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-rw-r--r--src/backend/utils/activity/backend_status.c88
-rw-r--r--src/backend/utils/adt/lockfuncs.c5
-rw-r--r--src/backend/utils/init/postinit.c55
3 files changed, 51 insertions, 97 deletions
diff --git a/src/backend/utils/activity/backend_status.c b/src/backend/utils/activity/backend_status.c
index 079321599d6..c7ed1e6d7ac 100644
--- a/src/backend/utils/activity/backend_status.c
+++ b/src/backend/utils/activity/backend_status.c
@@ -27,6 +27,18 @@
/* ----------
+ * Total number of backends including auxiliary
+ *
+ * We reserve a slot for each possible BackendId, plus one for each
+ * possible auxiliary process type. (This scheme assumes there is not
+ * more than one of any auxiliary process type at a time.) MaxBackends
+ * includes autovacuum workers and background workers as well.
+ * ----------
+ */
+#define NumBackendStatSlots (MaxBackends + NUM_AUXPROCTYPES)
+
+
+/* ----------
* GUC parameters
* ----------
*/
@@ -63,52 +75,36 @@ static MemoryContext backendStatusSnapContext;
static void pgstat_beshutdown_hook(int code, Datum arg);
static void pgstat_read_current_status(void);
static void pgstat_setup_backend_status_context(void);
-static inline int GetNumBackendStatSlots(void);
/*
- * Retrieve the total number of backends including auxiliary
- *
- * We reserve a slot for each possible BackendId, plus one for each possible
- * auxiliary process type. (This scheme assumes there is not more than one of
- * any auxiliary process type at a time.) MaxBackends includes autovacuum
- * workers and background workers as well.
- */
-static inline int
-GetNumBackendStatSlots(void)
-{
- return GetMaxBackends() + NUM_AUXPROCTYPES;
-}
-
-/*
* Report shared-memory space needed by CreateSharedBackendStatus.
*/
Size
BackendStatusShmemSize(void)
{
Size size;
- int numBackendStatSlots = GetNumBackendStatSlots();
/* BackendStatusArray: */
- size = mul_size(sizeof(PgBackendStatus), numBackendStatSlots);
+ size = mul_size(sizeof(PgBackendStatus), NumBackendStatSlots);
/* BackendAppnameBuffer: */
size = add_size(size,
- mul_size(NAMEDATALEN, numBackendStatSlots));
+ mul_size(NAMEDATALEN, NumBackendStatSlots));
/* BackendClientHostnameBuffer: */
size = add_size(size,
- mul_size(NAMEDATALEN, numBackendStatSlots));
+ mul_size(NAMEDATALEN, NumBackendStatSlots));
/* BackendActivityBuffer: */
size = add_size(size,
- mul_size(pgstat_track_activity_query_size, numBackendStatSlots));
+ mul_size(pgstat_track_activity_query_size, NumBackendStatSlots));
#ifdef USE_SSL
/* BackendSslStatusBuffer: */
size = add_size(size,
- mul_size(sizeof(PgBackendSSLStatus), numBackendStatSlots));
+ mul_size(sizeof(PgBackendSSLStatus), NumBackendStatSlots));
#endif
#ifdef ENABLE_GSS
/* BackendGssStatusBuffer: */
size = add_size(size,
- mul_size(sizeof(PgBackendGSSStatus), numBackendStatSlots));
+ mul_size(sizeof(PgBackendGSSStatus), NumBackendStatSlots));
#endif
return size;
}
@@ -124,10 +120,9 @@ CreateSharedBackendStatus(void)
bool found;
int i;
char *buffer;
- int numBackendStatSlots = GetNumBackendStatSlots();
/* Create or attach to the shared array */
- size = mul_size(sizeof(PgBackendStatus), numBackendStatSlots);
+ size = mul_size(sizeof(PgBackendStatus), NumBackendStatSlots);
BackendStatusArray = (PgBackendStatus *)
ShmemInitStruct("Backend Status Array", size, &found);
@@ -140,7 +135,7 @@ CreateSharedBackendStatus(void)
}
/* Create or attach to the shared appname buffer */
