transport-helper: drop read/write errno checks
[git.git] / run-command.c
blob3db26b7b0e2ab9b6b615387b36a2cd6b64800e9e
1 #include "cache.h"
2 #include "run-command.h"
3 #include "exec-cmd.h"
4 #include "sigchain.h"
5 #include "argv-array.h"
6 #include "thread-utils.h"
7 #include "strbuf.h"
8 #include "string-list.h"
9 #include "quote.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 {
25 pid_t pid;
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) {
43 trace_printf(
44 "trace: run_command: running exit handler for pid %"
45 PRIuMAX, (uintmax_t)p->pid
47 process->clean_on_exit_handler(process);
51 kill(p->pid, sig);
53 if (p->process && p->process->wait_after_clean) {
54 p->next = children_to_wait_for;
55 children_to_wait_for = p;
56 } else {
57 if (!in_signal)
58 free(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 */
69 if (!in_signal)
70 free(p);
74 static void cleanup_children_on_signal(int sig)
76 cleanup_children(sig, 1);
77 sigchain_pop(sig);
78 raise(sig);
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));
89 p->pid = pid;
90 p->process = process;
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;
110 free(clean_me);
111 return;
116 static inline void close_pair(int fd[2])
118 close(fd[0]);
119 close(fd[1]);
122 int is_executable(const char *name)
124 struct stat st;
126 if (stat(name, &st) || /* stat, not lstat */
127 !S_ISREG(st.st_mode))
128 return 0;
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"))
140 return S_IXUSR;
144 * Now that we know it does not have an executable extension,
145 * peek into the file instead.
147 char buf[3] = { 0 };
148 int n;
149 int fd = open(name, O_RDONLY);
150 st.st_mode &= ~S_IXUSR;
151 if (fd >= 0) {
152 n = read(fd, buf, 2);
153 if (n == 2)
154 /* look for a she-bang */
155 if (!strcmp(buf, "#!"))
156 st.st_mode |= S_IXUSR;
157 close(fd);
160 #endif
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
171 * separators.
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
179 * "foo.exe").
181 static char *locate_in_PATH(const char *file)
183 const char *p = getenv("PATH");
184 struct strbuf buf = STRBUF_INIT;
186 if (!p || !*p)
187 return NULL;
189 while (1) {
190 const char *end = strchrnul(p, ':');
192 strbuf_reset(&buf);
194 /* POSIX specifies an empty entry as the current directory. */
195 if (end != p) {
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);
204 if (!*end)
205 break;
206 p = end + 1;
209 strbuf_release(&buf);
210 return NULL;
213 static int exists_in_PATH(const char *file)
215 char *r = locate_in_PATH(file);
216 free(r);
217 return r != NULL;
220 int sane_execvp(const char *file, char * const argv[])
222 if (!execvp(file, argv))
223 return 0; /* cannot happen ;-) */
226 * When a command can't be found because one of the directories
227 * listed in $PATH is unsearchable, execvp reports EACCES, but
228 * careful usability testing (read: analysis of occasional bug
229 * reports) reveals that "No such file or directory" is more
230 * intuitive.
232 * We avoid commands with "/", because execvp will not do $PATH
233 * lookups in that case.
235 * The reassignment of EACCES to errno looks like a no-op below,
236 * but we need to protect against exists_in_PATH overwriting errno.
238 if (errno == EACCES && !strchr(file, '/'))
239 errno = exists_in_PATH(file) ? EACCES : ENOENT;
240 else if (errno == ENOTDIR && !strchr(file, '/'))
241 errno = ENOENT;
242 return -1;
245 static const char **prepare_shell_cmd(struct argv_array *out, const char **argv)
247 if (!argv[0])
248 BUG("shell command is empty");
250 if (strcspn(argv[0], "|&;<>()$`\\\"' \t\n*?[#~=%") != strlen(argv[0])) {
251 #ifndef GIT_WINDOWS_NATIVE
252 argv_array_push(out, SHELL_PATH);
253 #else
254 argv_array_push(out, "sh");
255 #endif
256 argv_array_push(out, "-c");
259 * If we have no extra arguments, we do not even need to
260 * bother with the "$@" magic.
262 if (!argv[1])
263 argv_array_push(out, argv[0]);
264 else
265 argv_array_pushf(out, "%s \"$@\"", argv[0]);
268 argv_array_pushv(out, argv);
269 return out->argv;
272 #ifndef GIT_WINDOWS_NATIVE
273 static int child_notifier = -1;
275 enum child_errcode {
276 CHILD_ERR_CHDIR,
277 CHILD_ERR_DUP2,
278 CHILD_ERR_CLOSE,
279 CHILD_ERR_SIGPROCMASK,
280 CHILD_ERR_ENOENT,
281 CHILD_ERR_SILENT,
282 CHILD_ERR_ERRNO
285 struct child_err {
286 enum child_errcode err;
287 int syserr; /* errno */
290 static void child_die(enum child_errcode err)
292 struct child_err buf;
294 buf.err = err;
295 buf.syserr = errno;
297 /* write(2) on buf smaller than PIPE_BUF (min 512) is atomic: */
298 xwrite(child_notifier, &buf, sizeof(buf));
299 _exit(1);
302 static void child_dup2(int fd, int to)
304 if (dup2(fd, to) < 0)
305 child_die(CHILD_ERR_DUP2);
308 static void child_close(int fd)
310 if (close(fd))
311 child_die(CHILD_ERR_CLOSE);
314 static void child_close_pair(int fd[2])
316 child_close(fd[0]);
317 child_close(fd[1]);
321 * parent will make it look like the child spewed a fatal error and died
322 * this is needed to prevent changes to t0061.
