run-command.c

   1 #include "cache.h"
   2 #include "run-command.h"
   3 #include "exec_cmd.h"
   4 #include "sigchain.h"
   5 #include "argv-array.h"
   6
   7 void child_process_init(struct child_process *child)
   8 {
   9         memset(child, 0, sizeof(*child));
  10         argv_array_init(&child->args);
  11         argv_array_init(&child->env_array);
  12 }
  13
  14 void child_process_clear(struct child_process *child)
  15 {
  16         argv_array_clear(&child->args);
  17         argv_array_clear(&child->env_array);
  18 }
  19
  20 struct child_to_clean {
  21         pid_t pid;
  22         struct child_to_clean *next;
  23 };
  24 static struct child_to_clean *children_to_clean;
  25 static int installed_child_cleanup_handler;
  26
  27 static void cleanup_children(int sig)
  28 {
  29         while (children_to_clean) {
  30                 struct child_to_clean *p = children_to_clean;
  31                 children_to_clean = p->next;
  32                 kill(p->pid, sig);
  33                 free(p);
  34         }
  35 }
  36
  37 static void cleanup_children_on_signal(int sig)
  38 {
  39         cleanup_children(sig);
  40         sigchain_pop(sig);
  41         raise(sig);
  42 }
  43
  44 static void cleanup_children_on_exit(void)
  45 {
  46         cleanup_children(SIGTERM);
  47 }
  48
  49 static void mark_child_for_cleanup(pid_t pid)
  50 {
  51         struct child_to_clean *p = xmalloc(sizeof(*p));
  52         p->pid = pid;
  53         p->next = children_to_clean;
  54         children_to_clean = p;
  55
  56         if (!installed_child_cleanup_handler) {
  57                 atexit(cleanup_children_on_exit);
  58                 sigchain_push_common(cleanup_children_on_signal);
  59                 installed_child_cleanup_handler = 1;
  60         }
  61 }
  62
  63 static void clear_child_for_cleanup(pid_t pid)
  64 {
  65         struct child_to_clean **pp;
  66
  67         for (pp = &children_to_clean; *pp; pp = &(*pp)->next) {
  68                 struct child_to_clean *clean_me = *pp;
  69
  70                 if (clean_me->pid == pid) {
  71                         *pp = clean_me->next;
  72                         free(clean_me);
  73                         return;
  74                 }
  75         }
  76 }
  77
  78 static inline void close_pair(int fd[2])
  79 {
  80         close(fd[0]);
  81         close(fd[1]);
  82 }
  83
  84 #ifndef GIT_WINDOWS_NATIVE
  85 static inline void dup_devnull(int to)
  86 {
  87         int fd = open("/dev/null", O_RDWR);
  88         if (fd < 0)
  89                 die_errno(_("open /dev/null failed"));
  90         if (dup2(fd, to) < 0)
  91                 die_errno(_("dup2(%d,%d) failed"), fd, to);
  92         close(fd);
  93 }
  94 #endif
  95
  96 static char *locate_in_PATH(const char *file)
  97 {
  98         const char *p = getenv("PATH");
  99         struct strbuf buf = STRBUF_INIT;
 100
 101         if (!p || !*p)
 102                 return NULL;
 103
 104         while (1) {
 105                 const char *end = strchrnul(p, ':');
 106
 107                 strbuf_reset(&buf);
 108
 109                 /* POSIX specifies an empty entry as the current directory. */
 110                 if (end != p) {
 111                         strbuf_add(&buf, p, end - p);
 112                         strbuf_addch(&buf, '/');
 113                 }
 114                 strbuf_addstr(&buf, file);
 115
 116                 if (!access(buf.buf, F_OK))
 117                         return strbuf_detach(&buf, NULL);
 118
 119                 if (!*end)
 120                         break;
 121                 p = end + 1;
 122         }
 123
 124         strbuf_release(&buf);
 125         return NULL;
 126 }
 127
 128 static int exists_in_PATH(const char *file)
 129 {
 130         char *r = locate_in_PATH(file);
 131         free(r);
 132         return r != NULL;
 133 }
 134
 135 int sane_execvp(const char *file, char * const argv[])
 136 {
 137         if (!execvp(file, argv))
 138                 return 0; /* cannot happen ;-) */
 139
 140         /*
 141          * When a command can't be found because one of the directories
 142          * listed in $PATH is unsearchable, execvp reports EACCES, but
 143          * careful usability testing (read: analysis of occasional bug
 144          * reports) reveals that "No such file or directory" is more
 145          * intuitive.
