2 #include "run-command.h"
5 #include "argv-array.h"
6 #include "thread-utils.h"
8 #include "string-list.h"
11 void child_process_init(struct child_process
*child
)
13 memset(child
, 0, sizeof(*child
));
14 argv_array_init(&child
->args
);
15 argv_array_init(&child
->env_array
);
18 void child_process_clear(struct child_process
*child
)
20 argv_array_clear(&child
->args
);
21 argv_array_clear(&child
->env_array
);
24 struct child_to_clean
{
26 struct child_process
*process
;
27 struct child_to_clean
*next
;
29 static struct child_to_clean
*children_to_clean
;
30 static int installed_child_cleanup_handler
;
32 static void cleanup_children(int sig
, int in_signal
)
34 struct child_to_clean
*children_to_wait_for
= NULL
;
36 while (children_to_clean
) {
37 struct child_to_clean
*p
= children_to_clean
;
38 children_to_clean
= p
->next
;
40 if (p
->process
&& !in_signal
) {
41 struct child_process
*process
= p
->process
;
42 if (process
->clean_on_exit_handler
) {
44 "trace: run_command: running exit handler for pid %"
45 PRIuMAX
, (uintmax_t)p
->pid
47 process
->clean_on_exit_handler(process
);
53 if (p
->process
&& p
->process
->wait_after_clean
) {
54 p
->next
= children_to_wait_for
;
55 children_to_wait_for
= p
;
62 while (children_to_wait_for
) {
63 struct child_to_clean
*p
= children_to_wait_for
;
64 children_to_wait_for
= p
->next
;
66 while (waitpid(p
->pid
, NULL
, 0) < 0 && errno
== EINTR
)
67 ; /* spin waiting for process exit or error */
74 static void cleanup_children_on_signal(int sig
)
76 cleanup_children(sig
, 1);
81 static void cleanup_children_on_exit(void)
83 cleanup_children(SIGTERM
, 0);
86 static void mark_child_for_cleanup(pid_t pid
, struct child_process
*process
)
88 struct child_to_clean
*p
= xmalloc(sizeof(*p
));
91 p
->next
= children_to_clean
;
92 children_to_clean
= p
;
94 if (!installed_child_cleanup_handler
) {
95 atexit(cleanup_children_on_exit
);
96 sigchain_push_common(cleanup_children_on_signal
);
97 installed_child_cleanup_handler
= 1;
101 static void clear_child_for_cleanup(pid_t pid
)
103 struct child_to_clean
**pp
;
105 for (pp
= &children_to_clean
; *pp
; pp
= &(*pp
)->next
) {
106 struct child_to_clean
*clean_me
= *pp
;
108 if (clean_me
->pid
== pid
) {
109 *pp
= clean_me
->next
;
116 static inline void close_pair(int fd
[2])
122 int is_executable(const char *name
)
126 if (stat(name
, &st
) || /* stat, not lstat */
127 !S_ISREG(st
.st_mode
))
130 #if defined(GIT_WINDOWS_NATIVE)
132 * On Windows there is no executable bit. The file extension
133 * indicates whether it can be run as an executable, and Git
134 * has special-handling to detect scripts and launch them
135 * through the indicated script interpreter. We test for the
136 * file extension first because virus scanners may make
137 * it quite expensive to open many files.
139 if (ends_with(name
, ".exe"))
144 * Now that we know it does not have an executable extension,
145 * peek into the file instead.
149 int fd
= open(name
, O_RDONLY
);
150 st
.st_mode
&= ~S_IXUSR
;
152 n
= read(fd
, buf
, 2);
154 /* look for a she-bang */
155 if (!strcmp(buf
, "#!"))
156 st
.st_mode
|= S_IXUSR
;
161 return st
.st_mode
& S_IXUSR
;
165 * Search $PATH for a command. This emulates the path search that
166 * execvp would perform, without actually executing the command so it
167 * can be used before fork() to prepare to run a command using
168 * execve() or after execvp() to diagnose why it failed.
170 * The caller should ensure that file contains no directory
173 * Returns the path to the command, as found in $PATH or NULL if the
174 * command could not be found. The caller inherits ownership of the memory
175 * used to store the resultant path.
177 * This should not be used on Windows, where the $PATH search rules
178 * are more complicated (e.g., a search for "foo" should find
181 static char *locate_in_PATH(const char *file
)
183 const char *p
= getenv("PATH");
184 struct strbuf buf
= STRBUF_INIT
;
190 const char *end
= strchrnul(p
, ':');
194 /* POSIX specifies an empty entry as the current directory. */
196 strbuf_add(&buf
, p
, end
- p
);
197 strbuf_addch(&buf
, '/');
199 strbuf_addstr(&buf
, file
);
201 if (is_executable(buf
.buf
))
202 return strbuf_detach(&buf
, NULL
);
209 strbuf_release(&buf
);
213 static int exists_in_PATH(const char *file
)
215 char *r
= locate_in_PATH(file
);
220 int sane_execvp(const char *file
, char * const argv
[])
222 #ifndef GIT_WINDOWS_NATIVE
224 * execvp() doesn't return, so we all we can do is tell trace2
225 * what we are about to do and let it leave a hint in the log
226 * (unless of course the execvp() fails).
228 * we skip this for Windows because the compat layer already
229 * has to emulate the execvp() call anyway.
231 int exec_id
= trace2_exec(file
, (const char **)argv
);
234 if (!execvp(file
, argv
))
235 return 0; /* cannot happen ;-) */
237 #ifndef GIT_WINDOWS_NATIVE
240 trace2_exec_result(exec_id
, ec
);
246 * When a command can't be found because one of the directories
247 * listed in $PATH is unsearchable, execvp reports EACCES, but
248 * careful usability testing (read: analysis of occasional bug
249 * reports) reveals that "No such file or directory" is more
252 * We avoid commands with "/", because execvp will not do $PATH
253 * lookups in that case.