324 static void fake_fatal(const char *err, va_list params)
326 vreportf("fatal: ", err, params);
329 static void child_error_fn(const char *err, va_list params)
331 const char msg[] = "error() should not be called in child\n";
332 xwrite(2, msg, sizeof(msg) - 1);
335 static void child_warn_fn(const char *err, va_list params)
337 const char msg[] = "warn() should not be called in child\n";
338 xwrite(2, msg, sizeof(msg) - 1);
341 static void NORETURN child_die_fn(const char *err, va_list params)
343 const char msg[] = "die() should not be called in child\n";
344 xwrite(2, msg, sizeof(msg) - 1);
345 _exit(2);
348 /* this runs in the parent process */
349 static void child_err_spew(struct child_process *cmd, struct child_err *cerr)
351 static void (*old_errfn)(const char *err, va_list params);
353 old_errfn = get_error_routine();
354 set_error_routine(fake_fatal);
355 errno = cerr->syserr;
357 switch (cerr->err) {
358 case CHILD_ERR_CHDIR:
359 error_errno("exec '%s': cd to '%s' failed",
360 cmd->argv[0], cmd->dir);
361 break;
362 case CHILD_ERR_DUP2:
363 error_errno("dup2() in child failed");
364 break;
365 case CHILD_ERR_CLOSE:
366 error_errno("close() in child failed");
367 break;
368 case CHILD_ERR_SIGPROCMASK:
369 error_errno("sigprocmask failed restoring signals");
370 break;
371 case CHILD_ERR_ENOENT:
372 error_errno("cannot run %s", cmd->argv[0]);
373 break;
374 case CHILD_ERR_SILENT:
375 break;
376 case CHILD_ERR_ERRNO:
377 error_errno("cannot exec '%s'", cmd->argv[0]);
378 break;
380 set_error_routine(old_errfn);
383 static int prepare_cmd(struct argv_array *out, const struct child_process *cmd)
385 if (!cmd->argv[0])
386 BUG("command is empty");
389 * Add SHELL_PATH so in the event exec fails with ENOEXEC we can
390 * attempt to interpret the command with 'sh'.
392 argv_array_push(out, SHELL_PATH);
394 if (cmd->git_cmd) {
395 argv_array_push(out, "git");
396 argv_array_pushv(out, cmd->argv);
397 } else if (cmd->use_shell) {
398 prepare_shell_cmd(out, cmd->argv);
399 } else {
400 argv_array_pushv(out, cmd->argv);
404 * If there are no '/' characters in the command then perform a path
405 * lookup and use the resolved path as the command to exec. If there
406 * are '/' characters, we have exec attempt to invoke the command
407 * directly.
409 if (!strchr(out->argv[1], '/')) {
410 char *program = locate_in_PATH(out->argv[1]);
411 if (program) {
412 free((char *)out->argv[1]);
413 out->argv[1] = program;
414 } else {
415 argv_array_clear(out);
416 errno = ENOENT;
417 return -1;
421 return 0;
424 static char **prep_childenv(const char *const *deltaenv)
426 extern char **environ;
427 char **childenv;
428 struct string_list env = STRING_LIST_INIT_DUP;
429 struct strbuf key = STRBUF_INIT;
430 const char *const *p;
431 int i;
433 /* Construct a sorted string list consisting of the current environ */
434 for (p = (const char *const *) environ; p && *p; p++) {
435 const char *equals = strchr(*p, '=');
437 if (equals) {
438 strbuf_reset(&key);
439 strbuf_add(&key, *p, equals - *p);
440 string_list_append(&env, key.buf)->util = (void *) *p;
441 } else {
442 string_list_append(&env, *p)->util = (void *) *p;
445 string_list_sort(&env);
447 /* Merge in 'deltaenv' with the current environ */
448 for (p = deltaenv; p && *p; p++) {
449 const char *equals = strchr(*p, '=');
451 if (equals) {
452 /* ('key=value'), insert or replace entry */
453 strbuf_reset(&key);
454 strbuf_add(&key, *p, equals - *p);
455 string_list_insert(&env, key.buf)->util = (void *) *p;
456 } else {
457 /* otherwise ('key') remove existing entry */
458 string_list_remove(&env, *p, 0);
462 /* Create an array of 'char *' to be used as the childenv */
463 ALLOC_ARRAY(childenv, env.nr + 1);
464 for (i = 0; i < env.nr; i++)
465 childenv[i] = env.items[i].util;
466 childenv[env.nr] = NULL;
468 string_list_clear(&env, 0);
469 strbuf_release(&key);
470 return childenv;
473 struct atfork_state {
474 #ifndef NO_PTHREADS
475 int cs;
476 #endif
477 sigset_t old;
480 #define CHECK_BUG(err, msg) \
481 do { \
482 int e = (err); \
483 if (e) \
484 BUG("%s: %s", msg, strerror(e)); \
485 } while(0)
487 static void atfork_prepare(struct atfork_state *as)
489 sigset_t all;
491 if (sigfillset(&all))
492 die_errno("sigfillset");
493 #ifdef NO_PTHREADS
494 if (sigprocmask(SIG_SETMASK, &all, &as->old))
495 die_errno("sigprocmask");
496 #else
497 CHECK_BUG(pthread_sigmask(SIG_SETMASK, &all, &as->old),
498 "blocking all signals");
499 CHECK_BUG(pthread_setcancelstate(PTHREAD_CANCEL_DISABLE, &as->cs),
500 "disabling cancellation");
501 #endif
504 static void atfork_parent(struct atfork_state *as)
506 #ifdef NO_PTHREADS
507 if (sigprocmask(SIG_SETMASK, &as->old, NULL))
508 die_errno("sigprocmask");
509 #else
510 CHECK_BUG(pthread_setcancelstate(as->cs, NULL),
511 "re-enabling cancellation");
512 CHECK_BUG(pthread_sigmask(SIG_SETMASK, &as->old, NULL),
513 "restoring signal mask");
514 #endif
516 #endif /* GIT_WINDOWS_NATIVE */
518 static inline void set_cloexec(int fd)
520 int flags = fcntl(fd, F_GETFD);
521 if (flags >= 0)
522 fcntl(fd, F_SETFD, flags | FD_CLOEXEC);
525 static int wait_or_whine(pid_t pid, const char *argv0, int in_signal)
527 int status, code = -1;
528 pid_t waiting;
529 int failed_errno = 0;
531 while ((waiting = waitpid(pid, &status, 0)) < 0 && errno == EINTR)
532 ; /* nothing */
533 if (in_signal)
534 return 0;
536 if (waiting < 0) {
537 failed_errno = errno;
538 error_errno("waitpid for %s failed", argv0);
539 } else if (waiting != pid) {
540 error("waitpid is confused (%s)", argv0);
541 } else if (WIFSIGNALED(status)) {
542 code = WTERMSIG(status);
543 if (code != SIGINT && code != SIGQUIT && code != SIGPIPE)
544 error("%s died of signal %d", argv0, code);
546 * This return value is chosen so that code & 0xff
547 * mimics the exit code that a POSIX shell would report for
548 * a program that died from this signal.
