Re: Postgres service stops when I kill client backend on Windows

Michael Paquier <michael(dot)paquier(at)gmail(dot)com> writes:
> On Tue, Oct 13, 2015 at 5:35 AM, Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us> wrote:
>> After poking around a bit more, I propose the attached patch. I've
>> checked that this is happy with an EXEC_BACKEND Unix build, but I'm not
>> able to test it on Windows ... would somebody do that?

> Looking at the patch, clearly +1 for the additional routine in both
> win32_shmem.c and sysv_shmem.c to clean up the shmem state at backend
> level. I have played as well with the patch on Windows and it behaves
> as expected: without the patch a process killed with taskkill /f stops
> straight the server even if restart_on_crash is on. With the patch the
> server restarts correctly.

OK, pushed with some additional comment-smithing.

I noticed while looking at this that for subprocesses that aren't supposed
to be attached to shared memory, we do pgwin32_ReserveSharedMemoryRegion()
anyway in internal_forkexec(), and then that's never undone anywhere,
so that that segment of the subprocess's memory space remains reserved.
I'm not sure if this is worth changing, but if it is, we could do so now
by calling VirtualFree() in PGSharedMemoryNoReAttach().

BTW, I am suspicious that the DSM stuff may have related issues --- do
we use inheritable mapping handles for DSM segments on Windows?

regards, tom lane