255 * The reassignment of EACCES to errno looks like a no-op below,
256 * but we need to protect against exists_in_PATH overwriting errno.
258 if (errno
== EACCES
&& !strchr(file
, '/'))
259 errno
= exists_in_PATH(file
) ? EACCES
: ENOENT
;
260 else if (errno
== ENOTDIR
&& !strchr(file
, '/'))
265 static const char **prepare_shell_cmd(struct argv_array
*out
, const char **argv
)
268 BUG("shell command is empty");
270 if (strcspn(argv
[0], "|&;<>()$`\\\"' \t\n*?[#~=%") != strlen(argv
[0])) {
271 #ifndef GIT_WINDOWS_NATIVE
272 argv_array_push(out
, SHELL_PATH
);
274 argv_array_push(out
, "sh");
276 argv_array_push(out
, "-c");
279 * If we have no extra arguments, we do not even need to
280 * bother with the "$@" magic.
283 argv_array_push(out
, argv
[0]);
285 argv_array_pushf(out
, "%s \"$@\"", argv
[0]);
288 argv_array_pushv(out
, argv
);
292 #ifndef GIT_WINDOWS_NATIVE
293 static int child_notifier
= -1;
299 CHILD_ERR_SIGPROCMASK
,
306 enum child_errcode err
;
307 int syserr
; /* errno */
310 static void child_die(enum child_errcode err
)
312 struct child_err buf
;
317 /* write(2) on buf smaller than PIPE_BUF (min 512) is atomic: */
318 xwrite(child_notifier
, &buf
, sizeof(buf
));
322 static void child_dup2(int fd
, int to
)
324 if (dup2(fd
, to
) < 0)
325 child_die(CHILD_ERR_DUP2
);
328 static void child_close(int fd
)
331 child_die(CHILD_ERR_CLOSE
);
334 static void child_close_pair(int fd
[2])
341 * parent will make it look like the child spewed a fatal error and died
342 * this is needed to prevent changes to t0061.
344 static void fake_fatal(const char *err
, va_list params
)
346 vreportf("fatal: ", err
, params
);
349 static void child_error_fn(const char *err
, va_list params
)
351 const char msg
[] = "error() should not be called in child\n";
352 xwrite(2, msg
, sizeof(msg
) - 1);
355 static void child_warn_fn(const char *err
, va_list params
)
357 const char msg
[] = "warn() should not be called in child\n";
358 xwrite(2, msg
, sizeof(msg
) - 1);
361 static void NORETURN
child_die_fn(const char *err
, va_list params
)
363 const char msg
[] = "die() should not be called in child\n";
364 xwrite(2, msg
, sizeof(msg
) - 1);
368 /* this runs in the parent process */
369 static void child_err_spew(struct child_process
*cmd
, struct child_err
*cerr
)
371 static void (*old_errfn
)(const char *err
, va_list params
);
373 old_errfn
= get_error_routine();
374 set_error_routine(fake_fatal
);
375 errno
= cerr
->syserr
;
378 case CHILD_ERR_CHDIR
:
379 error_errno("exec '%s': cd to '%s' failed",
380 cmd
->argv
[0], cmd
->dir
);
383 error_errno("dup2() in child failed");
385 case CHILD_ERR_CLOSE
:
386 error_errno("close() in child failed");
388 case CHILD_ERR_SIGPROCMASK
:
389 error_errno("sigprocmask failed restoring signals");
391 case CHILD_ERR_ENOENT
:
392 error_errno("cannot run %s", cmd
->argv
[0]);
394 case CHILD_ERR_SILENT
:
396 case CHILD_ERR_ERRNO
:
397 error_errno("cannot exec '%s'", cmd
->argv
[0]);
400 set_error_routine(old_errfn
);
403 static int prepare_cmd(struct argv_array
*out
, const struct child_process
*cmd
)
406 BUG("command is empty");
409 * Add SHELL_PATH so in the event exec fails with ENOEXEC we can
410 * attempt to interpret the command with 'sh'.
