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-rw-r--r--src/backend/postmaster/checkpointer.c18
1 files changed, 16 insertions, 2 deletions
diff --git a/src/backend/postmaster/checkpointer.c b/src/backend/postmaster/checkpointer.c
index 624a3238b80..45f5deca72e 100644
--- a/src/backend/postmaster/checkpointer.c
+++ b/src/backend/postmaster/checkpointer.c
@@ -209,8 +209,9 @@ CheckpointerMain(void)
*/
pqsignal(SIGCHLD, SIG_DFL);
- /* We allow SIGQUIT (quickdie) at all times */
+ /* We allow SIGQUIT (SignalHandlerForCrashExit) at all times */
sigdelset(&BlockSig, SIGQUIT);
+ PG_SETMASK(&BlockSig);
/*
* Initialize so that first time-driven event happens at the correct time.
@@ -231,7 +232,20 @@ CheckpointerMain(void)
/*
* If an exception is encountered, processing resumes here.
*
- * See notes in postgres.c about the design of this coding.
+ * You might wonder why this isn't coded as an infinite loop around a
+ * PG_TRY construct. The reason is that this is the bottom of the
+ * exception stack, and so with PG_TRY there would be no exception handler
+ * in force at all during the CATCH part. By leaving the outermost setjmp
+ * always active, we have at least some chance of recovering from an error
+ * during error recovery. (If we get into an infinite loop thereby, it
+ * will soon be stopped by overflow of elog.c's internal state stack.)
+ *
+ * Note that we use sigsetjmp(..., 1), so that the prevailing signal mask
+ * (to wit, BlockSig) will be restored when longjmp'ing to here. Thus,
+ * signals other than SIGQUIT will be blocked until we complete error
+ * recovery. It might seem that this policy makes the HOLD_INTERRUPTS()
+ * call redundant, but it is not since InterruptPending might be set
+ * already.
*/
if (sigsetjmp(local_sigjmp_buf, 1) != 0)
{