bpo-20104: Remove posix_spawn from 3.7 (GH-6794)

Remove os.posix_spawn, the API isn't complete and we're still figuring out how it should look. wait for 3.8.

Author: pablogsal

Doc/library/os.rst

@@ -3365,47 +3365,6 @@ written in Python, such as a mail server's external command delivery program.
    subprocesses.
 
 
-.. function:: posix_spawn(path, argv, env, file_actions=None)
-
-   Wraps the :c:func:`posix_spawn` C library API for use from Python.
-
-   Most users should use :func:`subprocess.run` instead of :func:`posix_spawn`.
-
-   The *path*, *args*, and *env* arguments are similar to :func:`execve`.
-
-   The *file_actions* argument may be a sequence of tuples describing actions
-   to take on specific file descriptors in the child process between the C
-   library implementation's :c:func:`fork` and :c:func:`exec` steps.
-   The first item in each tuple must be one of the three type indicator
-   listed below describing the remaining tuple elements:
-
-   .. data:: POSIX_SPAWN_OPEN
-
-      (``os.POSIX_SPAWN_OPEN``, *fd*, *path*, *flags*, *mode*)
-
-      Performs ``os.dup2(os.open(path, flags, mode), fd)``.
-
-   .. data:: POSIX_SPAWN_CLOSE
-
-      (``os.POSIX_SPAWN_CLOSE``, *fd*)
-
-      Performs ``os.close(fd)``.
-
-   .. data:: POSIX_SPAWN_DUP2
-
-      (``os.POSIX_SPAWN_DUP2``, *fd*, *new_fd*)
-
-      Performs ``os.dup2(fd, new_fd)``.
-
-   These tuples correspond to the C library
-   :c:func:`posix_spawn_file_actions_addopen`,
-   :c:func:`posix_spawn_file_actions_addclose`, and
-   :c:func:`posix_spawn_file_actions_adddup2` API calls used to prepare
-   for the :c:func:`posix_spawn` call itself.
-
-   .. versionadded:: 3.7
-
-
 .. function:: register_at_fork(*, before=None, after_in_parent=None, \
                                after_in_child=None)
 

Doc/whatsnew/3.7.rst

@@ -616,10 +616,6 @@ Exposed the system calls *preadv*, *preadv2*, *pwritev* and *pwritev2* through
 the new functions :func:`~os.preadv` and :func:`~os.pwritev`. (Contributed by
 Pablo Galindo in :issue:`31368`.)
 
-Exposed the system call *posix_spawn* through the new function
-:func:`~os.posix_spawn`. (Contributed by Pablo Galindo, Serhiy Storchaka and
-Gregory P. Smith in :issue:`20104`.)
-
 pdb
 ---
 

Lib/test/test_posix.py

@@ -1421,168 +1421,9 @@ def test_setgroups(self):
             posix.setgroups(groups)
             self.assertListEqual(groups, posix.getgroups())
 