412 argv_array_push(out
, SHELL_PATH
);
415 argv_array_push(out
, "git");
416 argv_array_pushv(out
, cmd
->argv
);
417 } else if (cmd
->use_shell
) {
418 prepare_shell_cmd(out
, cmd
->argv
);
420 argv_array_pushv(out
, cmd
->argv
);
424 * If there are no '/' characters in the command then perform a path
425 * lookup and use the resolved path as the command to exec. If there
426 * are '/' characters, we have exec attempt to invoke the command
429 if (!strchr(out
->argv
[1], '/')) {
430 char *program
= locate_in_PATH(out
->argv
[1]);
432 free((char *)out
->argv
[1]);
433 out
->argv
[1] = program
;
435 argv_array_clear(out
);
444 static char **prep_childenv(const char *const *deltaenv
)
446 extern char **environ
;
448 struct string_list env
= STRING_LIST_INIT_DUP
;
449 struct strbuf key
= STRBUF_INIT
;
450 const char *const *p
;
453 /* Construct a sorted string list consisting of the current environ */
454 for (p
= (const char *const *) environ
; p
&& *p
; p
++) {
455 const char *equals
= strchr(*p
, '=');
459 strbuf_add(&key
, *p
, equals
- *p
);
460 string_list_append(&env
, key
.buf
)->util
= (void *) *p
;
462 string_list_append(&env
, *p
)->util
= (void *) *p
;
465 string_list_sort(&env
);
467 /* Merge in 'deltaenv' with the current environ */
468 for (p
= deltaenv
; p
&& *p
; p
++) {
469 const char *equals
= strchr(*p
, '=');
472 /* ('key=value'), insert or replace entry */
474 strbuf_add(&key
, *p
, equals
- *p
);
475 string_list_insert(&env
, key
.buf
)->util
= (void *) *p
;
477 /* otherwise ('key') remove existing entry */
478 string_list_remove(&env
, *p
, 0);
482 /* Create an array of 'char *' to be used as the childenv */
483 ALLOC_ARRAY(childenv
, env
.nr
+ 1);
484 for (i
= 0; i
< env
.nr
; i
++)
485 childenv
[i
] = env
.items
[i
].util
;
486 childenv
[env
.nr
] = NULL
;
488 string_list_clear(&env
, 0);
489 strbuf_release(&key
);
493 struct atfork_state
{
500 #define CHECK_BUG(err, msg) \
504 BUG("%s: %s", msg, strerror(e)); \
507 static void atfork_prepare(struct atfork_state
*as
)
511 if (sigfillset(&all
))
512 die_errno("sigfillset");
514 if (sigprocmask(SIG_SETMASK
, &all
, &as
->old
))
515 die_errno("sigprocmask");
517 CHECK_BUG(pthread_sigmask(SIG_SETMASK
, &all
, &as
->old
),
518 "blocking all signals");
519 CHECK_BUG(pthread_setcancelstate(PTHREAD_CANCEL_DISABLE
, &as
->cs
),
520 "disabling cancellation");
524 static void atfork_parent(struct atfork_state
*as
)
527 if (sigprocmask(SIG_SETMASK
, &as
->old
, NULL
))
528 die_errno("sigprocmask");
530 CHECK_BUG(pthread_setcancelstate(as
->cs
, NULL
),
531 "re-enabling cancellation");
532 CHECK_BUG(pthread_sigmask(SIG_SETMASK
, &as
->old
, NULL
),
533 "restoring signal mask");
536 #endif /* GIT_WINDOWS_NATIVE */
538 static inline void set_cloexec(int fd
)
540 int flags
= fcntl(fd
, F_GETFD
);
542 fcntl(fd
, F_SETFD
, flags
| FD_CLOEXEC
);
545 static int wait_or_whine(pid_t pid
, const char *argv0
, int in_signal
)
547 int status
, code
= -1;
549 int failed_errno
= 0;
551 while ((waiting
= waitpid(pid
, &status
, 0)) < 0 && errno
== EINTR
)
557 failed_errno
= errno
;
558 error_errno("waitpid for %s failed", argv0
);
559 } else if (waiting
!= pid
) {
560 error("waitpid is confused (%s)", argv0
);
561 } else if (WIFSIGNALED(status
)) {
562 code
= WTERMSIG(status
);
563 if (code
!= SIGINT
&& code
!= SIGQUIT
&& code
!= SIGPIPE
)
564 error("%s died of signal %d", argv0
, code
);
566 * This return value is chosen so that code & 0xff
567 * mimics the exit code that a POSIX shell would report for
568 * a program that died from this signal.
571 } else if (WIFEXITED(status
)) {
572 code
= WEXITSTATUS(status
);
574 error("waitpid is confused (%s)", argv0
);
577 clear_child_for_cleanup(pid
);
579 errno
= failed_errno
;
583 static void trace_add_env(struct strbuf
*dst
, const char *const *deltaenv
)
585 struct string_list envs
= STRING_LIST_INIT_DUP
;
586 const char *const *e
;
588 int printed_unset
= 0;
590 /* Last one wins, see run-command.c:prep_childenv() for context */
591 for (e
= deltaenv
; e
&& *e
; e
++) {
592 struct strbuf key
= STRBUF_INIT
;
593 char *equals
= strchr(*e
, '=');
596 strbuf_add(&key
, *e
, equals
- *e
);
597 string_list_insert(&envs
, key
.buf
)->util
= equals
+ 1;
599 string_list_insert(&envs
, *e
)->util
= NULL
;
601 strbuf_release(&key
);
604 /* "unset X Y...;" */
605 for (i
= 0; i
< envs
.nr
; i
++) {
606 const char *var
= envs
.items
[i
].string
;
607 const char *val
= envs
.items
[i
].util
;
609 if (val
|| !getenv(var
))
612 if (!printed_unset
) {
613 strbuf_addstr(dst
, " unset");
616 strbuf_addf(dst
, " %s", var
);
619 strbuf_addch(dst
, ';');
621 /* ... followed by "A=B C=D ..." */
622 for (i
= 0; i
< envs
.nr
; i
++) {
623 const char *var
= envs
.items
[i
].string
;
624 const char *val
= envs
.items
[i
].util
;
630 oldval
= getenv(var
);
631 if (oldval
&& !strcmp(val
, oldval
))
634 strbuf_addf(dst
, " %s=", var
);
635 sq_quote_buf_pretty(dst
, val
);
637 string_list_clear(&envs
, 0);
640 static void trace_run_command(const struct child_process
*cp
)
642 struct strbuf buf
= STRBUF_INIT
;
644 if (!trace_want(&trace_default_key
))
647 strbuf_addstr(&buf
, "trace: run_command:");
649 strbuf_addstr(&buf
, " cd ");
650 sq_quote_buf_pretty(&buf
, cp
->dir
);
651 strbuf_addch(&buf
, ';');
654 * The caller is responsible for initializing cp->env from
655 * cp->env_array if needed. We only check one place.
658 trace_add_env(&buf
, cp
->env
);
660 strbuf_addstr(&buf
, " git");
661 sq_quote_argv_pretty(&buf
, cp
->argv
);
663 trace_printf("%s", buf
.buf
);
664 strbuf_release(&buf
);
667 int start_command(struct child_process
*cmd
)
669 int need_in
, need_out
, need_err
;
670 int fdin
[2], fdout
[2], fderr
[2];
675 cmd
->argv
= cmd
->args
.argv
;
677 cmd
->env
= cmd
->env_array
.argv
;
680 * In case of errors we must keep the promise to close FDs
681 * that have been passed in via ->in and ->out.
