#include "exec_cmd.h"
#include "sigchain.h"
#include "argv-array.h"
+#include "thread-utils.h"
+#include "strbuf.h"
void child_process_init(struct child_process *child)
{
struct child_to_clean {
pid_t pid;
+ struct child_process *process;
struct child_to_clean *next;
};
static struct child_to_clean *children_to_clean;
static void cleanup_children(int sig, int in_signal)
{
+ struct child_to_clean *children_to_wait_for = NULL;
+
while (children_to_clean) {
struct child_to_clean *p = children_to_clean;
children_to_clean = p->next;
+
+ if (p->process && !in_signal) {
+ struct child_process *process = p->process;
+ if (process->clean_on_exit_handler) {
+ trace_printf(
+ "trace: run_command: running exit handler for pid %"
+ PRIuMAX, (uintmax_t)p->pid
+ );
+ process->clean_on_exit_handler(process);
+ }
+ }
+
kill(p->pid, sig);
+
+ if (p->process && p->process->wait_after_clean) {
+ p->next = children_to_wait_for;
+ children_to_wait_for = p;
+ } else {
+ if (!in_signal)
+ free(p);
+ }
+ }
+
+ while (children_to_wait_for) {
+ struct child_to_clean *p = children_to_wait_for;
+ children_to_wait_for = p->next;
+
+ while (waitpid(p->pid, NULL, 0) < 0 && errno == EINTR)
+ ; /* spin waiting for process exit or error */
+
if (!in_signal)
free(p);
}
cleanup_children(SIGTERM, 0);
}
-static void mark_child_for_cleanup(pid_t pid)
+static void mark_child_for_cleanup(pid_t pid, struct child_process *process)
{
struct child_to_clean *p = xmalloc(sizeof(*p));
p->pid = pid;
+ p->process = process;
p->next = children_to_clean;
children_to_clean = p;
close(fd[1]);
}
-#ifndef GIT_WINDOWS_NATIVE
-static inline void dup_devnull(int to)
+int is_executable(const char *name)
{
- int fd = open("/dev/null", O_RDWR);
- if (fd < 0)
- die_errno(_("open /dev/null failed"));
- if (dup2(fd, to) < 0)
- die_errno(_("dup2(%d,%d) failed"), fd, to);
- close(fd);
+ struct stat st;
+
+ if (stat(name, &st) || /* stat, not lstat */
+ !S_ISREG(st.st_mode))
+ return 0;
+
+#if defined(GIT_WINDOWS_NATIVE)
+ /*
+ * On Windows there is no executable bit. The file extension
+ * indicates whether it can be run as an executable, and Git
+ * has special-handling to detect scripts and launch them
+ * through the indicated script interpreter. We test for the
+ * file extension first because virus scanners may make
+ * it quite expensive to open many files.
+ */
+ if (ends_with(name, ".exe"))
+ return S_IXUSR;
+
+{
+ /*
+ * Now that we know it does not have an executable extension,
+ * peek into the file instead.
+ */
+ char buf[3] = { 0 };
+ int n;
+ int fd = open(name, O_RDONLY);
+ st.st_mode &= ~S_IXUSR;
+ if (fd >= 0) {
+ n = read(fd, buf, 2);
+ if (n == 2)
+ /* look for a she-bang */
+ if (!strcmp(buf, "#!"))
+ st.st_mode |= S_IXUSR;
+ close(fd);
+ }
}
#endif
+ return st.st_mode & S_IXUSR;
+}
+/*
+ * Search $PATH for a command. This emulates the path search that
+ * execvp would perform, without actually executing the command so it
+ * can be used before fork() to prepare to run a command using
+ * execve() or after execvp() to diagnose why it failed.
+ *
+ * The caller should ensure that file contains no directory
+ * separators.
+ *
+ * Returns the path to the command, as found in $PATH or NULL if the
+ * command could not be found. The caller inherits ownership of the memory
+ * used to store the resultant path.
