Re: Clog handling on exec'ed backend

Committed --- I need to make more changes in this area in my next patch.

---------------------------------------------------------------------------

Bruce Momjian wrote:
> Here is a another patch on the way to exec'ed Unix and Win32.
>
> It basically makes one of the Clog data structures into a shared memory
> area when using exec (EXEC_BACKEND is defined). It passes all the
> regression/initdb tests on Unix.
>
> --
> Bruce Momjian | http://candle.pha.pa.us
> pgman(at)candle(dot)pha(dot)pa(dot)us | (610) 359-1001
> + If your life is a hard drive, | 13 Roberts Road
> + Christ can be your backup. | Newtown Square, Pennsylvania 19073

> Index: src/backend/access/transam/clog.c
> ===================================================================
> RCS file: /cvsroot/pgsql-server/src/backend/access/transam/clog.c,v
> retrieving revision 1.14
> diff -c -c -r1.14 clog.c
> *** src/backend/access/transam/clog.c 2 May 2003 21:59:31 -0000 1.14
> --- src/backend/access/transam/clog.c 2 May 2003 22:09:26 -0000
> ***************
> *** 157,163 ****
> * The value is automatically inherited by backends via fork, and
> * doesn't need to be in shared memory.
> */
> ! static LWLockId ClogBufferLocks[NUM_CLOG_BUFFERS]; /* Per-buffer I/O locks */
>
> /*
> * ClogDir is set during CLOGShmemInit and does not change thereafter.
> --- 157,163 ----
> * The value is automatically inherited by backends via fork, and
> * doesn't need to be in shared memory.
> */
> ! static LWLockId *ClogBufferLocks; /* Per-buffer I/O locks */
>
> /*
> * ClogDir is set during CLOGShmemInit and does not change thereafter.
> ***************
> *** 271,311 ****
> /*
> * Initialization of shared memory for CLOG
> */
> -
> int
> CLOGShmemSize(void)
> {
> ! return MAXALIGN(sizeof(ClogCtlData) + CLOG_BLCKSZ * NUM_CLOG_BUFFERS);
> }
>
> void
> CLOGShmemInit(void)
> {
> bool found;
> - char *bufptr;
> int slotno;
>
> /* this must agree with space requested by CLOGShmemSize() */
> ! ClogCtl = (ClogCtlData *)
> ! ShmemInitStruct("CLOG Ctl",
> ! MAXALIGN(sizeof(ClogCtlData) +
> ! CLOG_BLCKSZ * NUM_CLOG_BUFFERS),
> ! &found);
> ! Assert(!found);
>
> ! memset(ClogCtl, 0, sizeof(ClogCtlData));
>
> ! bufptr = ((char *) ClogCtl) + sizeof(ClogCtlData);
>
> ! for (slotno = 0; slotno < NUM_CLOG_BUFFERS; slotno++)
> ! {
> ! ClogCtl->page_buffer[slotno] = bufptr;
> ! ClogCtl->page_status[slotno] = CLOG_PAGE_EMPTY;
> ! ClogBufferLocks[slotno] = LWLockAssign();
> ! bufptr += CLOG_BLCKSZ;
> }
>
> ! /* ClogCtl->latest_page_number will be set later */
>
> /* Init CLOG directory path */
> snprintf(ClogDir, MAXPGPATH, "%s/pg_clog", DataDir);
> --- 271,337 ----
> /*
> * Initialization of shared memory for CLOG
> */
> int
> CLOGShmemSize(void)
> {
> ! return MAXALIGN(sizeof(ClogCtlData) + CLOG_BLCKSZ * NUM_CLOG_BUFFERS)
> ! #ifdef EXEC_BACKEND
> ! + MAXALIGN(NUM_CLOG_BUFFERS * sizeof(LWLockId))
> ! #endif
> ! ;
> }
>
> +
> void
> CLOGShmemInit(void)
> {
> bool found;
> int slotno;
>
> + /* Handle ClogCtl */
> +
