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authorJames Ross-Gowan <rossymiles@gmail.com>2014-11-22 17:21:33 +1100
committerJames Ross-Gowan <rossymiles@gmail.com>2014-11-22 18:15:13 +1100
commitef0d1cddb6d1719b60933fd1dc00f938c095c00c (patch)
treec6ce0882254c12c4bc21e4442ffed382e6ea94b5 /osdep/subprocess-posix.c
parentb2d048440472c8b22abd1945e9ca2cfdfd27f2d0 (diff)
downloadmpv-ef0d1cddb6d1719b60933fd1dc00f938c095c00c.tar.bz2
mpv-ef0d1cddb6d1719b60933fd1dc00f938c095c00c.tar.xz
lua: subprocess: move to osdep/subprocess-{win,posix}.c
The subprocess code was already split into fairly general functions, separate from the Lua code. It's getting pretty big though, especially the Windows-specific parts, so move it into its own files.
Diffstat (limited to 'osdep/subprocess-posix.c')
-rw-r--r--osdep/subprocess-posix.c146
1 files changed, 146 insertions, 0 deletions
diff --git a/osdep/subprocess-posix.c b/osdep/subprocess-posix.c
new file mode 100644
index 0000000000..8dcc5f6304
--- /dev/null
+++ b/osdep/subprocess-posix.c
@@ -0,0 +1,146 @@
+/*
+ * This file is part of mpv.
+ *
+ * mpv is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * mpv is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with mpv. If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include "osdep/subprocess.h"
+
+#include <spawn.h>
+#include <poll.h>
+#include <unistd.h>
+#include <sys/types.h>
+#include <sys/wait.h>
+#include <errno.h>
+#include <signal.h>
+
+#include "osdep/io.h"
+#include "common/common.h"
+
+// Normally, this must be declared manually, but glibc is retarded.
+#ifndef __GLIBC__
+extern char **environ;
+#endif
+
+// A silly helper: automatically skips entries with negative FDs
+static int sparse_poll(struct pollfd *fds, int num_fds, int timeout)
+{
+ struct pollfd p_fds[10];
+ int map[10];
+ if (num_fds > MP_ARRAY_SIZE(p_fds))
+ return -1;
+ int p_num_fds = 0;
+ for (int n = 0; n < num_fds; n++) {
+ map[n] = -1;
+ if (fds[n].fd < 0)
+ continue;
+ map[n] = p_num_fds;
+ p_fds[p_num_fds++] = fds[n];
+ }
+ int r = poll(p_fds, p_num_fds, timeout);
+ for (int n = 0; n < num_fds; n++)
+ fds[n].revents = (map[n] < 0 && r >= 0) ? 0 : p_fds[map[n]].revents;
+ return r;
+}
+
+int mp_subprocess(char **args, struct mp_cancel *cancel, void *ctx,
+ subprocess_read_cb on_stdout, subprocess_read_cb on_stderr,
+ char **error)
+{
+ posix_spawn_file_actions_t fa;
+ bool fa_destroy = false;
+ int status = -1;
+ int p_stdout[2] = {-1, -1};
+ int p_stderr[2] = {-1, -1};
+ pid_t pid = -1;
+
+ if (mp_make_cloexec_pipe(p_stdout) < 0)
+ goto done;
+ if (mp_make_cloexec_pipe(p_stderr) < 0)
+ goto done;
+
+ if (posix_spawn_file_actions_init(&fa))
+ goto done;
+ fa_destroy = true;
+ // redirect stdout and stderr
+ if (posix_spawn_file_actions_adddup2(&fa, p_stdout[1], 1))
+ goto done;
+ if (posix_spawn_file_actions_adddup2(&fa, p_stderr[1], 2))
+ goto done;
+
+ if (posix_spawnp(&pid, args[0], &fa, NULL, args, environ)) {
+ pid = -1;
+ goto done;
+ }
+
+ close(p_stdout[1]);
+ p_stdout[1] = -1;
+ close(p_stderr[1]);
+ p_stderr[1] = -1;
+
+ int *read_fds[2] = {&p_stdout[0], &p_stderr[0]};
+ subprocess_read_cb read_cbs[2] = {on_stdout, on_stderr};
+
+ while (p_stdout[0] >= 0 || p_stderr[0] >= 0) {
+ struct pollfd fds[] = {
+ {.events = POLLIN, .fd = *read_fds[0]},
+ {.events = POLLIN, .fd = *read_fds[1]},
+ {.events = POLLIN, .fd = cancel ? mp_cancel_get_fd(cancel) : -1},
+ };
+ if (sparse_poll(fds, MP_ARRAY_SIZE(fds), -1) < 0 && errno != EINTR)
+ break;
+ for (int n = 0; n < 2; n++) {
+ if (fds[n].revents) {
+ char buf[4096];
+ ssize_t r = read(*read_fds[n], buf, sizeof(buf));
+ if (r < 0 && errno == EINTR)
+ continue;
+ if (r > 0 && read_cbs[n])
+ read_cbs[n](ctx, buf, r);
+ if (r <= 0) {
+ close(*read_fds[n]);
+ *read_fds[n] = -1;
+ }
+ }
+ }
+ if (fds[2].revents) {
+ kill(pid, SIGKILL);
+ break;
+ }
+ }
+
+ // Note: it can happen that a child process closes the pipe, but does not
+ // terminate yet. In this case, we would have to run waitpid() in
+ // a separate thread and use pthread_cancel(), or use other weird
+ // and laborious tricks. So this isn't handled yet.
+ while (waitpid(pid, &status, 0) < 0 && errno == EINTR) {}
+
+done:
+ if (fa_destroy)
+ posix_spawn_file_actions_destroy(&fa);
+ close(p_stdout[0]);
+ close(p_stdout[1]);
+ close(p_stderr[0]);
+ close(p_stderr[1]);
+
+ if (WIFEXITED(status) && WEXITSTATUS(status) != 127) {
+ *error = NULL;
+ status = WEXITSTATUS(status);
+ } else {
+ *error = WEXITSTATUS(status) == 127 ? "init" : "killed";
+ status = -1;
+ }
+
+ return status;
+}