diff options
| -rw-r--r-- | src/backend/port/sysv_shmem.c | 8 | ||||
| -rw-r--r-- | src/backend/port/win32/shmem.c | 62 | ||||
| -rw-r--r-- | src/backend/postmaster/postmaster.c | 23 | ||||
| -rw-r--r-- | src/include/port/win32.h | 5 |
4 files changed, 93 insertions, 5 deletions
diff --git a/src/backend/port/sysv_shmem.c b/src/backend/port/sysv_shmem.c index 04d8e6f09f9..956883579a4 100644 --- a/src/backend/port/sysv_shmem.c +++ b/src/backend/port/sysv_shmem.c @@ -10,7 +10,7 @@ * Portions Copyright (c) 1994, Regents of the University of California * * IDENTIFICATION - * $PostgreSQL: pgsql/src/backend/port/sysv_shmem.c,v 1.47.2.2 2010/05/01 22:46:50 tgl Exp $ + * $PostgreSQL: pgsql/src/backend/port/sysv_shmem.c,v 1.47.2.3 2010/07/23 13:53:29 mha Exp $ * *------------------------------------------------------------------------- */ @@ -49,6 +49,9 @@ typedef int IpcMemoryId; /* shared memory ID returned by shmget(2) */ unsigned long UsedShmemSegID = 0; void *UsedShmemSegAddr = NULL; +#ifdef WIN32 +Size UsedShmemSegSize = 0; +#endif static void *InternalIpcMemoryCreate(IpcMemoryKey memKey, Size size); static void IpcMemoryDetach(int status, Datum shmaddr); @@ -446,6 +449,9 @@ PGSharedMemoryCreate(Size size, bool makePrivate, int port) /* Save info for possible future use */ UsedShmemSegAddr = memAddress; UsedShmemSegID = (unsigned long) NextShmemSegID; +#ifdef WIN32 + UsedShmemSegSize = size; +#endif return hdr; } diff --git a/src/backend/port/win32/shmem.c b/src/backend/port/win32/shmem.c index c7865bda325..2ba144c9a4a 100644 --- a/src/backend/port/win32/shmem.c +++ b/src/backend/port/win32/shmem.c @@ -6,14 +6,17 @@ * Portions Copyright (c) 1996-2006, PostgreSQL Global Development Group * * IDENTIFICATION - * $PostgreSQL: pgsql/src/backend/port/win32/shmem.c,v 1.13.2.1 2009/05/04 08:36:42 mha Exp $ + * $PostgreSQL: pgsql/src/backend/port/win32/shmem.c,v 1.13.2.2 2010/07/23 13:53:30 mha Exp $ * *------------------------------------------------------------------------- */ #include "postgres.h" +#include "miscadmin.h" static DWORD s_segsize = 0; +extern void *UsedShmemSegAddr; +extern Size UsedShmemSegSize; /* Detach from a shared mem area based on its address */ int @@ -29,6 +32,13 @@ shmdt(const void *shmaddr) void * shmat(int memId, void *shmaddr, int flag) { + /* Release the memory region reserved in the postmaster */ + if (IsUnderPostmaster) + { + if (VirtualFree(shmaddr, 0, MEM_RELEASE) == 0) + elog(FATAL, "failed to release reserved memory region (addr=%p): %lu", + shmaddr, GetLastError()); + } /* TODO -- shmat needs to count # attached to shared mem */ void *lpmem = MapViewOfFileEx((HANDLE) memId, FILE_MAP_WRITE | FILE_MAP_READ, @@ -128,3 +138,53 @@ shmget(int memKey, int size, int flag) return (int) hmap; } + +/* + * pgwin32_ReserveSharedMemoryRegion(hChild) + * + * Reserve the memory region that will be used for shared memory in a child + * process. It is called before the child process starts, to make sure the + * memory is available. + * + * Once the child starts, DLLs loading in different order or threads getting + * scheduled differently may allocate memory which can conflict with the + * address space we need for our shared memory. By reserving the shared + * memory region before the child starts, and freeing it only just before we + * attempt to get access to the shared memory forces these allocations to + * be given different address ranges that don't conflict. + * + * NOTE! This function executes