- size = mul_size(NAMEDATALEN, numBackendStatSlots);
+ size = mul_size(NAMEDATALEN, NumBackendStatSlots);
BackendAppnameBuffer = (char *)
ShmemInitStruct("Backend Application Name Buffer", size, &found);
@@ -150,7 +145,7 @@ CreateSharedBackendStatus(void)
/* Initialize st_appname pointers. */
buffer = BackendAppnameBuffer;
- for (i = 0; i < numBackendStatSlots; i++)
+ for (i = 0; i < NumBackendStatSlots; i++)
{
BackendStatusArray[i].st_appname = buffer;
buffer += NAMEDATALEN;
@@ -158,7 +153,7 @@ CreateSharedBackendStatus(void)
}
/* Create or attach to the shared client hostname buffer */
- size = mul_size(NAMEDATALEN, numBackendStatSlots);
+ size = mul_size(NAMEDATALEN, NumBackendStatSlots);
BackendClientHostnameBuffer = (char *)
ShmemInitStruct("Backend Client Host Name Buffer", size, &found);
@@ -168,7 +163,7 @@ CreateSharedBackendStatus(void)
/* Initialize st_clienthostname pointers. */
buffer = BackendClientHostnameBuffer;
- for (i = 0; i < numBackendStatSlots; i++)
+ for (i = 0; i < NumBackendStatSlots; i++)
{
BackendStatusArray[i].st_clienthostname = buffer;
buffer += NAMEDATALEN;
@@ -177,7 +172,7 @@ CreateSharedBackendStatus(void)
/* Create or attach to the shared activity buffer */
BackendActivityBufferSize = mul_size(pgstat_track_activity_query_size,
- numBackendStatSlots);
+ NumBackendStatSlots);
BackendActivityBuffer = (char *)
ShmemInitStruct("Backend Activity Buffer",
BackendActivityBufferSize,
@@ -189,7 +184,7 @@ CreateSharedBackendStatus(void)
/* Initialize st_activity pointers. */
buffer = BackendActivityBuffer;
- for (i = 0; i < numBackendStatSlots; i++)
+ for (i = 0; i < NumBackendStatSlots; i++)
{
BackendStatusArray[i].st_activity_raw = buffer;
buffer += pgstat_track_activity_query_size;
@@ -198,7 +193,7 @@ CreateSharedBackendStatus(void)
#ifdef USE_SSL
/* Create or attach to the shared SSL status buffer */
- size = mul_size(sizeof(PgBackendSSLStatus), numBackendStatSlots);
+ size = mul_size(sizeof(PgBackendSSLStatus), NumBackendStatSlots);
BackendSslStatusBuffer = (PgBackendSSLStatus *)
ShmemInitStruct("Backend SSL Status Buffer", size, &found);
@@ -210,7 +205,7 @@ CreateSharedBackendStatus(void)
/* Initialize st_sslstatus pointers. */
ptr = BackendSslStatusBuffer;
- for (i = 0; i < numBackendStatSlots; i++)
+ for (i = 0; i < NumBackendStatSlots; i++)
{
BackendStatusArray[i].st_sslstatus = ptr;
ptr++;
@@ -220,7 +215,7 @@ CreateSharedBackendStatus(void)
#ifdef ENABLE_GSS
/* Create or attach to the shared GSSAPI status buffer */
- size = mul_size(sizeof(PgBackendGSSStatus), numBackendStatSlots);
+ size = mul_size(sizeof(PgBackendGSSStatus), NumBackendStatSlots);
BackendGssStatusBuffer = (PgBackendGSSStatus *)
ShmemInitStruct("Backend GSS Status Buffer", size, &found);
@@ -232,7 +227,7 @@ CreateSharedBackendStatus(void)
/* Initialize st_gssstatus pointers. */
ptr = BackendGssStatusBuffer;
- for (i = 0; i < numBackendStatSlots; i++)
+ for (i = 0; i < NumBackendStatSlots; i++)
{
BackendStatusArray[i].st_gssstatus = ptr;
ptr++;
@@ -256,7 +251,7 @@ pgstat_beinit(void)
/* Initialize MyBEEntry */
if (MyBackendId != InvalidBackendId)
{
- Assert(MyBackendId >= 1 && MyBackendId <= GetMaxBackends());
+ Assert(MyBackendId >= 1 && MyBackendId <= MaxBackends);
MyBEEntry = &BackendStatusArray[MyBackendId - 1];
}
else
@@ -272,7 +267,7 @@ pgstat_beinit(void)
* MaxBackends + AuxBackendType + 1 as the index of the slot for an
* auxiliary process.