550 code += 128;
551 } else if (WIFEXITED(status)) {
552 code = WEXITSTATUS(status);
553 } else {
554 error("waitpid is confused (%s)", argv0);
557 clear_child_for_cleanup(pid);
559 errno = failed_errno;
560 return code;
563 static void trace_add_env(struct strbuf *dst, const char *const *deltaenv)
565 struct string_list envs = STRING_LIST_INIT_DUP;
566 const char *const *e;
567 int i;
568 int printed_unset = 0;
570 /* Last one wins, see run-command.c:prep_childenv() for context */
571 for (e = deltaenv; e && *e; e++) {
572 struct strbuf key = STRBUF_INIT;
573 char *equals = strchr(*e, '=');
575 if (equals) {
576 strbuf_add(&key, *e, equals - *e);
577 string_list_insert(&envs, key.buf)->util = equals + 1;
578 } else {
579 string_list_insert(&envs, *e)->util = NULL;
581 strbuf_release(&key);
584 /* "unset X Y...;" */
585 for (i = 0; i < envs.nr; i++) {
586 const char *var = envs.items[i].string;
587 const char *val = envs.items[i].util;
589 if (val || !getenv(var))
590 continue;
592 if (!printed_unset) {
593 strbuf_addstr(dst, " unset");
594 printed_unset = 1;
596 strbuf_addf(dst, " %s", var);
598 if (printed_unset)
599 strbuf_addch(dst, ';');
601 /* ... followed by "A=B C=D ..." */
602 for (i = 0; i < envs.nr; i++) {
603 const char *var = envs.items[i].string;
604 const char *val = envs.items[i].util;
605 const char *oldval;
607 if (!val)
608 continue;
610 oldval = getenv(var);
611 if (oldval && !strcmp(val, oldval))
612 continue;
614 strbuf_addf(dst, " %s=", var);
615 sq_quote_buf_pretty(dst, val);
617 string_list_clear(&envs, 0);
620 static void trace_run_command(const struct child_process *cp)
622 struct strbuf buf = STRBUF_INIT;
624 if (!trace_want(&trace_default_key))
625 return;
627 strbuf_addstr(&buf, "trace: run_command:");
628 if (cp->dir) {
629 strbuf_addstr(&buf, " cd ");
630 sq_quote_buf_pretty(&buf, cp->dir);
631 strbuf_addch(&buf, ';');
634 * The caller is responsible for initializing cp->env from
635 * cp->env_array if needed. We only check one place.
637 if (cp->env)
638 trace_add_env(&buf, cp->env);
639 if (cp->git_cmd)
640 strbuf_addstr(&buf, " git");
641 sq_quote_argv_pretty(&buf, cp->argv);
643 trace_printf("%s", buf.buf);
644 strbuf_release(&buf);
647 int start_command(struct child_process *cmd)
649 int need_in, need_out, need_err;
650 int fdin[2], fdout[2], fderr[2];
651 int failed_errno;
652 char *str;
654 if (!cmd->argv)
655 cmd->argv = cmd->args.argv;
656 if (!cmd->env)
657 cmd->env = cmd->env_array.argv;
660 * In case of errors we must keep the promise to close FDs
661 * that have been passed in via ->in and ->out.
664 need_in = !cmd->no_stdin && cmd->in < 0;
665 if (need_in) {
666 if (pipe(fdin) < 0) {
667 failed_errno = errno;
668 if (cmd->out > 0)
669 close(cmd->out);
670 str = "standard input";
671 goto fail_pipe;
673 cmd->in = fdin[1];
676 need_out = !cmd->no_stdout
677 && !cmd->stdout_to_stderr
678 && cmd->out < 0;
679 if (need_out) {
680 if (pipe(fdout) < 0) {
681 failed_errno = errno;
682 if (need_in)
683 close_pair(fdin);
684 else if (cmd->in)
685 close(cmd->in);
686 str = "standard output";
687 goto fail_pipe;
689 cmd->out = fdout[0];
692 need_err = !cmd->no_stderr && cmd->err < 0;
693 if (need_err) {
694 if (pipe(fderr) < 0) {
695 failed_errno = errno;
696 if (need_in)
697 close_pair(fdin);
698 else if (cmd->in)
699 close(cmd->in);
700 if (need_out)
701 close_pair(fdout);
702 else if (cmd->out)
703 close(cmd->out);
704 str = "standard error";
705 fail_pipe:
706 error("cannot create %s pipe for %s: %s",
707 str, cmd->argv[0], strerror(failed_errno));
708 child_process_clear(cmd);
709 errno = failed_errno;
710 return -1;
712 cmd->err = fderr[0];
715 trace_run_command(cmd);
717 fflush(NULL);
719 #ifndef GIT_WINDOWS_NATIVE
721 int notify_pipe[2];
722 int null_fd = -1;
723 char **childenv;
724 struct argv_array argv = ARGV_ARRAY_INIT;
725 struct child_err cerr;
726 struct atfork_state as;
728 if (prepare_cmd(&argv, cmd) < 0) {
729 failed_errno = errno;
730 cmd->pid = -1;
731 if (!cmd->silent_exec_failure)
732 error_errno("cannot run %s", cmd->argv[0]);
733 goto end_of_spawn;
736 if (pipe(notify_pipe))
737 notify_pipe[0] = notify_pipe[1] = -1;
739 if (cmd->no_stdin || cmd->no_stdout || cmd->no_stderr) {
740 null_fd = open("/dev/null", O_RDWR | O_CLOEXEC);
741 if (null_fd < 0)
742 die_errno(_("open /dev/null failed"));
743 set_cloexec(null_fd);
746 childenv = prep_childenv(cmd->env);
747 atfork_prepare(&as);
750 * NOTE: In order to prevent deadlocking when using threads special
751 * care should be taken with the function calls made in between the
752 * fork() and exec() calls. No calls should be made to functions which
753 * require acquiring a lock (e.g. malloc) as the lock could have been
754 * held by another thread at the time of forking, causing the lock to
755 * never be released in the child process. This means only
756 * Async-Signal-Safe functions are permitted in the child.
