2 #include "run-command.h"
5 #include "argv-array.h"
6 #include "thread-utils.h"
8 #include "string-list.h"
11 void child_process_init(struct child_process *child)
13 memset(child, 0, sizeof(*child));
14 argv_array_init(&child->args);
15 argv_array_init(&child->env_array);
18 void child_process_clear(struct child_process *child)
20 argv_array_clear(&child->args);
21 argv_array_clear(&child->env_array);
24 struct child_to_clean {
26 struct child_process *process;
27 struct child_to_clean *next;
29 static struct child_to_clean *children_to_clean;
30 static int installed_child_cleanup_handler;
32 static void cleanup_children(int sig, int in_signal)
34 struct child_to_clean *children_to_wait_for = NULL;
36 while (children_to_clean) {
37 struct child_to_clean *p = children_to_clean;
38 children_to_clean = p->next;
40 if (p->process && !in_signal) {
41 struct child_process *process = p->process;
42 if (process->clean_on_exit_handler) {
44 "trace: run_command: running exit handler for pid %"
45 PRIuMAX, (uintmax_t)p->pid
47 process->clean_on_exit_handler(process);
53 if (p->process && p->process->wait_after_clean) {
54 p->next = children_to_wait_for;
55 children_to_wait_for = p;
62 while (children_to_wait_for) {
63 struct child_to_clean *p = children_to_wait_for;
64 children_to_wait_for = p->next;
66 while (waitpid(p->pid, NULL, 0) < 0 && errno == EINTR)
67 ; /* spin waiting for process exit or error */
74 static void cleanup_children_on_signal(int sig)
76 cleanup_children(sig, 1);
81 static void cleanup_children_on_exit(void)
83 cleanup_children(SIGTERM, 0);
86 static void mark_child_for_cleanup(pid_t pid, struct child_process *process)
88 struct child_to_clean *p = xmalloc(sizeof(*p));
91 p->next = children_to_clean;
92 children_to_clean = p;
94 if (!installed_child_cleanup_handler) {
95 atexit(cleanup_children_on_exit);
96 sigchain_push_common(cleanup_children_on_signal);
97 installed_child_cleanup_handler = 1;
101 static void clear_child_for_cleanup(pid_t pid)
103 struct child_to_clean **pp;
105 for (pp = &children_to_clean; *pp; pp = &(*pp)->next) {
106 struct child_to_clean *clean_me = *pp;
108 if (clean_me->pid == pid) {
109 *pp = clean_me->next;
116 static inline void close_pair(int fd[2])
122 int is_executable(const char *name)
126 if (stat(name, &st) || /* stat, not lstat */
127 !S_ISREG(st.st_mode))
130 #if defined(GIT_WINDOWS_NATIVE)
132 * On Windows there is no executable bit. The file extension
133 * indicates whether it can be run as an executable, and Git
134 * has special-handling to detect scripts and launch them
135 * through the indicated script interpreter. We test for the
136 * file extension first because virus scanners may make
137 * it quite expensive to open many files.
139 if (ends_with(name, ".exe"))
144 * Now that we know it does not have an executable extension,
145 * peek into the file instead.
149 int fd = open(name, O_RDONLY);
150 st.st_mode &= ~S_IXUSR;
152 n = read(fd, buf, 2);
154 /* look for a she-bang */
155 if (!strcmp(buf, "#!"))
156 st.st_mode |= S_IXUSR;
161 return st.st_mode & S_IXUSR;
165 * Search $PATH for a command. This emulates the path search that
166 * execvp would perform, without actually executing the command so it
167 * can be used before fork() to prepare to run a command using
168 * execve() or after execvp() to diagnose why it failed.
170 * The caller should ensure that file contains no directory
173 * Returns the path to the command, as found in $PATH or NULL if the
174 * command could not be found. The caller inherits ownership of the memory
175 * used to store the resultant path.
177 * This should not be used on Windows, where the $PATH search rules
178 * are more complicated (e.g., a search for "foo" should find
181 static char *locate_in_PATH(const char *file)
183 const char *p = getenv("PATH");
184 struct strbuf buf = STRBUF_INIT;
190 const char *end = strchrnul(p, ':');
194 /* POSIX specifies an empty entry as the current directory. */
196 strbuf_add(&buf, p, end - p);
197 strbuf_addch(&buf, '/');
199 strbuf_addstr(&buf, file);
201 if (is_executable(buf.buf))
202 return strbuf_detach(&buf, NULL);
209 strbuf_release(&buf);
213 static int exists_in_PATH(const char *file)
215 char *r = locate_in_PATH(file);
220 int sane_execvp(const char *file, char * const argv[])
222 #ifndef GIT_WINDOWS_NATIVE
224 * execvp() doesn't return, so we all we can do is tell trace2
225 * what we are about to do and let it leave a hint in the log
226 * (unless of course the execvp() fails).
228 * we skip this for Windows because the compat layer already
229 * has to emulate the execvp() call anyway.
231 int exec_id = trace2_exec(file, (const char **)argv);
234 if (!execvp(file, argv))
235 return 0; /* cannot happen ;-) */
237 #ifndef GIT_WINDOWS_NATIVE
240 trace2_exec_result(exec_id, ec);
246 * When a command can't be found because one of the directories
247 * listed in $PATH is unsearchable, execvp reports EACCES, but
248 * careful usability testing (read: analysis of occasional bug
249 * reports) reveals that "No such file or directory" is more
252 * We avoid commands with "/", because execvp will not do $PATH
253 * lookups in that case.
