,
+ volatile slock_t *lock,
+ const char *file, const int line)
{
struct timeval delay;
+ unsigned max_spins;
+
+ if (microsec > 0)
+ {
+ delay.tv_sec = 0;
+ delay.tv_usec = microsec;
+ /* two-minute timeout in this case */
+ max_spins = 120000000 / microsec;
+ }
+ else
+ {
+ delay.tv_sec = 0;
+ delay.tv_usec = s_spincycle[spins % S_NSPINCYCLE];
+ max_spins = S_MAX_BUSY;
+ }
+
+ if (spins > max_spins)
+ s_lock_stuck(lock, file, line);
- delay.tv_sec = 0;
- delay.tv_usec = s_spincycle[spin % S_NSPINCYCLE];
(void) select(0, NULL, NULL, NULL, &delay);
}
@@ -71,14 +98,13 @@ s_lock(volatile slock_t *lock, const char *file, const int line)
{
unsigned spins = 0;
+ /*
+ * If you are thinking of changing this code, be careful. This same
+ * loop logic is used in other places that call TAS() directly.
+ */
while (TAS(lock))
{
- s_lock_sleep(spins);
- if (++spins > S_MAX_BUSY)
- {
- /* It's been over a minute... */
- s_lock_stuck(lock, file, line);
- }
+ s_lock_sleep(spins++, 0, lock, file, line);
}
}
generated by cgit v1.2.3 (git 2.25.1) at 2025-08-03 01:47:59 +0000