758 cmd->pid = fork();
759 failed_errno = errno;
760 if (!cmd->pid) {
761 int sig;
763 * Ensure the default die/error/warn routines do not get
764 * called, they can take stdio locks and malloc.
766 set_die_routine(child_die_fn);
767 set_error_routine(child_error_fn);
768 set_warn_routine(child_warn_fn);
770 close(notify_pipe[0]);
771 set_cloexec(notify_pipe[1]);
772 child_notifier = notify_pipe[1];
774 if (cmd->no_stdin)
775 child_dup2(null_fd, 0);
776 else if (need_in) {
777 child_dup2(fdin[0], 0);
778 child_close_pair(fdin);
779 } else if (cmd->in) {
780 child_dup2(cmd->in, 0);
781 child_close(cmd->in);
784 if (cmd->no_stderr)
785 child_dup2(null_fd, 2);
786 else if (need_err) {
787 child_dup2(fderr[1], 2);
788 child_close_pair(fderr);
789 } else if (cmd->err > 1) {
790 child_dup2(cmd->err, 2);
791 child_close(cmd->err);
794 if (cmd->no_stdout)
795 child_dup2(null_fd, 1);
796 else if (cmd->stdout_to_stderr)
797 child_dup2(2, 1);
798 else if (need_out) {
799 child_dup2(fdout[1], 1);
800 child_close_pair(fdout);
801 } else if (cmd->out > 1) {
802 child_dup2(cmd->out, 1);
803 child_close(cmd->out);
806 if (cmd->dir && chdir(cmd->dir))
807 child_die(CHILD_ERR_CHDIR);
810 * restore default signal handlers here, in case
811 * we catch a signal right before execve below
813 for (sig = 1; sig < NSIG; sig++) {
814 /* ignored signals get reset to SIG_DFL on execve */
815 if (signal(sig, SIG_DFL) == SIG_IGN)
816 signal(sig, SIG_IGN);
819 if (sigprocmask(SIG_SETMASK, &as.old, NULL) != 0)
820 child_die(CHILD_ERR_SIGPROCMASK);
823 * Attempt to exec using the command and arguments starting at
824 * argv.argv[1]. argv.argv[0] contains SHELL_PATH which will
825 * be used in the event exec failed with ENOEXEC at which point
826 * we will try to interpret the command using 'sh'.
828 execve(argv.argv[1], (char *const *) argv.argv + 1,
829 (char *const *) childenv);
830 if (errno == ENOEXEC)
831 execve(argv.argv[0], (char *const *) argv.argv,
832 (char *const *) childenv);
834 if (errno == ENOENT) {
835 if (cmd->silent_exec_failure)
836 child_die(CHILD_ERR_SILENT);
837 child_die(CHILD_ERR_ENOENT);
838 } else {
839 child_die(CHILD_ERR_ERRNO);
842 atfork_parent(&as);
843 if (cmd->pid < 0)
844 error_errno("cannot fork() for %s", cmd->argv[0]);
845 else if (cmd->clean_on_exit)
846 mark_child_for_cleanup(cmd->pid, cmd);
849 * Wait for child's exec. If the exec succeeds (or if fork()
850 * failed), EOF is seen immediately by the parent. Otherwise, the
851 * child process sends a child_err struct.
852 * Note that use of this infrastructure is completely advisory,
853 * therefore, we keep error checks minimal.
855 close(notify_pipe[1]);
856 if (xread(notify_pipe[0], &cerr, sizeof(cerr)) == sizeof(cerr)) {
858 * At this point we know that fork() succeeded, but exec()
859 * failed. Errors have been reported to our stderr.
861 wait_or_whine(cmd->pid, cmd->argv[0], 0);
862 child_err_spew(cmd, &cerr);
863 failed_errno = errno;
864 cmd->pid = -1;
866 close(notify_pipe[0]);
868 if (null_fd >= 0)
869 close(null_fd);
870 argv_array_clear(&argv);
871 free(childenv);
873 end_of_spawn:
875 #else
877 int fhin = 0, fhout = 1, fherr = 2;
878 const char **sargv = cmd->argv;
879 struct argv_array nargv = ARGV_ARRAY_INIT;
881 if (cmd->no_stdin)
882 fhin = open("/dev/null", O_RDWR);
883 else if (need_in)
884 fhin = dup(fdin[0]);
885 else if (cmd->in)
886 fhin = dup(cmd->in);
888 if (cmd->no_stderr)
889 fherr = open("/dev/null", O_RDWR);
890 else if (need_err)
891 fherr = dup(fderr[1]);
892 else if (cmd->err > 2)
893 fherr = dup(cmd->err);
895 if (cmd->no_stdout)
896 fhout = open("/dev/null", O_RDWR);
897 else if (cmd->stdout_to_stderr)
898 fhout = dup(fherr);
899 else if (need_out)
900 fhout = dup(fdout[1]);
901 else if (cmd->out > 1)
902 fhout = dup(cmd->out);
904 if (cmd->git_cmd)
905 cmd->argv = prepare_git_cmd(&nargv, cmd->argv);
906 else if (cmd->use_shell)
907 cmd->argv = prepare_shell_cmd(&nargv, cmd->argv);
909 cmd->pid = mingw_spawnvpe(cmd->argv[0], cmd->argv, (char**) cmd->env,
910 cmd->dir, fhin, fhout, fherr);
911 failed_errno = errno;
912 if (cmd->pid < 0 && (!cmd->silent_exec_failure || errno != ENOENT))
913 error_errno("cannot spawn %s", cmd->argv[0]);
914 if (cmd->clean_on_exit && cmd->pid >= 0)
915 mark_child_for_cleanup(cmd->pid, cmd);
917 argv_array_clear(&nargv);
918 cmd->argv = sargv;
919 if (fhin != 0)
920 close(fhin);
921 if (fhout != 1)
922 close(fhout);
923 if (fherr != 2)
924 close(fherr);
926 #endif
928 if (cmd->pid < 0) {
929 if (need_in)
930 close_pair(fdin);
931 else if (cmd->in)
932 close(cmd->in);
933 if (need_out)
934 close_pair(fdout);
935 else if (cmd->out)
936 close(cmd->out);
937 if (need_err)
938 close_pair(fderr);
939 else if (cmd->err)
940 close(cmd->err);
941 child_process_clear(cmd);
942 errno = failed_errno;
943 return -1;
946 if (need_in)
947 close(fdin[0]);
948 else if (cmd->in)
949 close(cmd->in);
951 if (need_out)
952 close(fdout[1]);
953 else if (cmd->out)
954 close(cmd->out);
956 if (need_err)
957 close(fderr[1]);
958 else if (cmd->err)
959 close(cmd->err);
961 return 0;
964 int finish_command(struct child_process *cmd)
966 int ret = wait_or_whine(cmd->pid, cmd->argv[0], 0);
967 child_process_clear(cmd);
968 return ret;
971 int finish_command_in_signal(struct child_process *cmd)
