/*
* CreateSharedMemoryAndSemaphores
* Creates and initializes shared memory and semaphores.
*
* This is called by the postmaster or by a standalone backend.
* It is also called by a backend forked from the postmaster in the
* EXEC_BACKEND case. In the latter case, the shared memory segment
* already exists and has been physically attached to, but we have to
* initialize pointers in local memory that reference the shared structures,
* because we didn't inherit the correct pointer values from the postmaster
* as we do in the fork() scenario. The easiest way to do that is to run
* through the same code as before. (Note that the called routines mostly
* check IsUnderPostmaster, rather than EXEC_BACKEND, to detect this case.
* This is a bit code-wasteful and could be cleaned up.)
*
* If "makePrivate" is true then we only need private memory, not shared
* memory. This is true for a standalone backend, false for a postmaster.
*/
void
CreateSharedMemoryAndSemaphores(bool makePrivate, int port)
{
if (!IsUnderPostmaster)
{
PGShmemHeader *seghdr;
Size size;
int 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 during this phase 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, SpinlockSemaSize());
size = add_size(size, hash_estimate_size(SHMEM_INDEX_SIZE,
sizeof(ShmemIndexEnt)));
size = add_size(size, BufferShmemSize());
size = add_size(size, LockShmemSize());
size = add_size(size, PredicateLockShmemSize());
size = add_size(size, ProcGlobalShmemSize());
size = add_size(size, XLOGShmemSize());
size = add_size(size, CLOGShmemSize());
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, WalSndShmemSize());
size = add_size(size, WalRcvShmemSize());
size = add_size(size, BTreeShmemSize());
size = add_size(size, SyncScanShmemSize());
size = add_size(size, AsyncShmemSize());
#ifdef EXEC_BACKEND
size = add_size(size, ShmemBackendArraySize());
#endif
/* freeze the addin request size and include it */
addin_request_allowed = false;
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));
elog(DEBUG3, "invoking IpcMemoryCreate(size=%zu)", size);
/*
* Create the shmem segment
*/
seghdr = PGSharedMemoryCreate(size, makePrivate, port);
InitShmemAccess(seghdr);
/*
* Create semaphores
*/
numSemas = ProcGlobalSemas();
numSemas += SpinlockSemas();
PGReserveSemaphores(numSemas, port);
}
else
{
/*
* We are reattaching to an existing shared memory segment. This
* should only be reached in the EXEC_BACKEND case, and even then only
* with makePrivate == false.
*/
#ifdef EXEC_BACKEND
Assert(!makePrivate);
#else
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();
/*
* Set up xlog, clog, and buffers
*/
XLOGShmemInit();
CLOGShmemInit();
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();
WalSndShmemInit();
WalRcvShmemInit();
/*
* Set up other modules that need some shared memory space
*/
BTreeShmemInit();
SyncScanShmemInit();
AsyncShmemInit();
#ifdef EXEC_BACKEND
/*
* Alloc the win32 shared backend array
*/
if (!IsUnderPostmaster)
ShmemBackendArrayAllocation();
#endif
/* Initialize dynamic shared memory facilities. */
if (!IsUnderPostmaster)
dsm_postmaster_startup();
/*
* Now give loadable modules a chance to set up their shmem allocations
*/
if (shmem_startup_hook)
shmem_startup_hook();
}
int
main(int argc, char **argv)
{
MyStorage *storage;
int cpid;
printf("Creating shared memory ... ");
fflush(stdout);
storage = (MyStorage *) PGSharedMemoryCreate(8192, false, 5433);
storage->flag = 1234;
printf("OK\n");
printf("Creating semaphores ... ");
fflush(stdout);
PGReserveSemaphores(2, 5433);
PGSemaphoreCreate(&storage->sem);
printf("OK\n");
/* sema initial value is 1, so lock should work */
printf("Testing Lock ... ");
fflush(stdout);
PGSemaphoreLock(&storage->sem, false);
printf("OK\n");
/* now sema value is 0, so trylock should fail */
printf("Testing TryLock ... ");
fflush(stdout);
if (PGSemaphoreTryLock(&storage->sem))
printf("unexpected result!\n");
else
printf("OK\n");
/* unlocking twice and then locking twice should work... */
printf("Testing Multiple Lock ... ");
fflush(stdout);
PGSemaphoreUnlock(&storage->sem);
PGSemaphoreUnlock(&storage->sem);
PGSemaphoreLock(&storage->sem, false);
PGSemaphoreLock(&storage->sem, false);
printf("OK\n");
/* check Reset too */
printf("Testing Reset ... ");
fflush(stdout);
PGSemaphoreUnlock(&storage->sem);
PGSemaphoreReset(&storage->sem);
if (PGSemaphoreTryLock(&storage->sem))
printf("unexpected result!\n");
else
printf("OK\n");
/* Fork a child process and see if it can communicate */
printf("Forking child process ... ");
fflush(stdout);
cpid = fork();
if (cpid == 0)
{
/* In child */
on_exit_reset();
sleep(3);
storage->flag++;
PGSemaphoreUnlock(&storage->sem);
proc_exit(0);
}
if (cpid < 0)
{
/* Fork failed */
printf("failed: %s\n", strerror(errno));
proc_exit(1);
}
printf("forked child pid %d OK\n", cpid);
if (storage->flag != 1234)
printf("Wrong value found in shared memory!\n");
printf("Waiting for child (should wait 3 sec here) ... ");
fflush(stdout);
PGSemaphoreLock(&storage->sem, false);
printf("OK\n");
if (storage->flag != 1235)
printf("Wrong value found in shared memory!\n");
/* Test shutdown */
printf("Running shmem_exit processing ... ");
fflush(stdout);
shmem_exit(0);
printf("OK\n");
printf("Tests complete.\n");
proc_exit(0);
return 0; /* not reached */
}
/*
* CreateSharedMemoryAndSemaphores
* Creates and initializes shared memory and semaphores.
