Merge branch 'rd/doc-remote-tracking-with-hyphen'
[git/debian.git] / run-command.c
blob84b883c2132bb07bc7fa21434368d64664587b8b
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 void 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 no '/' characters or if the command wasn't found in the path,
407 * have exec attempt to invoke the command 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;
418 static char **prep_childenv(const char *const *deltaenv)
420 extern char **environ;
421 char **childenv;
422 struct string_list env = STRING_LIST_INIT_DUP;
423 struct strbuf key = STRBUF_INIT;
424 const char *const *p;
425 int i;
427 /* Construct a sorted string list consisting of the current environ */
428 for (p = (const char *const *) environ; p && *p; p++) {
429 const char *equals = strchr(*p, '=');
431 if (equals) {
432 strbuf_reset(&key);
433 strbuf_add(&key, *p, equals - *p);
434 string_list_append(&env, key.buf)->util = (void *) *p;
435 } else {
436 string_list_append(&env, *p)->util = (void *) *p;
439 string_list_sort(&env);
441 /* Merge in 'deltaenv' with the current environ */
442 for (p = deltaenv; p && *p; p++) {
443 const char *equals = strchr(*p, '=');
445 if (equals) {
446 /* ('key=value'), insert or replace entry */
447 strbuf_reset(&key);
448 strbuf_add(&key, *p, equals - *p);
449 string_list_insert(&env, key.buf)->util = (void *) *p;
450 } else {
451 /* otherwise ('key') remove existing entry */
452 string_list_remove(&env, *p, 0);
456 /* Create an array of 'char *' to be used as the childenv */
457 ALLOC_ARRAY(childenv, env.nr + 1);
458 for (i = 0; i < env.nr; i++)
459 childenv[i] = env.items[i].util;
460 childenv[env.nr] = NULL;
462 string_list_clear(&env, 0);
463 strbuf_release(&key);
464 return childenv;
467 struct atfork_state {
468 #ifndef NO_PTHREADS
469 int cs;
470 #endif
471 sigset_t old;
474 #define CHECK_BUG(err, msg) \
475 do { \
476 int e = (err); \
477 if (e) \
478 BUG("%s: %s", msg, strerror(e)); \
479 } while(0)
481 static void atfork_prepare(struct atfork_state *as)
483 sigset_t all;
485 if (sigfillset(&all))
486 die_errno("sigfillset");
487 #ifdef NO_PTHREADS
488 if (sigprocmask(SIG_SETMASK, &all, &as->old))
489 die_errno("sigprocmask");
490 #else
491 CHECK_BUG(pthread_sigmask(SIG_SETMASK, &all, &as->old),
492 "blocking all signals");
493 CHECK_BUG(pthread_setcancelstate(PTHREAD_CANCEL_DISABLE, &as->cs),
494 "disabling cancellation");
495 #endif
498 static void atfork_parent(struct atfork_state *as)
500 #ifdef NO_PTHREADS
501 if (sigprocmask(SIG_SETMASK, &as->old, NULL))
502 die_errno("sigprocmask");
503 #else
504 CHECK_BUG(pthread_setcancelstate(as->cs, NULL),
505 "re-enabling cancellation");
506 CHECK_BUG(pthread_sigmask(SIG_SETMASK, &as->old, NULL),
507 "restoring signal mask");
508 #endif
510 #endif /* GIT_WINDOWS_NATIVE */
512 static inline void set_cloexec(int fd)
514 int flags = fcntl(fd, F_GETFD);
515 if (flags >= 0)
516 fcntl(fd, F_SETFD, flags | FD_CLOEXEC);
519 static int wait_or_whine(pid_t pid, const char *argv0, int in_signal)
521 int status, code = -1;
522 pid_t waiting;
523 int failed_errno = 0;
525 while ((waiting = waitpid(pid, &status, 0)) < 0 && errno == EINTR)
526 ; /* nothing */
527 if (in_signal)
528 return 0;
530 if (waiting < 0) {
531 failed_errno = errno;
532 error_errno("waitpid for %s failed", argv0);
533 } else if (waiting != pid) {
534 error("waitpid is confused (%s)", argv0);
535 } else if (WIFSIGNALED(status)) {
536 code = WTERMSIG(status);
537 if (code != SIGINT && code != SIGQUIT && code != SIGPIPE)
538 error("%s died of signal %d", argv0, code);
540 * This return value is chosen so that code & 0xff
541 * mimics the exit code that a POSIX shell would report for
542 * a program that died from this signal.