 146          *
 147          * We avoid commands with "/", because execvp will not do $PATH
 148          * lookups in that case.
 149          *
 150          * The reassignment of EACCES to errno looks like a no-op below,
 151          * but we need to protect against exists_in_PATH overwriting errno.
 152          */
 153         if (errno == EACCES && !strchr(file, '/'))
 154                 errno = exists_in_PATH(file) ? EACCES : ENOENT;
 155         else if (errno == ENOTDIR && !strchr(file, '/'))
 156                 errno = ENOENT;
 157         return -1;
 158 }
 159
 160 static const char **prepare_shell_cmd(const char **argv)
 161 {
 162         int argc, nargc = 0;
 163         const char **nargv;
 164
 165         for (argc = 0; argv[argc]; argc++)
 166                 ; /* just counting */
 167         /* +1 for NULL, +3 for "sh -c" plus extra $0 */
 168         nargv = xmalloc(sizeof(*nargv) * (argc + 1 + 3));
 169
 170         if (argc < 1)
 171                 die("BUG: shell command is empty");
 172
 173         if (strcspn(argv[0], "|&;<>()$`\\\"' \t\n*?[#~=%") != strlen(argv[0])) {
 174 #ifndef GIT_WINDOWS_NATIVE
 175                 nargv[nargc++] = SHELL_PATH;
 176 #else
 177                 nargv[nargc++] = "sh";
 178 #endif
 179                 nargv[nargc++] = "-c";
 180
 181                 if (argc < 2)
 182                         nargv[nargc++] = argv[0];
 183                 else {
 184                         struct strbuf arg0 = STRBUF_INIT;
 185                         strbuf_addf(&arg0, "%s \"$@\"", argv[0]);
 186                         nargv[nargc++] = strbuf_detach(&arg0, NULL);
 187                 }
 188         }
 189
 190         for (argc = 0; argv[argc]; argc++)
 191                 nargv[nargc++] = argv[argc];
 192         nargv[nargc] = NULL;
 193
 194         return nargv;
 195 }
 196
 197 #ifndef GIT_WINDOWS_NATIVE
 198 static int execv_shell_cmd(const char **argv)
 199 {
 200         const char **nargv = prepare_shell_cmd(argv);
 201         trace_argv_printf(nargv, "trace: exec:");
 202         sane_execvp(nargv[0], (char **)nargv);
 203         free(nargv);
 204         return -1;
 205 }
 206 #endif
 207
 208 #ifndef GIT_WINDOWS_NATIVE
 209 static int child_err = 2;
 210 static int child_notifier = -1;
 211
 212 static void notify_parent(void)
 213 {
 214         /*
 215          * execvp failed.  If possible, we'd like to let start_command
 216          * know, so failures like ENOENT can be handled right away; but
 217          * otherwise, finish_command will still report the error.
 218          */
 219         xwrite(child_notifier, "", 1);
 220 }
 221
 222 static NORETURN void die_child(const char *err, va_list params)
 223 {
 224         vwritef(child_err, "fatal: ", err, params);
 225         exit(128);
 226 }
 227
 228 static void error_child(const char *err, va_list params)
 229 {
 230         vwritef(child_err, "error: ", err, params);
 231 }
 232 #endif
 233
 234 static inline void set_cloexec(int fd)
 235 {
 236         int flags = fcntl(fd, F_GETFD);
 237         if (flags >= 0)
 238                 fcntl(fd, F_SETFD, flags | FD_CLOEXEC);
 239 }
 240
 241 static int wait_or_whine(pid_t pid, const char *argv0)
 242 {
 243         int status, code = -1;
 244         pid_t waiting;
 245         int failed_errno = 0;
 246
 247         while ((waiting = waitpid(pid, &status, 0)) < 0 && errno == EINTR)
 248                 ;       /* nothing */
 249
 250         if (waiting < 0) {
 251                 failed_errno = errno;
 252                 error("waitpid for %s failed: %s", argv0, strerror(errno));
 253         } else if (waiting != pid) {
 254                 error("waitpid is confused (%s)", argv0);
 255         } else if (WIFSIGNALED(status)) {
 256                 code = WTERMSIG(status);
 257                 if (code != SIGINT && code != SIGQUIT)
 258                         error("%s died of signal %d", argv0, code);
 259                 /*
 260                  * This return value is chosen so that code & 0xff
 261                  * mimics the exit code that a POSIX shell would report for
 262                  * a program that died from this signal.
