On 2/8/19 1:23 PM, Corinna Vinschen wrote:
> On Feb 8 13:21, Corinna Vinschen wrote:
>> On Feb 8 12:51, Michael Haubenwallner wrote:
>>>
>>> For now it seems like there's an inconsistency with PIDs:
>>> A first process PID 100, receives PID 101 from spawn(),
>>> but in the new process getpid() returns 102:
>>>
>>> $ ./dospawn /bin/bash -c 'echo $$'
>>> 12625
>>> waitpid: pid 12624 status 0x0
>>
>> Oh, hmm. If you call spawnve, rather than execve, a new child pid
>> is generated in spawnve, rather than just keeping the callers pid.
>>
>> However, apparently the child invents its own pid in pinfo::thisproc
>> after being spawned. But actually this should only occur for forked
>> processes aore processes started from non-Cygwin parents.
>
> Does that help, by any chance:
>
> diff --git a/winsup/cygwin/dcrt0.cc b/winsup/cygwin/dcrt0.cc
> index 78506d43de29..0b274287d9f6 100644
> --- a/winsup/cygwin/dcrt0.cc
> +++ b/winsup/cygwin/dcrt0.cc
> @@ -656,7 +656,7 @@ child_info_spawn::handle_spawn ()
> !DuplicateHandle (GetCurrentProcess (), moreinfo->myself_pinfo,
> GetCurrentProcess (), &h, 0,
> FALSE, DUPLICATE_SAME_ACCESS | DUPLICATE_CLOSE_SOURCE))
> - h = NULL;
> + h = INVALID_HANDLE_VALUE;
>
> /* Setup our write end of the process pipe. Clear the one in the
> structure.
> The destructor should never be called for this but, it can't hurt to be
> diff --git a/winsup/cygwin/pinfo.cc b/winsup/cygwin/pinfo.cc
> index 445bd35b224e..d10c4fc4580c 100644
> --- a/winsup/cygwin/pinfo.cc
> +++ b/winsup/cygwin/pinfo.cc
> @@ -62,6 +62,8 @@ pinfo::thisproc (HANDLE h)
> cygheap->pid = create_cygwin_pid ();
> flags |= PID_NEW;
> }
> + else if (h == INVALID_HANDLE_VALUE)
> + h = NULL;
No, because cygheap->pid still is the parent's pid here, not the new child's
one.
How should the child be informed at all about the new cygpid value generated in
parent's child_info_spawn::worker() ?
/haubi/
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