255 * The reassignment of EACCES to errno looks like a no-op below,
256 * but we need to protect against exists_in_PATH overwriting errno.
258 if (errno == EACCES && !strchr(file, '/'))
259 errno = exists_in_PATH(file) ? EACCES : ENOENT;
260 else if (errno == ENOTDIR && !strchr(file, '/'))
265 static const char **prepare_shell_cmd(struct argv_array *out, const char **argv)
268 BUG("shell command is empty");
270 if (strcspn(argv[0], "|&;<>()$`\\\"' \t\n*?[#~=%") != strlen(argv[0])) {
271 #ifndef GIT_WINDOWS_NATIVE
272 argv_array_push(out, SHELL_PATH);
274 argv_array_push(out, "sh");
276 argv_array_push(out, "-c");
279 * If we have no extra arguments, we do not even need to
280 * bother with the "$@" magic.
283 argv_array_push(out, argv[0]);
285 argv_array_pushf(out, "%s \"$@\"", argv[0]);
288 argv_array_pushv(out, argv);
292 #ifndef GIT_WINDOWS_NATIVE
293 static int child_notifier = -1;
299 CHILD_ERR_SIGPROCMASK,
306 enum child_errcode err;
307 int syserr; /* errno */
310 static void child_die(enum child_errcode err)
312 struct child_err buf;
317 /* write(2) on buf smaller than PIPE_BUF (min 512) is atomic: */
318 xwrite(child_notifier, &buf, sizeof(buf));
322 static void child_dup2(int fd, int to)
324 if (dup2(fd, to) < 0)
325 child_die(CHILD_ERR_DUP2);
328 static void child_close(int fd)
331 child_die(CHILD_ERR_CLOSE);
334 static void child_close_pair(int fd[2])
341 * parent will make it look like the child spewed a fatal error and died
342 * this is needed to prevent changes to t0061.
344 static void fake_fatal(const char *err, va_list params)
346 vreportf("fatal: ", err, params);
349 static void child_error_fn(const char *err, va_list params)
351 const char msg[] = "error() should not be called in child\n";
352 xwrite(2, msg, sizeof(msg) - 1);
355 static void child_warn_fn(const char *err, va_list params)
357 const char msg[] = "warn() should not be called in child\n";
358 xwrite(2, msg, sizeof(msg) - 1);
361 static void NORETURN child_die_fn(const char *err, va_list params)
363 const char msg[] = "die() should not be called in child\n";
364 xwrite(2, msg, sizeof(msg) - 1);
368 /* this runs in the parent process */
369 static void child_err_spew(struct child_process *cmd, struct child_err *cerr)
371 static void (*old_errfn)(const char *err, va_list params);
373 old_errfn = get_error_routine();
374 set_error_routine(fake_fatal);
375 errno = cerr->syserr;
378 case CHILD_ERR_CHDIR:
379 error_errno("exec '%s': cd to '%s' failed",
380 cmd->argv[0], cmd->dir);
383 error_errno("dup2() in child failed");
385 case CHILD_ERR_CLOSE:
386 error_errno("close() in child failed");
388 case CHILD_ERR_SIGPROCMASK:
389 error_errno("sigprocmask failed restoring signals");
391 case CHILD_ERR_ENOENT:
392 error_errno("cannot run %s", cmd->argv[0]);
394 case CHILD_ERR_SILENT:
396 case CHILD_ERR_ERRNO:
397 error_errno("cannot exec '%s'", cmd->argv[0]);
400 set_error_routine(old_errfn);
403 static int prepare_cmd(struct argv_array *out, const struct child_process *cmd)
406 BUG("command is empty");
409 * Add SHELL_PATH so in the event exec fails with ENOEXEC we can
410 * attempt to interpret the command with 'sh'.