684 need_in
= !cmd
->no_stdin
&& cmd
->in
< 0;
686 if (pipe(fdin
) < 0) {
687 failed_errno
= errno
;
690 str
= "standard input";
696 need_out
= !cmd
->no_stdout
697 && !cmd
->stdout_to_stderr
700 if (pipe(fdout
) < 0) {
701 failed_errno
= errno
;
706 str
= "standard output";
712 need_err
= !cmd
->no_stderr
&& cmd
->err
< 0;
714 if (pipe(fderr
) < 0) {
715 failed_errno
= errno
;
724 str
= "standard error";
726 error("cannot create %s pipe for %s: %s",
727 str
, cmd
->argv
[0], strerror(failed_errno
));
728 child_process_clear(cmd
);
729 errno
= failed_errno
;
735 trace2_child_start(cmd
);
736 trace_run_command(cmd
);
740 #ifndef GIT_WINDOWS_NATIVE
745 struct argv_array argv
= ARGV_ARRAY_INIT
;
746 struct child_err cerr
;
747 struct atfork_state as
;
749 if (prepare_cmd(&argv
, cmd
) < 0) {
750 failed_errno
= errno
;
752 if (!cmd
->silent_exec_failure
)
753 error_errno("cannot run %s", cmd
->argv
[0]);
757 if (pipe(notify_pipe
))
758 notify_pipe
[0] = notify_pipe
[1] = -1;
760 if (cmd
->no_stdin
|| cmd
->no_stdout
|| cmd
->no_stderr
) {
761 null_fd
= open("/dev/null", O_RDWR
| O_CLOEXEC
);
763 die_errno(_("open /dev/null failed"));
764 set_cloexec(null_fd
);
767 childenv
= prep_childenv(cmd
->env
);
771 * NOTE: In order to prevent deadlocking when using threads special
772 * care should be taken with the function calls made in between the
773 * fork() and exec() calls. No calls should be made to functions which
774 * require acquiring a lock (e.g. malloc) as the lock could have been
775 * held by another thread at the time of forking, causing the lock to
776 * never be released in the child process. This means only
777 * Async-Signal-Safe functions are permitted in the child.
780 failed_errno
= errno
;
784 * Ensure the default die/error/warn routines do not get
785 * called, they can take stdio locks and malloc.
787 set_die_routine(child_die_fn
);
788 set_error_routine(child_error_fn
);
789 set_warn_routine(child_warn_fn
);
791 close(notify_pipe
[0]);
792 set_cloexec(notify_pipe
[1]);
793 child_notifier
= notify_pipe
[1];
796 child_dup2(null_fd
, 0);
798 child_dup2(fdin
[0], 0);
799 child_close_pair(fdin
);
800 } else if (cmd
->in
) {
801 child_dup2(cmd
->in
, 0);
802 child_close(cmd
->in
);
806 child_dup2(null_fd
, 2);
808 child_dup2(fderr
[1], 2);
809 child_close_pair(fderr
);
810 } else if (cmd
->err
> 1) {
811 child_dup2(cmd
->err
, 2);
812 child_close(cmd
->err
);
816 child_dup2(null_fd
, 1);
817 else if (cmd
->stdout_to_stderr
)
820 child_dup2(fdout
[1], 1);
821 child_close_pair(fdout
);
822 } else if (cmd
->out
> 1) {
823 child_dup2(cmd
->out
, 1);
824 child_close(cmd
->out
);
827 if (cmd
->dir
&& chdir(cmd
->dir
))
828 child_die(CHILD_ERR_CHDIR
);
831 * restore default signal handlers here, in case
832 * we catch a signal right before execve below
834 for (sig
= 1; sig
< NSIG
; sig
++) {
835 /* ignored signals get reset to SIG_DFL on execve */
836 if (signal(sig
, SIG_DFL
) == SIG_IGN
)
837 signal(sig
, SIG_IGN
);
840 if (sigprocmask(SIG_SETMASK
, &as
.old
, NULL
) != 0)
841 child_die(CHILD_ERR_SIGPROCMASK
);
844 * Attempt to exec using the command and arguments starting at
845 * argv.argv[1]. argv.argv[0] contains SHELL_PATH which will
846 * be used in the event exec failed with ENOEXEC at which point
847 * we will try to interpret the command using 'sh'.
849 execve(argv
.argv
[1], (char *const *) argv
.argv
+ 1,
850 (char *const *) childenv
);
851 if (errno
== ENOEXEC
)
852 execve(argv
.argv
[0], (char *const *) argv
.argv
,
853 (char *const *) childenv
);
855 if (errno
== ENOENT
) {
856 if (cmd
->silent_exec_failure
)
857 child_die(CHILD_ERR_SILENT
);
858 child_die(CHILD_ERR_ENOENT
);
860 child_die(CHILD_ERR_ERRNO
);
865 error_errno("cannot fork() for %s", cmd
->argv
[0]);
866 else if (cmd
->clean_on_exit
)
867 mark_child_for_cleanup(cmd
->pid
, cmd
);
870 * Wait for child's exec. If the exec succeeds (or if fork()
871 * failed), EOF is seen immediately by the parent. Otherwise, the
872 * child process sends a child_err struct.
873 * Note that use of this infrastructure is completely advisory,
874 * therefore, we keep error checks minimal.
876 close(notify_pipe
[1]);
877 if (xread(notify_pipe
[0], &cerr
, sizeof(cerr
)) == sizeof(cerr
)) {
879 * At this point we know that fork() succeeded, but exec()
880 * failed. Errors have been reported to our stderr.
