#include "postgres.h"
#include "access/clog.h"
#include "access/commit_ts.h"
#include "access/heapam.h"
#include "access/multixact.h"
#include "access/nbtree.h"
#include "access/subtrans.h"
#include "access/syncscan.h"
#include "access/twophase.h"
#include "access/xlogprefetcher.h"
#include "access/xlogrecovery.h"
#include "commands/async.h"
#include "miscadmin.h"
#include "pgstat.h"
#include "postmaster/autovacuum.h"
#include "postmaster/bgworker_internals.h"
#include "postmaster/bgwriter.h"
#include "postmaster/postmaster.h"
#include "replication/logicallauncher.h"
#include "replication/origin.h"
#include "replication/slot.h"
#include "replication/walreceiver.h"
#include "replication/walsender.h"
#include "storage/bufmgr.h"
#include "storage/dsm.h"
#include "storage/ipc.h"
#include "storage/pg_shmem.h"
#include "storage/pmsignal.h"
#include "storage/predicate.h"
#include "storage/proc.h"
#include "storage/procarray.h"
#include "storage/procsignal.h"
#include "storage/sinvaladt.h"
#include "storage/spin.h"
#include "utils/guc.h"
#include "utils/snapmgr.h"
#include "utils/wait_event.h"

Include dependency graph for ipci.c:

Functions
void	RequestAddinShmemSpace (Size size)

Size	CalculateShmemSize (int *num_semaphores)

void	CreateSharedMemoryAndSemaphores (void)

void	InitializeShmemGUCs (void)

Variables
int	shared_memory_type = DEFAULT_SHARED_MEMORY_TYPE

shmem_startup_hook_type	shmem_startup_hook = NULL

static Size	total_addin_request = 0

Function Documentation

◆ CalculateShmemSize()

Size CalculateShmemSize ( int * num_semaphores )

Definition at line 86 of file ipci.c.

 {
     Size        size;
     int         numSemas;
  
     /* Compute number of semaphores we'll need */
     numSemas = ProcGlobalSemas();
     numSemas += SpinlockSemas();
  
     /* Return the number of semaphores if requested by the caller */
     if (num_semaphores)
         *num_semaphores = numSemas;
  
     /*
      * Size of the Postgres shared-memory block is estimated via moderately-
      * accurate estimates for the big hogs, plus 100K for the stuff that's too
      * small to bother with estimating.
      *
      * We take some care to ensure that the total size request doesn't
      * overflow size_t.  If this gets through, we don't need to be so careful
      * during the actual allocation phase.
      */
     size = 100000;
     size = add_size(size, PGSemaphoreShmemSize(numSemas));
     size = add_size(size, SpinlockSemaSize());
     size = add_size(size, hash_estimate_size(SHMEM_INDEX_SIZE,
                                              sizeof(ShmemIndexEnt)));
     size = add_size(size, dsm_estimate_size());
     size = add_size(size, BufferShmemSize());
     size = add_size(size, LockShmemSize());
     size = add_size(size, PredicateLockShmemSize());
     size = add_size(size, ProcGlobalShmemSize());
     size = add_size(size, XLogPrefetchShmemSize());
     size = add_size(size, XLOGShmemSize());
     size = add_size(size, XLogRecoveryShmemSize());
     size = add_size(size, CLOGShmemSize());
     size = add_size(size, CommitTsShmemSize());
     size = add_size(size, SUBTRANSShmemSize());
     size = add_size(size, TwoPhaseShmemSize());
     size = add_size(size, BackgroundWorkerShmemSize());
     size = add_size(size, MultiXactShmemSize());
     size = add_size(size, LWLockShmemSize());
     size = add_size(size, ProcArrayShmemSize());
     size = add_size(size, BackendStatusShmemSize());
     size = add_size(size, SInvalShmemSize());
     size = add_size(size, PMSignalShmemSize());
     size = add_size(size, ProcSignalShmemSize());
     size = add_size(size, CheckpointerShmemSize());
     size = add_size(size, AutoVacuumShmemSize());
     size = add_size(size, ReplicationSlotsShmemSize());
     size = add_size(size, ReplicationOriginShmemSize());
     size = add_size(size, WalSndShmemSize());
     size = add_size(size, WalRcvShmemSize());
     size = add_size(size, PgArchShmemSize());
     size = add_size(size, ApplyLauncherShmemSize());
     size = add_size(size, BTreeShmemSize());
     size = add_size(size, SyncScanShmemSize());
     size = add_size(size, AsyncShmemSize());
     size = add_size(size, StatsShmemSize());
     size = add_size(size, WaitEventExtensionShmemSize());
 #ifdef EXEC_BACKEND
     size = add_size(size, ShmemBackendArraySize());
 #endif
  