*
* This is called by the postmaster or by a standalone backend.
* It is also called by a backend forked from the postmaster in the
* EXEC_BACKEND case. In the latter case, the shared memory segment
* already exists and has been physically attached to, but we have to
* initialize pointers in local memory that reference the shared structures,
* because we didn't inherit the correct pointer values from the postmaster
* as we do in the fork() scenario. The easiest way to do that is to run
* through the same code as before. (Note that the called routines mostly
* check IsUnderPostmaster, rather than EXEC_BACKEND, to detect this case.
* This is a bit code-wasteful and could be cleaned up.)
*
* If "makePrivate" is true then we only need private memory, not shared
* memory. This is true for a standalone backend, false for a postmaster.
*/
void
CreateSharedMemoryAndSemaphores(bool makePrivate, int port)
{
if (!IsUnderPostmaster)
{
PGShmemHeader *seghdr;
Size size;
int 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 during this phase 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 = 150000;
size = add_size(size, hash_estimate_size(SHMEM_INDEX_SIZE,
sizeof(ShmemIndexEnt)));
size = add_size(size, BufferShmemSize());
size = add_size(size, LockShmemSize());
size = add_size(size, workfile_mgr_shmem_size());
if (Gp_role == GP_ROLE_DISPATCH)
{
size = add_size(size, AppendOnlyWriterShmemSize());
if(ResourceScheduler)
{
size = add_size(size, ResSchedulerShmemSize());
size = add_size(size, ResPortalIncrementShmemSize());
}
}
size = add_size(size, ProcGlobalShmemSize());
size = add_size(size, XLOGShmemSize());
size = add_size(size, DistributedLog_ShmemSize());
size = add_size(size, CLOGShmemSize());
size = add_size(size, ChangeTrackingShmemSize());
size = add_size(size, SUBTRANSShmemSize());
size = add_size(size, TwoPhaseShmemSize());
size = add_size(size, MultiXactShmemSize());
size = add_size(size, LWLockShmemSize());
size = add_size(size, ProcArrayShmemSize());
size = add_size(size, BackendStatusShmemSize());
size = add_size(size, SharedSnapshotShmemSize());
size = add_size(size, SInvalShmemSize());
size = add_size(size, PMSignalShmemSize());
size = add_size(size, ProcSignalShmemSize());
size = add_size(size, primaryMirrorModeShmemSize());
size = add_size(size, FreeSpaceShmemSize());
//size = add_size(size, AutoVacuumShmemSize());
size = add_size(size, FtsShmemSize());
size = add_size(size, tmShmemSize());
size = add_size(size, SeqServerShmemSize());
size = add_size(size, PersistentFileSysObj_ShmemSize());
size = add_size(size, PersistentFilespace_ShmemSize());
size = add_size(size, PersistentTablespace_ShmemSize());
size = add_size(size, PersistentDatabase_ShmemSize());
size = add_size(size, PersistentRelation_ShmemSize());
size = add_size(size, Pass2Recovery_ShmemSize());
/*Add shared memory for PT verification checks*/
if (Gp_role == GP_ROLE_DISPATCH && debug_persistent_ptcat_verification)
{
size = add_size(size, Persistent_PostDTMRecv_ShmemSize());
}
if (GPAreFileReplicationStructuresRequired()) {
size = add_size(size, FileRep_SubProcShmemSize());
size = add_size(size, FileRep_ShmemSize());
size = add_size(size, FileRepAck_ShmemSize());
size = add_size(size, FileRepAckPrimary_ShmemSize());
size = add_size(size, FileRepResync_ShmemSize());
size = add_size(size, FileRepIpc_ShmemSize());
size = add_size(size, FileRepLog_ShmemSize());
size = add_size(size, FileRepStats_ShmemSize());
}
#ifdef FAULT_INJECTOR
size = add_size(size, FaultInjector_ShmemSize());
#endif
#ifdef EXEC_BACKEND
size = add_size(size, ShmemBackendArraySize());
#endif
#ifdef USE_TEST_UTILS
if (gp_simex_init)
{
// initialize SimEx
simex_init();
size = add_size(size, SyncBitVector_ShmemSize(simex_get_subclass_count()));
}
#endif
/* This elog happens before we know the name of the log file we are supposed to use */
elog(DEBUG1, "Size not including the buffer pool %lu",
(unsigned long) size);
size = add_size(size, BgWriterShmemSize());
size = add_size(size, AutoVacuumShmemSize());
size = add_size(size, BTreeShmemSize());
size = add_size(size, SyncScanShmemSize());
size = add_size(size, CheckpointShmemSize());
size = add_size(size, WalSndShmemSize());
size = add_size(size, WalRcvShmemSize());
/* freeze the addin request size and include it */
addin_request_allowed = false;
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, BLCKSZ - (size % BLCKSZ));
/* Consider the size of the SessionState array */
size = add_size(size, SessionState_ShmemSize());
/*
* Create the shmem segment
*/
seghdr = PGSharedMemoryCreate(size, makePrivate, port);
InitShmemAccess(seghdr);
/*
* Create semaphores
*/
numSemas = ProcGlobalSemas();
numSemas += SpinlockSemas();
if (GPAreFileReplicationStructuresRequired())
{
numSemas += FileRepSemas();
}
elog(DEBUG3,"reserving %d semaphores",numSemas);
PGReserveSemaphores(numSemas, port);
}
else
{
/*
* We are reattaching to an existing shared memory segment. This
* should only be reached in the EXEC_BACKEND case, and even then only
* with makePrivate == false.