544 code += 128;
545 } else if (WIFEXITED(status)) {
546 code = WEXITSTATUS(status);
547 } else {
548 error("waitpid is confused (%s)", argv0);
551 clear_child_for_cleanup(pid);
553 errno = failed_errno;
554 return code;
557 static void trace_add_env(struct strbuf *dst, const char *const *deltaenv)
559 struct string_list envs = STRING_LIST_INIT_DUP;
560 const char *const *e;
561 int i;
562 int printed_unset = 0;
564 /* Last one wins, see run-command.c:prep_childenv() for context */
565 for (e = deltaenv; e && *e; e++) {
566 struct strbuf key = STRBUF_INIT;
567 char *equals = strchr(*e, '=');
569 if (equals) {
570 strbuf_add(&key, *e, equals - *e);
571 string_list_insert(&envs, key.buf)->util = equals + 1;
572 } else {
573 string_list_insert(&envs, *e)->util = NULL;
575 strbuf_release(&key);
578 /* "unset X Y...;" */
579 for (i = 0; i < envs.nr; i++) {
580 const char *var = envs.items[i].string;
581 const char *val = envs.items[i].util;
583 if (val || !getenv(var))
584 continue;
586 if (!printed_unset) {
587 strbuf_addstr(dst, " unset");
588 printed_unset = 1;
590 strbuf_addf(dst, " %s", var);
592 if (printed_unset)
593 strbuf_addch(dst, ';');
595 /* ... followed by "A=B C=D ..." */
596 for (i = 0; i < envs.nr; i++) {
597 const char *var = envs.items[i].string;
598 const char *val = envs.items[i].util;
599 const char *oldval;
601 if (!val)
602 continue;
604 oldval = getenv(var);
605 if (oldval && !strcmp(val, oldval))
606 continue;
608 strbuf_addf(dst, " %s=", var);
609 sq_quote_buf_pretty(dst, val);
611 string_list_clear(&envs, 0);
614 static void trace_run_command(const struct child_process *cp)
616 struct strbuf buf = STRBUF_INIT;
618 if (!trace_want(&trace_default_key))
619 return;
621 strbuf_addstr(&buf, "trace: run_command:");
622 if (cp->dir) {
623 strbuf_addstr(&buf, " cd ");
624 sq_quote_buf_pretty(&buf, cp->dir);
625 strbuf_addch(&buf, ';');
628 * The caller is responsible for initializing cp->env from
629 * cp->env_array if needed. We only check one place.
631 if (cp->env)
632 trace_add_env(&buf, cp->env);
633 if (cp->git_cmd)
634 strbuf_addstr(&buf, " git");
635 sq_quote_argv_pretty(&buf, cp->argv);
637 trace_printf("%s", buf.buf);
638 strbuf_release(&buf);
641 int start_command(struct child_process *cmd)
643 int need_in, need_out, need_err;
644 int fdin[2], fdout[2], fderr[2];
645 int failed_errno;
646 char *str;
648 if (!cmd->argv)
649 cmd->argv = cmd->args.argv;
650 if (!cmd->env)
651 cmd->env = cmd->env_array.argv;
654 * In case of errors we must keep the promise to close FDs
655 * that have been passed in via ->in and ->out.
658 need_in = !cmd->no_stdin && cmd->in < 0;
659 if (need_in) {
660 if (pipe(fdin) < 0) {
661 failed_errno = errno;
662 if (cmd->out > 0)
663 close(cmd->out);
664 str = "standard input";
665 goto fail_pipe;
667 cmd->in = fdin[1];
670 need_out = !cmd->no_stdout
671 && !cmd->stdout_to_stderr
672 && cmd->out < 0;
673 if (need_out) {
674 if (pipe(fdout) < 0) {
675 failed_errno = errno;
676 if (need_in)
677 close_pair(fdin);
678 else if (cmd->in)
679 close(cmd->in);
680 str = "standard output";
681 goto fail_pipe;
683 cmd->out = fdout[0];
686 need_err = !cmd->no_stderr && cmd->err < 0;
687 if (need_err) {
688 if (pipe(fderr) < 0) {
689 failed_errno = errno;
690 if (need_in)
691 close_pair(fdin);
692 else if (cmd->in)
693 close(cmd->in);
694 if (need_out)
695 close_pair(fdout);
696 else if (cmd->out)
697 close(cmd->out);
698 str = "standard error";
699 fail_pipe:
700 error("cannot create %s pipe for %s: %s",
701 str, cmd->argv[0], strerror(failed_errno));
702 child_process_clear(cmd);
703 errno = failed_errno;
704 return -1;
706 cmd->err = fderr[0];
709 trace_run_command(cmd);
711 fflush(NULL);
713 #ifndef GIT_WINDOWS_NATIVE
715 int notify_pipe[2];
716 int null_fd = -1;
717 char **childenv;
718 struct argv_array argv = ARGV_ARRAY_INIT;
719 struct child_err cerr;
720 struct atfork_state as;
722 if (pipe(notify_pipe))
723 notify_pipe[0] = notify_pipe[1] = -1;
725 if (cmd->no_stdin || cmd->no_stdout || cmd->no_stderr) {
726 null_fd = open("/dev/null", O_RDWR | O_CLOEXEC);
727 if (null_fd < 0)
728 die_errno(_("open /dev/null failed"));
729 set_cloexec(null_fd);
732 prepare_cmd(&argv, cmd);
733 childenv = prep_childenv(cmd->env);
734 atfork_prepare(&as);
737 * NOTE: In order to prevent deadlocking when using threads special
738 * care should be taken with the function calls made in between the
739 * fork() and exec() calls. No calls should be made to functions which
740 * require acquiring a lock (e.g. malloc) as the lock could have been
741 * held by another thread at the time of forking, causing the lock to
742 * never be released in the child process. This means only
743 * Async-Signal-Safe functions are permitted in the child.