     /* include additional requested shmem from preload libraries */
     size = add_size(size, total_addin_request);
  
     /* might as well round it off to a multiple of a typical page size */
     size = add_size(size, 8192 - (size % 8192));
  
     return size;
 }

References add_size(), ApplyLauncherShmemSize(), AsyncShmemSize(), AutoVacuumShmemSize(), BackendStatusShmemSize(), BackgroundWorkerShmemSize(), BTreeShmemSize(), BufferShmemSize(), CheckpointerShmemSize(), CLOGShmemSize(), CommitTsShmemSize(), dsm_estimate_size(), hash_estimate_size(), LockShmemSize(), LWLockShmemSize(), MultiXactShmemSize(), PgArchShmemSize(), PGSemaphoreShmemSize(), PMSignalShmemSize(), PredicateLockShmemSize(), ProcArrayShmemSize(), ProcGlobalSemas(), ProcGlobalShmemSize(), ProcSignalShmemSize(), ReplicationOriginShmemSize(), ReplicationSlotsShmemSize(), SHMEM_INDEX_SIZE, SInvalShmemSize(), SpinlockSemas(), SpinlockSemaSize(), StatsShmemSize(), SUBTRANSShmemSize(), SyncScanShmemSize(), total_addin_request, TwoPhaseShmemSize(), WaitEventExtensionShmemSize(), WalRcvShmemSize(), WalSndShmemSize(), XLogPrefetchShmemSize(), XLogRecoveryShmemSize(), and XLOGShmemSize().

Referenced by CreateSharedMemoryAndSemaphores(), and InitializeShmemGUCs().

◆ CreateSharedMemoryAndSemaphores()

void CreateSharedMemoryAndSemaphores ( void )

Definition at line 175 of file ipci.c.

 {
     PGShmemHeader *shim = NULL;
  
     if (!IsUnderPostmaster)
     {
         PGShmemHeader *seghdr;
         Size        size;
         int         numSemas;
  
         /* Compute the size of the shared-memory block */
         size = CalculateShmemSize(&numSemas);
         elog(DEBUG3, "invoking IpcMemoryCreate(size=%zu)", size);
  
         /*
          * Create the shmem segment
          */
         seghdr = PGSharedMemoryCreate(size, &shim);
  
         /*
          * Make sure that huge pages are never reported as "unknown" while the
          * server is running.
          */
         Assert(strcmp("unknown",
                       GetConfigOption("huge_pages_status", false, false)) != 0);
  
         InitShmemAccess(seghdr);
  
         /*
          * Create semaphores
          */
         PGReserveSemaphores(numSemas);
  
         /*
          * If spinlocks are disabled, initialize emulation layer (which
          * depends on semaphores, so the order is important here).
          */
 #ifndef HAVE_SPINLOCKS
         SpinlockSemaInit();
 #endif
     }
     else
     {
         /*
          * We are reattaching to an existing shared memory segment. This
          * should only be reached in the EXEC_BACKEND case.
          */
 #ifndef EXEC_BACKEND
         elog(PANIC, "should be attached to shared memory already");
 #endif
     }
  
     /*
      * Set up shared memory allocation mechanism
      */
     if (!IsUnderPostmaster)
         InitShmemAllocation();
  
     /*
      * Now initialize LWLocks, which do shared memory allocation and are
      * needed for InitShmemIndex.
      */
     CreateLWLocks();
  
     /*
      * Set up shmem.c index hashtable
      */
     InitShmemIndex();
  
     dsm_shmem_init();
  
     /*
      * Set up xlog, clog, and buffers
      */
     XLOGShmemInit();
     XLogPrefetchShmemInit();
     XLogRecoveryShmemInit();
     CLOGShmemInit();
     CommitTsShmemInit();
     SUBTRANSShmemInit();
     MultiXactShmemInit();
     InitBufferPool();
  
     /*
      * Set up lock manager
      */
     InitLocks();
  
     /*
      * Set up predicate lock manager
      */
     InitPredicateLocks();
  
     /*
      * Set up process table
      */
     if (!IsUnderPostmaster)
         InitProcGlobal();
     CreateSharedProcArray();
     CreateSharedBackendStatus();
     TwoPhaseShmemInit();
     BackgroundWorkerShmemInit();
  