-
-@unittest.skipUnless(hasattr(os, 'posix_spawn'), "test needs os.posix_spawn")
-class TestPosixSpawn(unittest.TestCase):
-    def test_returns_pid(self):
-        pidfile = support.TESTFN
-        self.addCleanup(support.unlink, pidfile)
-        script = f"""if 1:
-            import os
-            with open({pidfile!r}, "w") as pidfile:
-                pidfile.write(str(os.getpid()))
-            """
-        pid = posix.posix_spawn(sys.executable,
-                                [sys.executable, '-c', script],
-                                os.environ)
-        self.assertEqual(os.waitpid(pid, 0), (pid, 0))
-        with open(pidfile) as f:
-            self.assertEqual(f.read(), str(pid))
-
-    def test_no_such_executable(self):
-        no_such_executable = 'no_such_executable'
-        try:
-            pid = posix.posix_spawn(no_such_executable,
-                                    [no_such_executable],
-                                    os.environ)
-        except FileNotFoundError as exc:
-            self.assertEqual(exc.filename, no_such_executable)
-        else:
-            pid2, status = os.waitpid(pid, 0)
-            self.assertEqual(pid2, pid)
-            self.assertNotEqual(status, 0)
-
-    def test_specify_environment(self):
-        envfile = support.TESTFN
-        self.addCleanup(support.unlink, envfile)
-        script = f"""if 1:
-            import os
-            with open({envfile!r}, "w") as envfile:
-                envfile.write(os.environ['foo'])
-        """
-        pid = posix.posix_spawn(sys.executable,
-                                [sys.executable, '-c', script],
-                                {**os.environ, 'foo': 'bar'})
-        self.assertEqual(os.waitpid(pid, 0), (pid, 0))
-        with open(envfile) as f:
-            self.assertEqual(f.read(), 'bar')
-
-    def test_empty_file_actions(self):
-        pid = posix.posix_spawn(
-            sys.executable,
-            [sys.executable, '-c', 'pass'],
-            os.environ,
-            []
-        )
-        self.assertEqual(os.waitpid(pid, 0), (pid, 0))
-
-    def test_multiple_file_actions(self):
-        file_actions = [
-            (os.POSIX_SPAWN_OPEN, 3, os.path.realpath(__file__), os.O_RDONLY, 0),
-            (os.POSIX_SPAWN_CLOSE, 0),
-            (os.POSIX_SPAWN_DUP2, 1, 4),
-        ]
-        pid = posix.posix_spawn(sys.executable,
-                                [sys.executable, "-c", "pass"],
-                                os.environ, file_actions)
-        self.assertEqual(os.waitpid(pid, 0), (pid, 0))
-
-    def test_bad_file_actions(self):
-        with self.assertRaises(TypeError):
-            posix.posix_spawn(sys.executable,
-                              [sys.executable, "-c", "pass"],
-                              os.environ, [None])
-        with self.assertRaises(TypeError):
-            posix.posix_spawn(sys.executable,
-                              [sys.executable, "-c", "pass"],
-                              os.environ, [()])
-        with self.assertRaises(TypeError):
-            posix.posix_spawn(sys.executable,
-                              [sys.executable, "-c", "pass"],
-                              os.environ, [(None,)])
-        with self.assertRaises(TypeError):
-            posix.posix_spawn(sys.executable,
-                              [sys.executable, "-c", "pass"],
-                              os.environ, [(12345,)])
-        with self.assertRaises(TypeError):
-            posix.posix_spawn(sys.executable,
-                              [sys.executable, "-c", "pass"],
-                              os.environ, [(os.POSIX_SPAWN_CLOSE,)])
-        with self.assertRaises(TypeError):
-            posix.posix_spawn(sys.executable,
-                              [sys.executable, "-c", "pass"],
-                              os.environ, [(os.POSIX_SPAWN_CLOSE, 1, 2)])
-        with self.assertRaises(TypeError):
-            posix.posix_spawn(sys.executable,
-                              [sys.executable, "-c", "pass"],
-                              os.environ, [(os.POSIX_SPAWN_CLOSE, None)])
-        with self.assertRaises(ValueError):
-            posix.posix_spawn(sys.executable,
-                              [sys.executable, "-c", "pass"],
-                              os.environ,
-                              [(os.POSIX_SPAWN_OPEN, 3, __file__ + '\0',
-                                os.O_RDONLY, 0)])
-
-    def test_open_file(self):
-        outfile = support.TESTFN
-        self.addCleanup(support.unlink, outfile)
-        script = """if 1:
-            import sys
-            sys.stdout.write("hello")
-            """
-        file_actions = [
-            (os.POSIX_SPAWN_OPEN, 1, outfile,
-                os.O_WRONLY | os.O_CREAT | os.O_TRUNC,
-                stat.S_IRUSR | stat.S_IWUSR),
-        ]
-        pid = posix.posix_spawn(sys.executable,
-                                [sys.executable, '-c', script],
-                                os.environ, file_actions)
-        self.assertEqual(os.waitpid(pid, 0), (pid, 0))
-        with open(outfile) as f:
-            self.assertEqual(f.read(), 'hello')
-
-    def test_close_file(self):
-        closefile = support.TESTFN
-        self.addCleanup(support.unlink, closefile)
-        script = f"""if 1:
-            import os
-            try:
-                os.fstat(0)
-            except OSError as e:
-                with open({closefile!r}, 'w') as closefile:
-                    closefile.write('is closed %d' % e.errno)
-            """
-        pid = posix.posix_spawn(sys.executable,
-                                [sys.executable, '-c', script],
-                                os.environ,
-                                [(os.POSIX_SPAWN_CLOSE, 0),])
-        self.assertEqual(os.waitpid(pid, 0), (pid, 0))
-        with open(closefile) as f:
-            self.assertEqual(f.read(), 'is closed %d' % errno.EBADF)
-
-    def test_dup2(self):
-        dupfile = support.TESTFN
-        self.addCleanup(support.unlink, dupfile)
-        script = """if 1:
-            import sys
-            sys.stdout.write("hello")
-            """
-        with open(dupfile, "wb") as childfile:
-            file_actions = [
-                (os.POSIX_SPAWN_DUP2, childfile.fileno(), 1),
-            ]
-            pid = posix.posix_spawn(sys.executable,
-                                    [sys.executable, '-c', script],
-                                    os.environ, file_actions)
-            self.assertEqual(os.waitpid(pid, 0), (pid, 0))
-        with open(dupfile) as f:
-            self.assertEqual(f.read(), 'hello')
-
-
 def test_main():
     try:
-        support.run_unittest(PosixTester, PosixGroupsTester, TestPosixSpawn)
+        support.run_unittest(PosixTester, PosixGroupsTester)
     finally:
         support.reap_children()
 