745 cmd->pid = fork();
746 failed_errno = errno;
747 if (!cmd->pid) {
748 int sig;
750 * Ensure the default die/error/warn routines do not get
751 * called, they can take stdio locks and malloc.
753 set_die_routine(child_die_fn);
754 set_error_routine(child_error_fn);
755 set_warn_routine(child_warn_fn);
757 close(notify_pipe[0]);
758 set_cloexec(notify_pipe[1]);
759 child_notifier = notify_pipe[1];
761 if (cmd->no_stdin)
762 child_dup2(null_fd, 0);
763 else if (need_in) {
764 child_dup2(fdin[0], 0);
765 child_close_pair(fdin);
766 } else if (cmd->in) {
767 child_dup2(cmd->in, 0);
768 child_close(cmd->in);
771 if (cmd->no_stderr)
772 child_dup2(null_fd, 2);
773 else if (need_err) {
774 child_dup2(fderr[1], 2);
775 child_close_pair(fderr);
776 } else if (cmd->err > 1) {
777 child_dup2(cmd->err, 2);
778 child_close(cmd->err);
781 if (cmd->no_stdout)
782 child_dup2(null_fd, 1);
783 else if (cmd->stdout_to_stderr)
784 child_dup2(2, 1);
785 else if (need_out) {
786 child_dup2(fdout[1], 1);
787 child_close_pair(fdout);
788 } else if (cmd->out > 1) {
789 child_dup2(cmd->out, 1);
790 child_close(cmd->out);
793 if (cmd->dir && chdir(cmd->dir))
794 child_die(CHILD_ERR_CHDIR);
797 * restore default signal handlers here, in case
798 * we catch a signal right before execve below
800 for (sig = 1; sig < NSIG; sig++) {
801 /* ignored signals get reset to SIG_DFL on execve */
802 if (signal(sig, SIG_DFL) == SIG_IGN)
803 signal(sig, SIG_IGN);
806 if (sigprocmask(SIG_SETMASK, &as.old, NULL) != 0)
807 child_die(CHILD_ERR_SIGPROCMASK);
810 * Attempt to exec using the command and arguments starting at
811 * argv.argv[1]. argv.argv[0] contains SHELL_PATH which will
812 * be used in the event exec failed with ENOEXEC at which point
813 * we will try to interpret the command using 'sh'.
815 execve(argv.argv[1], (char *const *) argv.argv + 1,
816 (char *const *) childenv);
817 if (errno == ENOEXEC)
818 execve(argv.argv[0], (char *const *) argv.argv,
819 (char *const *) childenv);
821 if (errno == ENOENT) {
822 if (cmd->silent_exec_failure)
823 child_die(CHILD_ERR_SILENT);
824 child_die(CHILD_ERR_ENOENT);
825 } else {
826 child_die(CHILD_ERR_ERRNO);
829 atfork_parent(&as);
830 if (cmd->pid < 0)
831 error_errno("cannot fork() for %s", cmd->argv[0]);
832 else if (cmd->clean_on_exit)
833 mark_child_for_cleanup(cmd->pid, cmd);
836 * Wait for child's exec. If the exec succeeds (or if fork()
837 * failed), EOF is seen immediately by the parent. Otherwise, the
838 * child process sends a child_err struct.
839 * Note that use of this infrastructure is completely advisory,
840 * therefore, we keep error checks minimal.
842 close(notify_pipe[1]);
843 if (xread(notify_pipe[0], &cerr, sizeof(cerr)) == sizeof(cerr)) {
845 * At this point we know that fork() succeeded, but exec()
846 * failed. Errors have been reported to our stderr.