     /*
      * Set up shared-inval messaging
      */
     CreateSharedInvalidationState();
  
     /*
      * Set up interprocess signaling mechanisms
      */
     PMSignalShmemInit();
     ProcSignalShmemInit();
     CheckpointerShmemInit();
     AutoVacuumShmemInit();
     ReplicationSlotsShmemInit();
     ReplicationOriginShmemInit();
     WalSndShmemInit();
     WalRcvShmemInit();
     PgArchShmemInit();
     ApplyLauncherShmemInit();
  
     /*
      * Set up other modules that need some shared memory space
      */
     BTreeShmemInit();
     SyncScanShmemInit();
     AsyncShmemInit();
     StatsShmemInit();
     WaitEventExtensionShmemInit();
  
 #ifdef EXEC_BACKEND
  
     /*
      * Alloc the win32 shared backend array
      */
     if (!IsUnderPostmaster)
         ShmemBackendArrayAllocation();
 #endif
  
     /* Initialize dynamic shared memory facilities. */
     if (!IsUnderPostmaster)
         dsm_postmaster_startup(shim);
  
     /*
      * Now give loadable modules a chance to set up their shmem allocations
      */
     if (shmem_startup_hook)
         shmem_startup_hook();
 }

References ApplyLauncherShmemInit(), Assert(), AsyncShmemInit(), AutoVacuumShmemInit(), BackgroundWorkerShmemInit(), BTreeShmemInit(), CalculateShmemSize(), CheckpointerShmemInit(), CLOGShmemInit(), CommitTsShmemInit(), CreateLWLocks(), CreateSharedBackendStatus(), CreateSharedInvalidationState(), CreateSharedProcArray(), DEBUG3, dsm_postmaster_startup(), dsm_shmem_init(), elog(), GetConfigOption(), InitBufferPool(), InitLocks(), InitPredicateLocks(), InitProcGlobal(), InitShmemAccess(), InitShmemAllocation(), InitShmemIndex(), IsUnderPostmaster, MultiXactShmemInit(), PANIC, PgArchShmemInit(), PGReserveSemaphores(), PGSharedMemoryCreate(), PMSignalShmemInit(), ProcSignalShmemInit(), ReplicationOriginShmemInit(), ReplicationSlotsShmemInit(), shmem_startup_hook, SpinlockSemaInit(), StatsShmemInit(), SUBTRANSShmemInit(), SyncScanShmemInit(), TwoPhaseShmemInit(), WaitEventExtensionShmemInit(), WalRcvShmemInit(), WalSndShmemInit(), XLogPrefetchShmemInit(), XLogRecoveryShmemInit(), and XLOGShmemInit().

Referenced by BootstrapModeMain(), PostgresSingleUserMain(), PostmasterMain(), and PostmasterStateMachine().

◆ InitializeShmemGUCs()

void InitializeShmemGUCs ( void )

Definition at line 333 of file ipci.c.

 {
     char        buf[64];
     Size        size_b;
     Size        size_mb;
     Size        hp_size;
  
     /*
      * Calculate the shared memory size and round up to the nearest megabyte.
      */
     size_b = CalculateShmemSize(NULL);
     size_mb = add_size(size_b, (1024 * 1024) - 1) / (1024 * 1024);
     sprintf(buf, "%zu", size_mb);
     SetConfigOption("shared_memory_size", buf,
                     PGC_INTERNAL, PGC_S_DYNAMIC_DEFAULT);
  
     /*
      * Calculate the number of huge pages required.
      */
     GetHugePageSize(&hp_size, NULL);
     if (hp_size != 0)
     {
         Size        hp_required;
  
         hp_required = add_size(size_b / hp_size, 1);
         sprintf(buf, "%zu", hp_required);
         SetConfigOption("shared_memory_size_in_huge_pages", buf,
                         PGC_INTERNAL, PGC_S_DYNAMIC_DEFAULT);
     }
 }

References add_size(), buf, CalculateShmemSize(), GetHugePageSize(), PGC_INTERNAL, PGC_S_DYNAMIC_DEFAULT, SetConfigOption(), and sprintf.

Referenced by PostgresSingleUserMain(), and PostmasterMain().

◆ RequestAddinShmemSpace()

void RequestAddinShmemSpace ( Size size )

Definition at line 71 of file ipci.c.

 {
     if (!process_shmem_requests_in_progress)
         elog(FATAL, "cannot request additional shared memory outside shmem_request_hook");
     total_addin_request = add_size(total_addin_request, size);
 }