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Significant cleanups in SysV IPC handling (shared mem and semaphores).

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IPC key assignment will now work correctly even when multiple postmasters
are using same logical port number (which is possible given -k switch).
There is only one shared-mem segment per postmaster now, not 3.
Rip out broken code for non-TAS case in bufmgr and xlog, substitute a
complete S_LOCK emulation using semaphores in spin.c.  TAS and non-TAS
logic is now exactly the same.
When deadlock is detected, "Deadlock detected" is now the elog(ERROR)
message, rather than a NOTICE that comes out before an unhelpful ERROR.
This commit is contained in:
Tom Lane
2000-11-28 23:27:57 +00:00
parent 914822713c
commit c715fdea26
27 changed files with 1172 additions and 1755 deletions
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103
src/backend/storage/ipc/sinvaladt.c
View File

@@ -8,7 +8,7 @@
*
*
* IDENTIFICATION
* $Header: /cvsroot/pgsql/src/backend/storage/ipc/sinvaladt.c,v 1.35 2000/11/12 20:51:51 tgl Exp $
* $Header: /cvsroot/pgsql/src/backend/storage/ipc/sinvaladt.c,v 1.36 2000/11/28 23:27:56 tgl Exp $
*
*-------------------------------------------------------------------------
*/
@@ -25,95 +25,38 @@
SISeg *shmInvalBuffer;
static void SISegmentAttach(IpcMemoryId shmid);
static void SISegInit(SISeg *segP, int maxBackends);
static void CleanupInvalidationState(int status, Datum arg);
static void SISetProcStateInvalid(SISeg *segP);
/*
* SISegmentInit
* Create a new SI memory segment, or attach to an existing one
*
* This is called with createNewSegment = true by the postmaster (or by
* a standalone backend), and subsequently with createNewSegment = false
* by backends started by the postmaster.
*
* Note: maxBackends param is only valid when createNewSegment is true
* SInvalShmemSize --- return shared-memory space needed
*/
int
SISegmentInit(bool createNewSegment, IPCKey key, int maxBackends)
SInvalShmemSize(int maxBackends)
{
/*
* Figure space needed. Note sizeof(SISeg) includes the first
* ProcState entry.
*/
return sizeof(SISeg) + sizeof(ProcState) * (maxBackends - 1);
}
/*
* SIBufferInit
* Create and initialize a new SI message buffer
*/
void
SIBufferInit(int maxBackends)
{
int segSize;
IpcMemoryId shmId;
if (createNewSegment)
{
/* Kill existing segment, if any */
IpcMemoryKill(key);
/*
* Figure space needed. Note sizeof(SISeg) includes the first
* ProcState entry.
*/
segSize = sizeof(SISeg) + sizeof(ProcState) * (maxBackends - 1);
/* Get a shared segment */
shmId = IpcMemoryCreate(key, segSize, IPCProtection);
if (shmId < 0)
{
perror("SISegmentInit: segment create failed");
return -1; /* an error */
}
/* Attach to the shared cache invalidation segment */
/* sets the global variable shmInvalBuffer */
SISegmentAttach(shmId);
/* Init shared memory contents */
SISegInit(shmInvalBuffer, maxBackends);
}
else
{
/* find existing segment */
shmId = IpcMemoryIdGet(key, 0);
if (shmId < 0)
{
perror("SISegmentInit: segment get failed");
return -1; /* an error */
}
/* Attach to the shared cache invalidation segment */
/* sets the global variable shmInvalBuffer */
SISegmentAttach(shmId);
}
return 1;
}
/*
* SISegmentAttach
* Attach to specified shared memory segment
*/
static void
SISegmentAttach(IpcMemoryId shmid)
{
shmInvalBuffer = (SISeg *) IpcMemoryAttach(shmid);
if (shmInvalBuffer == IpcMemAttachFailed)
{
/* XXX use validity function */
elog(FATAL, "SISegmentAttach: Could not attach segment: %m");
}
}
/*
* SISegInit
* Initialize contents of a new shared memory sinval segment
*/
static void
SISegInit(SISeg *segP, int maxBackends)
{
SISeg *segP;
int i;
/* Allocate space in shared memory */
segSize = SInvalShmemSize(maxBackends);
shmInvalBuffer = segP = (SISeg *) ShmemAlloc(segSize);
/* Clear message counters, save size of procState array */
segP->minMsgNum = 0;
segP->maxMsgNum = 0;