882 wait_or_whine(cmd
->pid
, cmd
->argv
[0], 0);
883 child_err_spew(cmd
, &cerr
);
884 failed_errno
= errno
;
887 close(notify_pipe
[0]);
891 argv_array_clear(&argv
);
898 int fhin
= 0, fhout
= 1, fherr
= 2;
899 const char **sargv
= cmd
->argv
;
900 struct argv_array nargv
= ARGV_ARRAY_INIT
;
903 fhin
= open("/dev/null", O_RDWR
);
910 fherr
= open("/dev/null", O_RDWR
);
912 fherr
= dup(fderr
[1]);
913 else if (cmd
->err
> 2)
914 fherr
= dup(cmd
->err
);
917 fhout
= open("/dev/null", O_RDWR
);
918 else if (cmd
->stdout_to_stderr
)
921 fhout
= dup(fdout
[1]);
922 else if (cmd
->out
> 1)
923 fhout
= dup(cmd
->out
);
926 cmd
->argv
= prepare_git_cmd(&nargv
, cmd
->argv
);
927 else if (cmd
->use_shell
)
928 cmd
->argv
= prepare_shell_cmd(&nargv
, cmd
->argv
);
930 cmd
->pid
= mingw_spawnvpe(cmd
->argv
[0], cmd
->argv
, (char**) cmd
->env
,
931 cmd
->dir
, fhin
, fhout
, fherr
);
932 failed_errno
= errno
;
933 if (cmd
->pid
< 0 && (!cmd
->silent_exec_failure
|| errno
!= ENOENT
))
934 error_errno("cannot spawn %s", cmd
->argv
[0]);
935 if (cmd
->clean_on_exit
&& cmd
->pid
>= 0)
936 mark_child_for_cleanup(cmd
->pid
, cmd
);
938 argv_array_clear(&nargv
);
950 trace2_child_exit(cmd
, -1);
964 child_process_clear(cmd
);
965 errno
= failed_errno
;
987 int finish_command(struct child_process
*cmd
)
989 int ret
= wait_or_whine(cmd
->pid
, cmd
->argv
[0], 0);
990 trace2_child_exit(cmd
, ret
);
991 child_process_clear(cmd
);
992 invalidate_lstat_cache();
996 int finish_command_in_signal(struct child_process
*cmd
)
998 int ret
= wait_or_whine(cmd
->pid
, cmd
->argv
[0], 1);
999 trace2_child_exit(cmd
, ret
);
1004 int run_command(struct child_process
*cmd
)
1008 if (cmd
->out
< 0 || cmd
->err
< 0)
1009 BUG("run_command with a pipe can cause deadlock");
1011 code
= start_command(cmd
);
1014 return finish_command(cmd
);
1017 int run_command_v_opt(const char **argv
, int opt
)
1019 return run_command_v_opt_cd_env(argv
, opt
, NULL
, NULL
);
1022 int run_command_v_opt_tr2(const char **argv
, int opt
, const char *tr2_class
)
1024 return run_command_v_opt_cd_env_tr2(argv
, opt
, NULL
, NULL
, tr2_class
);
1027 int run_command_v_opt_cd_env(const char **argv
, int opt
, const char *dir
, const char *const *env
)
1029 return run_command_v_opt_cd_env_tr2(argv
, opt
, dir
, env
, NULL
);
1032 int run_command_v_opt_cd_env_tr2(const char **argv
, int opt
, const char *dir
,
1033 const char *const *env
, const char *tr2_class
)
1035 struct child_process cmd
= CHILD_PROCESS_INIT
;
1037 cmd
.no_stdin
= opt
& RUN_COMMAND_NO_STDIN
? 1 : 0;
1038 cmd
.git_cmd
= opt
& RUN_GIT_CMD
? 1 : 0;
1039 cmd
.stdout_to_stderr
= opt
& RUN_COMMAND_STDOUT_TO_STDERR
? 1 : 0;
1040 cmd
.silent_exec_failure
= opt
& RUN_SILENT_EXEC_FAILURE
? 1 : 0;
1041 cmd
.use_shell
= opt
& RUN_USING_SHELL
? 1 : 0;
1042 cmd
.clean_on_exit
= opt
& RUN_CLEAN_ON_EXIT
? 1 : 0;
1045 cmd
.trace2_child_class
= tr2_class
;
1046 return run_command(&cmd
);
1050 static pthread_t main_thread
;
1051 static int main_thread_set
;
1052 static pthread_key_t async_key
;
1053 static pthread_key_t async_die_counter
;
1055 static void *run_thread(void *data
)
1057 struct async
*async
= data
;
1060 if (async
->isolate_sigpipe
) {
1063 sigaddset(&mask
, SIGPIPE
);
1064 if (pthread_sigmask(SIG_BLOCK
, &mask
, NULL
) < 0) {
1065 ret
= error("unable to block SIGPIPE in async thread");
1070 pthread_setspecific(async_key
, async
);
1071 ret
= async
->proc(async
->proc_in
, async
->proc_out
, async
->data
);
1075 static NORETURN
void die_async(const char *err
, va_list params
)
1077 vreportf("fatal: ", err
, params
);
1080 struct async
*async
= pthread_getspecific(async_key
);
1081 if (async
->proc_in
>= 0)
1082 close(async
->proc_in
);
1083 if (async
->proc_out
>= 0)
1084 close(async
->proc_out
);
1085 pthread_exit((void *)128);
1091 static int async_die_is_recursing(void)
1093 void *ret
= pthread_getspecific(async_die_counter
);
1094 pthread_setspecific(async_die_counter
, (void *)1);
1100 if (!main_thread_set
)
1101 return 0; /* no asyncs started yet */
1102 return !pthread_equal(main_thread
, pthread_self());
1105 static void NORETURN