848 wait_or_whine(cmd->pid, cmd->argv[0], 0);
849 child_err_spew(cmd, &cerr);
850 failed_errno = errno;
851 cmd->pid = -1;
853 close(notify_pipe[0]);
855 if (null_fd >= 0)
856 close(null_fd);
857 argv_array_clear(&argv);
858 free(childenv);
860 #else
862 int fhin = 0, fhout = 1, fherr = 2;
863 const char **sargv = cmd->argv;
864 struct argv_array nargv = ARGV_ARRAY_INIT;
866 if (cmd->no_stdin)
867 fhin = open("/dev/null", O_RDWR);
868 else if (need_in)
869 fhin = dup(fdin[0]);
870 else if (cmd->in)
871 fhin = dup(cmd->in);
873 if (cmd->no_stderr)
874 fherr = open("/dev/null", O_RDWR);
875 else if (need_err)
876 fherr = dup(fderr[1]);
877 else if (cmd->err > 2)
878 fherr = dup(cmd->err);
880 if (cmd->no_stdout)
881 fhout = open("/dev/null", O_RDWR);
882 else if (cmd->stdout_to_stderr)
883 fhout = dup(fherr);
884 else if (need_out)
885 fhout = dup(fdout[1]);
886 else if (cmd->out > 1)
887 fhout = dup(cmd->out);
889 if (cmd->git_cmd)
890 cmd->argv = prepare_git_cmd(&nargv, cmd->argv);
891 else if (cmd->use_shell)
892 cmd->argv = prepare_shell_cmd(&nargv, cmd->argv);
894 cmd->pid = mingw_spawnvpe(cmd->argv[0], cmd->argv, (char**) cmd->env,
895 cmd->dir, fhin, fhout, fherr);
896 failed_errno = errno;
897 if (cmd->pid < 0 && (!cmd->silent_exec_failure || errno != ENOENT))
898 error_errno("cannot spawn %s", cmd->argv[0]);
899 if (cmd->clean_on_exit && cmd->pid >= 0)
900 mark_child_for_cleanup(cmd->pid, cmd);
902 argv_array_clear(&nargv);
903 cmd->argv = sargv;
904 if (fhin != 0)
905 close(fhin);
906 if (fhout != 1)
907 close(fhout);
908 if (fherr != 2)
909 close(fherr);
911 #endif
913 if (cmd->pid < 0) {
914 if (need_in)
915 close_pair(fdin);
916 else if (cmd->in)
917 close(cmd->in);
918 if (need_out)
919 close_pair(fdout);
920 else if (cmd->out)
921 close(cmd->out);
922 if (need_err)
923 close_pair(fderr);
924 else if (cmd->err)
925 close(cmd->err);
926 child_process_clear(cmd);
927 errno = failed_errno;
928 return -1;
931 if (need_in)
932 close(fdin[0]);
933 else if (cmd->in)
934 close(cmd->in);
936 if (need_out)
937 close(fdout[1]);
938 else if (cmd->out)
939 close(cmd->out);
941 if (need_err)
942 close(fderr[1]);
943 else if (cmd->err)
944 close(cmd->err);
946 return 0;
949 int finish_command(struct child_process *cmd)
951 int ret = wait_or_whine(cmd->pid, cmd->argv[0], 0);
952 child_process_clear(cmd);
953 return ret;
956 int finish_command_in_signal(struct child_process *cmd)
958 return wait_or_whine(cmd->pid, cmd->argv[0], 1);
962 int run_command(struct child_process *cmd)
964 int code;
966 if (cmd->out < 0 || cmd->err < 0)
967 BUG("run_command with a pipe can cause deadlock");
969 code = start_command(cmd);
970 if (code)
971 return code;
972 return finish_command(cmd);
975 int run_command_v_opt(const char **argv, int opt)
977 return run_command_v_opt_cd_env(argv, opt, NULL, NULL);
980 int run_command_v_opt_cd_env(const char **argv, int opt, const char *dir, const char *const *env)
982 struct child_process cmd = CHILD_PROCESS_INIT;
983 cmd.argv = argv;
984 cmd.no_stdin = opt & RUN_COMMAND_NO_STDIN ? 1 : 0;
985 cmd.git_cmd = opt & RUN_GIT_CMD ? 1 : 0;
986 cmd.stdout_to_stderr = opt & RUN_COMMAND_STDOUT_TO_STDERR ? 1 : 0;
987 cmd.silent_exec_failure = opt & RUN_SILENT_EXEC_FAILURE ? 1 : 0;
988 cmd.use_shell = opt & RUN_USING_SHELL ? 1 : 0;
989 cmd.clean_on_exit = opt & RUN_CLEAN_ON_EXIT ? 1 : 0;
990 cmd.dir = dir;
991 cmd.env = env;
992 return run_command(&cmd);
995 #ifndef NO_PTHREADS
996 static pthread_t main_thread;
997 static int main_thread_set;
998 static pthread_key_t async_key;
999 static pthread_key_t async_die_counter;
1001 static void *run_thread(void *data)
1003 struct async *async = data;
1004 intptr_t ret;
1006 if (async->isolate_sigpipe) {
1007 sigset_t mask;
1008 sigemptyset(&mask);
1009 sigaddset(&mask, SIGPIPE);
1010 if (pthread_sigmask(SIG_BLOCK, &mask, NULL) < 0) {
1011 ret = error("unable to block SIGPIPE in async thread");
1012 return (void *)ret;
1016 pthread_setspecific(async_key, async);
1017 ret = async->proc(async->proc_in, async->proc_out, async->data);
1018 return (void *)ret;
1021 static NORETURN void die_async(const char *err, va_list params)
1023 vreportf("fatal: ", err, params);
1025 if (in_async()) {
1026 struct async *async = pthread_getspecific(async_key);
1027 if (async->proc_in >= 0)
1028 close(async->proc_in);
1029 if (async->proc_out >= 0)
1030 close(async->proc_out);
1031 pthread_exit((void *)128);
1034 exit(128);
1037 static int async_die_is_recursing(void)
1039 void *ret = pthread_getspecific(async_die_counter);
1040 pthread_setspecific(async_die_counter, (void *)1);
1041 return ret != NULL;
1044 int in_async(void)
1046 if (!main_thread_set)
1047 return 0; /* no asyncs started yet */
1048 return !pthread_equal(main_thread, pthread_self());
1051 static void NORETURN async_exit(int code)
1053 pthread_exit((void *)(intptr_t)code);
1056 #else
1058 static struct {
1059 void (**handlers)(void);
1060 size_t nr;
1061 size_t alloc;
1062 } git_atexit_hdlrs;
1064 static int git_atexit_installed;
1066 static void git_atexit_dispatch(void)
1068 size_t i;
