2 #include "run-command.h"
6 #include "thread-utils.h"
8 #include "string-list.h"
12 void child_process_init(struct child_process *child)
14 memset(child, 0, sizeof(*child));
15 strvec_init(&child->args);
16 strvec_init(&child->env_array);
19 void child_process_clear(struct child_process *child)
21 strvec_clear(&child->args);
22 strvec_clear(&child->env_array);
25 struct child_to_clean {
27 struct child_process *process;
28 struct child_to_clean *next;
30 static struct child_to_clean *children_to_clean;
31 static int installed_child_cleanup_handler;
33 static void cleanup_children(int sig, int in_signal)
35 struct child_to_clean *children_to_wait_for = NULL;
37 while (children_to_clean) {
38 struct child_to_clean *p = children_to_clean;
39 children_to_clean = p->next;
41 if (p->process && !in_signal) {
42 struct child_process *process = p->process;
43 if (process->clean_on_exit_handler) {
45 "trace: run_command: running exit handler for pid %"
46 PRIuMAX, (uintmax_t)p->pid
48 process->clean_on_exit_handler(process);
54 if (p->process && p->process->wait_after_clean) {
55 p->next = children_to_wait_for;
56 children_to_wait_for = p;
63 while (children_to_wait_for) {
64 struct child_to_clean *p = children_to_wait_for;
65 children_to_wait_for = p->next;
67 while (waitpid(p->pid, NULL, 0) < 0 && errno == EINTR)
68 ; /* spin waiting for process exit or error */
75 static void cleanup_children_on_signal(int sig)
77 cleanup_children(sig, 1);
82 static void cleanup_children_on_exit(void)
84 cleanup_children(SIGTERM, 0);
87 static void mark_child_for_cleanup(pid_t pid, struct child_process *process)
89 struct child_to_clean *p = xmalloc(sizeof(*p));
92 p->next = children_to_clean;
93 children_to_clean = p;
95 if (!installed_child_cleanup_handler) {
96 atexit(cleanup_children_on_exit);
97 sigchain_push_common(cleanup_children_on_signal);
98 installed_child_cleanup_handler = 1;
102 static void clear_child_for_cleanup(pid_t pid)
104 struct child_to_clean **pp;
106 for (pp = &children_to_clean; *pp; pp = &(*pp)->next) {
107 struct child_to_clean *clean_me = *pp;
109 if (clean_me->pid == pid) {
110 *pp = clean_me->next;
117 static inline void close_pair(int fd[2])
123 int is_executable(const char *name)
127 if (stat(name, &st) || /* stat, not lstat */
128 !S_ISREG(st.st_mode))
131 #if defined(GIT_WINDOWS_NATIVE)
133 * On Windows there is no executable bit. The file extension
134 * indicates whether it can be run as an executable, and Git
135 * has special-handling to detect scripts and launch them
136 * through the indicated script interpreter. We test for the
137 * file extension first because virus scanners may make
138 * it quite expensive to open many files.
140 if (ends_with(name, ".exe"))
145 * Now that we know it does not have an executable extension,
146 * peek into the file instead.
150 int fd = open(name, O_RDONLY);
151 st.st_mode &= ~S_IXUSR;
153 n = read(fd, buf, 2);
155 /* look for a she-bang */
156 if (!strcmp(buf, "#!"))
157 st.st_mode |= S_IXUSR;
162 return st.st_mode & S_IXUSR;
166 * Search $PATH for a command. This emulates the path search that
167 * execvp would perform, without actually executing the command so it
168 * can be used before fork() to prepare to run a command using
169 * execve() or after execvp() to diagnose why it failed.
171 * The caller should ensure that file contains no directory
174 * Returns the path to the command, as found in $PATH or NULL if the
175 * command could not be found. The caller inherits ownership of the memory
176 * used to store the resultant path.
178 * This should not be used on Windows, where the $PATH search rules
179 * are more complicated (e.g., a search for "foo" should find
182 static char *locate_in_PATH(const char *file)
184 const char *p = getenv("PATH");
185 struct strbuf buf = STRBUF_INIT;
191 const char *end = strchrnul(p, ':');
195 /* POSIX specifies an empty entry as the current directory. */
197 strbuf_add(&buf, p, end - p);
198 strbuf_addch(&buf, '/');
200 strbuf_addstr(&buf, file);
202 if (is_executable(buf.buf))
203 return strbuf_detach(&buf, NULL);
210 strbuf_release(&buf);
214 static int exists_in_PATH(const char *file)
216 char *r = locate_in_PATH(file);
217 int found = r != NULL;
222 int sane_execvp(const char *file, char * const argv[])
224 #ifndef GIT_WINDOWS_NATIVE
226 * execvp() doesn't return, so we all we can do is tell trace2
227 * what we are about to do and let it leave a hint in the log
228 * (unless of course the execvp() fails).
230 * we skip this for Windows because the compat layer already
231 * has to emulate the execvp() call anyway.
233 int exec_id = trace2_exec(file, (const char **)argv);
236 if (!execvp(file, argv))
237 return 0; /* cannot happen ;-) */
239 #ifndef GIT_WINDOWS_NATIVE
242 trace2_exec_result(exec_id, ec);
248 * When a command can't be found because one of the directories
249 * listed in $PATH is unsearchable, execvp reports EACCES, but
250 * careful usability testing (read: analysis of occasional bug
251 * reports) reveals that "No such file or directory" is more
254 * We avoid commands with "/", because execvp will not do $PATH
255 * lookups in that case.
