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Diffstat (limited to 'lib/wait-process.c')
| -rw-r--r-- | lib/wait-process.c | 361 |
1 files changed, 0 insertions, 361 deletions
diff --git a/lib/wait-process.c b/lib/wait-process.c deleted file mode 100644 index 17a2430f..00000000 --- a/lib/wait-process.c +++ /dev/null @@ -1,361 +0,0 @@ -/* Waiting for a subprocess to finish. - Copyright (C) 2001-2003, 2005-2013 Free Software Foundation, Inc. - Written by Bruno Haible <haible@clisp.cons.org>, 2001. - - This program is free software: you can redistribute it and/or modify - it under the terms of the GNU General Public License as published by - the Free Software Foundation; either version 3 of the License, or - (at your option) any later version. - - This program is distributed in the hope that it will be useful, - but WITHOUT ANY WARRANTY; without even the implied warranty of - MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the - GNU General Public License for more details. - - You should have received a copy of the GNU General Public License - along with this program. If not, see <http://www.gnu.org/licenses/>. */ - - -#include <config.h> - -/* Specification. */ -#include "wait-process.h" - -#include <errno.h> -#include <stdlib.h> -#include <string.h> -#include <signal.h> - -#include <sys/types.h> -#include <sys/wait.h> - -#include "error.h" -#include "fatal-signal.h" -#include "xalloc.h" -#include "gettext.h" - -#define _(str) gettext (str) - -#define SIZEOF(a) (sizeof(a) / sizeof(a[0])) - - -#if defined _MSC_VER || defined __MINGW32__ - -#define WIN32_LEAN_AND_MEAN -#include <windows.h> - -/* The return value of spawnvp() is really a process handle as returned - by CreateProcess(). Therefore we can kill it using TerminateProcess. */ -#define kill(pid,sig) TerminateProcess ((HANDLE) (pid), sig) - -#endif - - -/* Type of an entry in the slaves array. - The 'used' bit determines whether this entry is currently in use. - (If pid_t was an atomic type like sig_atomic_t, we could just set the - 'child' field to 0 when unregistering a slave process, and wouldn't need - the 'used' field.) - The 'used' and 'child' fields are accessed from within the cleanup_slaves() - action, therefore we mark them as 'volatile'. */ -typedef struct -{ - volatile sig_atomic_t used; - volatile pid_t child; -} -slaves_entry_t; - -/* The registered slave subprocesses. */ -static slaves_entry_t static_slaves[32]; -static slaves_entry_t * volatile slaves = static_slaves; -static sig_atomic_t volatile slaves_count = 0; -static size_t slaves_allocated = SIZEOF (static_slaves); - -/* The termination signal for slave subprocesses. - 2003-10-07: Terminator becomes Governator. */ -#ifdef SIGHUP -# define TERMINATOR SIGHUP -#else -# define TERMINATOR SIGTERM -#endif - -/* The cleanup action. It gets called asynchronously. */ -static void -cleanup_slaves (void) -{ - for (;;) - { - /* Get the last registered slave. */ - size_t n = slaves_count; - if (n == 0) - break; - n--; - slaves_count = n; - /* Skip unused entries in the slaves array. */ - if (slaves[n].used) - { - pid_t slave = slaves[n].child; - - /* Kill the slave. */ - kill (slave, TERMINATOR); - } - } -} - -/* Register a subprocess as being a slave process. This means that the - subprocess will be terminated when its creator receives a catchable fatal - signal or exits normally. Registration ends when wait_subprocess() - notices that the subprocess has exited. */ -void -register_slave_subprocess (pid_t child) -{ - static bool cleanup_slaves_registered = false; - if (!cleanup_slaves_registered) - { - atexit (cleanup_slaves); - at_fatal_signal (cleanup_slaves); - cleanup_slaves_registered = true; - } - - /* Try to store the new slave in an unused entry of the slaves array. */ - { - slaves_entry_t *s = slaves; - slaves_entry_t *s_end = s + slaves_count; - - for (; s < s_end; s++) - if (!s->used) - { - /* The two uses of 'volatile' in the slaves_entry_t type above - (and ISO C 99 section 5.1.2.3.(5)) ensure that we mark the - entry as used only after the child pid has been written to the - memory location s->child. */ - s->child = child; - s->used = 1; - return; - } - } - - if (slaves_count == slaves_allocated) - { - /* Extend the slaves array. Note that we cannot use xrealloc(), - because then the cleanup_slaves() function could access an already - deallocated array. */ - slaves_entry_t *old_slaves = slaves; - size_t new_slaves_allocated = 2 * slaves_allocated; - slaves_entry_t *new_slaves = - (slaves_entry_t *) - malloc (new_slaves_allocated * sizeof (slaves_entry_t)); - if (new_slaves == NULL) - { - /* xalloc_die() will call exit() which will invoke cleanup_slaves(). - Additionally we need to kill child, because it's not yet among - the slaves list. */ - kill (child, TERMINATOR); - xalloc_die (); - } - memcpy (new_slaves, old_slaves, - slaves_allocated * sizeof (slaves_entry_t)); - slaves = new_slaves; - slaves_allocated = new_slaves_allocated; - /* Now we can free the old slaves array. */ - if (old_slaves != static_slaves) - free (old_slaves); - } - /* The three uses of 'volatile' in the types above (and ISO C 99 section - 5.1.2.3.