Misc/NEWS.d/3.7.0b1.rst

@@ -142,6 +142,7 @@ Remove the STORE_ANNOTATION bytecode.
 .. section: Core and Builtins
 
 Expose posix_spawn as a low level API in the os module.
+(removed before 3.7.0rc1)
 
 ..
 

Misc/NEWS.d/next/Core and Builtins/2018-05-14-11-34-55.bpo-20104.kqBNzv.rst

@@ -0,0 +1,2 @@
+The new `os.posix_spawn` added in 3.7.0b1 was removed as we are still
+working on what the API should look like.  Expect this in 3.8 instead.

Modules/clinic/posixmodule.c.h

@@ -1727,54 +1727,6 @@ os_execve(PyObject *module, PyObject *const *args, Py_ssize_t nargs, PyObject *k
 
 #endif /* defined(HAVE_EXECV) */
 
-#if defined(HAVE_POSIX_SPAWN)
-
-PyDoc_STRVAR(os_posix_spawn__doc__,
-"posix_spawn($module, path, argv, env, file_actions=None, /)\n"
-"--\n"
-"\n"
-"Execute the program specified by path in a new process.\n"
-"\n"
-"  path\n"
-"    Path of executable file.\n"
-"  argv\n"
-"    Tuple or list of strings.\n"
-"  env\n"
-"    Dictionary of strings mapping to strings.\n"
-"  file_actions\n"
-"    A sequence of file action tuples.");
-
-#define OS_POSIX_SPAWN_METHODDEF    \
-    {"posix_spawn", (PyCFunction)os_posix_spawn, METH_FASTCALL, os_posix_spawn__doc__},
-
-static PyObject *
-os_posix_spawn_impl(PyObject *module, path_t *path, PyObject *argv,
-                    PyObject *env, PyObject *file_actions);
-
-static PyObject *
-os_posix_spawn(PyObject *module, PyObject *const *args, Py_ssize_t nargs)
-{
-    PyObject *return_value = NULL;
-    path_t path = PATH_T_INITIALIZE("posix_spawn", "path", 0, 0);
-    PyObject *argv;
-    PyObject *env;
-    PyObject *file_actions = Py_None;
-
-    if (!_PyArg_ParseStack(args, nargs, "O&OO|O:posix_spawn",
-        path_converter, &path, &argv, &env, &file_actions)) {
-        goto exit;
-    }
-    return_value = os_posix_spawn_impl(module, &path, argv, env, file_actions);
-
-exit:
-    /* Cleanup for path */
-    path_cleanup(&path);
-
-    return return_value;
-}
-
-#endif /* defined(HAVE_POSIX_SPAWN) */
-
 #if (defined(HAVE_SPAWNV) || defined(HAVE_WSPAWNV))
 
 PyDoc_STRVAR(os_spawnv__doc__,
@@ -6194,10 +6146,6 @@ os_getrandom(PyObject *module, PyObject *const *args, Py_ssize_t nargs, PyObject
     #define OS_EXECVE_METHODDEF
 #endif /* !defined(OS_EXECVE_METHODDEF) */
 
-#ifndef OS_POSIX_SPAWN_METHODDEF
-    #define OS_POSIX_SPAWN_METHODDEF
-#endif /* !defined(OS_POSIX_SPAWN_METHODDEF) */
-
 #ifndef OS_SPAWNV_METHODDEF
     #define OS_SPAWNV_METHODDEF
 #endif /* !defined(OS_SPAWNV_METHODDEF) */
@@ -6589,4 +6537,4 @@ os_getrandom(PyObject *module, PyObject *const *args, Py_ssize_t nargs, PyObject
 #ifndef OS_GETRANDOM_METHODDEF
     #define OS_GETRANDOM_METHODDEF
 #endif /* !defined(OS_GETRANDOM_METHODDEF) */
-/*[clinic end generated code: output=8d3d9dddf254c3c2 input=a9049054013a1b77]*/
+/*[clinic end generated code: output=c966c821d557b7c0 input=a9049054013a1b77]*/