257 * The reassignment of EACCES to errno looks like a no-op below,
258 * but we need to protect against exists_in_PATH overwriting errno.
260 if (errno == EACCES && !strchr(file, '/'))
261 errno = exists_in_PATH(file) ? EACCES : ENOENT;
262 else if (errno == ENOTDIR && !strchr(file, '/'))
267 static const char **prepare_shell_cmd(struct strvec *out, const char **argv)
270 BUG("shell command is empty");
272 if (strcspn(argv[0], "|&;<>()$`\\\"' \t\n*?[#~=%") != strlen(argv[0])) {
273 #ifndef GIT_WINDOWS_NATIVE
274 strvec_push(out, SHELL_PATH);
276 strvec_push(out, "sh");
278 strvec_push(out, "-c");
281 * If we have no extra arguments, we do not even need to
282 * bother with the "$@" magic.
285 strvec_push(out, argv[0]);
287 strvec_pushf(out, "%s \"$@\"", argv[0]);
290 strvec_pushv(out, argv);
294 #ifndef GIT_WINDOWS_NATIVE
295 static int child_notifier = -1;
301 CHILD_ERR_SIGPROCMASK,
308 enum child_errcode err;
309 int syserr; /* errno */
312 static void child_die(enum child_errcode err)
314 struct child_err buf;
319 /* write(2) on buf smaller than PIPE_BUF (min 512) is atomic: */
320 xwrite(child_notifier, &buf, sizeof(buf));
324 static void child_dup2(int fd, int to)
326 if (dup2(fd, to) < 0)
327 child_die(CHILD_ERR_DUP2);
330 static void child_close(int fd)
333 child_die(CHILD_ERR_CLOSE);
336 static void child_close_pair(int fd[2])
343 * parent will make it look like the child spewed a fatal error and died
344 * this is needed to prevent changes to t0061.
346 static void fake_fatal(const char *err, va_list params)
348 vreportf("fatal: ", err, params);
351 static void child_error_fn(const char *err, va_list params)
353 const char msg[] = "error() should not be called in child\n";
354 xwrite(2, msg, sizeof(msg) - 1);
357 static void child_warn_fn(const char *err, va_list params)
359 const char msg[] = "warn() should not be called in child\n";
360 xwrite(2, msg, sizeof(msg) - 1);
363 static void NORETURN child_die_fn(const char *err, va_list params)
365 const char msg[] = "die() should not be called in child\n";
366 xwrite(2, msg, sizeof(msg) - 1);
370 /* this runs in the parent process */
371 static void child_err_spew(struct child_process *cmd, struct child_err *cerr)
373 static void (*old_errfn)(const char *err, va_list params);
375 old_errfn = get_error_routine();
376 set_error_routine(fake_fatal);
377 errno = cerr->syserr;
380 case CHILD_ERR_CHDIR:
381 error_errno("exec '%s': cd to '%s' failed",
382 cmd->argv[0], cmd->dir);
385 error_errno("dup2() in child failed");
387 case CHILD_ERR_CLOSE:
388 error_errno("close() in child failed");
390 case CHILD_ERR_SIGPROCMASK:
391 error_errno("sigprocmask failed restoring signals");
393 case CHILD_ERR_ENOENT:
394 error_errno("cannot run %s", cmd->argv[0]);
396 case CHILD_ERR_SILENT:
398 case CHILD_ERR_ERRNO:
399 error_errno("cannot exec '%s'", cmd->argv[0]);
402 set_error_routine(old_errfn);
405 static int prepare_cmd(struct strvec *out, const struct child_process *cmd)
408 BUG("command is empty");
411 * Add SHELL_PATH so in the event exec fails with ENOEXEC we can
412 * attempt to interpret the command with 'sh'.
414 strvec_push(out, SHELL_PATH);
417 prepare_git_cmd(out, cmd->argv);
418 } else if (cmd->use_shell) {
419 prepare_shell_cmd(out, cmd->argv);
421 strvec_pushv(out, cmd->argv);
425 * If there are no dir separator characters in the command then perform
426 * a path lookup and use the resolved path as the command to exec. If
427 * there are dir separator characters, we have exec attempt to invoke
428 * the command directly.