*/
- MyBEEntry = &BackendStatusArray[GetMaxBackends() + MyAuxProcType];
+ MyBEEntry = &BackendStatusArray[MaxBackends + MyAuxProcType];
}
/* Set up a process-exit hook to clean up */
@@ -744,7 +739,6 @@ pgstat_read_current_status(void)
PgBackendGSSStatus *localgssstatus;
#endif
int i;
- int numBackendStatSlots = GetNumBackendStatSlots();
if (localBackendStatusTable)
return; /* already done */
@@ -761,32 +755,32 @@ pgstat_read_current_status(void)
*/
localtable = (LocalPgBackendStatus *)
MemoryContextAlloc(backendStatusSnapContext,
- sizeof(LocalPgBackendStatus) * numBackendStatSlots);
+ sizeof(LocalPgBackendStatus) * NumBackendStatSlots);
localappname = (char *)
MemoryContextAlloc(backendStatusSnapContext,
- NAMEDATALEN * numBackendStatSlots);
+ NAMEDATALEN * NumBackendStatSlots);
localclienthostname = (char *)
MemoryContextAlloc(backendStatusSnapContext,
- NAMEDATALEN * numBackendStatSlots);
+ NAMEDATALEN * NumBackendStatSlots);
localactivity = (char *)
MemoryContextAllocHuge(backendStatusSnapContext,
- pgstat_track_activity_query_size * numBackendStatSlots);
+ pgstat_track_activity_query_size * NumBackendStatSlots);
#ifdef USE_SSL
localsslstatus = (PgBackendSSLStatus *)
MemoryContextAlloc(backendStatusSnapContext,
- sizeof(PgBackendSSLStatus) * numBackendStatSlots);
+ sizeof(PgBackendSSLStatus) * NumBackendStatSlots);
#endif
#ifdef ENABLE_GSS
localgssstatus = (PgBackendGSSStatus *)
MemoryContextAlloc(backendStatusSnapContext,
- sizeof(PgBackendGSSStatus) * numBackendStatSlots);
+ sizeof(PgBackendGSSStatus) * NumBackendStatSlots);
#endif
localNumBackends = 0;
beentry = BackendStatusArray;
localentry = localtable;
- for (i = 1; i <= numBackendStatSlots; i++)
+ for (i = 1; i <= NumBackendStatSlots; i++)
{
/*
* Follow the protocol of retrying if st_changecount changes while we
@@ -899,10 +893,9 @@ pgstat_get_backend_current_activity(int pid, bool checkUser)
{
PgBackendStatus *beentry;
int i;
- int max_backends = GetMaxBackends();
beentry = BackendStatusArray;
- for (i = 1; i <= max_backends; i++)
+ for (i = 1; i <= MaxBackends; i++)
{
/*
* Although we expect the target backend's entry to be stable, that
@@ -978,7 +971,6 @@ pgstat_get_crashed_backend_activity(int pid, char *buffer, int buflen)
{
volatile PgBackendStatus *beentry;
int i;
- int max_backends = GetMaxBackends();
beentry = BackendStatusArray;
@@ -989,7 +981,7 @@ pgstat_get_crashed_backend_activity(int pid, char *buffer, int buflen)
if (beentry == NULL || BackendActivityBuffer == NULL)
return NULL;
- for (i = 1; i <= max_backends; i++)
+ for (i = 1; i <= MaxBackends; i++)
{
if (beentry->st_procpid == pid)
{
diff --git a/src/backend/utils/adt/lockfuncs.c b/src/backend/utils/adt/lockfuncs.c
index 944cd6df03f..023a004ac89 100644
--- a/src/backend/utils/adt/lockfuncs.c
+++ b/src/backend/utils/adt/lockfuncs.c
@@ -559,14 +559,13 @@ pg_safe_snapshot_blocking_pids(PG_FUNCTION_ARGS)
int *blockers;
int num_blockers;
Datum *blocker_datums;
- int max_backends = GetMaxBackends();
/* A buffer big enough for any possible blocker list without truncation */
- blockers = (int *) palloc(max_backends * sizeof(int));
+ blockers = (int *) palloc(MaxBackends * sizeof(int));
/* Collect a snapshot of processes waited for by GetSafeSnapshot */
num_blockers =
- GetSafeSnapshotBlockingPids(blocked_pid, blockers, max_backends);
+ GetSafeSnapshotBlockingPids(blocked_pid, blockers, MaxBackends);
/* Convert int array to Datum array */
if (num_blockers > 0)