412 argv_array_push(out, SHELL_PATH);
415 prepare_git_cmd(out, cmd->argv);
416 } else if (cmd->use_shell) {
417 prepare_shell_cmd(out, cmd->argv);
419 argv_array_pushv(out, cmd->argv);
423 * If there are no '/' characters in the command then perform a path
424 * lookup and use the resolved path as the command to exec. If there
425 * are '/' characters, we have exec attempt to invoke the command
428 if (!strchr(out->argv[1], '/')) {
429 char *program = locate_in_PATH(out->argv[1]);
431 free((char *)out->argv[1]);
432 out->argv[1] = program;
434 argv_array_clear(out);
443 static char **prep_childenv(const char *const *deltaenv)
445 extern char **environ;
447 struct string_list env = STRING_LIST_INIT_DUP;
448 struct strbuf key = STRBUF_INIT;
449 const char *const *p;
452 /* Construct a sorted string list consisting of the current environ */
453 for (p = (const char *const *) environ; p && *p; p++) {
454 const char *equals = strchr(*p, '=');
458 strbuf_add(&key, *p, equals - *p);
459 string_list_append(&env, key.buf)->util = (void *) *p;
461 string_list_append(&env, *p)->util = (void *) *p;
464 string_list_sort(&env);
466 /* Merge in 'deltaenv' with the current environ */
467 for (p = deltaenv; p && *p; p++) {
468 const char *equals = strchr(*p, '=');
471 /* ('key=value'), insert or replace entry */
473 strbuf_add(&key, *p, equals - *p);
474 string_list_insert(&env, key.buf)->util = (void *) *p;
476 /* otherwise ('key') remove existing entry */
477 string_list_remove(&env, *p, 0);
481 /* Create an array of 'char *' to be used as the childenv */
482 ALLOC_ARRAY(childenv, env.nr + 1);
483 for (i = 0; i < env.nr; i++)
484 childenv[i] = env.items[i].util;
485 childenv[env.nr] = NULL;
487 string_list_clear(&env, 0);
488 strbuf_release(&key);
492 struct atfork_state {
499 #define CHECK_BUG(err, msg) \
503 BUG("%s: %s", msg, strerror(e)); \
506 static void atfork_prepare(struct atfork_state *as)
510 if (sigfillset(&all))
511 die_errno("sigfillset");
513 if (sigprocmask(SIG_SETMASK, &all, &as->old))
514 die_errno("sigprocmask");
516 CHECK_BUG(pthread_sigmask(SIG_SETMASK, &all, &as->old),
517 "blocking all signals");
518 CHECK_BUG(pthread_setcancelstate(PTHREAD_CANCEL_DISABLE, &as->cs),
519 "disabling cancellation");
523 static void atfork_parent(struct atfork_state *as)
526 if (sigprocmask(SIG_SETMASK, &as->old, NULL))
527 die_errno("sigprocmask");
529 CHECK_BUG(pthread_setcancelstate(as->cs, NULL),
530 "re-enabling cancellation");
531 CHECK_BUG(pthread_sigmask(SIG_SETMASK, &as->old, NULL),
532 "restoring signal mask");
535 #endif /* GIT_WINDOWS_NATIVE */
537 static inline void set_cloexec(int fd)
539 int flags = fcntl(fd, F_GETFD);
541 fcntl(fd, F_SETFD, flags | FD_CLOEXEC);
544 static int wait_or_whine(pid_t pid, const char *argv0, int in_signal)
546 int status, code = -1;
548 int failed_errno = 0;
550 while ((waiting = waitpid(pid, &status, 0)) < 0 && errno == EINTR)
556 failed_errno = errno;
557 error_errno("waitpid for %s failed", argv0);
558 } else if (waiting != pid) {
559 error("waitpid is confused (%s)", argv0);
560 } else if (WIFSIGNALED(status)) {
561 code = WTERMSIG(status);
562 if (code != SIGINT && code != SIGQUIT && code != SIGPIPE)
563 error("%s died of signal %d", argv0, code);
565 * This return value is chosen so that code & 0xff
566 * mimics the exit code that a POSIX shell would report for
567 * a program that died from this signal.
570 } else if (WIFEXITED(status)) {
571 code = WEXITSTATUS(status);
573 error("waitpid is confused (%s)", argv0);
576 clear_child_for_cleanup(pid);
578 errno = failed_errno;
582 static void trace_add_env(struct strbuf *dst, const char *const *deltaenv)
584 struct string_list envs = STRING_LIST_INIT_DUP;
585 const char *const *e;
587 int printed_unset = 0;
589 /* Last one wins, see run-command.c:prep_childenv() for context */
590 for (e = deltaenv; e && *e; e++) {
591 struct strbuf key = STRBUF_INIT;
592 char *equals = strchr(*e, '=');
595 strbuf_add(&key, *e, equals - *e);
596 string_list_insert(&envs, key.buf)->util = equals + 1;
598 string_list_insert(&envs, *e)->util = NULL;
600 strbuf_release(&key);
603 /* "unset X Y...;" */
604 for (i = 0; i < envs.nr; i++) {
605 const char *var = envs.items[i].string;
606 const char *val = envs.items[i].util;
608 if (val || !getenv(var))
611 if (!printed_unset) {
612 strbuf_addstr(dst, " unset");
615 strbuf_addf(dst, " %s", var);
618 strbuf_addch(dst, ';');
620 /* ... followed by "A=B C=D ..." */
621 for (i = 0; i < envs.nr; i++) {
622 const char *var = envs.items[i].string;
623 const char *val = envs.items[i].util;
629 oldval = getenv(var);
630 if (oldval && !strcmp(val, oldval))
633 strbuf_addf(dst, " %s=", var);
634 sq_quote_buf_pretty(dst, val);
636 string_list_clear(&envs, 0);
639 static void trace_run_command(const struct child_process *cp)
641 struct strbuf buf = STRBUF_INIT;
643 if (!trace_want(&trace_default_key))
646 strbuf_addstr(&buf, "trace: run_command:");
648 strbuf_addstr(&buf, " cd ");
649 sq_quote_buf_pretty(&buf, cp->dir);
650 strbuf_addch(&buf, ';');
653 * The caller is responsible for initializing cp->env from
654 * cp->env_array if needed. We only check one place.
