From eeae797d33ab9c45f70b52c3e19d7ac271b59f77 Mon Sep 17 00:00:00 2001 From: Tom Lane Date: Thu, 1 Dec 2005 20:24:49 +0000 Subject: [PATCH] Retry in FileRead and FileWrite if Windows returns ERROR_NO_SYSTEM_RESOURCES. Also add a retry for Unixen returning EINTR, which hasn't been reported as an issue but at least theoretically could be. Patch by Qingqing Zhou, some minor adjustments by me. --- src/backend/storage/file/fd.c | 61 +++++++++++++++++++++++++++++++++-- 1 file changed, 58 insertions(+), 3 deletions(-) diff --git a/src/backend/storage/file/fd.c b/src/backend/storage/file/fd.c index a7540c1fc4..e7dd00e62c 100644 --- a/src/backend/storage/file/fd.c +++ b/src/backend/storage/file/fd.c @@ -7,7 +7,7 @@ * Portions Copyright (c) 1994, Regents of the University of California * * IDENTIFICATION - * $PostgreSQL: pgsql/src/backend/storage/file/fd.c,v 1.115.4.1 2005/08/07 18:47:38 tgl Exp $ + * $PostgreSQL: pgsql/src/backend/storage/file/fd.c,v 1.115.4.2 2005/12/01 20:24:49 tgl Exp $ * * NOTES: * @@ -983,11 +983,41 @@ FileRead(File file, char *buffer, int amount) if (returnCode < 0) return returnCode; +retry: returnCode = read(VfdCache[file].fd, buffer, amount); - if (returnCode > 0) + + if (returnCode >= 0) VfdCache[file].seekPos += returnCode; else + { + /* + * Windows may run out of kernel buffers and return "Insufficient + * system resources" error. Wait a bit and retry to solve it. + * + * It is rumored that EINTR is also possible on some Unix filesystems, + * in which case immediate retry is indicated. + */ +#ifdef WIN32 + DWORD error = GetLastError(); + + switch (error) + { + case ERROR_NO_SYSTEM_RESOURCES: + pg_usleep(1000L); + errno = EINTR; + break; + default: + _dosmaperr(error); + break; + } +#endif + /* OK to retry if interrupted */ + if (errno == EINTR) + goto retry; + + /* Trouble, so assume we don't know the file position anymore */ VfdCache[file].seekPos = FileUnknownPos; + } return returnCode; } @@ -1007,6 +1037,7 @@ FileWrite(File file, char *buffer, int amount) if (returnCode < 0) return returnCode; +retry: errno = 0; returnCode = write(VfdCache[file].fd, buffer, amount); @@ -1014,10 +1045,34 @@ FileWrite(File file, char *buffer, int amount) if (returnCode != amount && errno == 0) errno = ENOSPC; - if (returnCode > 0) + if (returnCode >= 0) VfdCache[file].seekPos += returnCode; else + { + /* + * See comments in FileRead() + */ +#ifdef WIN32 + DWORD error = GetLastError(); + + switch (error) + { + case ERROR_NO_SYSTEM_RESOURCES: + pg_usleep(1000L); + errno = EINTR; + break; + default: + _dosmaperr(error); + break; + } +#endif + /* OK to retry if interrupted */ + if (errno == EINTR) + goto retry; + + /* Trouble, so assume we don't know the file position anymore */ VfdCache[file].seekPos = FileUnknownPos; + } return returnCode; }