+ *
+ * This should not be used on Windows, where the $PATH search rules
+ * are more complicated (e.g., a search for "foo" should find
+ * "foo.exe").
+ */
static char *locate_in_PATH(const char *file)
{
const char *p = getenv("PATH");
}
strbuf_addstr(&buf, file);
- if (!access(buf.buf, F_OK))
+ if (is_executable(buf.buf))
return strbuf_detach(&buf, NULL);
if (!*end)
return -1;
}
-static const char **prepare_shell_cmd(const char **argv)
+static const char **prepare_shell_cmd(struct argv_array *out, const char **argv)
{
- int argc, nargc = 0;
- const char **nargv;
-
- for (argc = 0; argv[argc]; argc++)
- ; /* just counting */
- /* +1 for NULL, +3 for "sh -c" plus extra $0 */
- nargv = xmalloc(sizeof(*nargv) * (argc + 1 + 3));
-
- if (argc < 1)
+ if (!argv[0])
die("BUG: shell command is empty");
if (strcspn(argv[0], "|&;<>()$`\\\"' \t\n*?[#~=%") != strlen(argv[0])) {
#ifndef GIT_WINDOWS_NATIVE
- nargv[nargc++] = SHELL_PATH;
+ argv_array_push(out, SHELL_PATH);
#else
- nargv[nargc++] = "sh";
+ argv_array_push(out, "sh");
#endif
- nargv[nargc++] = "-c";
-
- if (argc < 2)
- nargv[nargc++] = argv[0];
- else {
- struct strbuf arg0 = STRBUF_INIT;
- strbuf_addf(&arg0, "%s \"$@\"", argv[0]);
- nargv[nargc++] = strbuf_detach(&arg0, NULL);
- }
- }
+ argv_array_push(out, "-c");
- for (argc = 0; argv[argc]; argc++)
- nargv[nargc++] = argv[argc];
- nargv[nargc] = NULL;
+ /*
+ * If we have no extra arguments, we do not even need to
+ * bother with the "$@" magic.
+ */
+ if (!argv[1])
+ argv_array_push(out, argv[0]);
+ else
+ argv_array_pushf(out, "%s \"$@\"", argv[0]);
+ }
- return nargv;
+ argv_array_pushv(out, argv);
+ return out->argv;
}
#ifndef GIT_WINDOWS_NATIVE
-static int execv_shell_cmd(const char **argv)
+static int child_notifier = -1;
+
+enum child_errcode {
+ CHILD_ERR_CHDIR,
+ CHILD_ERR_DUP2,
+ CHILD_ERR_CLOSE,
+ CHILD_ERR_SIGPROCMASK,
+ CHILD_ERR_ENOENT,
+ CHILD_ERR_SILENT,
+ CHILD_ERR_ERRNO
+};
+
+struct child_err {
+ enum child_errcode err;
+ int syserr; /* errno */
+};
+
+static void child_die(enum child_errcode err)
{
- const char **nargv = prepare_shell_cmd(argv);
- trace_argv_printf(nargv, "trace: exec:");
- sane_execvp(nargv[0], (char **)nargv);
- free(nargv);
- return -1;
+ struct child_err buf;
+
+ buf.err = err;
+ buf.syserr = errno;
+
+ /* write(2) on buf smaller than PIPE_BUF (min 512) is atomic: */
+ xwrite(child_notifier, &buf, sizeof(buf));
+ _exit(1);
}
-#endif
-#ifndef GIT_WINDOWS_NATIVE
-static int child_notifier = -1;
+static void child_dup2(int fd, int to)
+{
+ if (dup2(fd, to) < 0)
+ child_die(CHILD_ERR_DUP2);
+}
+
+static void child_close(int fd)
+{
+ if (close(fd))
+ child_die(CHILD_ERR_CLOSE);
+}
+
+static void child_close_pair(int fd[2])
+{
+ child_close(fd[0]);
+ child_close(fd[1]);
+}
+
+/*
+ * parent will make it look like the child spewed a fatal error and died
+ * this is needed to prevent changes to t0061.