async_exit(int code
)
1107 pthread_exit((void *)(intptr_t)code
);
1113 void (**handlers
)(void);
1118 static int git_atexit_installed
;
1120 static void git_atexit_dispatch(void)
1124 for (i
=git_atexit_hdlrs
.nr
; i
; i
--)
1125 git_atexit_hdlrs
.handlers
[i
-1]();
1128 static void git_atexit_clear(void)
1130 free(git_atexit_hdlrs
.handlers
);
1131 memset(&git_atexit_hdlrs
, 0, sizeof(git_atexit_hdlrs
));
1132 git_atexit_installed
= 0;
1136 int git_atexit(void (*handler
)(void))
1138 ALLOC_GROW(git_atexit_hdlrs
.handlers
, git_atexit_hdlrs
.nr
+ 1, git_atexit_hdlrs
.alloc
);
1139 git_atexit_hdlrs
.handlers
[git_atexit_hdlrs
.nr
++] = handler
;
1140 if (!git_atexit_installed
) {
1141 if (atexit(&git_atexit_dispatch
))
1143 git_atexit_installed
= 1;
1147 #define atexit git_atexit
1149 static int process_is_async
;
1152 return process_is_async
;
1155 static void NORETURN
async_exit(int code
)
1162 void check_pipe(int err
)
1168 signal(SIGPIPE
, SIG_DFL
);
1170 /* Should never happen, but just in case... */
1175 int start_async(struct async
*async
)
1177 int need_in
, need_out
;
1178 int fdin
[2], fdout
[2];
1179 int proc_in
, proc_out
;
1181 need_in
= async
->in
< 0;
1183 if (pipe(fdin
) < 0) {
1186 return error_errno("cannot create pipe");
1188 async
->in
= fdin
[1];
1191 need_out
= async
->out
< 0;
1193 if (pipe(fdout
) < 0) {
1198 return error_errno("cannot create pipe");
1200 async
->out
= fdout
[0];
1206 proc_in
= async
->in
;
1211 proc_out
= fdout
[1];
1212 else if (async
->out
)
1213 proc_out
= async
->out
;
1218 /* Flush stdio before fork() to avoid cloning buffers */
1221 async
->pid
= fork();
1222 if (async
->pid
< 0) {
1223 error_errno("fork (async) failed");
1232 process_is_async
= 1;
1233 exit(!!async
->proc(proc_in
, proc_out
, async
->data
));
1236 mark_child_for_cleanup(async
->pid
, NULL
);
1245 else if (async
->out
)
1248 if (!main_thread_set
) {
1250 * We assume that the first time that start_async is called
1251 * it is from the main thread.
1253 main_thread_set
= 1;
1254 main_thread
= pthread_self();
1255 pthread_key_create(&async_key
, NULL
);
1256 pthread_key_create(&async_die_counter
, NULL
);
1257 set_die_routine(die_async
);
1258 set_die_is_recursing_routine(async_die_is_recursing
);
1262 set_cloexec(proc_in
);
1264 set_cloexec(proc_out
);
1265 async
->proc_in
= proc_in
;
1266 async
->proc_out
= proc_out
;
1268 int err
= pthread_create(&async
->tid
, NULL
, run_thread
, async
);
1270 error(_("cannot create async thread: %s"), strerror(err
));
1285 else if (async
->out
)
1290 int finish_async(struct async
*async
)
1293 int ret
= wait_or_whine(async
->pid
, "child process", 0);
1295 invalidate_lstat_cache();
1299 void *ret
= (void *)(intptr_t)(-1);
1301 if (pthread_join(async
->tid
, &ret
))
1302 error("pthread_join failed");
1303 invalidate_lstat_cache();
1304 return (int)(intptr_t)ret
;
1309 int async_with_fork(void)
1318 const char *find_hook(const char *name
)
1320 static struct strbuf path
= STRBUF_INIT
;
1322 strbuf_reset(&path
);
1323 strbuf_git_path(&path
, "hooks/%s", name
);
1324 if (access(path
.buf
, X_OK
) < 0) {
1327 #ifdef STRIP_EXTENSION
1328 strbuf_addstr(&path
, STRIP_EXTENSION
);
1329 if (access(path
.buf
, X_OK
) >= 0)
1331 if (errno
== EACCES
)
1335 if (err
== EACCES
&& advice_ignored_hook
) {
1336 static struct string_list advise_given
= STRING_LIST_INIT_DUP
;
1338 if (!string_list_lookup(&advise_given
, name
)) {
1339 string_list_insert(&advise_given
, name
);
1340 advise(_("The '%s' hook was ignored because "
1341 "it's not set as executable.\n"
1342 "You can disable this warning with "
1343 "`git config advice.ignoredHook false`."),
1352 int run_hook_ve(const char *const *env
, const char *name
, va_list args
)
1354 struct child_process hook
= CHILD_PROCESS_INIT
;
1357 p
= find_hook(name
);
1361 argv_array_push(&hook
.args
, p
);
1362 while ((p
= va_arg(args
, const char *)))
1363 argv_array_push(&hook
.args
, p
);
1366 hook
.stdout_to_stderr
= 1;
1367 hook
.trace2_hook_name
= name
;
1369 return run_command(&hook
);
1372 int run_hook_le(const char *const *env
, const char *name
, ...)