 263                  */
 264                 code += 128;
 265         } else if (WIFEXITED(status)) {
 266                 code = WEXITSTATUS(status);
 267                 /*
 268                  * Convert special exit code when execvp failed.
 269                  */
 270                 if (code == 127) {
 271                         code = -1;
 272                         failed_errno = ENOENT;
 273                 }
 274         } else {
 275                 error("waitpid is confused (%s)", argv0);
 276         }
 277
 278         clear_child_for_cleanup(pid);
 279
 280         errno = failed_errno;
 281         return code;
 282 }
 283
 284 int start_command(struct child_process *cmd)
 285 {
 286         int need_in, need_out, need_err;
 287         int fdin[2], fdout[2], fderr[2];
 288         int failed_errno;
 289         char *str;
 290
 291         if (!cmd->argv)
 292                 cmd->argv = cmd->args.argv;
 293         if (!cmd->env)
 294                 cmd->env = cmd->env_array.argv;
 295
 296         /*
 297          * In case of errors we must keep the promise to close FDs
 298          * that have been passed in via ->in and ->out.
 299          */
 300
 301         need_in = !cmd->no_stdin && cmd->in < 0;
 302         if (need_in) {
 303                 if (pipe(fdin) < 0) {
 304                         failed_errno = errno;
 305                         if (cmd->out > 0)
 306                                 close(cmd->out);
 307                         str = "standard input";
 308                         goto fail_pipe;
 309                 }
 310                 cmd->in = fdin[1];
 311         }
 312
 313         need_out = !cmd->no_stdout
 314                 && !cmd->stdout_to_stderr
 315                 && cmd->out < 0;
 316         if (need_out) {
 317                 if (pipe(fdout) < 0) {
 318                         failed_errno = errno;
 319                         if (need_in)
 320                                 close_pair(fdin);
 321                         else if (cmd->in)
 322                                 close(cmd->in);
 323                         str = "standard output";
 324                         goto fail_pipe;
 325                 }
 326                 cmd->out = fdout[0];
 327         }
 328
 329         need_err = !cmd->no_stderr && cmd->err < 0;
 330         if (need_err) {
 331                 if (pipe(fderr) < 0) {
 332                         failed_errno = errno;
 333                         if (need_in)
 334                                 close_pair(fdin);
 335                         else if (cmd->in)
 336                                 close(cmd->in);
 337                         if (need_out)
 338                                 close_pair(fdout);
 339                         else if (cmd->out)
 340                                 close(cmd->out);
 341                         str = "standard error";
 342 fail_pipe:
 343                         error("cannot create %s pipe for %s: %s",
 344                                 str, cmd->argv[0], strerror(failed_errno));
 345                         child_process_clear(cmd);
 346                         errno = failed_errno;
 347                         return -1;
 348                 }
 349                 cmd->err = fderr[0];
 350         }
 351
 352         trace_argv_printf(cmd->argv, "trace: run_command:");
 353         fflush(NULL);
 354
 355 #ifndef GIT_WINDOWS_NATIVE
 356 {
 357         int notify_pipe[2];
 358         if (pipe(notify_pipe))
 359                 notify_pipe[0] = notify_pipe[1] = -1;
 360
 361         cmd->pid = fork();
 362         failed_errno = errno;
 363         if (!cmd->pid) {
 364                 /*
 365                  * Redirect the channel to write syscall error messages to
 366                  * before redirecting the process's stderr so that all die()
 367                  * in subsequent call paths use the parent's stderr.