diff --git a/src/backend/utils/init/postinit.c b/src/backend/utils/init/postinit.c
index a85c2e0260d..9139fe895c0 100644
--- a/src/backend/utils/init/postinit.c
+++ b/src/backend/utils/init/postinit.c
@@ -25,7 +25,6 @@
#include "access/session.h"
#include "access/sysattr.h"
#include "access/tableam.h"
-#include "access/twophase.h"
#include "access/xact.h"
#include "access/xlog.h"
#include "access/xloginsert.h"
@@ -68,9 +67,6 @@
#include "utils/syscache.h"
#include "utils/timeout.h"
-static int MaxBackends = 0;
-static int MaxBackendsInitialized = false;
-
static HeapTuple GetDatabaseTuple(const char *dbname);
static HeapTuple GetDatabaseTupleByOid(Oid dboid);
static void PerformAuthentication(Port *port);
@@ -542,8 +538,9 @@ pg_split_opts(char **argv, int *argcp, const char *optstr)
/*
* Initialize MaxBackends value from config options.
*
- * This must be called after modules have had the chance to alter GUCs in
- * shared_preload_libraries and before shared memory size is determined.
+ * This must be called after modules have had the chance to register background
+ * workers in shared_preload_libraries, and before shared memory size is
+ * determined.
*
* Note that in EXEC_BACKEND environment, the value is passed down from
* postmaster to subprocesses via BackendParameters in SubPostmasterMain; only
@@ -553,49 +550,15 @@ pg_split_opts(char **argv, int *argcp, const char *optstr)
void
InitializeMaxBackends(void)
{
- /* the extra unit accounts for the autovacuum launcher */
- SetMaxBackends(MaxConnections + autovacuum_max_workers + 1 +
- max_worker_processes + max_wal_senders);
-}
+ Assert(MaxBackends == 0);
-/*
- * Safely retrieve the value of MaxBackends.
- *
- * Previously, MaxBackends was externally visible, but it was often used before
- * it was initialized (e.g., in preloaded libraries' _PG_init() functions).
- * Unfortunately, we cannot initialize MaxBackends before processing
- * shared_preload_libraries because the libraries sometimes alter GUCs that are
- * used to calculate its value. Instead, we provide this function for accessing
- * MaxBackends, and we ERROR if someone calls it before it is initialized.
- */
-int
-GetMaxBackends(void)
-{
- if (unlikely(!MaxBackendsInitialized))
- elog(ERROR, "MaxBackends not yet initialized");
-
- return MaxBackends;
-}
-
-/*
- * Set the value of MaxBackends.
- *
- * This should only be used by InitializeMaxBackends() and
- * restore_backend_variables(). If MaxBackends is already initialized or the
- * specified value is greater than the maximum, this will ERROR.
- */
-void
-SetMaxBackends(int max_backends)
-{
- if (MaxBackendsInitialized)
- elog(ERROR, "MaxBackends already initialized");
+ /* the extra unit accounts for the autovacuum launcher */
+ MaxBackends = MaxConnections + autovacuum_max_workers + 1 +
+ max_worker_processes + max_wal_senders;
/* internal error because the values were all checked previously */
- if (max_backends > MAX_BACKENDS)
+ if (MaxBackends > MAX_BACKENDS)
elog(ERROR, "too many backends configured");
-
- MaxBackends = max_backends;
- MaxBackendsInitialized = true;
}
/*
@@ -707,7 +670,7 @@ InitPostgres(const char *in_dbname, Oid dboid, const char *username,
SharedInvalBackendInit(false);
- if (MyBackendId > GetMaxBackends() || MyBackendId <= 0)
+ if (MyBackendId > MaxBackends || MyBackendId <= 0)
elog(FATAL, "bad backend ID: %d", MyBackendId);
/* Now that we have a BackendId, we can participate in ProcSignal */
generated by cgit v1.2.3 (git 2.25.1) at 2025-08-07 21:01:46 +0000