On 3/3/2024 7:27 PM, Dan Shelton via Cygwin wrote:
On Tue, 27 Feb 2024 at 07:34, <gs-cygwin....@gluelogic.com> wrote:
On Tue, Feb 27, 2024 at 06:54:42AM +0100, Dan Shelton via Cygwin wrote:
On Tue, 27 Feb 2024 at 06:47, Brian Inglis via Cygwin <cygwin@cygwin.com> wrote:
On 2024-02-26 20:23, Dan Shelton via Cygwin wrote:
Does Cygwin implement a native, i.e. without form(),exec(), implementation of
posix_spawn()?
Check the API compatibility docs online:
https://cygwin.com/cygwin-api/compatibility.html#std-susv4
or optional locally installed package cygwin-doc:
/usr/share/doc/cygwin-doc/html/cygwin-api/compatibility.html#std-susv4
That document does not answer my question.
I know posix_spawn() is there. But the question is: Does it use just
Cygwin fork(),exec(), or the native Win32 spawn() api?
Dan
--
Dan Shelton - Cluster Specialist Win/Lin/Bsd
If you were going to make a small effort to answer the question
yourself, you could use strace, you could step through a debugger, or
you could check the source code. Have you tried any of these? What did
you find? If you are unable to take any of those steps, why does
posix_spawn() matter to you?
strace does not help, as I need the Win32 calls BELOW posix_spawn(),
to see the implementation details.
Check the source code, then. It's at:
https://cygwin.com/cgit/newlib-cygwin/tree/winsup/cygwin/fork.cc
Look at line 587; there's the static function dofork(). Look at the
thirty or so lines above that; there's both fork() and
__posix_spawn_fork() calling dofork(). So both those user-level
functions call into the exact same internals. (BTW __posix_spawn_fork()
is called from posix_spawn(); the latter is in newlib and not Cygwin.)
You can even see the reason it's done this way by reading the comment.
..mark
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