 368                  */
 369                 if (cmd->no_stderr || need_err) {
 370                         child_err = dup(2);
 371                         set_cloexec(child_err);
 372                 }
 373                 set_die_routine(die_child);
 374                 set_error_routine(error_child);
 375
 376                 close(notify_pipe[0]);
 377                 set_cloexec(notify_pipe[1]);
 378                 child_notifier = notify_pipe[1];
 379                 atexit(notify_parent);
 380
 381                 if (cmd->no_stdin)
 382                         dup_devnull(0);
 383                 else if (need_in) {
 384                         dup2(fdin[0], 0);
 385                         close_pair(fdin);
 386                 } else if (cmd->in) {
 387                         dup2(cmd->in, 0);
 388                         close(cmd->in);
 389                 }
 390
 391                 if (cmd->no_stderr)
 392                         dup_devnull(2);
 393                 else if (need_err) {
 394                         dup2(fderr[1], 2);
 395                         close_pair(fderr);
 396                 } else if (cmd->err > 1) {
 397                         dup2(cmd->err, 2);
 398                         close(cmd->err);
 399                 }
 400
 401                 if (cmd->no_stdout)
 402                         dup_devnull(1);
 403                 else if (cmd->stdout_to_stderr)
 404                         dup2(2, 1);
 405                 else if (need_out) {
 406                         dup2(fdout[1], 1);
 407                         close_pair(fdout);
 408                 } else if (cmd->out > 1) {
 409                         dup2(cmd->out, 1);
 410                         close(cmd->out);
 411                 }
 412
 413                 if (cmd->dir && chdir(cmd->dir))
 414                         die_errno("exec '%s': cd to '%s' failed", cmd->argv[0],
 415                             cmd->dir);
 416                 if (cmd->env) {
 417                         for (; *cmd->env; cmd->env++) {
 418                                 if (strchr(*cmd->env, '='))
 419                                         putenv((char *)*cmd->env);
 420                                 else
 421                                         unsetenv(*cmd->env);
 422                         }
 423                 }
 424                 if (cmd->git_cmd)
 425                         execv_git_cmd(cmd->argv);
 426                 else if (cmd->use_shell)
 427                         execv_shell_cmd(cmd->argv);
 428                 else
 429                         sane_execvp(cmd->argv[0], (char *const*) cmd->argv);
 430                 if (errno == ENOENT) {
 431                         if (!cmd->silent_exec_failure)
 432                                 error("cannot run %s: %s", cmd->argv[0],
 433                                         strerror(ENOENT));
 434                         exit(127);
 435                 } else {
 436                         die_errno("cannot exec '%s'", cmd->argv[0]);
 437                 }
 438         }
 439         if (cmd->pid < 0)
 440                 error("cannot fork() for %s: %s", cmd->argv[0],
 441                         strerror(errno));
 442         else if (cmd->clean_on_exit)
 443                 mark_child_for_cleanup(cmd->pid);
 444
 445         /*
 446          * Wait for child's execvp. If the execvp succeeds (or if fork()
 447          * failed), EOF is seen immediately by the parent. Otherwise, the
 448          * child process sends a single byte.
 449          * Note that use of this infrastructure is completely advisory,
 450          * therefore, we keep error checks minimal.
 451          */
 452         close(notify_pipe[1]);
 453         if (read(notify_pipe[0], &notify_pipe[1], 1) == 1) {
 454                 /*
 455                  * At this point we know that fork() succeeded, but execvp()
 456                  * failed. Errors have been reported to our stderr.