+ */
+static void fake_fatal(const char *err, va_list params)
+{
+ vreportf("fatal: ", err, params);
+}
+
+static void child_error_fn(const char *err, va_list params)
+{
+ const char msg[] = "error() should not be called in child\n";
+ xwrite(2, msg, sizeof(msg) - 1);
+}
+
+static void child_warn_fn(const char *err, va_list params)
+{
+ const char msg[] = "warn() should not be called in child\n";
+ xwrite(2, msg, sizeof(msg) - 1);
+}
-static void notify_parent(void)
+static void NORETURN child_die_fn(const char *err, va_list params)
{
+ const char msg[] = "die() should not be called in child\n";
+ xwrite(2, msg, sizeof(msg) - 1);
+ _exit(2);
+}
+
+/* this runs in the parent process */
+static void child_err_spew(struct child_process *cmd, struct child_err *cerr)
+{
+ static void (*old_errfn)(const char *err, va_list params);
+
+ old_errfn = get_error_routine();
+ set_error_routine(fake_fatal);
+ errno = cerr->syserr;
+
+ switch (cerr->err) {
+ case CHILD_ERR_CHDIR:
+ error_errno("exec '%s': cd to '%s' failed",
+ cmd->argv[0], cmd->dir);
+ break;
+ case CHILD_ERR_DUP2:
+ error_errno("dup2() in child failed");
+ break;
+ case CHILD_ERR_CLOSE:
+ error_errno("close() in child failed");
+ break;
+ case CHILD_ERR_SIGPROCMASK:
+ error_errno("sigprocmask failed restoring signals");
+ break;
+ case CHILD_ERR_ENOENT:
+ error_errno("cannot run %s", cmd->argv[0]);
+ break;
+ case CHILD_ERR_SILENT:
+ break;
+ case CHILD_ERR_ERRNO:
+ error_errno("cannot exec '%s'", cmd->argv[0]);
+ break;
+ }
+ set_error_routine(old_errfn);
+}
+
+static void prepare_cmd(struct argv_array *out, const struct child_process *cmd)
+{
+ if (!cmd->argv[0])
+ die("BUG: command is empty");
+
+ /*
+ * Add SHELL_PATH so in the event exec fails with ENOEXEC we can
+ * attempt to interpret the command with 'sh'.
+ */
+ argv_array_push(out, SHELL_PATH);
+
+ if (cmd->git_cmd) {
+ argv_array_push(out, "git");
+ argv_array_pushv(out, cmd->argv);
+ } else if (cmd->use_shell) {
+ prepare_shell_cmd(out, cmd->argv);
+ } else {
+ argv_array_pushv(out, cmd->argv);
+ }
+
/*
- * execvp failed. If possible, we'd like to let start_command
- * know, so failures like ENOENT can be handled right away; but
- * otherwise, finish_command will still report the error.
+ * If there are no '/' characters in the command then perform a path
+ * lookup and use the resolved path as the command to exec. If there
+ * are no '/' characters or if the command wasn't found in the path,
+ * have exec attempt to invoke the command directly.
