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| author | Tom Lane <tgl@sss.pgh.pa.us> | 2018-04-30 20:09:31 -0400 |
|---|---|---|
| committer | Tom Lane <tgl@sss.pgh.pa.us> | 2018-04-30 20:09:31 -0400 |
| commit | 23078689a9921968ac0873b017be6e7f772f10bc (patch) | |
| tree | 6fef1968de6ded86c972eb2e0a234ddd5bede4e1 /src | |
| parent | 73042b8d136fe985746dc762fcb2a4356460842d (diff) | |
| download | postgresql-23078689a9921968ac0873b017be6e7f772f10bc.tar.gz postgresql-23078689a9921968ac0873b017be6e7f772f10bc.zip | |
Does it help to wait before reattaching?
Revert the map/unmap dance I tried in commit 73042b8d1; that helps
not at all.
Instead, speculate that the unwanted allocation is being done on
another thread, and thus timing variations explain the apparent
unpredictability. Temporarily add a 1-second sleep before the
VirtualFree call, in hopes that any such other threads will
quiesce and not jog our elbow.
This is obviously not a desirable long-term fix, but as a means of
investigation it seems useful.
Discussion: https://postgr.es/m/25495.1524517820@sss.pgh.pa.us
Diffstat (limited to 'src')
| -rw-r--r-- | src/backend/port/win32_shmem.c | 19 |
1 files changed, 4 insertions, 15 deletions
diff --git a/src/backend/port/win32_shmem.c b/src/backend/port/win32_shmem.c index 0f140e7a369..71b1bc3ec4c 100644 --- a/src/backend/port/win32_shmem.c +++ b/src/backend/port/win32_shmem.c @@ -456,22 +456,11 @@ PGSharedMemoryReAttach(void) /* Ensure buf is big enough that it won't grow mid-operation */ initStringInfo(&buf); enlargeStringInfo(&buf, 128 * 1024); + /* ... and let's just be sure all that space is committed */ + memset(buf.data, 0, buf.maxlen); - dumpmem(&buf, "beginning PGSharedMemoryReAttach"); - - hdr = (PGShmemHeader *) MapViewOfFileEx(UsedShmemSegID, FILE_MAP_READ | FILE_MAP_WRITE, 0, 0, 0, NULL); - if (hdr) - { - if (!UnmapViewOfFile(hdr)) - elog(LOG, "could not unmap temporary view of shared memory: error code %lu", - GetLastError()); - } - else - { - /* This isn't fatal, just unpromising ... */ - elog(LOG, "could not attach to shared memory (key=%p) at any address: error code %lu", - UsedShmemSegID, GetLastError()); - } + /* Test: see if this lets the process address space quiesce */ + pg_usleep(1000000L); dumpmem(&buf, "before VirtualFree"); |