430 if (!has_dir_sep(out->v[1])) {
431 char *program = locate_in_PATH(out->v[1]);
433 free((char *)out->v[1]);
445 static char **prep_childenv(const char *const *deltaenv)
447 extern char **environ;
449 struct string_list env = STRING_LIST_INIT_DUP;
450 struct strbuf key = STRBUF_INIT;
451 const char *const *p;
454 /* Construct a sorted string list consisting of the current environ */
455 for (p = (const char *const *) environ; p && *p; p++) {
456 const char *equals = strchr(*p, '=');
460 strbuf_add(&key, *p, equals - *p);
461 string_list_append(&env, key.buf)->util = (void *) *p;
463 string_list_append(&env, *p)->util = (void *) *p;
466 string_list_sort(&env);
468 /* Merge in 'deltaenv' with the current environ */
469 for (p = deltaenv; p && *p; p++) {
470 const char *equals = strchr(*p, '=');
473 /* ('key=value'), insert or replace entry */
475 strbuf_add(&key, *p, equals - *p);
476 string_list_insert(&env, key.buf)->util = (void *) *p;
478 /* otherwise ('key') remove existing entry */
479 string_list_remove(&env, *p, 0);
483 /* Create an array of 'char *' to be used as the childenv */
484 ALLOC_ARRAY(childenv, env.nr + 1);
485 for (i = 0; i < env.nr; i++)
486 childenv[i] = env.items[i].util;
487 childenv[env.nr] = NULL;
489 string_list_clear(&env, 0);
490 strbuf_release(&key);
494 struct atfork_state {
501 #define CHECK_BUG(err, msg) \
505 BUG("%s: %s", msg, strerror(e)); \
508 static void atfork_prepare(struct atfork_state *as)
512 if (sigfillset(&all))
513 die_errno("sigfillset");
515 if (sigprocmask(SIG_SETMASK, &all, &as->old))
516 die_errno("sigprocmask");
518 CHECK_BUG(pthread_sigmask(SIG_SETMASK, &all, &as->old),
519 "blocking all signals");
520 CHECK_BUG(pthread_setcancelstate(PTHREAD_CANCEL_DISABLE, &as->cs),
521 "disabling cancellation");
525 static void atfork_parent(struct atfork_state *as)
528 if (sigprocmask(SIG_SETMASK, &as->old, NULL))
529 die_errno("sigprocmask");
531 CHECK_BUG(pthread_setcancelstate(as->cs, NULL),
532 "re-enabling cancellation");
533 CHECK_BUG(pthread_sigmask(SIG_SETMASK, &as->old, NULL),
534 "restoring signal mask");
537 #endif /* GIT_WINDOWS_NATIVE */
539 static inline void set_cloexec(int fd)
541 int flags = fcntl(fd, F_GETFD);
543 fcntl(fd, F_SETFD, flags | FD_CLOEXEC);
546 static int wait_or_whine(pid_t pid, const char *argv0, int in_signal)
548 int status, code = -1;
550 int failed_errno = 0;
552 while ((waiting = waitpid(pid, &status, 0)) < 0 && errno == EINTR)
555 if (WIFEXITED(status))
556 code = WEXITSTATUS(status);
561 failed_errno = errno;
562 error_errno("waitpid for %s failed", argv0);
563 } else if (waiting != pid) {
564 error("waitpid is confused (%s)", argv0);
565 } else if (WIFSIGNALED(status)) {
566 code = WTERMSIG(status);
567 if (code != SIGINT && code != SIGQUIT && code != SIGPIPE)
568 error("%s died of signal %d", argv0, code);
570 * This return value is chosen so that code & 0xff
571 * mimics the exit code that a POSIX shell would report for
572 * a program that died from this signal.
575 } else if (WIFEXITED(status)) {
576 code = WEXITSTATUS(status);
578 error("waitpid is confused (%s)", argv0);
581 clear_child_for_cleanup(pid);
583 errno = failed_errno;
587 static void trace_add_env(struct strbuf *dst, const char *const *deltaenv)
589 struct string_list envs = STRING_LIST_INIT_DUP;
590 const char *const *e;
592 int printed_unset = 0;
594 /* Last one wins, see run-command.c:prep_childenv() for context */
595 for (e = deltaenv; e && *e; e++) {
596 struct strbuf key = STRBUF_INIT;
597 char *equals = strchr(*e, '=');
600 strbuf_add(&key, *e, equals - *e);
601 string_list_insert(&envs, key.buf)->util = equals + 1;
603 string_list_insert(&envs, *e)->util = NULL;
605 strbuf_release(&key);
608 /* "unset X Y...;" */
609 for (i = 0; i < envs.nr; i++) {
610 const char *var = envs.items[i].string;
611 const char *val = envs.items[i].util;
613 if (val || !getenv(var))
616 if (!printed_unset) {
617 strbuf_addstr(dst, " unset");
620 strbuf_addf(dst, " %s", var);
623 strbuf_addch(dst, ';');
625 /* ... followed by "A=B C=D ..." */
626 for (i = 0; i < envs.nr; i++) {
627 const char *var = envs.items[i].string;
628 const char *val = envs.items[i].util;
634 oldval = getenv(var);
635 if (oldval && !strcmp(val, oldval))
638 strbuf_addf(dst, " %s=", var);
639 sq_quote_buf_pretty(dst, val);
641 string_list_clear(&envs, 0);
644 static void trace_run_command(const struct child_process *cp)
646 struct strbuf buf = STRBUF_INIT;
648 if (!trace_want(&trace_default_key))
651 strbuf_addstr(&buf, "trace: run_command:");
653 strbuf_addstr(&buf, " cd ");
654 sq_quote_buf_pretty(&buf, cp->dir);
655 strbuf_addch(&buf, ';');
658 * The caller is responsible for initializing cp->env from
659 * cp->env_array if needed. We only check one place.
662 trace_add_env(&buf, cp->env);
664 strbuf_addstr(&buf, " git");
665 sq_quote_argv_pretty(&buf, cp->argv);
667 trace_printf("%s", buf.buf);
668 strbuf_release(&buf);
671 int start_command(struct child_process *cmd)
673 int need_in, need_out, need_err;
674 int fdin[2], fdout[2], fderr[2];
679 cmd->argv = cmd->args.v;
681 cmd->env = cmd->env_array.v;
684 * In case of errors we must keep the promise to close FDs
685 * that have been passed in via ->in and ->out.
