Try to get some info about Windows can't-reattach-to-shared-memory errors.

Add some debug printouts focused on the idea that MapViewOfFileEx might
be rounding its virtual memory allocation up more than we expect (and,
in particular, more than VirtualAllocEx does).

Once we've seen what this reports in one of the failures on buildfarm
members dory or jacana, we might revert this ... or perhaps just
decrease the log level.

Discussion: https://postgr.es/m/25495.1524517820@sss.pgh.pa.us
This commit is contained in:
Tom Lane 2018-04-27 21:59:58 -04:00
parent 2e83e6bd74
commit 63ca350ef9
1 changed files with 23 additions and 1 deletions

View File

@ -191,6 +191,7 @@ PGSharedMemoryCreate(Size size, bool makePrivate, int port,
SIZE_T largePageSize = 0;
Size orig_size = size;
DWORD flProtect = PAGE_READWRITE;
MEMORY_BASIC_INFORMATION info;
/* Room for a header? */
Assert(size > MAXALIGN(sizeof(PGShmemHeader)));
@ -359,6 +360,14 @@ retry:
/* Register on-exit routine to delete the new segment */
on_shmem_exit(pgwin32_SharedMemoryDelete, PointerGetDatum(hmap2));
/* Log information about the segment's virtual memory use */
if (VirtualQuery(memAddress, &info, sizeof(info)) != 0)
elog(LOG, "mapped shared memory segment at %p, requested size %zu, mapped size %zu",
memAddress, size, info.RegionSize);
else
elog(LOG, "VirtualQuery(%p) failed: error code %lu",
memAddress, GetLastError());
*shim = hdr;
return hdr;
}
@ -392,8 +401,21 @@ PGSharedMemoryReAttach(void)
hdr = (PGShmemHeader *) MapViewOfFileEx(UsedShmemSegID, FILE_MAP_READ | FILE_MAP_WRITE, 0, 0, 0, UsedShmemSegAddr);
if (!hdr)
{
DWORD maperr = GetLastError();
MEMORY_BASIC_INFORMATION info;
if (VirtualQuery(UsedShmemSegAddr, &info, sizeof(info)) != 0)
elog(LOG, "VirtualQuery(%p) reports region of size %zu, base %p, has state 0x%lx",
UsedShmemSegAddr, info.RegionSize,
info.AllocationBase, info.State);
else
elog(LOG, "VirtualQuery(%p) failed: error code %lu",
UsedShmemSegAddr, GetLastError());
elog(FATAL, "could not reattach to shared memory (key=%p, addr=%p): error code %lu",
UsedShmemSegID, UsedShmemSegAddr, GetLastError());
UsedShmemSegID, UsedShmemSegAddr, maperr);
}
if (hdr != origUsedShmemSegAddr)
elog(FATAL, "reattaching to shared memory returned unexpected address (got %p, expected %p)",
hdr, origUsedShmemSegAddr);