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Keep track of the last active slot in the shared ProcState array, so

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that search loops only have to scan that far and not through all maxBackends
entries.  This eliminates a performance penalty for setting maxBackends
much higher than the average number of active backends.  Also, eliminate
no-longer-used 'backend tag' concept.  Remove setting of environment
variables at backend start (except for CYR_RECODE), since none of them
are being examined by the backend any longer.
This commit is contained in:
Tom Lane
2000-11-12 20:51:52 +00:00
parent c48025e799
commit ebb0a20149
10 changed files with 153 additions and 235 deletions
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88
src/backend/utils/init/postinit.c
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@ -8,7 +8,7 @@
*
*
* IDENTIFICATION
* $Header: /cvsroot/pgsql/src/backend/utils/init/postinit.c,v 1.69 2000/10/28 16:20:58 vadim Exp $
* $Header: /cvsroot/pgsql/src/backend/utils/init/postinit.c,v 1.70 2000/11/12 20:51:52 tgl Exp $
*
*
*-------------------------------------------------------------------------
@ -138,75 +138,37 @@ ReverifyMyDatabase(const char *name)
*
* This routine initializes stuff needed for ipc, locking, etc.
* it should be called something more informative.
*
* Note:
* This does not set MyBackendId. MyBackendTag is set, however.
* --------------------------------
*/
static void
InitCommunication()
{
char *postid; /* value of environment variable */
char *postport; /* value of environment variable */
char *ipc_key; /* value of environemnt variable */
IPCKey key = 0;
/* ----------------
* try and get the backend tag from POSTID
* ----------------
*/
MyBackendId = -1;
postid = getenv("POSTID");
if (!PointerIsValid(postid))
MyBackendTag = -1;
else
{
MyBackendTag = atoi(postid);
Assert(MyBackendTag >= 0);
}
ipc_key = getenv("IPC_KEY");
if (!PointerIsValid(ipc_key))
key = -1;
else
{
key = atoi(ipc_key);
Assert(MyBackendTag >= 0);
}
postport = getenv("POSTPORT");
if (PointerIsValid(postport))
{
if (MyBackendTag == -1)
elog(FATAL, "InitCommunication: missing POSTID");
}
else if (IsUnderPostmaster)
{
elog(FATAL,
"InitCommunication: under postmaster and POSTPORT not set");
}
else
{
/* ----------------
* assume we're running a postgres backend by itself with
* no front end or postmaster.
* ----------------
*/
if (MyBackendTag == -1)
MyBackendTag = 1;
key = PrivateIPCKey;
}
/* ----------------
* initialize shared memory and semaphores appropriately.
* ----------------
*/
if (!IsUnderPostmaster) /* postmaster already did this */
{
/* ----------------
* we're running a postgres backend by itself with
* no front end or postmaster.
* ----------------
*/
char *ipc_key; /* value of environment variable */
IPCKey key;
ipc_key = getenv("IPC_KEY");
if (!PointerIsValid(ipc_key))
{
/* Normal standalone backend */
key = PrivateIPCKey;
}
else
{
/* Allow standalone's IPC key to be set */
key = atoi(ipc_key);
}
PostgresIpcKey = key;
AttachSharedMemoryAndSemaphores(key);
}
@ -343,14 +305,12 @@ InitPostgres(const char *dbname, const char *username)
*
* Sets up MyBackendId, a unique backend identifier.
*/
MyBackendId = InvalidBackendId;
InitSharedInvalidationState();
if (MyBackendId > MAXBACKENDS || MyBackendId <= 0)
{
elog(FATAL, "cinit2: bad backend id %d (%d)",
MyBackendTag,
MyBackendId);
}
elog(FATAL, "cinit2: bad backend id %d", MyBackendId);
/*
* Initialize the access methods. Does not touch files (?) - thomas