> /* this must agree with space requested by CLOGShmemSize() */
> ! ClogCtl = (ClogCtlData *) ShmemInitStruct("CLOG Ctl",
> ! MAXALIGN(sizeof(ClogCtlData) +
> ! CLOG_BLCKSZ * NUM_CLOG_BUFFERS), &found);
> !
> ! if (!IsUnderPostmaster)
> ! /* Initialize ClogCtl shared memory area */
> ! {
> ! char *bufptr;
>
> ! Assert(!found);
>
> ! memset(ClogCtl, 0, sizeof(ClogCtlData));
>
> ! bufptr = (char *)ClogCtl + sizeof(ClogCtlData);
> !
> ! for (slotno = 0; slotno < NUM_CLOG_BUFFERS; slotno++)
> ! {
> ! ClogCtl->page_buffer[slotno] = bufptr;
> ! ClogCtl->page_status[slotno] = CLOG_PAGE_EMPTY;
> ! bufptr += CLOG_BLCKSZ;
> ! }
> !
> ! /* ClogCtl->latest_page_number will be set later */
> }
> + else
> + Assert(found);
>
> ! /* Handle ClogBufferLocks */
> !
> ! #ifdef EXEC_BACKEND
> ! ClogBufferLocks = (LWLockId *) ShmemInitStruct("CLOG Buffer Locks",
> ! NUM_CLOG_BUFFERS * sizeof(LWLockId), &found);
> ! Assert((!found && !IsUnderPostmaster) || (found && IsUnderPostmaster));
> ! #else
> ! ClogBufferLocks = malloc(NUM_CLOG_BUFFERS * sizeof(LWLockId));
> ! Assert(ClogBufferLocks);
> ! #endif
> !
> ! if (!IsUnderPostmaster)
> ! for (slotno = 0; slotno < NUM_CLOG_BUFFERS; slotno++)
> ! ClogBufferLocks[slotno] = LWLockAssign();
>
> /* Init CLOG directory path */
> snprintf(ClogDir, MAXPGPATH, "%s/pg_clog", DataDir);
> Index: src/backend/bootstrap/bootstrap.c
> ===================================================================
> RCS file: /cvsroot/pgsql-server/src/backend/bootstrap/bootstrap.c,v
> retrieving revision 1.150
> diff -c -c -r1.150 bootstrap.c
> *** src/backend/bootstrap/bootstrap.c 2 May 2003 21:59:31 -0000 1.150
> --- src/backend/bootstrap/bootstrap.c 2 May 2003 22:09:28 -0000
> ***************
> *** 301,306 ****
> --- 301,311 ----
>
> Assert(dbName);
>
> + if (IsUnderPostmaster && ExecBackend && MyProc /* ordinary backend */)
> + {
> + AttachSharedMemoryAndSemaphores();
> + }
> +
> if (!IsUnderPostmaster)
> {
> if (!potential_DataDir)
> Index: src/backend/postmaster/postmaster.c
> ===================================================================
> RCS file: /cvsroot/pgsql-server/src/backend/postmaster/postmaster.c,v
> retrieving revision 1.319
> diff -c -c -r1.319 postmaster.c
> *** src/backend/postmaster/postmaster.c 2 May 2003 22:02:47 -0000 1.319
> --- src/backend/postmaster/postmaster.c 2 May 2003 22:09:30 -0000
> ***************
> *** 172,177 ****
> --- 172,184 ----
> static int ServerSock_UNIX = INVALID_SOCK; /* stream socket server */
> #endif
>
> + /* Used to reduce macros tests */
> + #ifdef EXEC_BACKEND
> + const bool ExecBackend = true;
> + #else
> + const bool ExecBackend = false;
> + #endif
> +
> /*
> * Set by the -o option
> */
> ***************
> *** 1407,1413 ****
> elog(DEBUG1, "processCancelRequest: CheckPointPID in cancel request for process %d", backendPID);
> return;
> }
> !
> /* See if we have a matching backend */
>
> for (curr = DLGetHead(BackendList); curr; curr = DLGetSucc(curr))
> --- 1414,1424 ----
> elog(DEBUG1, "processCancelRequest: CheckPointPID in cancel request for process %d", backendPID);
