On Thu, Mar 16, 2023 at 2:00 AM Alexander Lakhin <exclus...@gmail.com> wrote: > 15.03.2023 11:43, Thomas Munro wrote: > > Do you know how it fails in non-assert builds, without the fix?
> So at least with my test script that doesn't lead to a crash or something. Thanks. We were wondering if the retry mechanism might somehow be hiding this in non-assert builds, but, looking more closely, that is tied specifically to the memory reservation operation. I noticed that d41a178b missed a comment explaining why we used malloc() instead of palloc(), but that isn't true anymore, so here's a small patch to clean that up.
From 774e1acd27b49fc8d4b017686eeb9260032d6bce Mon Sep 17 00:00:00 2001 From: Thomas Munro <thomas.mu...@gmail.com> Date: Thu, 16 Mar 2023 09:42:57 +1300 Subject: [PATCH] Small tidyup for commit d41a178b. A comment was left behind claiming that we needed to use malloc() rather than palloc() because the corresponding free would run in another thread, but that's not true anymore. Adjust the comment. And, with that reason being gone, we might as well use palloc(). Back-patch to supported releases, like d41a178b. diff --git a/src/backend/postmaster/postmaster.c b/src/backend/postmaster/postmaster.c index 71198b72c8..27184fb3c4 100644 --- a/src/backend/postmaster/postmaster.c +++ b/src/backend/postmaster/postmaster.c @@ -4786,13 +4786,10 @@ retry: /* * Queue a waiter to signal when this child dies. The wait will be handled - * automatically by an operating system thread pool. - * - * Note: use malloc instead of palloc, since it needs to be thread-safe. - * Struct will be free():d from the callback function that runs on a - * different thread. + * automatically by an operating system thread pool. The memory will be + * freed by a later call to waitpid(). */ - childinfo = malloc(sizeof(win32_deadchild_waitinfo)); + childinfo = palloc(sizeof(win32_deadchild_waitinfo)); if (!childinfo) ereport(FATAL, (errcode(ERRCODE_OUT_OF_MEMORY), @@ -6463,7 +6460,7 @@ waitpid(pid_t pid, int *exitstatus, int options) * Free struct that was allocated before the call to * RegisterWaitForSingleObject() */ - free(childinfo); + pfree(childinfo); return pid; } -- 2.39.2
