Обсуждение: Use proc_exit() in WalRcvWaitForStartPosition
Hi, While working on another patch, I happened to notice that WalRcvWaitForStartPosition() calls raw exit(1). I think this shoulduse proc_exit(1) instead, so that the normal cleanup machinery is not bypassed. This tiny patch just replaces exit(1) with proc_exit(1) in WalRcvWaitForStartPosition(). Best regards, -- Chao Li (Evan) HighGo Software Co., Ltd. https://www.highgo.com/
Вложения
On 4/8/26 11:08 AM, Chao Li wrote: > While working on another patch, I happened to notice that WalRcvWaitForStartPosition() calls raw exit(1). I think thisshould use proc_exit(1) instead, so that the normal cleanup machinery is not bypassed. > > This tiny patch just replaces exit(1) with proc_exit(1) in WalRcvWaitForStartPosition(). This looks likely to be correct since when we exit in WalReceiverMain() (on WALRCV_STOPPING and WALRCV_STOPPED) we call proc_exit(1). I feel we should exit the same way in WalRcvWaitForStartPosition() as we do in WalReceiverMain() and if not I would like a comment explaining why those two cases are different. Andreas
On Thu, Apr 9, 2026 at 5:00 AM Andreas Karlsson <andreas@proxel.se> wrote: > > On 4/8/26 11:08 AM, Chao Li wrote: > > While working on another patch, I happened to notice that WalRcvWaitForStartPosition() calls raw exit(1). I think thisshould use proc_exit(1) instead, so that the normal cleanup machinery is not bypassed. > > > > This tiny patch just replaces exit(1) with proc_exit(1) in WalRcvWaitForStartPosition(). > > This looks likely to be correct since when we exit in WalReceiverMain() > (on WALRCV_STOPPING and WALRCV_STOPPED) we call proc_exit(1). I feel we > should exit the same way in WalRcvWaitForStartPosition() as we do in > WalReceiverMain() and if not I would like a comment explaining why those > two cases are different. +1 WalRcvWaitForStartPosition, WALRCV_STOPPING before entering wait loop uses proc_exit(0) for WALRCV_STOPPING, while this path should probably use proc_exit(0) as well (not proc_exit(1)), since the stop was a requested shutdown, not an error. Using exit code 1 for a clean stop-on-request seems inconsistent. -- Best, Xuneng
On Thu, Apr 9, 2026 at 10:09 AM Xuneng Zhou <xunengzhou@gmail.com> wrote: > > On Thu, Apr 9, 2026 at 5:00 AM Andreas Karlsson <andreas@proxel.se> wrote: > > > > On 4/8/26 11:08 AM, Chao Li wrote: > > > While working on another patch, I happened to notice that WalRcvWaitForStartPosition() calls raw exit(1). I think thisshould use proc_exit(1) instead, so that the normal cleanup machinery is not bypassed. > > > > > > This tiny patch just replaces exit(1) with proc_exit(1) in WalRcvWaitForStartPosition(). > > > > This looks likely to be correct since when we exit in WalReceiverMain() > > (on WALRCV_STOPPING and WALRCV_STOPPED) we call proc_exit(1). I feel we > > should exit the same way in WalRcvWaitForStartPosition() as we do in > > WalReceiverMain() and if not I would like a comment explaining why those > > two cases are different. > > +1 +1 > WalRcvWaitForStartPosition, WALRCV_STOPPING before entering wait loop > uses proc_exit(0) for WALRCV_STOPPING, while this path should probably > use proc_exit(0) as well (not proc_exit(1)), since the stop was a > requested shutdown, not an error. Using exit code 1 for a clean > stop-on-request seems inconsistent. The requested shutdown is handled in ShutdownWalRcv(), which sets the state to WALRCV_STOPPING and sends SIGTERM to the walreceiver. Although this might be considered a normal shutdown (suggesting exit code 0), when the walreceiver receives SIGTERM it exits via ereport(FATAL), resulting in exit code 1. In contrast, if it exits early in WalRcvWaitForStartPosition() due to the WALRCV_STOPPING state, it uses exit code 0, as you noted. So there seems to be some inconsistency in exit codes. That said, the exit code (0 vs 1) does not affect behavior, since the postmaster treats both as non-crash exits. For consistency, I would prefer using exit code 1 in proc_exit() in WalRcvWaitForStartPosition(), to match the ereport(FATAL) path. But I'm fine with other approaches as well. Also, the comment at the top of walreceiver.c may need updating: * Normal termination is by SIGTERM, which instructs the walreceiver to * exit(0). Emergency termination is by SIGQUIT; like any postmaster child * process, the walreceiver will simply abort and exit on SIGQUIT. A close * of the connection and a FATAL error are treated not as a crash but as * normal operation. Regards, -- Fujii Masao