> return;
> }
> ! else if (ExecBackend)
> ! {
> ! AttachSharedMemoryAndSemaphores();
> ! }
> !
> /* See if we have a matching backend */
>
> for (curr = DLGetHead(BackendList); curr; curr = DLGetSucc(curr))
> Index: src/backend/storage/ipc/ipci.c
> ===================================================================
> RCS file: /cvsroot/pgsql-server/src/backend/storage/ipc/ipci.c,v
> retrieving revision 1.51
> diff -c -c -r1.51 ipci.c
> *** src/backend/storage/ipc/ipci.c 2 May 2003 21:59:31 -0000 1.51
> --- src/backend/storage/ipc/ipci.c 2 May 2003 22:09:30 -0000
> ***************
> *** 134,136 ****
> --- 134,149 ----
> */
> PMSignalInit();
> }
> +
> +
> + /*
> + * AttachSharedMemoryAndSemaphores
> + * Attaches to the existing shared resources when exec()'d off
> + * by the postmaster.
> + */
> + void
> + AttachSharedMemoryAndSemaphores(void)
> + {
> + CLOGShmemInit();
> + }
> +
> Index: src/backend/tcop/postgres.c
> ===================================================================
> RCS file: /cvsroot/pgsql-server/src/backend/tcop/postgres.c,v
> retrieving revision 1.329
> diff -c -c -r1.329 postgres.c
> *** src/backend/tcop/postgres.c 2 May 2003 21:59:31 -0000 1.329
> --- src/backend/tcop/postgres.c 2 May 2003 22:09:32 -0000
> ***************
> *** 1453,1458 ****
> --- 1453,1459 ----
> break;
> }
>
> +
> /*
> * -d is not the same as setting
> * log_min_messages because it enables other
> ***************
> *** 1577,1582 ****
> --- 1578,1586 ----
> * restart... */
> }
> BaseInit();
> + #ifdef EXECBACKEND
> + AttachSharedMemoryAndSemaphores();
> + #endif
> }
> else
> {
> Index: src/include/miscadmin.h
> ===================================================================
> RCS file: /cvsroot/pgsql-server/src/include/miscadmin.h,v
> retrieving revision 1.120
> diff -c -c -r1.120 miscadmin.h
> *** src/include/miscadmin.h 2 May 2003 21:59:31 -0000 1.120
> --- src/include/miscadmin.h 2 May 2003 22:09:33 -0000
> ***************
> *** 106,111 ****
> --- 106,112 ----
> */
> extern bool IsUnderPostmaster;
> extern bool ClientAuthInProgress;
> + extern const bool ExecBackend;
>
> extern int PostmasterMain(int argc, char *argv[]);
> extern void ClosePostmasterPorts(bool pgstat_too);
> Index: src/include/storage/ipc.h
> ===================================================================
> RCS file: /cvsroot/pgsql-server/src/include/storage/ipc.h,v
> retrieving revision 1.59
> diff -c -c -r1.59 ipc.h
> *** src/include/storage/ipc.h 2 May 2003 21:59:31 -0000 1.59
> --- src/include/storage/ipc.h 2 May 2003 22:09:33 -0000
> ***************
> *** 32,36 ****
> --- 32,37 ----
> extern void CreateSharedMemoryAndSemaphores(bool makePrivate,
> int maxBackends,
> int port);
> + extern void AttachSharedMemoryAndSemaphores(void);
>
> #endif /* IPC_H */

>
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--
Bruce Momjian | http://candle.pha.pa.us
pgman(at)candle(dot)pha(dot)pa(dot)us | (610) 359-1001
+ If your life is a hard drive, | 13 Roberts Road
+ Christ can be your backup. | Newtown Square, Pennsylvania 19073