973 return wait_or_whine(cmd->pid, cmd->argv[0], 1);
977 int run_command(struct child_process *cmd)
979 int code;
981 if (cmd->out < 0 || cmd->err < 0)
982 BUG("run_command with a pipe can cause deadlock");
984 code = start_command(cmd);
985 if (code)
986 return code;
987 return finish_command(cmd);
990 int run_command_v_opt(const char **argv, int opt)
992 return run_command_v_opt_cd_env(argv, opt, NULL, NULL);
995 int run_command_v_opt_cd_env(const char **argv, int opt, const char *dir, const char *const *env)
997 struct child_process cmd = CHILD_PROCESS_INIT;
998 cmd.argv = argv;
999 cmd.no_stdin = opt & RUN_COMMAND_NO_STDIN ? 1 : 0;
1000 cmd.git_cmd = opt & RUN_GIT_CMD ? 1 : 0;
1001 cmd.stdout_to_stderr = opt & RUN_COMMAND_STDOUT_TO_STDERR ? 1 : 0;
1002 cmd.silent_exec_failure = opt & RUN_SILENT_EXEC_FAILURE ? 1 : 0;
1003 cmd.use_shell = opt & RUN_USING_SHELL ? 1 : 0;
1004 cmd.clean_on_exit = opt & RUN_CLEAN_ON_EXIT ? 1 : 0;
1005 cmd.dir = dir;
1006 cmd.env = env;
1007 return run_command(&cmd);
1010 #ifndef NO_PTHREADS
1011 static pthread_t main_thread;
1012 static int main_thread_set;
1013 static pthread_key_t async_key;
1014 static pthread_key_t async_die_counter;
1016 static void *run_thread(void *data)
1018 struct async *async = data;
1019 intptr_t ret;
1021 if (async->isolate_sigpipe) {
1022 sigset_t mask;
1023 sigemptyset(&mask);
1024 sigaddset(&mask, SIGPIPE);
1025 if (pthread_sigmask(SIG_BLOCK, &mask, NULL) < 0) {
1026 ret = error("unable to block SIGPIPE in async thread");
1027 return (void *)ret;
1031 pthread_setspecific(async_key, async);
1032 ret = async->proc(async->proc_in, async->proc_out, async->data);
1033 return (void *)ret;
1036 static NORETURN void die_async(const char *err, va_list params)
1038 vreportf("fatal: ", err, params);
1040 if (in_async()) {
1041 struct async *async = pthread_getspecific(async_key);
1042 if (async->proc_in >= 0)
1043 close(async->proc_in);
1044 if (async->proc_out >= 0)
1045 close(async->proc_out);
1046 pthread_exit((void *)128);
1049 exit(128);
1052 static int async_die_is_recursing(void)
1054 void *ret = pthread_getspecific(async_die_counter);
1055 pthread_setspecific(async_die_counter, (void *)1);
1056 return ret != NULL;
1059 int in_async(void)
1061 if (!main_thread_set)
1062 return 0; /* no asyncs started yet */
1063 return !pthread_equal(main_thread, pthread_self());
1066 static void NORETURN async_exit(int code)
1068 pthread_exit((void *)(intptr_t)code);
1071 #else
1073 static struct {
1074 void (**handlers)(void);
1075 size_t nr;
1076 size_t alloc;
1077 } git_atexit_hdlrs;
1079 static int git_atexit_installed;
1081 static void git_atexit_dispatch(void)
1083 size_t i;
1085 for (i=git_atexit_hdlrs.nr ; i ; i--)
1086 git_atexit_hdlrs.handlers[i-1]();
1089 static void git_atexit_clear(void)
1091 free(git_atexit_hdlrs.handlers);
1092 memset(&git_atexit_hdlrs, 0, sizeof(git_atexit_hdlrs));
1093 git_atexit_installed = 0;
1096 #undef atexit
1097 int git_atexit(void (*handler)(void))
1099 ALLOC_GROW(git_atexit_hdlrs.handlers, git_atexit_hdlrs.nr + 1, git_atexit_hdlrs.alloc);
1100 git_atexit_hdlrs.handlers[git_atexit_hdlrs.nr++] = handler;
1101 if (!git_atexit_installed) {
1102 if (atexit(&git_atexit_dispatch))
1103 return -1;
1104 git_atexit_installed = 1;
1106 return 0;
1108 #define atexit git_atexit
1110 static int process_is_async;
1111 int in_async(void)
1113 return process_is_async;
1116 static void NORETURN async_exit(int code)
1118 exit(code);
1121 #endif
1123 void check_pipe(int err)
1125 if (err == EPIPE) {
1126 if (in_async())
1127 async_exit(141);
1129 signal(SIGPIPE, SIG_DFL);
1130 raise(SIGPIPE);
1131 /* Should never happen, but just in case... */
1132 exit(141);
1136 int start_async(struct async *async)
1138 int need_in, need_out;
1139 int fdin[2], fdout[2];
1140 int proc_in, proc_out;
1142 need_in = async->in < 0;
1143 if (need_in) {
1144 if (pipe(fdin) < 0) {
1145 if (async->out > 0)
1146 close(async->out);
1147 return error_errno("cannot create pipe");
1149 async->in = fdin[1];
1152 need_out = async->out < 0;
1153 if (need_out) {
1154 if (pipe(fdout) < 0) {
1155 if (need_in)
1156 close_pair(fdin);
1157 else if (async->in)
1158 close(async->in);
1159 return error_errno("cannot create pipe");
1161 async->out = fdout[0];
1164 if (need_in)
1165 proc_in = fdin[0];
1166 else if (async->in)
1167 proc_in = async->in;
1168 else
1169 proc_in = -1;
1171 if (need_out)
1172 proc_out = fdout[1];
1173 else if (async->out)
1174 proc_out = async->out;
1175 else
1176 proc_out = -1;
1178 #ifdef NO_PTHREADS
1179 /* Flush stdio before fork() to avoid cloning buffers */
1180 fflush(NULL);
1182 async->pid = fork();
1183 if (async->pid < 0) {
1184 error_errno("fork (async) failed");
1185 goto error;
1187 if (!async->pid) {
1188 if (need_in)
1189 close(fdin[1]);
1190 if (need_out)
1191 close(fdout[0]);
1192 git_atexit_clear();
1193 process_is_async = 1;
1194 exit(!!async->proc(proc_in, proc_out, async->data));
1197 mark_child_for_cleanup(async->pid, NULL);
1199 if (need_in)
1200 close(fdin[0]);
1201 else if (async->in)
1202 close(async->in);
1204 if (need_out)
1205 close(fdout[1]);
1206 else if (async->out)
1207 close(async->out);
1208 #else
1209 if (!main_thread_set) {
1211 * We assume that the first time that start_async is called
1212 * it is from the main thread.