688 need_in = !cmd->no_stdin && cmd->in < 0;
690 if (pipe(fdin) < 0) {
691 failed_errno = errno;
694 str = "standard input";
700 need_out = !cmd->no_stdout
701 && !cmd->stdout_to_stderr
704 if (pipe(fdout) < 0) {
705 failed_errno = errno;
710 str = "standard output";
716 need_err = !cmd->no_stderr && cmd->err < 0;
718 if (pipe(fderr) < 0) {
719 failed_errno = errno;
728 str = "standard error";
730 error("cannot create %s pipe for %s: %s",
731 str, cmd->argv[0], strerror(failed_errno));
732 child_process_clear(cmd);
733 errno = failed_errno;
739 trace2_child_start(cmd);
740 trace_run_command(cmd);
744 #ifndef GIT_WINDOWS_NATIVE
749 struct strvec argv = STRVEC_INIT;
750 struct child_err cerr;
751 struct atfork_state as;
753 if (prepare_cmd(&argv, cmd) < 0) {
754 failed_errno = errno;
756 if (!cmd->silent_exec_failure)
757 error_errno("cannot run %s", cmd->argv[0]);
761 if (pipe(notify_pipe))
762 notify_pipe[0] = notify_pipe[1] = -1;
764 if (cmd->no_stdin || cmd->no_stdout || cmd->no_stderr) {
765 null_fd = open("/dev/null", O_RDWR | O_CLOEXEC);
767 die_errno(_("open /dev/null failed"));
768 set_cloexec(null_fd);
771 childenv = prep_childenv(cmd->env);
775 * NOTE: In order to prevent deadlocking when using threads special
776 * care should be taken with the function calls made in between the
777 * fork() and exec() calls. No calls should be made to functions which
778 * require acquiring a lock (e.g. malloc) as the lock could have been
779 * held by another thread at the time of forking, causing the lock to
780 * never be released in the child process. This means only
781 * Async-Signal-Safe functions are permitted in the child.
784 failed_errno = errno;
788 * Ensure the default die/error/warn routines do not get
789 * called, they can take stdio locks and malloc.
791 set_die_routine(child_die_fn);
792 set_error_routine(child_error_fn);
793 set_warn_routine(child_warn_fn);
795 close(notify_pipe[0]);
796 set_cloexec(notify_pipe[1]);
797 child_notifier = notify_pipe[1];
800 child_dup2(null_fd, 0);
802 child_dup2(fdin[0], 0);
803 child_close_pair(fdin);
804 } else if (cmd->in) {
805 child_dup2(cmd->in, 0);
806 child_close(cmd->in);
810 child_dup2(null_fd, 2);
812 child_dup2(fderr[1], 2);
813 child_close_pair(fderr);
814 } else if (cmd->err > 1) {
815 child_dup2(cmd->err, 2);
816 child_close(cmd->err);
820 child_dup2(null_fd, 1);
821 else if (cmd->stdout_to_stderr)
824 child_dup2(fdout[1], 1);
825 child_close_pair(fdout);
826 } else if (cmd->out > 1) {
827 child_dup2(cmd->out, 1);
828 child_close(cmd->out);
831 if (cmd->dir && chdir(cmd->dir))
832 child_die(CHILD_ERR_CHDIR);
835 * restore default signal handlers here, in case
836 * we catch a signal right before execve below
838 for (sig = 1; sig < NSIG; sig++) {
839 /* ignored signals get reset to SIG_DFL on execve */
840 if (signal(sig, SIG_DFL) == SIG_IGN)
841 signal(sig, SIG_IGN);
844 if (sigprocmask(SIG_SETMASK, &as.old, NULL) != 0)
845 child_die(CHILD_ERR_SIGPROCMASK);
848 * Attempt to exec using the command and arguments starting at
849 * argv.argv[1]. argv.argv[0] contains SHELL_PATH which will
850 * be used in the event exec failed with ENOEXEC at which point
851 * we will try to interpret the command using 'sh'.
853 execve(argv.v[1], (char *const *) argv.v + 1,
854 (char *const *) childenv);
855 if (errno == ENOEXEC)
856 execve(argv.v[0], (char *const *) argv.v,
857 (char *const *) childenv);
859 if (errno == ENOENT) {
860 if (cmd->silent_exec_failure)
861 child_die(CHILD_ERR_SILENT);
862 child_die(CHILD_ERR_ENOENT);
864 child_die(CHILD_ERR_ERRNO);
869 error_errno("cannot fork() for %s", cmd->argv[0]);
870 else if (cmd->clean_on_exit)
871 mark_child_for_cleanup(cmd->pid, cmd);
874 * Wait for child's exec. If the exec succeeds (or if fork()
875 * failed), EOF is seen immediately by the parent. Otherwise, the
876 * child process sends a child_err struct.
877 * Note that use of this infrastructure is completely advisory,
878 * therefore, we keep error checks minimal.
880 close(notify_pipe[1]);
881 if (xread(notify_pipe[0], &cerr, sizeof(cerr)) == sizeof(cerr)) {
883 * At this point we know that fork() succeeded, but exec()
884 * failed. Errors have been reported to our stderr.
