Hello,
This patch using VirtualAlloc()/VirtualFree() to avoid failing in
reattach to shared memory.
Can this be added to CommitFest ?
Recent threads in pgsql-bugs are
http://archives.postgresql.org/pgsql-bugs/2009-07/msg00036.php
This fix is almost same as previous patch. debug code is deleted.
http://archives.postgresql.org/pgsql-bugs/2009-07/msg00078.php
Regards,
--
Tsutomu Yamada
SRA OSS, Inc. Japan
Index: src/backend/port/win32_shmem.c
===================================================================
RCS file: /mnt/prj/pg/cvsmirror/pg/pgsql/src/backend/port/win32_shmem.c,v
retrieving revision 1.11
diff -c -r1.11 win32_shmem.c
*** src/backend/port/win32_shmem.c 11 Jun 2009 14:49:00 -0000 1.11
--- src/backend/port/win32_shmem.c 14 Jul 2009 10:11:44 -0000
***************
*** 18,23 ****
--- 18,24 ----
unsigned long UsedShmemSegID = 0;
void *UsedShmemSegAddr = NULL;
+ static Size UsedShmemSegSize = 0;
static void pgwin32_SharedMemoryDelete(int status, Datum shmId);
***************
*** 233,238 ****
--- 234,240 ----
/* Save info for possible future use */
UsedShmemSegAddr = memAddress;
+ UsedShmemSegSize = size;
UsedShmemSegID = (unsigned long) hmap2;
return hdr;
***************
*** 257,262 ****
--- 259,273 ----
Assert(UsedShmemSegAddr != NULL);
Assert(IsUnderPostmaster);
+ /* release memory region
+ * that reserved by parant process
+ */
+ if (VirtualFree(UsedShmemSegAddr, 0, MEM_RELEASE) == 0)
+ {
+ elog(LOG, "failed to release reserved memory region (addr=%p):
%lu",
+ UsedShmemSegAddr, GetLastError());
+ }
+
hdr = (PGShmemHeader *) MapViewOfFileEx((HANDLE) UsedShmemSegID,
FILE_MAP_READ | FILE_MAP_WRITE, 0, 0, 0, UsedShmemSegAddr);
if (!hdr)
elog(FATAL, "could not reattach to shared memory (key=%d,
addr=%p): %lu",
***************
*** 302,304 ****
--- 313,335 ----
if (!CloseHandle((HANDLE) DatumGetInt32(shmId)))
elog(LOG, "could not close handle to shared memory: %lu",
GetLastError());
}
+
+ /*
+ * pgwin32_ReserveSharedMemory(HANDLE pChild)
+ * Reserve shared memory area,
+ * BEFORE child process allocates memory for DLL and/or others.
+ */
+ void
+ pgwin32_ReserveSharedMemory(HANDLE pChild)
+ {
+ void *memAddress;
+
+ Assert(UsedShmemSegAddr != NULL);
+ Assert(UsedShmemSegSize != 0);
+ memAddress = VirtualAllocEx(pChild, UsedShmemSegAddr, UsedShmemSegSize,
+ MEM_RESERVE,
PAGE_READWRITE);
+ if (memAddress == NULL) {
+ elog(LOG, "could not reserve shared memory region (addr=%p):
%lu",
+ UsedShmemSegAddr, GetLastError());
+ }
+ }
Index: src/backend/postmaster/postmaster.c
===================================================================
RCS file: /mnt/prj/pg/cvsmirror/pg/pgsql/src/backend/postmaster/postmaster.c,v
retrieving revision 1.584
diff -c -r1.584 postmaster.c
*** src/backend/postmaster/postmaster.c 8 Jul 2009 18:55:35 -0000 1.584
--- src/backend/postmaster/postmaster.c 13 Jul 2009 08:40:36 -0000
***************
*** 3643,3648 ****
--- 3643,3655 ----
elog(LOG, "could not close handle to backend parameter file:
error code %d",
(int) GetLastError());
+ {
+ /* reserve shared memory area before ResumeThread() */
+ /* XXX: if it fail ? */
+ extern void pgwin32_ReserveSharedMemory(HANDLE);
+ pgwin32_ReserveSharedMemory(pi.hProcess);
+ }
+
/*
* 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
--
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