1070 for (i=git_atexit_hdlrs.nr ; i ; i--)
1071 git_atexit_hdlrs.handlers[i-1]();
1074 static void git_atexit_clear(void)
1076 free(git_atexit_hdlrs.handlers);
1077 memset(&git_atexit_hdlrs, 0, sizeof(git_atexit_hdlrs));
1078 git_atexit_installed = 0;
1081 #undef atexit
1082 int git_atexit(void (*handler)(void))
1084 ALLOC_GROW(git_atexit_hdlrs.handlers, git_atexit_hdlrs.nr + 1, git_atexit_hdlrs.alloc);
1085 git_atexit_hdlrs.handlers[git_atexit_hdlrs.nr++] = handler;
1086 if (!git_atexit_installed) {
1087 if (atexit(&git_atexit_dispatch))
1088 return -1;
1089 git_atexit_installed = 1;
1091 return 0;
1093 #define atexit git_atexit
1095 static int process_is_async;
1096 int in_async(void)
1098 return process_is_async;
1101 static void NORETURN async_exit(int code)
1103 exit(code);
1106 #endif
1108 void check_pipe(int err)
1110 if (err == EPIPE) {
1111 if (in_async())
1112 async_exit(141);
1114 signal(SIGPIPE, SIG_DFL);
1115 raise(SIGPIPE);
1116 /* Should never happen, but just in case... */
1117 exit(141);
1121 int start_async(struct async *async)
1123 int need_in, need_out;
1124 int fdin[2], fdout[2];
1125 int proc_in, proc_out;
1127 need_in = async->in < 0;
1128 if (need_in) {
1129 if (pipe(fdin) < 0) {
1130 if (async->out > 0)
1131 close(async->out);
1132 return error_errno("cannot create pipe");
1134 async->in = fdin[1];
1137 need_out = async->out < 0;
1138 if (need_out) {
1139 if (pipe(fdout) < 0) {
1140 if (need_in)
1141 close_pair(fdin);
1142 else if (async->in)
1143 close(async->in);
1144 return error_errno("cannot create pipe");
1146 async->out = fdout[0];
1149 if (need_in)
1150 proc_in = fdin[0];
1151 else if (async->in)
1152 proc_in = async->in;
1153 else
1154 proc_in = -1;
1156 if (need_out)
1157 proc_out = fdout[1];
1158 else if (async->out)
1159 proc_out = async->out;
1160 else
1161 proc_out = -1;
1163 #ifdef NO_PTHREADS
1164 /* Flush stdio before fork() to avoid cloning buffers */
1165 fflush(NULL);
1167 async->pid = fork();
1168 if (async->pid < 0) {
1169 error_errno("fork (async) failed");
1170 goto error;
1172 if (!async->pid) {
1173 if (need_in)
1174 close(fdin[1]);
1175 if (need_out)
1176 close(fdout[0]);
1177 git_atexit_clear();
1178 process_is_async = 1;
1179 exit(!!async->proc(proc_in, proc_out, async->data));
1182 mark_child_for_cleanup(async->pid, NULL);
1184 if (need_in)
1185 close(fdin[0]);
1186 else if (async->in)
1187 close(async->in);
1189 if (need_out)
1190 close(fdout[1]);
1191 else if (async->out)
1192 close(async->out);
1193 #else
1194 if (!main_thread_set) {
1196 * We assume that the first time that start_async is called
1197 * it is from the main thread.
1199 main_thread_set = 1;
1200 main_thread = pthread_self();
1201 pthread_key_create(&async_key, NULL);
1202 pthread_key_create(&async_die_counter, NULL);
1203 set_die_routine(die_async);
1204 set_die_is_recursing_routine(async_die_is_recursing);
1207 if (proc_in >= 0)
1208 set_cloexec(proc_in);
1209 if (proc_out >= 0)
1210 set_cloexec(proc_out);
1211 async->proc_in = proc_in;
1212 async->proc_out = proc_out;
1214 int err = pthread_create(&async->tid, NULL, run_thread, async);
1215 if (err) {
1216 error_errno("cannot create thread");
1217 goto error;
1220 #endif
1221 return 0;
1223 error:
1224 if (need_in)
1225 close_pair(fdin);
1226 else if (async->in)
1227 close(async->in);
1229 if (need_out)
1230 close_pair(fdout);
1231 else if (async->out)
1232 close(async->out);
1233 return -1;
1236 int finish_async(struct async *async)
1238 #ifdef NO_PTHREADS
1239 return wait_or_whine(async->pid, "child process", 0);
1240 #else
1241 void *ret = (void *)(intptr_t)(-1);
1243 if (pthread_join(async->tid, &ret))
1244 error("pthread_join failed");
1245 return (int)(intptr_t)ret;
1246 #endif
1249 const char *find_hook(const char *name)
1251 static struct strbuf path = STRBUF_INIT;
1253 strbuf_reset(&path);
1254 strbuf_git_path(&path, "hooks/%s", name);
1255 if (access(path.buf, X_OK) < 0) {
1256 int err = errno;
1258 #ifdef STRIP_EXTENSION
1259 strbuf_addstr(&path, STRIP_EXTENSION);
1260 if (access(path.buf, X_OK) >= 0)
1261 return path.buf;
1262 if (errno == EACCES)
1263 err = errno;
1264 #endif
1266 if (err == EACCES && advice_ignored_hook) {
1267 static struct string_list advise_given = STRING_LIST_INIT_DUP;
1269 if (!string_list_lookup(&advise_given, name)) {
1270 string_list_insert(&advise_given, name);
1271 advise(_("The '%s' hook was ignored because "
1272 "it's not set as executable.\n"
1273 "You can disable this warning with "
1274 "`git config advice.ignoredHook false`."),
1275 path.buf);
1278 return NULL;
1280 return path.buf;
1283 int run_hook_ve(const char *const *env, const char *name, va_list args)
1285 struct child_process hook = CHILD_PROCESS_INIT;
1286 const char *p;
1288 p = find_hook(name);
1289 if (!p)
1290 return 0;
1292 argv_array_push(&hook.args, p);
1293 while ((p = va_arg(args, const char *)))
1294 argv_array_push(&hook.args, p);
1295 hook.env = env;
1296 hook.no_stdin = 1;
1297 hook.stdout_to_stderr = 1;
1299 return run_command(&hook);
1302 int run_hook_le(const char *const *env, const char *name, ...)