886 wait_or_whine(cmd->pid, cmd->argv[0], 0);
887 child_err_spew(cmd, &cerr);
888 failed_errno = errno;
891 close(notify_pipe[0]);
902 int fhin = 0, fhout = 1, fherr = 2;
903 const char **sargv = cmd->argv;
904 struct strvec nargv = STRVEC_INIT;
907 fhin = open("/dev/null", O_RDWR);
914 fherr = open("/dev/null", O_RDWR);
916 fherr = dup(fderr[1]);
917 else if (cmd->err > 2)
918 fherr = dup(cmd->err);
921 fhout = open("/dev/null", O_RDWR);
922 else if (cmd->stdout_to_stderr)
925 fhout = dup(fdout[1]);
926 else if (cmd->out > 1)
927 fhout = dup(cmd->out);
930 cmd->argv = prepare_git_cmd(&nargv, cmd->argv);
931 else if (cmd->use_shell)
932 cmd->argv = prepare_shell_cmd(&nargv, cmd->argv);
934 cmd->pid = mingw_spawnvpe(cmd->argv[0], cmd->argv, (char**) cmd->env,
935 cmd->dir, fhin, fhout, fherr);
936 failed_errno = errno;
937 if (cmd->pid < 0 && (!cmd->silent_exec_failure || errno != ENOENT))
938 error_errno("cannot spawn %s", cmd->argv[0]);
939 if (cmd->clean_on_exit && cmd->pid >= 0)
940 mark_child_for_cleanup(cmd->pid, cmd);
942 strvec_clear(&nargv);
954 trace2_child_exit(cmd, -1);
968 child_process_clear(cmd);
969 errno = failed_errno;
991 int finish_command(struct child_process *cmd)
993 int ret = wait_or_whine(cmd->pid, cmd->argv[0], 0);
994 trace2_child_exit(cmd, ret);
995 child_process_clear(cmd);
996 invalidate_lstat_cache();
1000 int finish_command_in_signal(struct child_process *cmd)
1002 int ret = wait_or_whine(cmd->pid, cmd->argv[0], 1);
1003 trace2_child_exit(cmd, ret);
1008 int run_command(struct child_process *cmd)
1012 if (cmd->out < 0 || cmd->err < 0)
1013 BUG("run_command with a pipe can cause deadlock");
1015 code = start_command(cmd);
1018 return finish_command(cmd);
1021 int run_command_v_opt(const char **argv, int opt)
1023 return run_command_v_opt_cd_env(argv, opt, NULL, NULL);
1026 int run_command_v_opt_tr2(const char **argv, int opt, const char *tr2_class)
1028 return run_command_v_opt_cd_env_tr2(argv, opt, NULL, NULL, tr2_class);
1031 int run_command_v_opt_cd_env(const char **argv, int opt, const char *dir, const char *const *env)
1033 return run_command_v_opt_cd_env_tr2(argv, opt, dir, env, NULL);
1036 int run_command_v_opt_cd_env_tr2(const char **argv, int opt, const char *dir,
1037 const char *const *env, const char *tr2_class)
1039 struct child_process cmd = CHILD_PROCESS_INIT;
1041 cmd.no_stdin = opt & RUN_COMMAND_NO_STDIN ? 1 : 0;
1042 cmd.git_cmd = opt & RUN_GIT_CMD ? 1 : 0;
1043 cmd.stdout_to_stderr = opt & RUN_COMMAND_STDOUT_TO_STDERR ? 1 : 0;
1044 cmd.silent_exec_failure = opt & RUN_SILENT_EXEC_FAILURE ? 1 : 0;
1045 cmd.use_shell = opt & RUN_USING_SHELL ? 1 : 0;
1046 cmd.clean_on_exit = opt & RUN_CLEAN_ON_EXIT ? 1 : 0;
1047 cmd.wait_after_clean = opt & RUN_WAIT_AFTER_CLEAN ? 1 : 0;
1050 cmd.trace2_child_class = tr2_class;
1051 return run_command(&cmd);
1055 static pthread_t main_thread;
1056 static int main_thread_set;
1057 static pthread_key_t async_key;
1058 static pthread_key_t async_die_counter;
1060 static void *run_thread(void *data)
1062 struct async *async = data;
1065 if (async->isolate_sigpipe) {
1068 sigaddset(&mask, SIGPIPE);
1069 if (pthread_sigmask(SIG_BLOCK, &mask, NULL) < 0) {
1070 ret = error("unable to block SIGPIPE in async thread");
1075 pthread_setspecific(async_key, async);
1076 ret = async->proc(async->proc_in, async->proc_out, async->data);
1080 static NORETURN void die_async(const char *err, va_list params)
1082 vreportf("fatal: ", err, params);
1085 struct async *async = pthread_getspecific(async_key);
1086 if (async->proc_in >= 0)
1087 close(async->proc_in);
1088 if (async->proc_out >= 0)
1089 close(async->proc_out);
1090 pthread_exit((void *)128);
1096 static int async_die_is_recursing(void)
1098 void *ret = pthread_getspecific(async_die_counter);
1099 pthread_setspecific(async_die_counter, (void *)1);
1105 if (!main_thread_set)
1106 return 0; /* no asyncs started yet */
1107 return !pthread_equal(main_thread, pthread_self());