1214 main_thread_set = 1;
1215 main_thread = pthread_self();
1216 pthread_key_create(&async_key, NULL);
1217 pthread_key_create(&async_die_counter, NULL);
1218 set_die_routine(die_async);
1219 set_die_is_recursing_routine(async_die_is_recursing);
1222 if (proc_in >= 0)
1223 set_cloexec(proc_in);
1224 if (proc_out >= 0)
1225 set_cloexec(proc_out);
1226 async->proc_in = proc_in;
1227 async->proc_out = proc_out;
1229 int err = pthread_create(&async->tid, NULL, run_thread, async);
1230 if (err) {
1231 error(_("cannot create async thread: %s"), strerror(err));
1232 goto error;
1235 #endif
1236 return 0;
1238 error:
1239 if (need_in)
1240 close_pair(fdin);
1241 else if (async->in)
1242 close(async->in);
1244 if (need_out)
1245 close_pair(fdout);
1246 else if (async->out)
1247 close(async->out);
1248 return -1;
1251 int finish_async(struct async *async)
1253 #ifdef NO_PTHREADS
1254 return wait_or_whine(async->pid, "child process", 0);
1255 #else
1256 void *ret = (void *)(intptr_t)(-1);
1258 if (pthread_join(async->tid, &ret))
1259 error("pthread_join failed");
1260 return (int)(intptr_t)ret;
1261 #endif
1264 int async_with_fork(void)
1266 #ifdef NO_PTHREADS
1267 return 1;
1268 #else
1269 return 0;
1270 #endif
1273 const char *find_hook(const char *name)
1275 static struct strbuf path = STRBUF_INIT;
1277 strbuf_reset(&path);
1278 strbuf_git_path(&path, "hooks/%s", name);
1279 if (access(path.buf, X_OK) < 0) {
1280 int err = errno;
1282 #ifdef STRIP_EXTENSION
1283 strbuf_addstr(&path, STRIP_EXTENSION);
1284 if (access(path.buf, X_OK) >= 0)
1285 return path.buf;
1286 if (errno == EACCES)
1287 err = errno;
1288 #endif
1290 if (err == EACCES && advice_ignored_hook) {
1291 static struct string_list advise_given = STRING_LIST_INIT_DUP;
1293 if (!string_list_lookup(&advise_given, name)) {
1294 string_list_insert(&advise_given, name);
1295 advise(_("The '%s' hook was ignored because "
1296 "it's not set as executable.\n"
1297 "You can disable this warning with "
1298 "`git config advice.ignoredHook false`."),
1299 path.buf);
1302 return NULL;
1304 return path.buf;
1307 int run_hook_ve(const char *const *env, const char *name, va_list args)
1309 struct child_process hook = CHILD_PROCESS_INIT;
1310 const char *p;
1312 p = find_hook(name);
1313 if (!p)
1314 return 0;
1316 argv_array_push(&hook.args, p);
1317 while ((p = va_arg(args, const char *)))
1318 argv_array_push(&hook.args, p);
1319 hook.env = env;
1320 hook.no_stdin = 1;
1321 hook.stdout_to_stderr = 1;
1323 return run_command(&hook);
1326 int run_hook_le(const char *const *env, const char *name, ...)