1304 va_list args;
1305 int ret;
1307 va_start(args, name);
1308 ret = run_hook_ve(env, name, args);
1309 va_end(args);
1311 return ret;
1314 struct io_pump {
1315 /* initialized by caller */
1316 int fd;
1317 int type; /* POLLOUT or POLLIN */
1318 union {
1319 struct {
1320 const char *buf;
1321 size_t len;
1322 } out;
1323 struct {
1324 struct strbuf *buf;
1325 size_t hint;
1326 } in;
1327 } u;
1329 /* returned by pump_io */
1330 int error; /* 0 for success, otherwise errno */
1332 /* internal use */
1333 struct pollfd *pfd;
1336 static int pump_io_round(struct io_pump *slots, int nr, struct pollfd *pfd)
1338 int pollsize = 0;
1339 int i;
1341 for (i = 0; i < nr; i++) {
1342 struct io_pump *io = &slots[i];
1343 if (io->fd < 0)
1344 continue;
1345 pfd[pollsize].fd = io->fd;
1346 pfd[pollsize].events = io->type;
1347 io->pfd = &pfd[pollsize++];
1350 if (!pollsize)
1351 return 0;
1353 if (poll(pfd, pollsize, -1) < 0) {
1354 if (errno == EINTR)
1355 return 1;
1356 die_errno("poll failed");
1359 for (i = 0; i < nr; i++) {
1360 struct io_pump *io = &slots[i];
1362 if (io->fd < 0)
1363 continue;
1365 if (!(io->pfd->revents & (POLLOUT|POLLIN|POLLHUP|POLLERR|POLLNVAL)))
1366 continue;
1368 if (io->type == POLLOUT) {
1369 ssize_t len = xwrite(io->fd,
1370 io->u.out.buf, io->u.out.len);
1371 if (len < 0) {
1372 io->error = errno;
1373 close(io->fd);
1374 io->fd = -1;
1375 } else {
1376 io->u.out.buf += len;
1377 io->u.out.len -= len;
1378 if (!io->u.out.len) {
1379 close(io->fd);
1380 io->fd = -1;
1385 if (io->type == POLLIN) {
1386 ssize_t len = strbuf_read_once(io->u.in.buf,
1387 io->fd, io->u.in.hint);
1388 if (len < 0)
1389 io->error = errno;
1390 if (len <= 0) {
1391 close(io->fd);
1392 io->fd = -1;
1397 return 1;
1400 static int pump_io(struct io_pump *slots, int nr)
1402 struct pollfd *pfd;
1403 int i;
1405 for (i = 0; i < nr; i++)
1406 slots[i].error = 0;
1408 ALLOC_ARRAY(pfd, nr);
1409 while (pump_io_round(slots, nr, pfd))
1410 ; /* nothing */
1411 free(pfd);
1413 /* There may be multiple errno values, so just pick the first. */
1414 for (i = 0; i < nr; i++) {
1415 if (slots[i].error) {
1416 errno = slots[i].error;
1417 return -1;
1420 return 0;
1424 int pipe_command(struct child_process *cmd,
1425 const char *in, size_t in_len,
1426 struct strbuf *out, size_t out_hint,
1427 struct strbuf *err, size_t err_hint)
1429 struct io_pump io[3];
1430 int nr = 0;
1432 if (in)
1433 cmd->in = -1;
1434 if (out)
1435 cmd->out = -1;
1436 if (err)
1437 cmd->err = -1;
1439 if (start_command(cmd) < 0)
1440 return -1;
1442 if (in) {
1443 io[nr].fd = cmd->in;
1444 io[nr].type = POLLOUT;
1445 io[nr].u.out.buf = in;
1446 io[nr].u.out.len = in_len;
1447 nr++;
1449 if (out) {
1450 io[nr].fd = cmd->out;
1451 io[nr].type = POLLIN;
1452 io[nr].u.in.buf = out;
1453 io[nr].u.in.hint = out_hint;
1454 nr++;
1456 if (err) {
1457 io[nr].fd = cmd->err;
1458 io[nr].type = POLLIN;
1459 io[nr].u.in.buf = err;
1460 io[nr].u.in.hint = err_hint;
1461 nr++;
1464 if (pump_io(io, nr) < 0) {
1465 finish_command(cmd); /* throw away exit code */
1466 return -1;
1469 return finish_command(cmd);
1472 enum child_state {
1473 GIT_CP_FREE,
1474 GIT_CP_WORKING,
1475 GIT_CP_WAIT_CLEANUP,
1478 struct parallel_processes {
1479 void *data;
1481 int max_processes;
1482 int nr_processes;
1484 get_next_task_fn get_next_task;
1485 start_failure_fn start_failure;
1486 task_finished_fn task_finished;
1488 struct {
1489 enum child_state state;
1490 struct child_process process;
1491 struct strbuf err;
1492 void *data;
1493 } *children;
1495 * The struct pollfd is logically part of *children,
1496 * but the system call expects it as its own array.