> On Apr 10, 2026, at 14:16, Fujii Masao <masao.fujii@gmail.com> wrote: > > On Thu, Apr 9, 2026 at 10:09 AM Xuneng Zhou <xunengzhou@gmail.com> wrote: >> >> On Thu, Apr 9, 2026 at 5:00 AM Andreas Karlsson <andreas@proxel.se> wrote: >>> >>> On 4/8/26 11:08 AM, Chao Li wrote: >>>> While working on another patch, I happened to notice that WalRcvWaitForStartPosition() calls raw exit(1). I think thisshould use proc_exit(1) instead, so that the normal cleanup machinery is not bypassed. >>>> >>>> This tiny patch just replaces exit(1) with proc_exit(1) in WalRcvWaitForStartPosition(). >>> >>> This looks likely to be correct since when we exit in WalReceiverMain() >>> (on WALRCV_STOPPING and WALRCV_STOPPED) we call proc_exit(1). I feel we >>> should exit the same way in WalRcvWaitForStartPosition() as we do in >>> WalReceiverMain() and if not I would like a comment explaining why those >>> two cases are different. >> >> +1 > > +1 > > >> WalRcvWaitForStartPosition, WALRCV_STOPPING before entering wait loop >> uses proc_exit(0) for WALRCV_STOPPING, while this path should probably >> use proc_exit(0) as well (not proc_exit(1)), since the stop was a >> requested shutdown, not an error. Using exit code 1 for a clean >> stop-on-request seems inconsistent. > > The requested shutdown is handled in ShutdownWalRcv(), which sets the state to > WALRCV_STOPPING and sends SIGTERM to the walreceiver. > > Although this might be considered a normal shutdown (suggesting exit code 0), > when the walreceiver receives SIGTERM it exits via ereport(FATAL), resulting > in exit code 1. In contrast, if it exits early in WalRcvWaitForStartPosition() > due to the WALRCV_STOPPING state, it uses exit code 0, as you noted. So > there seems to be some inconsistency in exit codes. > > That said, the exit code (0 vs 1) does not affect behavior, since > the postmaster treats both as non-crash exits. > > For consistency, I would prefer using exit code 1 in proc_exit() in > WalRcvWaitForStartPosition(), to match the ereport(FATAL) path. But I'm fine > with other approaches as well. > > Also, the comment at the top of walreceiver.c may need updating: > > * Normal termination is by SIGTERM, which instructs the walreceiver to > * exit(0). Emergency termination is by SIGQUIT; like any postmaster child > * process, the walreceiver will simply abort and exit on SIGQUIT. A close > * of the connection and a FATAL error are treated not as a crash but as > * normal operation. > > Regards, > > -- > Fujii Masao PFA v2 - updated header comment of walreceive.c. I tried to avoid mentioning the exact exit value in the comment, so I justchanged “exit(0)” to “terminate”. Best regards, -- Chao Li (Evan) HighGo Software Co., Ltd. https://www.highgo.com/
Вложения
On Fri, Apr 10, 2026 at 4:07 PM Chao Li <li.evan.chao@gmail.com> wrote: > PFA v2 - updated header comment of walreceive.c. I tried to avoid mentioning the exact exit value in the comment, so Ijust changed “exit(0)” to “terminate”. Thanks for updating the patch! "termination instructs XXX to terminate" sounds a bit redundant. How about saying "to ereport(FATAL)" instead of “to terminate”? Regards, -- Fujii Masao
> On Apr 10, 2026, at 22:17, Fujii Masao <masao.fujii@gmail.com> wrote: > > On Fri, Apr 10, 2026 at 4:07 PM Chao Li <li.evan.chao@gmail.com> wrote: >> PFA v2 - updated header comment of walreceive.c. I tried to avoid mentioning the exact exit value in the comment, so Ijust changed “exit(0)” to “terminate”. > > Thanks for updating the patch! > > "termination instructs XXX to terminate" sounds a bit redundant. How > about saying > "to ereport(FATAL)" instead of “to terminate”? > > Regards, > > > -- > Fujii Masao Okay, yes, that was a bit redundant. I changed it to “to ereport(FATAL)” in v3. After that change, the line went over 80 columns, so I also adjusted a few nearby lines to keep everything within the 80-columnlimit. There is no content change. Best regards, -- Chao Li (Evan) HighGo Software Co., Ltd. https://www.highgo.com/
Вложения
On Mon, Apr 13, 2026 at 8:33 AM Chao Li <li.evan.chao@gmail.com> wrote: > Okay, yes, that was a bit redundant. I changed it to “to ereport(FATAL)” in v3. > > After that change, the line went over 80 columns, so I also adjusted a few nearby lines to keep everything within the 80-columnlimit. There is no content change. Thanks for updating the patch! I've pushed it. Regards, -- Fujii Masao
> On Apr 16, 2026, at 11:34, Fujii Masao <masao.fujii@gmail.com> wrote: > > On Mon, Apr 13, 2026 at 8:33 AM Chao Li <li.evan.chao@gmail.com> wrote: >> Okay, yes, that was a bit redundant. I changed it to “to ereport(FATAL)” in v3. >> >> After that change, the line went over 80 columns, so I also adjusted a few nearby lines to keep everything within the80-column limit. There is no content change. > > Thanks for updating the patch! I've pushed it. > > Regards, > > -- > Fujii Masao Hi Fujii san, thank you very much for pushing. Best regards, -- Chao Li (Evan) HighGo Software Co., Ltd. https://www.highgo.com/