657 trace_add_env(&buf, cp->env);
659 strbuf_addstr(&buf, " git");
660 sq_quote_argv_pretty(&buf, cp->argv);
662 trace_printf("%s", buf.buf);
663 strbuf_release(&buf);
666 int start_command(struct child_process *cmd)
668 int need_in, need_out, need_err;
669 int fdin[2], fdout[2], fderr[2];
674 cmd->argv = cmd->args.argv;
676 cmd->env = cmd->env_array.argv;
679 * In case of errors we must keep the promise to close FDs
680 * that have been passed in via ->in and ->out.
683 need_in = !cmd->no_stdin && cmd->in < 0;
685 if (pipe(fdin) < 0) {
686 failed_errno = errno;
689 str = "standard input";
695 need_out = !cmd->no_stdout
696 && !cmd->stdout_to_stderr
699 if (pipe(fdout) < 0) {
700 failed_errno = errno;
705 str = "standard output";
711 need_err = !cmd->no_stderr && cmd->err < 0;
713 if (pipe(fderr) < 0) {
714 failed_errno = errno;
723 str = "standard error";
725 error("cannot create %s pipe for %s: %s",
726 str, cmd->argv[0], strerror(failed_errno));
727 child_process_clear(cmd);
728 errno = failed_errno;
734 trace2_child_start(cmd);
735 trace_run_command(cmd);
739 #ifndef GIT_WINDOWS_NATIVE
744 struct argv_array argv = ARGV_ARRAY_INIT;
745 struct child_err cerr;
746 struct atfork_state as;
748 if (prepare_cmd(&argv, cmd) < 0) {
749 failed_errno = errno;
751 if (!cmd->silent_exec_failure)
752 error_errno("cannot run %s", cmd->argv[0]);
756 if (pipe(notify_pipe))
757 notify_pipe[0] = notify_pipe[1] = -1;
759 if (cmd->no_stdin || cmd->no_stdout || cmd->no_stderr) {
760 null_fd = open("/dev/null", O_RDWR | O_CLOEXEC);
762 die_errno(_("open /dev/null failed"));
763 set_cloexec(null_fd);
766 childenv = prep_childenv(cmd->env);
770 * NOTE: In order to prevent deadlocking when using threads special
771 * care should be taken with the function calls made in between the
772 * fork() and exec() calls. No calls should be made to functions which
773 * require acquiring a lock (e.g. malloc) as the lock could have been
774 * held by another thread at the time of forking, causing the lock to
775 * never be released in the child process. This means only
776 * Async-Signal-Safe functions are permitted in the child.
779 failed_errno = errno;
783 * Ensure the default die/error/warn routines do not get
784 * called, they can take stdio locks and malloc.
786 set_die_routine(child_die_fn);
787 set_error_routine(child_error_fn);
788 set_warn_routine(child_warn_fn);
790 close(notify_pipe[0]);
791 set_cloexec(notify_pipe[1]);
792 child_notifier = notify_pipe[1];
795 child_dup2(null_fd, 0);
797 child_dup2(fdin[0], 0);
798 child_close_pair(fdin);
799 } else if (cmd->in) {
800 child_dup2(cmd->in, 0);
801 child_close(cmd->in);
805 child_dup2(null_fd, 2);
807 child_dup2(fderr[1], 2);
808 child_close_pair(fderr);
809 } else if (cmd->err > 1) {
810 child_dup2(cmd->err, 2);
811 child_close(cmd->err);
815 child_dup2(null_fd, 1);
816 else if (cmd->stdout_to_stderr)
819 child_dup2(fdout[1], 1);
820 child_close_pair(fdout);
821 } else if (cmd->out > 1) {
822 child_dup2(cmd->out, 1);
823 child_close(cmd->out);
826 if (cmd->dir && chdir(cmd->dir))
827 child_die(CHILD_ERR_CHDIR);
830 * restore default signal handlers here, in case
831 * we catch a signal right before execve below
833 for (sig = 1; sig < NSIG; sig++) {
834 /* ignored signals get reset to SIG_DFL on execve */
835 if (signal(sig, SIG_DFL) == SIG_IGN)
836 signal(sig, SIG_IGN);
839 if (sigprocmask(SIG_SETMASK, &as.old, NULL) != 0)
840 child_die(CHILD_ERR_SIGPROCMASK);
843 * Attempt to exec using the command and arguments starting at
844 * argv.argv[1]. argv.argv[0] contains SHELL_PATH which will
845 * be used in the event exec failed with ENOEXEC at which point
846 * we will try to interpret the command using 'sh'.
848 execve(argv.argv[1], (char *const *) argv.argv + 1,
849 (char *const *) childenv);
850 if (errno == ENOEXEC)
851 execve(argv.argv[0], (char *const *) argv.argv,
852 (char *const *) childenv);
854 if (errno == ENOENT) {
855 if (cmd->silent_exec_failure)
856 child_die(CHILD_ERR_SILENT);
857 child_die(CHILD_ERR_ENOENT);
859 child_die(CHILD_ERR_ERRNO);
864 error_errno("cannot fork() for %s", cmd->argv[0]);
865 else if (cmd->clean_on_exit)
866 mark_child_for_cleanup(cmd->pid, cmd);
869 * Wait for child's exec. If the exec succeeds (or if fork()
870 * failed), EOF is seen immediately by the parent. Otherwise, the
871 * child process sends a child_err struct.