1110 static void NORETURN async_exit(int code)
1112 pthread_exit((void *)(intptr_t)code);
1118 void (**handlers)(void);
1123 static int git_atexit_installed;
1125 static void git_atexit_dispatch(void)
1129 for (i=git_atexit_hdlrs.nr ; i ; i--)
1130 git_atexit_hdlrs.handlers[i-1]();
1133 static void git_atexit_clear(void)
1135 free(git_atexit_hdlrs.handlers);
1136 memset(&git_atexit_hdlrs, 0, sizeof(git_atexit_hdlrs));
1137 git_atexit_installed = 0;
1141 int git_atexit(void (*handler)(void))
1143 ALLOC_GROW(git_atexit_hdlrs.handlers, git_atexit_hdlrs.nr + 1, git_atexit_hdlrs.alloc);
1144 git_atexit_hdlrs.handlers[git_atexit_hdlrs.nr++] = handler;
1145 if (!git_atexit_installed) {
1146 if (atexit(&git_atexit_dispatch))
1148 git_atexit_installed = 1;
1152 #define atexit git_atexit
1154 static int process_is_async;
1157 return process_is_async;
1160 static void NORETURN async_exit(int code)
1167 void check_pipe(int err)
1173 signal(SIGPIPE, SIG_DFL);
1175 /* Should never happen, but just in case... */
1180 int start_async(struct async *async)
1182 int need_in, need_out;
1183 int fdin[2], fdout[2];
1184 int proc_in, proc_out;
1186 need_in = async->in < 0;
1188 if (pipe(fdin) < 0) {
1191 return error_errno("cannot create pipe");
1193 async->in = fdin[1];
1196 need_out = async->out < 0;
1198 if (pipe(fdout) < 0) {
1203 return error_errno("cannot create pipe");
1205 async->out = fdout[0];
1211 proc_in = async->in;
1216 proc_out = fdout[1];
1217 else if (async->out)
1218 proc_out = async->out;
1223 /* Flush stdio before fork() to avoid cloning buffers */
1226 async->pid = fork();
1227 if (async->pid < 0) {
1228 error_errno("fork (async) failed");
1237 process_is_async = 1;
1238 exit(!!async->proc(proc_in, proc_out, async->data));
1241 mark_child_for_cleanup(async->pid, NULL);
1250 else if (async->out)
1253 if (!main_thread_set) {
1255 * We assume that the first time that start_async is called
1256 * it is from the main thread.
1258 main_thread_set = 1;
1259 main_thread = pthread_self();
1260 pthread_key_create(&async_key, NULL);
1261 pthread_key_create(&async_die_counter, NULL);
1262 set_die_routine(die_async);
1263 set_die_is_recursing_routine(async_die_is_recursing);
1267 set_cloexec(proc_in);
1269 set_cloexec(proc_out);
1270 async->proc_in = proc_in;
1271 async->proc_out = proc_out;
1273 int err = pthread_create(&async->tid, NULL, run_thread, async);
1275 error(_("cannot create async thread: %s"), strerror(err));
1290 else if (async->out)
1295 int finish_async(struct async *async)
1298 int ret = wait_or_whine(async->pid, "child process", 0);
1300 invalidate_lstat_cache();
1304 void *ret = (void *)(intptr_t)(-1);
1306 if (pthread_join(async->tid, &ret))
1307 error("pthread_join failed");
1308 invalidate_lstat_cache();
1309 return (int)(intptr_t)ret;
1314 int async_with_fork(void)
1323 const char *find_hook(const char *name)
1325 static struct strbuf path = STRBUF_INIT;
1327 strbuf_reset(&path);
1328 strbuf_git_path(&path, "hooks/%s", name);
1329 if (access(path.buf, X_OK) < 0) {
1332 #ifdef STRIP_EXTENSION
1333 strbuf_addstr(&path, STRIP_EXTENSION);
1334 if (access(path.buf, X_OK) >= 0)
1336 if (errno == EACCES)
1340 if (err == EACCES && advice_ignored_hook) {
1341 static struct string_list advise_given = STRING_LIST_INIT_DUP;
1343 if (!string_list_lookup(&advise_given, name)) {
1344 string_list_insert(&advise_given, name);
1345 advise(_("The '%s' hook was ignored because "
1346 "it's not set as executable.\n"
1347 "You can disable this warning with "
1348 "`git config advice.ignoredHook false`."),
1357 int run_hook_ve(const char *const *env, const char *name, va_list args)
1359 struct child_process hook = CHILD_PROCESS_INIT;
1362 p = find_hook(name);
1366 strvec_push(&hook.args, p);
1367 while ((p = va_arg(args, const char *)))
1368 strvec_push(&hook.args, p);
1371 hook.stdout_to_stderr = 1;
1372 hook.trace2_hook_name = name;
1374 return run_command(&hook);
1377 int run_hook_le(const char *const *env, const char *name, ...)