in the postmaster, and should for this + * reason not use elog(FATAL) since that would take down the postmaster. + */ +int +pgwin32_ReserveSharedMemoryRegion(HANDLE hChild) +{ + void *address; + + Assert(UsedShmemSegAddr != NULL); + Assert(UsedShmemSegSize != 0); + + address = VirtualAllocEx(hChild, UsedShmemSegAddr, UsedShmemSegSize, + MEM_RESERVE, PAGE_READWRITE); + if (address == NULL) { + /* Don't use FATAL since we're running in the postmaster */ + elog(LOG, "could not reserve shared memory region (addr=%p) for child %lu: %lu", + UsedShmemSegAddr, hChild, GetLastError()); + return false; + } + if (address != UsedShmemSegAddr) + { + /* + * Should never happen - in theory if allocation granularity causes strange + * effects it could, so check just in case. + * + * Don't use FATAL since we're running in the postmaster. + */ + elog(LOG, "reserved shared memory region got incorrect address %p, expected %p", + address, UsedShmemSegAddr); + VirtualFreeEx(hChild, address, 0, MEM_RELEASE); + return false; + } + + return true; +} diff --git a/src/backend/postmaster/postmaster.c b/src/backend/postmaster/postmaster.c index 69f37c02ad7..583604fcdf2 100644 --- a/src/backend/postmaster/postmaster.c +++ b/src/backend/postmaster/postmaster.c @@ -37,7 +37,7 @@ * * * IDENTIFICATION - * $PostgreSQL: pgsql/src/backend/postmaster/postmaster.c,v 1.505.2.8 2010/04/01 20:12:42 heikki Exp $ + * $PostgreSQL: pgsql/src/backend/postmaster/postmaster.c,v 1.505.2.9 2010/07/23 13:53:30 mha Exp $ * * NOTES * @@ -3186,7 +3186,7 @@ internal_forkexec(int argc, char *argv[], Port *port) return -1; /* log made by save_backend_variables */ } - /* Drop the shared memory that is now inherited to the backend */ + /* Drop the parameter shared memory that is now inherited to the backend */ if (!UnmapViewOfFile(param)) elog(LOG, "could not unmap view of backend parameter file: error code %d", (int) GetLastError()); @@ -3195,6 +3195,25 @@ internal_forkexec(int argc, char *argv[], Port *port) (int) GetLastError()); /* + * Reserve the memory region used by our main shared memory segment before we + * resume the child process. + */ + if (!pgwin32_ReserveSharedMemoryRegion(pi.hProcess)) + { + /* + * Failed to reserve the memory, so terminate the newly created + * process and give up. + */ + if (!TerminateProcess(pi.hProcess, 255)) + ereport(ERROR, + (errmsg_internal("could not terminate process that failed to reserve memory: error code %d", + (int) GetLastError()))); + CloseHandle(pi.hProcess); + CloseHandle(pi.hThread); + return -1; /* logging done made by pgwin32_ReserveSharedMemoryRegion() */ + } + + /* * Now that the backend variables are written out, we start the child * thread so it can start initializing while we set up the rest of the * parent state. diff --git a/src/include/port/win32.h b/src/include/port/win32.h index 514efcdb2d8..50c711e121f 100644 --- a/src/include/port/win32.h +++ b/src/include/port/win32.h @@ -1,4 +1,4 @@ -/* $PostgreSQL: pgsql/src/include/port/win32.h,v 1.63.2.3 2007/11/29 16:44:26 mha Exp $ */ +/* $PostgreSQL: pgsql/src/include/port/win32.h,v 1.63.2.4 2010/07/23 13:53:30 mha Exp $ */ #if defined(_MSC_VER) || defined(__BORLANDC__) #define WIN32_ONLY_COMPILER @@ -263,6 +263,9 @@ extern int pgwin32_is_admin(void); extern int pgwin32_is_service(void); #endif +/* in backend/port/win32/shmem.c */ +extern int pgwin32_ReserveSharedMemoryRegion(HANDLE); + /* in port/win32error.c */ extern void _dosmaperr(unsigned long); |