1328 va_list args;
1329 int ret;
1331 va_start(args, name);
1332 ret = run_hook_ve(env, name, args);
1333 va_end(args);
1335 return ret;
1338 struct io_pump {
1339 /* initialized by caller */
1340 int fd;
1341 int type; /* POLLOUT or POLLIN */
1342 union {
1343 struct {
1344 const char *buf;
1345 size_t len;
1346 } out;
1347 struct {
1348 struct strbuf *buf;
1349 size_t hint;
1350 } in;
1351 } u;
1353 /* returned by pump_io */
1354 int error; /* 0 for success, otherwise errno */
1356 /* internal use */
1357 struct pollfd *pfd;
1360 static int pump_io_round(struct io_pump *slots, int nr, struct pollfd *pfd)
1362 int pollsize = 0;
1363 int i;
1365 for (i = 0; i < nr; i++) {
1366 struct io_pump *io = &slots[i];
1367 if (io->fd < 0)
1368 continue;
1369 pfd[pollsize].fd = io->fd;
1370 pfd[pollsize].events = io->type;
1371 io->pfd = &pfd[pollsize++];
1374 if (!pollsize)
1375 return 0;
1377 if (poll(pfd, pollsize, -1) < 0) {
1378 if (errno == EINTR)
1379 return 1;
1380 die_errno("poll failed");
1383 for (i = 0; i < nr; i++) {
1384 struct io_pump *io = &slots[i];
1386 if (io->fd < 0)
1387 continue;
1389 if (!(io->pfd->revents & (POLLOUT|POLLIN|POLLHUP|POLLERR|POLLNVAL)))
1390 continue;
1392 if (io->type == POLLOUT) {
1393 ssize_t len = xwrite(io->fd,
1394 io->u.out.buf, io->u.out.len);
1395 if (len < 0) {
1396 io->error = errno;
1397 close(io->fd);
1398 io->fd = -1;
1399 } else {
1400 io->u.out.buf += len;
1401 io->u.out.len -= len;
1402 if (!io->u.out.len) {
1403 close(io->fd);
1404 io->fd = -1;
1409 if (io->type == POLLIN) {
1410 ssize_t len = strbuf_read_once(io->u.in.buf,
1411 io->fd, io->u.in.hint);
1412 if (len < 0)
1413 io->error = errno;
1414 if (len <= 0) {
1415 close(io->fd);
1416 io->fd = -1;
1421 return 1;
1424 static int pump_io(struct io_pump *slots, int nr)
1426 struct pollfd *pfd;
1427 int i;
1429 for (i = 0; i < nr; i++)
1430 slots[i].error = 0;
1432 ALLOC_ARRAY(pfd, nr);
1433 while (pump_io_round(slots, nr, pfd))
1434 ; /* nothing */
1435 free(pfd);
1437 /* There may be multiple errno values, so just pick the first. */
1438 for (i = 0; i < nr; i++) {
1439 if (slots[i].error) {
1440 errno = slots[i].error;
1441 return -1;
1444 return 0;
1448 int pipe_command(struct child_process *cmd,
1449 const char *in, size_t in_len,
1450 struct strbuf *out, size_t out_hint,
1451 struct strbuf *err, size_t err_hint)
1453 struct io_pump io[3];
1454 int nr = 0;
1456 if (in)
1457 cmd->in = -1;
1458 if (out)
1459 cmd->out = -1;
1460 if (err)
1461 cmd->err = -1;
1463 if (start_command(cmd) < 0)
1464 return -1;
1466 if (in) {
1467 io[nr].fd = cmd->in;
1468 io[nr].type = POLLOUT;
1469 io[nr].u.out.buf = in;
1470 io[nr].u.out.len = in_len;
1471 nr++;
1473 if (out) {
1474 io[nr].fd = cmd->out;
1475 io[nr].type = POLLIN;
1476 io[nr].u.in.buf = out;
1477 io[nr].u.in.hint = out_hint;
1478 nr++;
1480 if (err) {
1481 io[nr].fd = cmd->err;
1482 io[nr].type = POLLIN;
1483 io[nr].u.in.buf = err;
1484 io[nr].u.in.hint = err_hint;
1485 nr++;
1488 if (pump_io(io, nr) < 0) {
1489 finish_command(cmd); /* throw away exit code */
1490 return -1;
1493 return finish_command(cmd);
1496 enum child_state {
1497 GIT_CP_FREE,
1498 GIT_CP_WORKING,
1499 GIT_CP_WAIT_CLEANUP,
1502 struct parallel_processes {
1503 void *data;
1505 int max_processes;
1506 int nr_processes;
1508 get_next_task_fn get_next_task;
1509 start_failure_fn start_failure;
1510 task_finished_fn task_finished;
1512 struct {
1513 enum child_state state;
1514 struct child_process process;
1515 struct strbuf err;
1516 void *data;
1517 } *children;
1519 * The struct pollfd is logically part of *children,
1520 * but the system call expects it as its own array.
1522 struct pollfd *pfd;
1524 unsigned shutdown : 1;
1526 int output_owner;
1527 struct strbuf buffered_output; /* of finished children */
1530 static int default_start_failure(struct strbuf *out,
1531 void *pp_cb,
1532 void *pp_task_cb)
1534 return 0;
1537 static int default_task_finished(int result,
1538 struct strbuf *out,
1539 void *pp_cb,
1540 void *pp_task_cb)
1542 return 0;
1545 static void kill_children(struct parallel_processes *pp, int signo)
1547 int i, n = pp->max_processes;
1549 for (i = 0; i < n; i++)
1550 if (pp->children[i].state == GIT_CP_WORKING)
1551 kill(pp->children[i].process.pid, signo);
1554 static struct parallel_processes *pp_for_signal;
1556 static void handle_children_on_signal(int signo)
1558 kill_children(pp_for_signal, signo);
1559 sigchain_pop(signo);
1560 raise(signo);
1563 static void pp_init(struct parallel_processes *pp,
1564 int n,
1565 get_next_task_fn get_next_task,
1566 start_failure_fn start_failure,
1567 task_finished_fn task_finished,
1568 void *data)
1570 int i;
1572 if (n < 1)
1573 n = online_cpus();
1575 pp->max_processes = n;
1577 trace_printf("run_processes_parallel: preparing to run up to %d tasks", n);
1579 pp->data = data;
1580 if (!get_next_task)
1581 BUG("you need to specify a get_next_task function");
1582 pp->get_next_task = get_next_task;
1584 pp->start_failure = start_failure ? start_failure : default_start_failure;
1585 pp->task_finished = task_finished ? task_finished : default_task_finished;
1587 pp->nr_processes = 0;
1588 pp->output_owner = 0;
1589 pp->shutdown = 0;
1590 pp->children = xcalloc(n, sizeof(*pp->children));
1591 pp->pfd = xcalloc(n, sizeof(*pp->pfd));
1592 strbuf_init(&pp->buffered_output, 0);
1594 for (i = 0; i < n; i++) {
1595 strbuf_init(&pp->children[i].err, 0);
1596 child_process_init(&pp->children[i].process);
1597 pp->pfd[i].events = POLLIN | POLLHUP;
1598 pp->pfd[i].fd = -1;
1601 pp_for_signal = pp;
1602 sigchain_push_common(handle_children_on_signal);
1605 static void pp_cleanup(struct parallel_processes *pp)
1607 int i;
1609 trace_printf("run_processes_parallel: done");
1610 for (i = 0; i < pp->max_processes; i++) {
1611 strbuf_release(&pp->children[i].err);
1612 child_process_clear(&pp->children[i].process);
1615 free(pp->children);
1616 free(pp->pfd);
1619 * When get_next_task added messages to the buffer in its last
1620 * iteration, the buffered output is non empty.