1498 struct pollfd *pfd;
1500 unsigned shutdown : 1;
1502 int output_owner;
1503 struct strbuf buffered_output; /* of finished children */
1506 static int default_start_failure(struct strbuf *out,
1507 void *pp_cb,
1508 void *pp_task_cb)
1510 return 0;
1513 static int default_task_finished(int result,
1514 struct strbuf *out,
1515 void *pp_cb,
1516 void *pp_task_cb)
1518 return 0;
1521 static void kill_children(struct parallel_processes *pp, int signo)
1523 int i, n = pp->max_processes;
1525 for (i = 0; i < n; i++)
1526 if (pp->children[i].state == GIT_CP_WORKING)
1527 kill(pp->children[i].process.pid, signo);
1530 static struct parallel_processes *pp_for_signal;
1532 static void handle_children_on_signal(int signo)
1534 kill_children(pp_for_signal, signo);
1535 sigchain_pop(signo);
1536 raise(signo);
1539 static void pp_init(struct parallel_processes *pp,
1540 int n,
1541 get_next_task_fn get_next_task,
1542 start_failure_fn start_failure,
1543 task_finished_fn task_finished,
1544 void *data)
1546 int i;
1548 if (n < 1)
1549 n = online_cpus();
1551 pp->max_processes = n;
1553 trace_printf("run_processes_parallel: preparing to run up to %d tasks", n);
1555 pp->data = data;
1556 if (!get_next_task)
1557 BUG("you need to specify a get_next_task function");
1558 pp->get_next_task = get_next_task;
1560 pp->start_failure = start_failure ? start_failure : default_start_failure;
1561 pp->task_finished = task_finished ? task_finished : default_task_finished;
1563 pp->nr_processes = 0;
1564 pp->output_owner = 0;
1565 pp->shutdown = 0;
1566 pp->children = xcalloc(n, sizeof(*pp->children));
1567 pp->pfd = xcalloc(n, sizeof(*pp->pfd));
1568 strbuf_init(&pp->buffered_output, 0);
1570 for (i = 0; i < n; i++) {
1571 strbuf_init(&pp->children[i].err, 0);
1572 child_process_init(&pp->children[i].process);
1573 pp->pfd[i].events = POLLIN | POLLHUP;
1574 pp->pfd[i].fd = -1;
1577 pp_for_signal = pp;
1578 sigchain_push_common(handle_children_on_signal);
1581 static void pp_cleanup(struct parallel_processes *pp)
1583 int i;
1585 trace_printf("run_processes_parallel: done");
1586 for (i = 0; i < pp->max_processes; i++) {
1587 strbuf_release(&pp->children[i].err);
1588 child_process_clear(&pp->children[i].process);
1591 free(pp->children);
1592 free(pp->pfd);
1595 * When get_next_task added messages to the buffer in its last
1596 * iteration, the buffered output is non empty.
1598 strbuf_write(&pp->buffered_output, stderr);
1599 strbuf_release(&pp->buffered_output);
1601 sigchain_pop_common();
1604 /* returns
1605 * 0 if a new task was started.
1606 * 1 if no new jobs was started (get_next_task ran out of work, non critical
1607 * problem with starting a new command)
1608 * <0 no new job was started, user wishes to shutdown early. Use negative code
1609 * to signal the children.
