From 213c5aa3bdba5783529d3c0f103dbfadf4f93f50 Mon Sep 17 00:00:00 2001 From: Tom Lane Date: Tue, 25 Jan 2022 12:17:40 -0500 Subject: [PATCH] Revert "graceful shutdown" changes for Windows, in back branches only. This reverts commits 6051857fc and ed52c3707, but only in the back branches. Further testing has shown that while those changes do fix some things, they also break others; in particular, it looks like walreceivers fail to detect walsender-initiated connection close reliably if the walsender shuts down this way. We'll keep trying to improve matters in HEAD, but it now seems unwise to push these changes into stable releases. Discussion: https://postgr.es/m/CA+hUKG+OeoETZQ=Qw5Ub5h3tmwQhBmDA=nuNO3KG=zWfUypFAw@mail.gmail.com --- src/backend/libpq/pqcomm.c | 29 +++++++---------------------- 1 file changed, 7 insertions(+), 22 deletions(-) diff --git a/src/backend/libpq/pqcomm.c b/src/backend/libpq/pqcomm.c index 04ce58c47a..93f2e0b81d 100644 --- a/src/backend/libpq/pqcomm.c +++ b/src/backend/libpq/pqcomm.c @@ -284,30 +284,15 @@ socket_close(int code, Datum arg) secure_close(MyProcPort); /* - * On most platforms, we leave the socket open until the process dies. - * This allows clients to perform a "synchronous close" if they care - * --- wait till the transport layer reports connection closure, and - * you can be sure the backend has exited. Saves a kernel call, too. + * Formerly we did an explicit close() here, but it seems better to + * leave the socket open until the process dies. This allows clients + * to perform a "synchronous close" if they care --- wait till the + * transport layer reports connection closure, and you can be sure the + * backend has exited. * - * However, that does not work on Windows: if the kernel closes the - * socket it will invoke an "abortive shutdown" that discards any data - * not yet sent to the client. (This is a flat-out violation of the - * TCP RFCs, but count on Microsoft not to care about that.) To get - * the spec-compliant "graceful shutdown" behavior, we must invoke - * closesocket() explicitly. When using OpenSSL, it seems that clean - * shutdown also requires an explicit shutdown() call. - * - * This code runs late enough during process shutdown that we should - * have finished all externally-visible shutdown activities, so that - * in principle it's good enough to act as a synchronous close on - * Windows too. But it's a lot more fragile than the other way. + * We do set sock to PGINVALID_SOCKET to prevent any further I/O, + * though. */ -#ifdef WIN32 - shutdown(MyProcPort->sock, SD_SEND); - closesocket(MyProcPort->sock); -#endif - - /* In any case, set sock to PGINVALID_SOCKET to prevent further I/O */ MyProcPort->sock = PGINVALID_SOCKET; } }