872 * Note that use of this infrastructure is completely advisory,
873 * therefore, we keep error checks minimal.
875 close(notify_pipe[1]);
876 if (xread(notify_pipe[0], &cerr, sizeof(cerr)) == sizeof(cerr)) {
878 * At this point we know that fork() succeeded, but exec()
879 * failed. Errors have been reported to our stderr.
881 wait_or_whine(cmd->pid, cmd->argv[0], 0);
882 child_err_spew(cmd, &cerr);
883 failed_errno = errno;
886 close(notify_pipe[0]);
890 argv_array_clear(&argv);
897 int fhin = 0, fhout = 1, fherr = 2;
898 const char **sargv = cmd->argv;
899 struct argv_array nargv = ARGV_ARRAY_INIT;
902 fhin = open("/dev/null", O_RDWR);
909 fherr = open("/dev/null", O_RDWR);
911 fherr = dup(fderr[1]);
912 else if (cmd->err > 2)
913 fherr = dup(cmd->err);
916 fhout = open("/dev/null", O_RDWR);
917 else if (cmd->stdout_to_stderr)
920 fhout = dup(fdout[1]);
921 else if (cmd->out > 1)
922 fhout = dup(cmd->out);
925 cmd->argv = prepare_git_cmd(&nargv, cmd->argv);
926 else if (cmd->use_shell)
927 cmd->argv = prepare_shell_cmd(&nargv, cmd->argv);
929 cmd->pid = mingw_spawnvpe(cmd->argv[0], cmd->argv, (char**) cmd->env,
930 cmd->dir, fhin, fhout, fherr);
931 failed_errno = errno;
932 if (cmd->pid < 0 && (!cmd->silent_exec_failure || errno != ENOENT))
933 error_errno("cannot spawn %s", cmd->argv[0]);
934 if (cmd->clean_on_exit && cmd->pid >= 0)
935 mark_child_for_cleanup(cmd->pid, cmd);
937 argv_array_clear(&nargv);
949 trace2_child_exit(cmd, -1);
963 child_process_clear(cmd);
964 errno = failed_errno;
986 int finish_command(struct child_process *cmd)
988 int ret = wait_or_whine(cmd->pid, cmd->argv[0], 0);
989 trace2_child_exit(cmd, ret);
990 child_process_clear(cmd);
994 int finish_command_in_signal(struct child_process *cmd)
996 int ret = wait_or_whine(cmd->pid, cmd->argv[0], 1);
997 trace2_child_exit(cmd, ret);
1002 int run_command(struct child_process *cmd)
1006 if (cmd->out < 0 || cmd->err < 0)
1007 BUG("run_command with a pipe can cause deadlock");
1009 code = start_command(cmd);
1012 return finish_command(cmd);
1015 int run_command_v_opt(const char **argv, int opt)
1017 return run_command_v_opt_cd_env(argv, opt, NULL, NULL);
1020 int run_command_v_opt_tr2(const char **argv, int opt, const char *tr2_class)
1022 return run_command_v_opt_cd_env_tr2(argv, opt, NULL, NULL, tr2_class);
1025 int run_command_v_opt_cd_env(const char **argv, int opt, const char *dir, const char *const *env)
1027 return run_command_v_opt_cd_env_tr2(argv, opt, dir, env, NULL);
1030 int run_command_v_opt_cd_env_tr2(const char **argv, int opt, const char *dir,
1031 const char *const *env, const char *tr2_class)
1033 struct child_process cmd = CHILD_PROCESS_INIT;
1035 cmd.no_stdin = opt & RUN_COMMAND_NO_STDIN ? 1 : 0;
1036 cmd.git_cmd = opt & RUN_GIT_CMD ? 1 : 0;
1037 cmd.stdout_to_stderr = opt & RUN_COMMAND_STDOUT_TO_STDERR ? 1 : 0;
1038 cmd.silent_exec_failure = opt & RUN_SILENT_EXEC_FAILURE ? 1 : 0;
1039 cmd.use_shell = opt & RUN_USING_SHELL ? 1 : 0;
1040 cmd.clean_on_exit = opt & RUN_CLEAN_ON_EXIT ? 1 : 0;
1043 cmd.trace2_child_class = tr2_class;
1044 return run_command(&cmd);
1048 static pthread_t main_thread;
1049 static int main_thread_set;
1050 static pthread_key_t async_key;
1051 static pthread_key_t async_die_counter;
1053 static void *run_thread(void *data)
1055 struct async *async = data;
1058 if (async->isolate_sigpipe) {
1061 sigaddset(&mask, SIGPIPE);
1062 if (pthread_sigmask(SIG_BLOCK, &mask, NULL) < 0) {
1063 ret = error("unable to block SIGPIPE in async thread");
1068 pthread_setspecific(async_key, async);
1069 ret = async->proc(async->proc_in, async->proc_out, async->data);
1073 static NORETURN void die_async(const char *err, va_list params)
1075 vreportf("fatal: ", err, params);
1078 struct async *async = pthread_getspecific(async_key);
1079 if (async->proc_in >= 0)
1080 close(async->proc_in);
1081 if (async->proc_out >= 0)
1082 close(async->proc_out);
1083 pthread_exit((void *)128);
1089 static int async_die_is_recursing(void)
1091 void *ret = pthread_getspecific(async_die_counter);
1092 pthread_setspecific(async_die_counter, (void *)1);