*/
#ifdef EXEC_BACKEND
Assert(!makePrivate);
#else
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.
*/
if (!IsUnderPostmaster)
CreateLWLocks();
/*
* Set up shmem.c index hashtable
*/
InitShmemIndex();
primaryMirrorModeShmemInit();
/*
* Set up xlog, clog, and buffers
*/
XLOGShmemInit();
CLOGShmemInit();
ChangeTrackingShmemInit();
DistributedLog_ShmemInit();
SUBTRANSShmemInit();
TwoPhaseShmemInit();
MultiXactShmemInit();
FtsShmemInit();
tmShmemInit();
InitBufferPool();
/*
* Set up lock manager
*/
InitLocks();
/*
* Set up append only writer
*/
if (Gp_role == GP_ROLE_DISPATCH)
InitAppendOnlyWriter();
PersistentFileSysObj_ShmemInit();
PersistentFilespace_ShmemInit();
PersistentTablespace_ShmemInit();
PersistentDatabase_ShmemInit();
PersistentRelation_ShmemInit();
Pass2Recovery_ShmemInit();
if (Gp_role == GP_ROLE_DISPATCH && debug_persistent_ptcat_verification)
Persistent_PostDTMRecv_ShmemInit();
/*
* Set up resource schedular
*/
if (Gp_role == GP_ROLE_DISPATCH && ResourceScheduler)
{
InitResScheduler();
InitResPortalIncrementHash();
}
if (!IsUnderPostmaster)
{
/* Set up process table */
InitProcGlobal(PostmasterGetMppLocalProcessCounter());
}
/* Initialize SessionState shared memory array */
SessionState_ShmemInit();
/* Initialize vmem protection */
GPMemoryProtect_ShmemInit();
CreateSharedProcArray();
CreateSharedBackendStatus();
/*
* Set up Shared snapshot slots
*
* TODO: only need to do this if we aren't the QD. for now we are just
* doing it all the time and wasting shemem on the QD. This is
* because this happens at postmaster startup time when we don't
* know who we are.
*/
CreateSharedSnapshotArray();
/*
* Set up shared-inval messaging
*/
CreateSharedInvalidationState();
/*
* Set up free-space map
*/
InitFreeSpaceMap();
/*
* Set up interprocess signaling mechanisms
*/
PMSignalShmemInit();
ProcSignalShmemInit();
BgWriterShmemInit();
CheckpointShmemInit();
WalSndShmemInit();
WalRcvShmemInit();
//AutoVacuumShmemInit();
SeqServerShmemInit();
if (GPAreFileReplicationStructuresRequired()) {
FileRep_SubProcShmemInit();
FileRep_ShmemInit();
FileRepAck_ShmemInit();
FileRepAckPrimary_ShmemInit();
FileRepResync_ShmemInit();
FileRepIpc_ShmemInit();
FileRepLog_ShmemInit();
FileRepStats_ShmemInit();
}
#ifdef FAULT_INJECTOR
FaultInjector_ShmemInit();
#endif
#ifdef USE_TEST_UTILS
if (gp_simex_init)
{
// initialize shmem segment for SimEx
simex_set_sync_bitvector_container(
SyncBitVector_ShmemInit("SimEx bit vector container", simex_get_subclass_count()));
}
#endif /* USE_TEST_UTILS */
/*
* Set up other modules that need some shared memory space
*/
BTreeShmemInit();
SyncScanShmemInit();
workfile_mgr_cache_init();
#ifdef EXEC_BACKEND
/*
* Alloc the win32 shared backend array
*/
if (!IsUnderPostmaster)
ShmemBackendArrayAllocation();
#endif
BackoffStateInit();
if (gp_resqueue_memory_policy != RESQUEUE_MEMORY_POLICY_NONE)
{
SPI_InitMemoryReservation();
}
/*
* Now give loadable modules a chance to set up their shmem allocations
*/
if (shmem_startup_hook)
shmem_startup_hook();
}