 457                  */
 458                 wait_or_whine(cmd->pid, cmd->argv[0]);
 459                 failed_errno = errno;
 460                 cmd->pid = -1;
 461         }
 462         close(notify_pipe[0]);
 463 }
 464 #else
 465 {
 466         int fhin = 0, fhout = 1, fherr = 2;
 467         const char **sargv = cmd->argv;
 468
 469         if (cmd->no_stdin)
 470                 fhin = open("/dev/null", O_RDWR);
 471         else if (need_in)
 472                 fhin = dup(fdin[0]);
 473         else if (cmd->in)
 474                 fhin = dup(cmd->in);
 475
 476         if (cmd->no_stderr)
 477                 fherr = open("/dev/null", O_RDWR);
 478         else if (need_err)
 479                 fherr = dup(fderr[1]);
 480         else if (cmd->err > 2)
 481                 fherr = dup(cmd->err);
 482
 483         if (cmd->no_stdout)
 484                 fhout = open("/dev/null", O_RDWR);
 485         else if (cmd->stdout_to_stderr)
 486                 fhout = dup(fherr);
 487         else if (need_out)
 488                 fhout = dup(fdout[1]);
 489         else if (cmd->out > 1)
 490                 fhout = dup(cmd->out);
 491
 492         if (cmd->git_cmd)
 493                 cmd->argv = prepare_git_cmd(cmd->argv);
 494         else if (cmd->use_shell)
 495                 cmd->argv = prepare_shell_cmd(cmd->argv);
 496
 497         cmd->pid = mingw_spawnvpe(cmd->argv[0], cmd->argv, (char**) cmd->env,
 498                         cmd->dir, fhin, fhout, fherr);
 499         failed_errno = errno;
 500         if (cmd->pid < 0 && (!cmd->silent_exec_failure || errno != ENOENT))
 501                 error("cannot spawn %s: %s", cmd->argv[0], strerror(errno));
 502         if (cmd->clean_on_exit && cmd->pid >= 0)
 503                 mark_child_for_cleanup(cmd->pid);
 504
 505         if (cmd->git_cmd)
 506                 free(cmd->argv);
 507
 508         cmd->argv = sargv;
 509         if (fhin != 0)
 510                 close(fhin);
 511         if (fhout != 1)
 512                 close(fhout);
 513         if (fherr != 2)
 514                 close(fherr);
 515 }
 516 #endif
 517
 518         if (cmd->pid < 0) {
 519                 if (need_in)
 520                         close_pair(fdin);
 521                 else if (cmd->in)
 522                         close(cmd->in);
 523                 if (need_out)
 524                         close_pair(fdout);
 525                 else if (cmd->out)
 526                         close(cmd->out);
 527                 if (need_err)
 528                         close_pair(fderr);
 529                 else if (cmd->err)
 530                         close(cmd->err);
 531                 child_process_clear(cmd);
 532                 errno = failed_errno;
 533                 return -1;
 534         }
 535
 536         if (need_in)
 537                 close(fdin[0]);
 538         else if (cmd->in)
 539                 close(cmd->in);
 540
 541         if (need_out)
 542                 close(fdout[1]);
 543         else if (cmd->out)
 544                 close(cmd->out);
 545
 546         if (need_err)
 547                 close(fderr[1]);
 548         else if (cmd->err)
 549                 close(cmd->err);
 550
 551         return 0;
 552 }
 553
 554 int finish_command(struct child_process *cmd)
 555 {
 556         int ret = wait_or_whine(cmd->pid, cmd->argv[0]);
 557         child_process_clear(cmd);
 558         return ret;
 559 }
 560
 561 int run_command(struct child_process *cmd)
 562 {
 563         int code;
 564
 565         if (cmd->out < 0 || cmd->err < 0)
 566                 die("BUG: run_command with a pipe can cause deadlock");
 567
 568         code = start_command(cmd);
 569         if (code)
 570                 return code;
 571         return finish_command(cmd);
 572 }
 573
 574 int run_command_v_opt(const char **argv, int opt)
 575 {
 576         return run_command_v_opt_cd_env(argv, opt, NULL, NULL);
 577 }
 578
 579 int run_command_v_opt_cd_env(const char **argv, int opt, const char *dir, const char *const *env)
 580 {
 581         struct child_process cmd = CHILD_PROCESS_INIT;
 582         cmd.argv = argv;
 583         cmd.no_stdin = opt & RUN_COMMAND_NO_STDIN ? 1 : 0;
 584         cmd.git_cmd = opt & RUN_GIT_CMD ? 1 : 0;
 585         cmd.stdout_to_stderr = opt & RUN_COMMAND_STDOUT_TO_STDERR ? 1 : 0;
 586         cmd.silent_exec_failure = opt & RUN_SILENT_EXEC_FAILURE ? 1 : 0;
 587         cmd.use_shell = opt & RUN_USING_SHELL ? 1 : 0;
 588         cmd.clean_on_exit = opt & RUN_CLEAN_ON_EXIT ? 1 : 0;
 589         cmd.dir = dir;
 590         cmd.env = env;
 591         return run_command(&cmd);
 592 }
 593
 594 #ifndef NO_PTHREADS
 595 static pthread_t main_thread;
 596 static int main_thread_set;
 597 static pthread_key_t async_key;
 598 static pthread_key_t async_die_counter;