1377 va_start(args
, name
);
1378 ret
= run_hook_ve(env
, name
, args
);
1385 /* initialized by caller */
1387 int type
; /* POLLOUT or POLLIN */
1399 /* returned by pump_io */
1400 int error
; /* 0 for success, otherwise errno */
1406 static int pump_io_round(struct io_pump
*slots
, int nr
, struct pollfd
*pfd
)
1411 for (i
= 0; i
< nr
; i
++) {
1412 struct io_pump
*io
= &slots
[i
];
1415 pfd
[pollsize
].fd
= io
->fd
;
1416 pfd
[pollsize
].events
= io
->type
;
1417 io
->pfd
= &pfd
[pollsize
++];
1423 if (poll(pfd
, pollsize
, -1) < 0) {
1426 die_errno("poll failed");
1429 for (i
= 0; i
< nr
; i
++) {
1430 struct io_pump
*io
= &slots
[i
];
1435 if (!(io
->pfd
->revents
& (POLLOUT
|POLLIN
|POLLHUP
|POLLERR
|POLLNVAL
)))
1438 if (io
->type
== POLLOUT
) {
1439 ssize_t len
= xwrite(io
->fd
,
1440 io
->u
.out
.buf
, io
->u
.out
.len
);
1446 io
->u
.out
.buf
+= len
;
1447 io
->u
.out
.len
-= len
;
1448 if (!io
->u
.out
.len
) {
1455 if (io
->type
== POLLIN
) {
1456 ssize_t len
= strbuf_read_once(io
->u
.in
.buf
,
1457 io
->fd
, io
->u
.in
.hint
);
1470 static int pump_io(struct io_pump
*slots
, int nr
)
1475 for (i
= 0; i
< nr
; i
++)
1478 ALLOC_ARRAY(pfd
, nr
);
1479 while (pump_io_round(slots
, nr
, pfd
))
1483 /* There may be multiple errno values, so just pick the first. */
1484 for (i
= 0; i
< nr
; i
++) {
1485 if (slots
[i
].error
) {
1486 errno
= slots
[i
].error
;
1494 int pipe_command(struct child_process
*cmd
,
1495 const char *in
, size_t in_len
,
1496 struct strbuf
*out
, size_t out_hint
,
1497 struct strbuf
*err
, size_t err_hint
)
1499 struct io_pump io
[3];
1509 if (start_command(cmd
) < 0)
1513 io
[nr
].fd
= cmd
->in
;
1514 io
[nr
].type
= POLLOUT
;
1515 io
[nr
].u
.out
.buf
= in
;
1516 io
[nr
].u
.out
.len
= in_len
;
1520 io
[nr
].fd
= cmd
->out
;
1521 io
[nr
].type
= POLLIN
;
1522 io
[nr
].u
.in
.buf
= out
;
1523 io
[nr
].u
.in
.hint
= out_hint
;
1527 io
[nr
].fd
= cmd
->err
;
1528 io
[nr
].type
= POLLIN
;
1529 io
[nr
].u
.in
.buf
= err
;
1530 io
[nr
].u
.in
.hint
= err_hint
;
1534 if (pump_io(io
, nr
) < 0) {
1535 finish_command(cmd
); /* throw away exit code */
1539 return finish_command(cmd
);
1545 GIT_CP_WAIT_CLEANUP
,
1548 struct parallel_processes
{
1554 get_next_task_fn get_next_task
;
1555 start_failure_fn start_failure
;
1556 task_finished_fn task_finished
;
1559 enum child_state state
;
1560 struct child_process process
;
1565 * The struct pollfd is logically part of *children,
1566 * but the system call expects it as its own array.
1570 unsigned shutdown
: 1;
1573 struct strbuf buffered_output
; /* of finished children */
1576 static int default_start_failure(struct strbuf
*out
,
1583 static int default_task_finished(int result
,
1591 static void kill_children(struct parallel_processes
*pp
, int signo
)
1593 int i
, n
= pp
->max_processes
;
1595 for (i
= 0; i
< n
; i
++)
1596 if (pp
->children
[i
].state
== GIT_CP_WORKING
)
1597 kill(pp
->children
[i
].process
.pid
, signo
);
1600 static struct parallel_processes
*pp_for_signal
;
1602 static void handle_children_on_signal(int signo
)
1604 kill_children(pp_for_signal
, signo
);
1605 sigchain_pop(signo
);
1609 static void pp_init(struct parallel_processes
*pp
,
1611 get_next_task_fn get_next_task
,
1612 start_failure_fn start_failure
,
1613 task_finished_fn task_finished
,
1621 pp
->max_processes
= n
;
1623 trace_printf("run_processes_parallel: preparing to run up to %d tasks", n
);
1627 BUG("you need to specify a get_next_task function");
1628 pp
->get_next_task
= get_next_task
;
1630 pp
->start_failure
= start_failure
? start_failure
: default_start_failure
;
1631 pp
->task_finished
= task_finished
? task_finished
: default_task_finished
;
1633 pp
->nr_processes
= 0;
1634 pp
->output_owner
= 0;
1636 pp
->children
= xcalloc(n
, sizeof(*pp
->children
));
1637 pp
->pfd
= xcalloc(n
, sizeof(*pp
->pfd
));
1638 strbuf_init(&pp
->buffered_output
, 0);
1640 for (i
= 0; i
< n
; i
++) {
1641 strbuf_init(&pp
->children
[i
].err
, 0);
1642 child_process_init(&pp
->children
[i
].process
);
1643 pp
->pfd
[i
].events
= POLLIN
| POLLHUP
;
1648 sigchain_push_common(handle_children_on_signal
);
1651 static void pp_cleanup(struct parallel_processes
*pp
)
1655 trace_printf("run_processes_parallel: done");
1656 for (i
= 0; i
< pp
->max_processes
; i
++) {
1657 strbuf_release(&pp
->children
[i
].err
);
1658 child_process_clear(&pp
->children
[i
].process
);
1665 * When get_next_task added messages to the buffer in its last
1666 * iteration, the buffered output is non empty.
1668 strbuf_write(&pp
->buffered_output
, stderr
);
1669 strbuf_release(&pp
->buffered_output
);
1671 sigchain_pop_common();
1675 * 0 if a new task was started.
1676 * 1 if no new jobs was started (get_next_task ran out of work, non critical
1677 * problem with starting a new command)
1678 * <0 no new job was started, user wishes to shutdown early. Use negative code
1679 * to signal the children.