(5)) ensure that we increment the slaves_count only after the - new slave and its 'used' bit have been written to the memory locations - that make up slaves[slaves_count]. */ - slaves[slaves_count].child = child; - slaves[slaves_count].used = 1; - slaves_count++; -} - -/* Unregister a child from the list of slave subprocesses. */ -static void -unregister_slave_subprocess (pid_t child) -{ - /* The easiest way to remove an entry from a list that can be used by - an asynchronous signal handler is just to mark it as unused. For this, - we rely on sig_atomic_t. */ - slaves_entry_t *s = slaves; - slaves_entry_t *s_end = s + slaves_count; - - for (; s < s_end; s++) - if (s->used && s->child == child) - s->used = 0; -} - - -/* Wait for a subprocess to finish. Return its exit code. - If it didn't terminate correctly, exit if exit_on_error is true, otherwise - return 127. */ -int -wait_subprocess (pid_t child, const char *progname, - bool ignore_sigpipe, bool null_stderr, - bool slave_process, bool exit_on_error, - int *termsigp) -{ -#if HAVE_WAITID && defined WNOWAIT && 0 - /* Commented out because waitid() without WEXITED and with WNOWAIT doesn't - work: On Solaris 7 and OSF/1 4.0, it returns -1 and sets errno = ECHILD, - and on HP-UX 10.20 it just hangs. */ - /* Use of waitid() with WNOWAIT avoids a race condition: If slave_process is - true, and this process sleeps a very long time between the return from - waitpid() and the execution of unregister_slave_subprocess(), and - meanwhile another process acquires the same PID as child, and then - still - before unregister_slave_subprocess() - this process gets a fatal signal, - it would kill the other totally unrelated process. */ - siginfo_t info; - - if (termsigp != NULL) - *termsigp = 0; - for (;;) - { - if (waitid (P_PID, child, &info, WEXITED | (slave_process ? WNOWAIT : 0)) - < 0) - { -# ifdef EINTR - if (errno == EINTR) - continue; -# endif - if (exit_on_error || !null_stderr) - error (exit_on_error ? EXIT_FAILURE : 0, errno, - _("%s subprocess"), progname); - return 127; - } - - /* info.si_code is set to one of CLD_EXITED, CLD_KILLED, CLD_DUMPED, - CLD_TRAPPED, CLD_STOPPED, CLD_CONTINUED. Loop until the program - terminates. */ - if (info.si_code == CLD_EXITED - || info.si_code == CLD_KILLED || info.si_code == CLD_DUMPED) - break; - } - - /* The child process has exited or was signalled. */ - - if (slave_process) - { - /* Unregister the child from the list of slave subprocesses, so that - later, when we exit, we don't kill a totally unrelated process which - may have acquired the same pid. */ - unregister_slave_subprocess (child); - - /* Now remove the zombie from the process list. */ - for (;;) - { - if (waitid (P_PID, child, &info, WEXITED) < 0) - { -# ifdef EINTR - if (errno == EINTR) - continue; -# endif - if (exit_on_error || !null_stderr) - error (exit_on_error ? EXIT_FAILURE : 0, errno, - _("%s subprocess"), progname); - return 127; - } - break; - } - } - - switch (info.si_code) - { - case CLD_KILLED: - case CLD_DUMPED: - if (termsigp != NULL) - *termsigp = info.si_status; /* TODO: or info.si_signo? */ -# ifdef SIGPIPE - if (info.si_status == SIGPIPE && ignore_sigpipe) - return 0; -# endif - if (exit_on_error || (!null_stderr && termsigp == NULL)) - error (exit_on_error ? EXIT_FAILURE : 0, 0, - _("%s subprocess got fatal signal %d"), - progname, info.si_status); - return 127; - case CLD_EXITED: - if (info.si_status == 127) - { - if (exit_on_error || !null_stderr) - error (exit_on_error ? EXIT_FAILURE : 0, 0, - _("%s subprocess failed"), progname); - return 127; - } - return info.si_status; - default: - abort (); - } -#else - /* waitpid() is just as portable as wait() nowadays. */ - int status; - - if (termsigp != NULL) - *termsigp = 0; - status = 0; - for (;;) - { - int result = waitpid (child, &status, 0); - - if (result != child) - { -# ifdef EINTR - if (errno == EINTR) - continue; -# endif -# if 0 /* defined ECHILD */ - if (errno == ECHILD) - { - /* Child process nonexistent?! Assume it terminated - successfully. */ - status = 0; - break; - } -# endif - if (exit_on_error || !null_stderr) - error (exit_on_error ? EXIT_FAILURE : 0, errno, - _("%s subprocess"), progname); - return 127; - } - - /* One of WIFSIGNALED (status), WIFEXITED (status), WIFSTOPPED (status) - must always be true, since we did not specify WCONTINUED in the - waitpid() call. Loop until the program terminates. */ - if (!WIFSTOPPED (status)) - break; - } - - /* The child process has exited or was signalled. */ - - if (slave_process) - /* Unregister the child from the list of slave subprocesses, so that - later, when we exit, we don't kill a totally unrelated process which - may have acquired the same pid. */ - unregister_slave_subprocess (child); - - if (WIFSIGNALED (status)) - { - if (termsigp != NULL) - *termsigp = WTERMSIG (status); -# ifdef SIGPIPE - if (WTERMSIG (status) == SIGPIPE && ignore_sigpipe) - return 0; -# endif - if (exit_on_error || (!null_stderr && termsigp == NULL)) - error (exit_on_error ? EXIT_FAILURE : 0, 0, - _("%s subprocess got fatal signal %d"), - progname, (int) WTERMSIG (status)); - return 127; - } - if (!WIFEXITED (status)) - abort (); - if (WEXITSTATUS (status) == 127) - { - if (exit_on_error || !null_stderr) - error (exit_on_error ? EXIT_FAILURE : 0, 0, - _("%s subprocess failed"), progname); - return 127; - } - return WEXITSTATUS (status); -#endif -} |