1098 if (!main_thread_set)
1099 return 0; /* no asyncs started yet */
1100 return !pthread_equal(main_thread, pthread_self());
1103 static void NORETURN async_exit(int code)
1105 pthread_exit((void *)(intptr_t)code);
1111 void (**handlers)(void);
1116 static int git_atexit_installed;
1118 static void git_atexit_dispatch(void)
1122 for (i=git_atexit_hdlrs.nr ; i ; i--)
1123 git_atexit_hdlrs.handlers[i-1]();
1126 static void git_atexit_clear(void)
1128 free(git_atexit_hdlrs.handlers);
1129 memset(&git_atexit_hdlrs, 0, sizeof(git_atexit_hdlrs));
1130 git_atexit_installed = 0;
1134 int git_atexit(void (*handler)(void))
1136 ALLOC_GROW(git_atexit_hdlrs.handlers, git_atexit_hdlrs.nr + 1, git_atexit_hdlrs.alloc);
1137 git_atexit_hdlrs.handlers[git_atexit_hdlrs.nr++] = handler;
1138 if (!git_atexit_installed) {
1139 if (atexit(&git_atexit_dispatch))
1141 git_atexit_installed = 1;
1145 #define atexit git_atexit
1147 static int process_is_async;
1150 return process_is_async;
1153 static void NORETURN async_exit(int code)
1160 void check_pipe(int err)
1166 signal(SIGPIPE, SIG_DFL);
1168 /* Should never happen, but just in case... */
1173 int start_async(struct async *async)
1175 int need_in, need_out;
1176 int fdin[2], fdout[2];
1177 int proc_in, proc_out;
1179 need_in = async->in < 0;
1181 if (pipe(fdin) < 0) {
1184 return error_errno("cannot create pipe");
1186 async->in = fdin[1];
1189 need_out = async->out < 0;
1191 if (pipe(fdout) < 0) {
1196 return error_errno("cannot create pipe");
1198 async->out = fdout[0];
1204 proc_in = async->in;
1209 proc_out = fdout[1];
1210 else if (async->out)
1211 proc_out = async->out;
1216 /* Flush stdio before fork() to avoid cloning buffers */
1219 async->pid = fork();
1220 if (async->pid < 0) {
1221 error_errno("fork (async) failed");
1230 process_is_async = 1;
1231 exit(!!async->proc(proc_in, proc_out, async->data));
1234 mark_child_for_cleanup(async->pid, NULL);
1243 else if (async->out)
1246 if (!main_thread_set) {
1248 * We assume that the first time that start_async is called
1249 * it is from the main thread.
1251 main_thread_set = 1;
1252 main_thread = pthread_self();
1253 pthread_key_create(&async_key, NULL);
1254 pthread_key_create(&async_die_counter, NULL);
1255 set_die_routine(die_async);
1256 set_die_is_recursing_routine(async_die_is_recursing);
1260 set_cloexec(proc_in);
1262 set_cloexec(proc_out);
1263 async->proc_in = proc_in;
1264 async->proc_out = proc_out;
1266 int err = pthread_create(&async->tid, NULL, run_thread, async);
1268 error(_("cannot create async thread: %s"), strerror(err));
1283 else if (async->out)
1288 int finish_async(struct async *async)
1291 return wait_or_whine(async->pid, "child process", 0);
1293 void *ret = (void *)(intptr_t)(-1);
1295 if (pthread_join(async->tid, &ret))
1296 error("pthread_join failed");
1297 return (int)(intptr_t)ret;
1301 int async_with_fork(void)
1310 const char *find_hook(const char *name)
1312 static struct strbuf path = STRBUF_INIT;
1314 strbuf_reset(&path);
1315 strbuf_git_path(&path, "hooks/%s", name);
1316 if (access(path.buf, X_OK) < 0) {
1319 #ifdef STRIP_EXTENSION
1320 strbuf_addstr(&path, STRIP_EXTENSION);
1321 if (access(path.buf, X_OK) >= 0)
1323 if (errno == EACCES)
1327 if (err == EACCES && advice_ignored_hook) {
1328 static struct string_list advise_given = STRING_LIST_INIT_DUP;
1330 if (!string_list_lookup(&advise_given, name)) {
1331 string_list_insert(&advise_given, name);
1332 advise(_("The '%s' hook was ignored because "
1333 "it's not set as executable.\n"
1334 "You can disable this warning with "
1335 "`git config advice.ignoredHook false`."),
1344 int run_hook_ve(const char *const *env, const char *name, va_list args)
1346 struct child_process hook = CHILD_PROCESS_INIT;
1349 p = find_hook(name);
1353 argv_array_push(&hook.args, p);
1354 while ((p = va_arg(args, const char *)))
1355 argv_array_push(&hook.args, p);
1358 hook.stdout_to_stderr = 1;
1359 hook.trace2_hook_name = name;
1361 return run_command(&hook);
1364 int run_hook_le(const char *const *env, const char *name, ...)