1681 static int pp_start_one(struct parallel_processes
*pp
)
1685 for (i
= 0; i
< pp
->max_processes
; i
++)
1686 if (pp
->children
[i
].state
== GIT_CP_FREE
)
1688 if (i
== pp
->max_processes
)
1689 BUG("bookkeeping is hard");
1691 code
= pp
->get_next_task(&pp
->children
[i
].process
,
1692 &pp
->children
[i
].err
,
1694 &pp
->children
[i
].data
);
1696 strbuf_addbuf(&pp
->buffered_output
, &pp
->children
[i
].err
);
1697 strbuf_reset(&pp
->children
[i
].err
);
1700 pp
->children
[i
].process
.err
= -1;
1701 pp
->children
[i
].process
.stdout_to_stderr
= 1;
1702 pp
->children
[i
].process
.no_stdin
= 1;
1704 if (start_command(&pp
->children
[i
].process
)) {
1705 code
= pp
->start_failure(&pp
->children
[i
].err
,
1707 pp
->children
[i
].data
);
1708 strbuf_addbuf(&pp
->buffered_output
, &pp
->children
[i
].err
);
1709 strbuf_reset(&pp
->children
[i
].err
);
1716 pp
->children
[i
].state
= GIT_CP_WORKING
;
1717 pp
->pfd
[i
].fd
= pp
->children
[i
].process
.err
;
1721 static void pp_buffer_stderr(struct parallel_processes
*pp
, int output_timeout
)
1725 while ((i
= poll(pp
->pfd
, pp
->max_processes
, output_timeout
)) < 0) {
1732 /* Buffer output from all pipes. */
1733 for (i
= 0; i
< pp
->max_processes
; i
++) {
1734 if (pp
->children
[i
].state
== GIT_CP_WORKING
&&
1735 pp
->pfd
[i
].revents
& (POLLIN
| POLLHUP
)) {
1736 int n
= strbuf_read_once(&pp
->children
[i
].err
,
1737 pp
->children
[i
].process
.err
, 0);
1739 close(pp
->children
[i
].process
.err
);
1740 pp
->children
[i
].state
= GIT_CP_WAIT_CLEANUP
;
1742 if (errno
!= EAGAIN
)
1748 static void pp_output(struct parallel_processes
*pp
)
1750 int i
= pp
->output_owner
;
1751 if (pp
->children
[i
].state
== GIT_CP_WORKING
&&
1752 pp
->children
[i
].err
.len
) {
1753 strbuf_write(&pp
->children
[i
].err
, stderr
);
1754 strbuf_reset(&pp
->children
[i
].err
);
1758 static int pp_collect_finished(struct parallel_processes
*pp
)
1761 int n
= pp
->max_processes
;
1764 while (pp
->nr_processes
> 0) {
1765 for (i
= 0; i
< pp
->max_processes
; i
++)
1766 if (pp
->children
[i
].state
== GIT_CP_WAIT_CLEANUP
)
1768 if (i
== pp
->max_processes
)
1771 code
= finish_command(&pp
->children
[i
].process
);
1773 code
= pp
->task_finished(code
,
1774 &pp
->children
[i
].err
, pp
->data
,
1775 pp
->children
[i
].data
);
1783 pp
->children
[i
].state
= GIT_CP_FREE
;
1785 child_process_init(&pp
->children
[i
].process
);
1787 if (i
!= pp
->output_owner
) {
1788 strbuf_addbuf(&pp
->buffered_output
, &pp
->children
[i
].err
);
1789 strbuf_reset(&pp
->children
[i
].err
);
1791 strbuf_write(&pp
->children
[i
].err
, stderr
);
1792 strbuf_reset(&pp
->children
[i
].err
);
1794 /* Output all other finished child processes */
1795 strbuf_write(&pp
->buffered_output
, stderr
);
1796 strbuf_reset(&pp
->buffered_output
);
1799 * Pick next process to output live.
1801 * For now we pick it randomly by doing a round
1802 * robin. Later we may want to pick the one with
1803 * the most output or the longest or shortest
1804 * running process time.
1806 for (i
= 0; i
< n
; i
++)
1807 if (pp
->children
[(pp
->output_owner
+ i
) % n
].state
== GIT_CP_WORKING
)
1809 pp
->output_owner
= (pp
->output_owner
+ i
) % n
;
1815 int run_processes_parallel(int n
,
1816 get_next_task_fn get_next_task
,
1817 start_failure_fn start_failure
,
1818 task_finished_fn task_finished
,
1822 int output_timeout
= 100;
1824 struct parallel_processes pp
;
1826 pp_init(&pp
, n
, get_next_task
, start_failure
, task_finished
, pp_cb
);
1829 i
< spawn_cap
&& !pp
.shutdown
&&
1830 pp
.nr_processes
< pp
.max_processes
;
1832 code
= pp_start_one(&pp
);
1837 kill_children(&pp
, -code
);
1841 if (!pp
.nr_processes
)
1843 pp_buffer_stderr(&pp
, output_timeout
);
1845 code
= pp_collect_finished(&pp
);
1849 kill_children(&pp
, -code
);
1857 int run_processes_parallel_tr2(int n
, get_next_task_fn get_next_task
,
1858 start_failure_fn start_failure
,
1859 task_finished_fn task_finished
, void *pp_cb
,
1860 const char *tr2_category
, const char *tr2_label
)
1864 trace2_region_enter_printf(tr2_category
, tr2_label
, NULL
, "max:%d",
1865 ((n
< 1) ? online_cpus() : n
));
1867 result
= run_processes_parallel(n
, get_next_task
, start_failure
,
1868 task_finished
, pp_cb
);
1870 trace2_region_leave(tr2_category
, tr2_label
, NULL
);