execute, spawn-pipe: Make multithread-safe on native Windows

[Bruno Haible]

So far, the modules 'execute' and 'spawn-pipe' use, on native Windows,
the MSVCRT function _spawnvpe. But this function requires temporary
assignments to the stdin, stdout, or stderr file descriptors, which is
of course not multithread-safe.

With this patch, the modules use 'CreateProcess' directly. The new code
is multithread-safe.


2020-11-30  Bruno Haible  <bruno@clisp.org>

        execute, spawn-pipe: Make multithread-safe on native Windows.
        * lib/windows-spawn.h: Include <stdint.h>, <windows.h>.
        (dup_safer_noinherit, undup_safer_noinherit): Remove declarations.
        (spawnpvech): New declaration.
        * lib/windows-spawn.c: Include <stdio.h>, <process.h>, findprog.h.
        Don't include <unistd.h>, cloexec.h, error.h, gettext.h.
        (_): Remove macro.
        (dup_noinherit, fd_safer_noinherit, dup_safer_noinherit,
        undup_safer_noinherit): Remove functions.
        (spawnpvech): New function.
        * modules/windows-spawn (Depends-on): Add findprog-in, stdint. Remove
        cloexec, dup2, error, gettext-h.
        * lib/execute.c: Include msvc-nothrow.h.
        (execute) [WIN32]: Use _get_osfhandle, spawnpvech instead of _spawnvpe.
        * lib/spawn-pipe.c: Include msvc-nothrow.h.
        (create_pipe) [WIN32]: Use _get_osfhandle, DuplicateHandle, spawnpvech
        instead of _spawnvpe.
        * modules/execute (Depends-on): Add msvc-nothrow.
        * modules/spawn-pipe (Depends-on): Likewise.

2020-11-30  Bruno Haible  <bruno@clisp.org>

        execute, spawn-pipe: Improve documentation.
        * lib/execute.h: Describe progname, prog_path, prog_argv.
        * lib/spawn-pipe.h: Likewise.

0001-execute-spawn-pipe-Improve-documentation.patch
Description: Text Data

0002-execute-spawn-pipe-Make-multithread-safe-on-native-W.patch
Description: Text Data