 599
 600 static void *run_thread(void *data)
 601 {
 602         struct async *async = data;
 603         intptr_t ret;
 604
 605         pthread_setspecific(async_key, async);
 606         ret = async->proc(async->proc_in, async->proc_out, async->data);
 607         return (void *)ret;
 608 }
 609
 610 static NORETURN void die_async(const char *err, va_list params)
 611 {
 612         vreportf("fatal: ", err, params);
 613
 614         if (!pthread_equal(main_thread, pthread_self())) {
 615                 struct async *async = pthread_getspecific(async_key);
 616                 if (async->proc_in >= 0)
 617                         close(async->proc_in);
 618                 if (async->proc_out >= 0)
 619                         close(async->proc_out);
 620                 pthread_exit((void *)128);
 621         }
 622
 623         exit(128);
 624 }
 625
 626 static int async_die_is_recursing(void)
 627 {
 628         void *ret = pthread_getspecific(async_die_counter);
 629         pthread_setspecific(async_die_counter, (void *)1);
 630         return ret != NULL;
 631 }
 632
 633 #else
 634
 635 static struct {
 636         void (**handlers)(void);
 637         size_t nr;
 638         size_t alloc;
 639 } git_atexit_hdlrs;
 640
 641 static int git_atexit_installed;
 642
 643 static void git_atexit_dispatch(void)
 644 {
 645         size_t i;
 646
 647         for (i=git_atexit_hdlrs.nr ; i ; i--)
 648                 git_atexit_hdlrs.handlers[i-1]();
 649 }
 650
 651 static void git_atexit_clear(void)
 652 {
 653         free(git_atexit_hdlrs.handlers);
 654         memset(&git_atexit_hdlrs, 0, sizeof(git_atexit_hdlrs));
 655         git_atexit_installed = 0;
 656 }
 657
 658 #undef atexit
 659 int git_atexit(void (*handler)(void))
 660 {
 661         ALLOC_GROW(git_atexit_hdlrs.handlers, git_atexit_hdlrs.nr + 1, git_atexit_hdlrs.alloc);
 662         git_atexit_hdlrs.handlers[git_atexit_hdlrs.nr++] = handler;
 663         if (!git_atexit_installed) {
 664                 if (atexit(&git_atexit_dispatch))
 665                         return -1;
 666                 git_atexit_installed = 1;
 667         }
 668         return 0;
 669 }
 670 #define atexit git_atexit
 671
 672 #endif
 673
 674 int start_async(struct async *async)
 675 {
 676         int need_in, need_out;
 677         int fdin[2], fdout[2];
 678         int proc_in, proc_out;
 679
 680         need_in = async->in < 0;
 681         if (need_in) {
 682                 if (pipe(fdin) < 0) {
 683                         if (async->out > 0)
 684                                 close(async->out);
 685                         return error("cannot create pipe: %s", strerror(errno));
 686                 }
 687                 async->in = fdin[1];
 688         }
 689
 690         need_out = async->out < 0;
 691         if (need_out) {
 692                 if (pipe(fdout) < 0) {
 693                         if (need_in)
 694                                 close_pair(fdin);
 695                         else if (async->in)
 696                                 close(async->in);
 697                         return error("cannot create pipe: %s", strerror(errno));
 698                 }
 699                 async->out = fdout[0];
 700         }
 701
 702         if (need_in)
 703                 proc_in = fdin[0];
 704         else if (async->in)
 705                 proc_in = async->in;
 706         else
 707                 proc_in = -1;
 708
 709         if (need_out)
 710                 proc_out = fdout[1];
 711         else if (async->out)
 712                 proc_out = async->out;
 713         else
 714                 proc_out = -1;
 715
 716 #ifdef NO_PTHREADS
 717         /* Flush stdio before fork() to avoid cloning buffers */
 718         fflush(NULL);
 719
 720         async->pid = fork();
 721         if (async->pid < 0) {
 722                 error("fork (async) failed: %s", strerror(errno));
 723                 goto error;
 724         }
 725         if (!async->pid) {
 726                 if (need_in)
 727                         close(fdin[1]);
 728                 if (need_out)
 729                         close(fdout[0]);
 730                 git_atexit_clear();
 731                 exit(!!async->proc(proc_in, proc_out, async->data));
 732         }
 733
 734         mark_child_for_cleanup(async->pid);
 735
 736         if (need_in)
 737                 close(fdin[0]);
 738         else if (async->in)
 739                 close(async->in);
 740
 741         if (need_out)
 742                 close(fdout[1]);
 743         else if (async->out)
 744                 close(async->out);
 745 #else
 746         if (!main_thread_set) {
 747                 /*
 748                  * We assume that the first time that start_async is called
 749                  * it is from the main thread.