1622 strbuf_write(&pp->buffered_output, stderr);
1623 strbuf_release(&pp->buffered_output);
1625 sigchain_pop_common();
1628 /* returns
1629 * 0 if a new task was started.
1630 * 1 if no new jobs was started (get_next_task ran out of work, non critical
1631 * problem with starting a new command)
1632 * <0 no new job was started, user wishes to shutdown early. Use negative code
1633 * to signal the children.
1635 static int pp_start_one(struct parallel_processes *pp)
1637 int i, code;
1639 for (i = 0; i < pp->max_processes; i++)
1640 if (pp->children[i].state == GIT_CP_FREE)
1641 break;
1642 if (i == pp->max_processes)
1643 BUG("bookkeeping is hard");
1645 code = pp->get_next_task(&pp->children[i].process,
1646 &pp->children[i].err,
1647 pp->data,
1648 &pp->children[i].data);
1649 if (!code) {
1650 strbuf_addbuf(&pp->buffered_output, &pp->children[i].err);
1651 strbuf_reset(&pp->children[i].err);
1652 return 1;
1654 pp->children[i].process.err = -1;
1655 pp->children[i].process.stdout_to_stderr = 1;
1656 pp->children[i].process.no_stdin = 1;
1658 if (start_command(&pp->children[i].process)) {
1659 code = pp->start_failure(&pp->children[i].err,
1660 pp->data,
1661 pp->children[i].data);
1662 strbuf_addbuf(&pp->buffered_output, &pp->children[i].err);
1663 strbuf_reset(&pp->children[i].err);
1664 if (code)
1665 pp->shutdown = 1;
1666 return code;
1669 pp->nr_processes++;
1670 pp->children[i].state = GIT_CP_WORKING;
1671 pp->pfd[i].fd = pp->children[i].process.err;
1672 return 0;
1675 static void pp_buffer_stderr(struct parallel_processes *pp, int output_timeout)
1677 int i;
1679 while ((i = poll(pp->pfd, pp->max_processes, output_timeout)) < 0) {
1680 if (errno == EINTR)
1681 continue;
1682 pp_cleanup(pp);
1683 die_errno("poll");
1686 /* Buffer output from all pipes. */
1687 for (i = 0; i < pp->max_processes; i++) {
1688 if (pp->children[i].state == GIT_CP_WORKING &&
1689 pp->pfd[i].revents & (POLLIN | POLLHUP)) {
1690 int n = strbuf_read_once(&pp->children[i].err,
1691 pp->children[i].process.err, 0);
1692 if (n == 0) {
1693 close(pp->children[i].process.err);
1694 pp->children[i].state = GIT_CP_WAIT_CLEANUP;
1695 } else if (n < 0)
1696 if (errno != EAGAIN)
1697 die_errno("read");
1702 static void pp_output(struct parallel_processes *pp)
1704 int i = pp->output_owner;
1705 if (pp->children[i].state == GIT_CP_WORKING &&
1706 pp->children[i].err.len) {
1707 strbuf_write(&pp->children[i].err, stderr);
1708 strbuf_reset(&pp->children[i].err);
1712 static int pp_collect_finished(struct parallel_processes *pp)
1714 int i, code;
1715 int n = pp->max_processes;
1716 int result = 0;
1718 while (pp->nr_processes > 0) {
1719 for (i = 0; i < pp->max_processes; i++)
1720 if (pp->children[i].state == GIT_CP_WAIT_CLEANUP)
1721 break;
1722 if (i == pp->max_processes)
1723 break;
1725 code = finish_command(&pp->children[i].process);
1727 code = pp->task_finished(code,
1728 &pp->children[i].err, pp->data,
1729 pp->children[i].data);
1731 if (code)
1732 result = code;
1733 if (code < 0)
1734 break;
1736 pp->nr_processes--;
1737 pp->children[i].state = GIT_CP_FREE;
1738 pp->pfd[i].fd = -1;
1739 child_process_init(&pp->children[i].process);
1741 if (i != pp->output_owner) {
1742 strbuf_addbuf(&pp->buffered_output, &pp->children[i].err);
1743 strbuf_reset(&pp->children[i].err);
1744 } else {
1745 strbuf_write(&pp->children[i].err, stderr);
1746 strbuf_reset(&pp->children[i].err);
1748 /* Output all other finished child processes */
1749 strbuf_write(&pp->buffered_output, stderr);
1750 strbuf_reset(&pp->buffered_output);
1753 * Pick next process to output live.
1754 * NEEDSWORK:
1755 * For now we pick it randomly by doing a round
1756 * robin. Later we may want to pick the one with
1757 * the most output or the longest or shortest
1758 * running process time.
1760 for (i = 0; i < n; i++)
1761 if (pp->children[(pp->output_owner + i) % n].state == GIT_CP_WORKING)
1762 break;
1763 pp->output_owner = (pp->output_owner + i) % n;
1766 return result;
1769 int run_processes_parallel(int n,
1770 get_next_task_fn get_next_task,
1771 start_failure_fn start_failure,
1772 task_finished_fn task_finished,
1773 void *pp_cb)
1775 int i, code;
1776 int output_timeout = 100;
1777 int spawn_cap = 4;
1778 struct parallel_processes pp;
1780 pp_init(&pp, n, get_next_task, start_failure, task_finished, pp_cb);
1781 while (1) {
1782 for (i = 0;
1783 i < spawn_cap && !pp.shutdown &&
1784 pp.nr_processes < pp.max_processes;
1785 i++) {
1786 code = pp_start_one(&pp);
1787 if (!code)
1788 continue;
1789 if (code < 0) {
1790 pp.shutdown = 1;
1791 kill_children(&pp, -code);
1793 break;
1795 if (!pp.nr_processes)
1796 break;
1797 pp_buffer_stderr(&pp, output_timeout);
1798 pp_output(&pp);
1799 code = pp_collect_finished(&pp);
1800 if (code) {
1801 pp.shutdown = 1;
1802 if (code < 0)
1803 kill_children(&pp, -code);
1807 pp_cleanup(&pp);
1808 return 0;