1369 va_start(args, name);
1370 ret = run_hook_ve(env, name, args);
1377 /* initialized by caller */
1379 int type; /* POLLOUT or POLLIN */
1391 /* returned by pump_io */
1392 int error; /* 0 for success, otherwise errno */
1398 static int pump_io_round(struct io_pump *slots, int nr, struct pollfd *pfd)
1403 for (i = 0; i < nr; i++) {
1404 struct io_pump *io = &slots[i];
1407 pfd[pollsize].fd = io->fd;
1408 pfd[pollsize].events = io->type;
1409 io->pfd = &pfd[pollsize++];
1415 if (poll(pfd, pollsize, -1) < 0) {
1418 die_errno("poll failed");
1421 for (i = 0; i < nr; i++) {
1422 struct io_pump *io = &slots[i];
1427 if (!(io->pfd->revents & (POLLOUT|POLLIN|POLLHUP|POLLERR|POLLNVAL)))
1430 if (io->type == POLLOUT) {
1431 ssize_t len = xwrite(io->fd,
1432 io->u.out.buf, io->u.out.len);
1438 io->u.out.buf += len;
1439 io->u.out.len -= len;
1440 if (!io->u.out.len) {
1447 if (io->type == POLLIN) {
1448 ssize_t len = strbuf_read_once(io->u.in.buf,
1449 io->fd, io->u.in.hint);
1462 static int pump_io(struct io_pump *slots, int nr)
1467 for (i = 0; i < nr; i++)
1470 ALLOC_ARRAY(pfd, nr);
1471 while (pump_io_round(slots, nr, pfd))
1475 /* There may be multiple errno values, so just pick the first. */
1476 for (i = 0; i < nr; i++) {
1477 if (slots[i].error) {
1478 errno = slots[i].error;
1486 int pipe_command(struct child_process *cmd,
1487 const char *in, size_t in_len,
1488 struct strbuf *out, size_t out_hint,
1489 struct strbuf *err, size_t err_hint)
1491 struct io_pump io[3];
1501 if (start_command(cmd) < 0)
1505 io[nr].fd = cmd->in;
1506 io[nr].type = POLLOUT;
1507 io[nr].u.out.buf = in;
1508 io[nr].u.out.len = in_len;
1512 io[nr].fd = cmd->out;
1513 io[nr].type = POLLIN;
1514 io[nr].u.in.buf = out;
1515 io[nr].u.in.hint = out_hint;
1519 io[nr].fd = cmd->err;
1520 io[nr].type = POLLIN;
1521 io[nr].u.in.buf = err;
1522 io[nr].u.in.hint = err_hint;
1526 if (pump_io(io, nr) < 0) {
1527 finish_command(cmd); /* throw away exit code */
1531 return finish_command(cmd);
1537 GIT_CP_WAIT_CLEANUP,
1540 struct parallel_processes {
1546 get_next_task_fn get_next_task;
1547 start_failure_fn start_failure;
1548 task_finished_fn task_finished;
1551 enum child_state state;
1552 struct child_process process;
1557 * The struct pollfd is logically part of *children,
1558 * but the system call expects it as its own array.
1562 unsigned shutdown : 1;
1565 struct strbuf buffered_output; /* of finished children */
1568 static int default_start_failure(struct strbuf *out,
1575 static int default_task_finished(int result,
1583 static void kill_children(struct parallel_processes *pp, int signo)
1585 int i, n = pp->max_processes;
1587 for (i = 0; i < n; i++)
1588 if (pp->children[i].state == GIT_CP_WORKING)
1589 kill(pp->children[i].process.pid, signo);
1592 static struct parallel_processes *pp_for_signal;
1594 static void handle_children_on_signal(int signo)
1596 kill_children(pp_for_signal, signo);
1597 sigchain_pop(signo);
1601 static void pp_init(struct parallel_processes *pp,
1603 get_next_task_fn get_next_task,
1604 start_failure_fn start_failure,
1605 task_finished_fn task_finished,
1613 pp->max_processes = n;
1615 trace_printf("run_processes_parallel: preparing to run up to %d tasks", n);
1619 BUG("you need to specify a get_next_task function");
1620 pp->get_next_task = get_next_task;
1622 pp->start_failure = start_failure ? start_failure : default_start_failure;
1623 pp->task_finished = task_finished ? task_finished : default_task_finished;
1625 pp->nr_processes = 0;
1626 pp->output_owner = 0;
1628 pp->children = xcalloc(n, sizeof(*pp->children));
1629 pp->pfd = xcalloc(n, sizeof(*pp->pfd));
1630 strbuf_init(&pp->buffered_output, 0);
1632 for (i = 0; i < n; i++) {
1633 strbuf_init(&pp->children[i].err, 0);
1634 child_process_init(&pp->children[i].process);
1635 pp->pfd[i].events = POLLIN | POLLHUP;
1640 sigchain_push_common(handle_children_on_signal);
1643 static void pp_cleanup(struct parallel_processes *pp)
1647 trace_printf("run_processes_parallel: done");
1648 for (i = 0; i < pp->max_processes; i++) {
1649 strbuf_release(&pp->children[i].err);
1650 child_process_clear(&pp->children[i].process);
1657 * When get_next_task added messages to the buffer in its last
1658 * iteration, the buffered output is non empty.
1660 strbuf_write(&pp->buffered_output, stderr);
1661 strbuf_release(&pp->buffered_output);
1663 sigchain_pop_common();
1667 * 0 if a new task was started.