 750                  */
 751                 main_thread_set = 1;
 752                 main_thread = pthread_self();
 753                 pthread_key_create(&async_key, NULL);
 754                 pthread_key_create(&async_die_counter, NULL);
 755                 set_die_routine(die_async);
 756                 set_die_is_recursing_routine(async_die_is_recursing);
 757         }
 758
 759         if (proc_in >= 0)
 760                 set_cloexec(proc_in);
 761         if (proc_out >= 0)
 762                 set_cloexec(proc_out);
 763         async->proc_in = proc_in;
 764         async->proc_out = proc_out;
 765         {
 766                 int err = pthread_create(&async->tid, NULL, run_thread, async);
 767                 if (err) {
 768                         error("cannot create thread: %s", strerror(err));
 769                         goto error;
 770                 }
 771         }
 772 #endif
 773         return 0;
 774
 775 error:
 776         if (need_in)
 777                 close_pair(fdin);
 778         else if (async->in)
 779                 close(async->in);
 780
 781         if (need_out)
 782                 close_pair(fdout);
 783         else if (async->out)
 784                 close(async->out);
 785         return -1;
 786 }
 787
 788 int finish_async(struct async *async)
 789 {
 790 #ifdef NO_PTHREADS
 791         return wait_or_whine(async->pid, "child process");
 792 #else
 793         void *ret = (void *)(intptr_t)(-1);
 794
 795         if (pthread_join(async->tid, &ret))
 796                 error("pthread_join failed");
 797         return (int)(intptr_t)ret;
 798 #endif
 799 }
 800
 801 char *find_hook(const char *name)
 802 {
 803         char *path = git_path("hooks/%s", name);
 804         if (access(path, X_OK) < 0)
 805                 path = NULL;
 806
 807         return path;
 808 }
 809
 810 int run_hook_ve(const char *const *env, const char *name, va_list args)
 811 {
 812         struct child_process hook = CHILD_PROCESS_INIT;
 813         const char *p;
 814
 815         p = find_hook(name);
 816         if (!p)
 817                 return 0;
 818
 819         argv_array_push(&hook.args, p);
 820         while ((p = va_arg(args, const char *)))
 821                 argv_array_push(&hook.args, p);
 822         hook.env = env;
 823         hook.no_stdin = 1;
 824         hook.stdout_to_stderr = 1;
 825
 826         return run_command(&hook);
 827 }
 828
 829 int run_hook_le(const char *const *env, const char *name, ...)
 830 {
 831         va_list args;
 832         int ret;
 833
 834         va_start(args, name);
 835         ret = run_hook_ve(env, name, args);
 836         va_end(args);
 837
 838         return ret;
 839 }
 840
 841 int capture_command(struct child_process *cmd, struct strbuf *buf, size_t hint)
 842 {
 843         cmd->out = -1;
 844         if (start_command(cmd) < 0)
 845                 return -1;
 846
 847         if (strbuf_read(buf, cmd->out, hint) < 0) {
 848                 close(cmd->out);
 849                 finish_command(cmd); /* throw away exit code */
 850                 return -1;
 851         }
 852
 853         close(cmd->out);
 854         return finish_command(cmd);
 855 }