1382 va_start(args, name);
1383 ret = run_hook_ve(env, name, args);
1390 /* initialized by caller */
1392 int type; /* POLLOUT or POLLIN */
1404 /* returned by pump_io */
1405 int error; /* 0 for success, otherwise errno */
1411 static int pump_io_round(struct io_pump *slots, int nr, struct pollfd *pfd)
1416 for (i = 0; i < nr; i++) {
1417 struct io_pump *io = &slots[i];
1420 pfd[pollsize].fd = io->fd;
1421 pfd[pollsize].events = io->type;
1422 io->pfd = &pfd[pollsize++];
1428 if (poll(pfd, pollsize, -1) < 0) {
1431 die_errno("poll failed");
1434 for (i = 0; i < nr; i++) {
1435 struct io_pump *io = &slots[i];
1440 if (!(io->pfd->revents & (POLLOUT|POLLIN|POLLHUP|POLLERR|POLLNVAL)))
1443 if (io->type == POLLOUT) {
1444 ssize_t len = xwrite(io->fd,
1445 io->u.out.buf, io->u.out.len);
1451 io->u.out.buf += len;
1452 io->u.out.len -= len;
1453 if (!io->u.out.len) {
1460 if (io->type == POLLIN) {
1461 ssize_t len = strbuf_read_once(io->u.in.buf,
1462 io->fd, io->u.in.hint);
1475 static int pump_io(struct io_pump *slots, int nr)
1480 for (i = 0; i < nr; i++)
1483 ALLOC_ARRAY(pfd, nr);
1484 while (pump_io_round(slots, nr, pfd))
1488 /* There may be multiple errno values, so just pick the first. */
1489 for (i = 0; i < nr; i++) {
1490 if (slots[i].error) {
1491 errno = slots[i].error;
1499 int pipe_command(struct child_process *cmd,
1500 const char *in, size_t in_len,
1501 struct strbuf *out, size_t out_hint,
1502 struct strbuf *err, size_t err_hint)
1504 struct io_pump io[3];
1514 if (start_command(cmd) < 0)
1518 io[nr].fd = cmd->in;
1519 io[nr].type = POLLOUT;
1520 io[nr].u.out.buf = in;
1521 io[nr].u.out.len = in_len;
1525 io[nr].fd = cmd->out;
1526 io[nr].type = POLLIN;
1527 io[nr].u.in.buf = out;
1528 io[nr].u.in.hint = out_hint;
1532 io[nr].fd = cmd->err;
1533 io[nr].type = POLLIN;
1534 io[nr].u.in.buf = err;
1535 io[nr].u.in.hint = err_hint;
1539 if (pump_io(io, nr) < 0) {
1540 finish_command(cmd); /* throw away exit code */
1544 return finish_command(cmd);
1550 GIT_CP_WAIT_CLEANUP,
1553 struct parallel_processes {
1559 get_next_task_fn get_next_task;
1560 start_failure_fn start_failure;
1561 task_finished_fn task_finished;
1564 enum child_state state;
1565 struct child_process process;
1570 * The struct pollfd is logically part of *children,
1571 * but the system call expects it as its own array.
1575 unsigned shutdown : 1;
1578 struct strbuf buffered_output; /* of finished children */
1581 static int default_start_failure(struct strbuf *out,
1588 static int default_task_finished(int result,
1596 static void kill_children(struct parallel_processes *pp, int signo)
1598 int i, n = pp->max_processes;
1600 for (i = 0; i < n; i++)
1601 if (pp->children[i].state == GIT_CP_WORKING)
1602 kill(pp->children[i].process.pid, signo);
1605 static struct parallel_processes *pp_for_signal;
1607 static void handle_children_on_signal(int signo)
1609 kill_children(pp_for_signal, signo);
1610 sigchain_pop(signo);
1614 static void pp_init(struct parallel_processes *pp,
1616 get_next_task_fn get_next_task,
1617 start_failure_fn start_failure,
1618 task_finished_fn task_finished,
1626 pp->max_processes = n;
1628 trace_printf("run_processes_parallel: preparing to run up to %d tasks", n);
1632 BUG("you need to specify a get_next_task function");
1633 pp->get_next_task = get_next_task;
1635 pp->start_failure = start_failure ? start_failure : default_start_failure;
1636 pp->task_finished = task_finished ? task_finished : default_task_finished;
1638 pp->nr_processes = 0;
1639 pp->output_owner = 0;
1641 pp->children = xcalloc(n, sizeof(*pp->children));
1642 pp->pfd = xcalloc(n, sizeof(*pp->pfd));
1643 strbuf_init(&pp->buffered_output, 0);
1645 for (i = 0; i < n; i++) {
1646 strbuf_init(&pp->children[i].err, 0);
1647 child_process_init(&pp->children[i].process);
1648 pp->pfd[i].events = POLLIN | POLLHUP;
1653 sigchain_push_common(handle_children_on_signal);
1656 static void pp_cleanup(struct parallel_processes *pp)
1660 trace_printf("run_processes_parallel: done");
1661 for (i = 0; i < pp->max_processes; i++) {
1662 strbuf_release(&pp->children[i].err);
1663 child_process_clear(&pp->children[i].process);
1670 * When get_next_task added messages to the buffer in its last
1671 * iteration, the buffered output is non empty.
1673 strbuf_write(&pp->buffered_output, stderr);
1674 strbuf_release(&pp->buffered_output);
1676 sigchain_pop_common();
1680 * 0 if a new task was started.
1681 * 1 if no new jobs was started (get_next_task ran out of work, non critical
1682 * problem with starting a new command)
1683 * <0 no new job was started, user wishes to shutdown early. Use negative code
1684 * to signal the children.