1668 * 1 if no new jobs was started (get_next_task ran out of work, non critical
1669 * problem with starting a new command)
1670 * <0 no new job was started, user wishes to shutdown early. Use negative code
1671 * to signal the children.
1673 static int pp_start_one(struct parallel_processes *pp)
1677 for (i = 0; i < pp->max_processes; i++)
1678 if (pp->children[i].state == GIT_CP_FREE)
1680 if (i == pp->max_processes)
1681 BUG("bookkeeping is hard");
1683 code = pp->get_next_task(&pp->children[i].process,
1684 &pp->children[i].err,
1686 &pp->children[i].data);
1688 strbuf_addbuf(&pp->buffered_output, &pp->children[i].err);
1689 strbuf_reset(&pp->children[i].err);
1692 pp->children[i].process.err = -1;
1693 pp->children[i].process.stdout_to_stderr = 1;
1694 pp->children[i].process.no_stdin = 1;
1696 if (start_command(&pp->children[i].process)) {
1697 code = pp->start_failure(&pp->children[i].err,
1699 pp->children[i].data);
1700 strbuf_addbuf(&pp->buffered_output, &pp->children[i].err);
1701 strbuf_reset(&pp->children[i].err);
1708 pp->children[i].state = GIT_CP_WORKING;
1709 pp->pfd[i].fd = pp->children[i].process.err;
1713 static void pp_buffer_stderr(struct parallel_processes *pp, int output_timeout)
1717 while ((i = poll(pp->pfd, pp->max_processes, output_timeout)) < 0) {
1724 /* Buffer output from all pipes. */
1725 for (i = 0; i < pp->max_processes; i++) {
1726 if (pp->children[i].state == GIT_CP_WORKING &&
1727 pp->pfd[i].revents & (POLLIN | POLLHUP)) {
1728 int n = strbuf_read_once(&pp->children[i].err,
1729 pp->children[i].process.err, 0);
1731 close(pp->children[i].process.err);
1732 pp->children[i].state = GIT_CP_WAIT_CLEANUP;
1734 if (errno != EAGAIN)
1740 static void pp_output(struct parallel_processes *pp)
1742 int i = pp->output_owner;
1743 if (pp->children[i].state == GIT_CP_WORKING &&
1744 pp->children[i].err.len) {
1745 strbuf_write(&pp->children[i].err, stderr);
1746 strbuf_reset(&pp->children[i].err);
1750 static int pp_collect_finished(struct parallel_processes *pp)
1753 int n = pp->max_processes;
1756 while (pp->nr_processes > 0) {
1757 for (i = 0; i < pp->max_processes; i++)
1758 if (pp->children[i].state == GIT_CP_WAIT_CLEANUP)
1760 if (i == pp->max_processes)
1763 code = finish_command(&pp->children[i].process);
1765 code = pp->task_finished(code,
1766 &pp->children[i].err, pp->data,
1767 pp->children[i].data);
1775 pp->children[i].state = GIT_CP_FREE;
1777 child_process_init(&pp->children[i].process);
1779 if (i != pp->output_owner) {
1780 strbuf_addbuf(&pp->buffered_output, &pp->children[i].err);
1781 strbuf_reset(&pp->children[i].err);
1783 strbuf_write(&pp->children[i].err, stderr);
1784 strbuf_reset(&pp->children[i].err);
1786 /* Output all other finished child processes */
1787 strbuf_write(&pp->buffered_output, stderr);
1788 strbuf_reset(&pp->buffered_output);
1791 * Pick next process to output live.
1793 * For now we pick it randomly by doing a round
1794 * robin. Later we may want to pick the one with
1795 * the most output or the longest or shortest
1796 * running process time.
1798 for (i = 0; i < n; i++)
1799 if (pp->children[(pp->output_owner + i) % n].state == GIT_CP_WORKING)
1801 pp->output_owner = (pp->output_owner + i) % n;
1807 int run_processes_parallel(int n,
1808 get_next_task_fn get_next_task,
1809 start_failure_fn start_failure,
1810 task_finished_fn task_finished,
1814 int output_timeout = 100;
1816 struct parallel_processes pp;
1818 pp_init(&pp, n, get_next_task, start_failure, task_finished, pp_cb);
1821 i < spawn_cap && !pp.shutdown &&
1822 pp.nr_processes < pp.max_processes;
1824 code = pp_start_one(&pp);
1829 kill_children(&pp, -code);
1833 if (!pp.nr_processes)
1835 pp_buffer_stderr(&pp, output_timeout);
1837 code = pp_collect_finished(&pp);
1841 kill_children(&pp, -code);
1849 int run_processes_parallel_tr2(int n, get_next_task_fn get_next_task,
1850 start_failure_fn start_failure,
1851 task_finished_fn task_finished, void *pp_cb,
1852 const char *tr2_category, const char *tr2_label)
1856 trace2_region_enter_printf(tr2_category, tr2_label, NULL, "max:%d",
1857 ((n < 1) ? online_cpus() : n));
1859 result = run_processes_parallel(n, get_next_task, start_failure,
1860 task_finished, pp_cb);
1862 trace2_region_leave(tr2_category, tr2_label, NULL);