1611 static int pp_start_one(struct parallel_processes *pp)
1613 int i, code;
1615 for (i = 0; i < pp->max_processes; i++)
1616 if (pp->children[i].state == GIT_CP_FREE)
1617 break;
1618 if (i == pp->max_processes)
1619 BUG("bookkeeping is hard");
1621 code = pp->get_next_task(&pp->children[i].process,
1622 &pp->children[i].err,
1623 pp->data,
1624 &pp->children[i].data);
1625 if (!code) {
1626 strbuf_addbuf(&pp->buffered_output, &pp->children[i].err);
1627 strbuf_reset(&pp->children[i].err);
1628 return 1;
1630 pp->children[i].process.err = -1;
1631 pp->children[i].process.stdout_to_stderr = 1;
1632 pp->children[i].process.no_stdin = 1;
1634 if (start_command(&pp->children[i].process)) {
1635 code = pp->start_failure(&pp->children[i].err,
1636 pp->data,
1637 pp->children[i].data);
1638 strbuf_addbuf(&pp->buffered_output, &pp->children[i].err);
1639 strbuf_reset(&pp->children[i].err);
1640 if (code)
1641 pp->shutdown = 1;
1642 return code;
1645 pp->nr_processes++;
1646 pp->children[i].state = GIT_CP_WORKING;
1647 pp->pfd[i].fd = pp->children[i].process.err;
1648 return 0;
1651 static void pp_buffer_stderr(struct parallel_processes *pp, int output_timeout)
1653 int i;
1655 while ((i = poll(pp->pfd, pp->max_processes, output_timeout)) < 0) {
1656 if (errno == EINTR)
1657 continue;
1658 pp_cleanup(pp);
1659 die_errno("poll");
1662 /* Buffer output from all pipes. */
1663 for (i = 0; i < pp->max_processes; i++) {
1664 if (pp->children[i].state == GIT_CP_WORKING &&
1665 pp->pfd[i].revents & (POLLIN | POLLHUP)) {
1666 int n = strbuf_read_once(&pp->children[i].err,
1667 pp->children[i].process.err, 0);
1668 if (n == 0) {
1669 close(pp->children[i].process.err);
1670 pp->children[i].state = GIT_CP_WAIT_CLEANUP;
1671 } else if (n < 0)
1672 if (errno != EAGAIN)
1673 die_errno("read");
1678 static void pp_output(struct parallel_processes *pp)
1680 int i = pp->output_owner;
1681 if (pp->children[i].state == GIT_CP_WORKING &&
1682 pp->children[i].err.len) {
1683 strbuf_write(&pp->children[i].err, stderr);
1684 strbuf_reset(&pp->children[i].err);
1688 static int pp_collect_finished(struct parallel_processes *pp)
1690 int i, code;
1691 int n = pp->max_processes;
1692 int result = 0;
1694 while (pp->nr_processes > 0) {
1695 for (i = 0; i < pp->max_processes; i++)
1696 if (pp->children[i].state == GIT_CP_WAIT_CLEANUP)
1697 break;
1698 if (i == pp->max_processes)
1699 break;
1701 code = finish_command(&pp->children[i].process);
1703 code = pp->task_finished(code,
1704 &pp->children[i].err, pp->data,
1705 pp->children[i].data);
1707 if (code)
1708 result = code;
1709 if (code < 0)
1710 break;
1712 pp->nr_processes--;
1713 pp->children[i].state = GIT_CP_FREE;
1714 pp->pfd[i].fd = -1;
1715 child_process_init(&pp->children[i].process);
1717 if (i != pp->output_owner) {
1718 strbuf_addbuf(&pp->buffered_output, &pp->children[i].err);
1719 strbuf_reset(&pp->children[i].err);
1720 } else {
1721 strbuf_write(&pp->children[i].err, stderr);
1722 strbuf_reset(&pp->children[i].err);
1724 /* Output all other finished child processes */
1725 strbuf_write(&pp->buffered_output, stderr);
1726 strbuf_reset(&pp->buffered_output);
1729 * Pick next process to output live.
1730 * NEEDSWORK:
1731 * For now we pick it randomly by doing a round
1732 * robin. Later we may want to pick the one with
1733 * the most output or the longest or shortest
1734 * running process time.
1736 for (i = 0; i < n; i++)
1737 if (pp->children[(pp->output_owner + i) % n].state == GIT_CP_WORKING)
1738 break;
1739 pp->output_owner = (pp->output_owner + i) % n;
1742 return result;
1745 int run_processes_parallel(int n,
1746 get_next_task_fn get_next_task,
1747 start_failure_fn start_failure,
1748 task_finished_fn task_finished,
1749 void *pp_cb)
1751 int i, code;
1752 int output_timeout = 100;
1753 int spawn_cap = 4;
1754 struct parallel_processes pp;
1756 pp_init(&pp, n, get_next_task, start_failure, task_finished, pp_cb);
1757 while (1) {
1758 for (i = 0;
1759 i < spawn_cap && !pp.shutdown &&
1760 pp.nr_processes < pp.max_processes;
1761 i++) {
1762 code = pp_start_one(&pp);
1763 if (!code)
1764 continue;
1765 if (code < 0) {
1766 pp.shutdown = 1;
1767 kill_children(&pp, -code);
1769 break;
1771 if (!pp.nr_processes)
1772 break;
1773 pp_buffer_stderr(&pp, output_timeout);
1774 pp_output(&pp);
1775 code = pp_collect_finished(&pp);
1776 if (code) {
1777 pp.shutdown = 1;
1778 if (code < 0)
1779 kill_children(&pp, -code);
1783 pp_cleanup(&pp);
1784 return 0;