1686 static int pp_start_one(struct parallel_processes *pp)
1690 for (i = 0; i < pp->max_processes; i++)
1691 if (pp->children[i].state == GIT_CP_FREE)
1693 if (i == pp->max_processes)
1694 BUG("bookkeeping is hard");
1696 code = pp->get_next_task(&pp->children[i].process,
1697 &pp->children[i].err,
1699 &pp->children[i].data);
1701 strbuf_addbuf(&pp->buffered_output, &pp->children[i].err);
1702 strbuf_reset(&pp->children[i].err);
1705 pp->children[i].process.err = -1;
1706 pp->children[i].process.stdout_to_stderr = 1;
1707 pp->children[i].process.no_stdin = 1;
1709 if (start_command(&pp->children[i].process)) {
1710 code = pp->start_failure(&pp->children[i].err,
1712 pp->children[i].data);
1713 strbuf_addbuf(&pp->buffered_output, &pp->children[i].err);
1714 strbuf_reset(&pp->children[i].err);
1721 pp->children[i].state = GIT_CP_WORKING;
1722 pp->pfd[i].fd = pp->children[i].process.err;
1726 static void pp_buffer_stderr(struct parallel_processes *pp, int output_timeout)
1730 while ((i = poll(pp->pfd, pp->max_processes, output_timeout)) < 0) {
1737 /* Buffer output from all pipes. */
1738 for (i = 0; i < pp->max_processes; i++) {
1739 if (pp->children[i].state == GIT_CP_WORKING &&
1740 pp->pfd[i].revents & (POLLIN | POLLHUP)) {
1741 int n = strbuf_read_once(&pp->children[i].err,
1742 pp->children[i].process.err, 0);
1744 close(pp->children[i].process.err);
1745 pp->children[i].state = GIT_CP_WAIT_CLEANUP;
1747 if (errno != EAGAIN)
1753 static void pp_output(struct parallel_processes *pp)
1755 int i = pp->output_owner;
1756 if (pp->children[i].state == GIT_CP_WORKING &&
1757 pp->children[i].err.len) {
1758 strbuf_write(&pp->children[i].err, stderr);
1759 strbuf_reset(&pp->children[i].err);
1763 static int pp_collect_finished(struct parallel_processes *pp)
1766 int n = pp->max_processes;
1769 while (pp->nr_processes > 0) {
1770 for (i = 0; i < pp->max_processes; i++)
1771 if (pp->children[i].state == GIT_CP_WAIT_CLEANUP)
1773 if (i == pp->max_processes)
1776 code = finish_command(&pp->children[i].process);
1778 code = pp->task_finished(code,
1779 &pp->children[i].err, pp->data,
1780 pp->children[i].data);
1788 pp->children[i].state = GIT_CP_FREE;
1790 child_process_init(&pp->children[i].process);
1792 if (i != pp->output_owner) {
1793 strbuf_addbuf(&pp->buffered_output, &pp->children[i].err);
1794 strbuf_reset(&pp->children[i].err);
1796 strbuf_write(&pp->children[i].err, stderr);
1797 strbuf_reset(&pp->children[i].err);
1799 /* Output all other finished child processes */
1800 strbuf_write(&pp->buffered_output, stderr);
1801 strbuf_reset(&pp->buffered_output);
1804 * Pick next process to output live.
1806 * For now we pick it randomly by doing a round
1807 * robin. Later we may want to pick the one with
1808 * the most output or the longest or shortest
1809 * running process time.
1811 for (i = 0; i < n; i++)
1812 if (pp->children[(pp->output_owner + i) % n].state == GIT_CP_WORKING)
1814 pp->output_owner = (pp->output_owner + i) % n;
1820 int run_processes_parallel(int n,
1821 get_next_task_fn get_next_task,
1822 start_failure_fn start_failure,
1823 task_finished_fn task_finished,
1827 int output_timeout = 100;
1829 struct parallel_processes pp;
1831 pp_init(&pp, n, get_next_task, start_failure, task_finished, pp_cb);
1834 i < spawn_cap && !pp.shutdown &&
1835 pp.nr_processes < pp.max_processes;
1837 code = pp_start_one(&pp);
1842 kill_children(&pp, -code);
1846 if (!pp.nr_processes)
1848 pp_buffer_stderr(&pp, output_timeout);
1850 code = pp_collect_finished(&pp);
1854 kill_children(&pp, -code);
1862 int run_processes_parallel_tr2(int n, get_next_task_fn get_next_task,
1863 start_failure_fn start_failure,
1864 task_finished_fn task_finished, void *pp_cb,
1865 const char *tr2_category, const char *tr2_label)
1869 trace2_region_enter_printf(tr2_category, tr2_label, NULL, "max:%d",
1870 ((n < 1) ? online_cpus() : n));
1872 result = run_processes_parallel(n, get_next_task, start_failure,
1873 task_finished, pp_cb);
1875 trace2_region_leave(tr2_category, tr2_label, NULL);
1880 int run_auto_maintenance(int quiet)
1883 struct child_process maint = CHILD_PROCESS_INIT;
1885 if (!git_config_get_bool("maintenance.auto", &enabled) &&
1890 strvec_pushl(&maint.args, "maintenance", "run", "--auto", NULL);
1891 strvec_push(&maint.args, quiet ? "--quiet" : "--no-quiet");
1893 return run_command(&maint);