*/
- xwrite(child_notifier, "", 1);
+ if (!strchr(out->argv[1], '/')) {
+ char *program = locate_in_PATH(out->argv[1]);
+ if (program) {
+ free((char *)out->argv[1]);
+ out->argv[1] = program;
+ }
+ }
+}
+
+static char **prep_childenv(const char *const *deltaenv)
+{
+ extern char **environ;
+ char **childenv;
+ struct string_list env = STRING_LIST_INIT_DUP;
+ struct strbuf key = STRBUF_INIT;
+ const char *const *p;
+ int i;
+
+ /* Construct a sorted string list consisting of the current environ */
+ for (p = (const char *const *) environ; p && *p; p++) {
+ const char *equals = strchr(*p, '=');
+
+ if (equals) {
+ strbuf_reset(&key);
+ strbuf_add(&key, *p, equals - *p);
+ string_list_append(&env, key.buf)->util = (void *) *p;
+ } else {
+ string_list_append(&env, *p)->util = (void *) *p;
+ }
+ }
+ string_list_sort(&env);
+
+ /* Merge in 'deltaenv' with the current environ */
+ for (p = deltaenv; p && *p; p++) {
+ const char *equals = strchr(*p, '=');
+
+ if (equals) {
+ /* ('key=value'), insert or replace entry */
+ strbuf_reset(&key);
+ strbuf_add(&key, *p, equals - *p);
+ string_list_insert(&env, key.buf)->util = (void *) *p;
+ } else {
+ /* otherwise ('key') remove existing entry */
+ string_list_remove(&env, *p, 0);
+ }
+ }
+
+ /* Create an array of 'char *' to be used as the childenv */
+ ALLOC_ARRAY(childenv, env.nr + 1);
+ for (i = 0; i < env.nr; i++)
+ childenv[i] = env.items[i].util;
+ childenv[env.nr] = NULL;
+
+ string_list_clear(&env, 0);
+ strbuf_release(&key);
+ return childenv;
+}
+
+struct atfork_state {
+#ifndef NO_PTHREADS
+ int cs;
+#endif
+ sigset_t old;
+};
+
+#ifndef NO_PTHREADS
+static void bug_die(int err, const char *msg)
+{
+ if (err) {
+ errno = err;
+ die_errno("BUG: %s", msg);
+ }
}
#endif
+static void atfork_prepare(struct atfork_state *as)
+{
+ sigset_t all;
+
+ if (sigfillset(&all))
+ die_errno("sigfillset");
+#ifdef NO_PTHREADS
+ if (sigprocmask(SIG_SETMASK, &all, &as->old))
+ die_errno("sigprocmask");
+#else
+ bug_die(pthread_sigmask(SIG_SETMASK, &all, &as->old),
+ "blocking all signals");
+ bug_die(pthread_setcancelstate(PTHREAD_CANCEL_DISABLE, &as->cs),
+ "disabling cancellation");
+#endif
+}
+
+static void atfork_parent(struct atfork_state *as)
+{
+#ifdef NO_PTHREADS
+ if (sigprocmask(SIG_SETMASK, &as->old, NULL))
+ die_errno("sigprocmask");
+#else
+ bug_die(pthread_setcancelstate(as->cs, NULL),
+ "re-enabling cancellation");
+ bug_die(pthread_sigmask(SIG_SETMASK, &as->old, NULL),
+ "restoring signal mask");
+#endif
+}
+#endif /* GIT_WINDOWS_NATIVE */
+
static inline void set_cloexec(int fd)
{
int flags = fcntl(fd, F_GETFD);
if (waiting < 0) {
failed_errno = errno;
- error("waitpid for %s failed: %s", argv0, strerror(errno));
+ error_errno("waitpid for %s failed", argv0);
} else if (waiting != pid) {
error("waitpid is confused (%s)", argv0);
} else if (WIFSIGNALED(status)) {
code = WTERMSIG(status);
- if (code != SIGINT && code != SIGQUIT)
+ if (code != SIGINT && code != SIGQUIT && code != SIGPIPE)
error("%s died of signal %d", argv0, code);
/*
* This return value is chosen so that code & 0xff
code += 128;
} else if (WIFEXITED(status)) {
code = WEXITSTATUS(status);
- /*
- * Convert special exit code when execvp failed.
- */
- if (code == 127) {
- code = -1;
- failed_errno = ENOENT;
- }
} else {
error("waitpid is confused (%s)", argv0);
}
#ifndef GIT_WINDOWS_NATIVE
{
int notify_pipe[2];
+ int null_fd = -1;
+ char **childenv;
+ struct argv_array argv = ARGV_ARRAY_INIT;
+ struct child_err cerr;
+ struct atfork_state as;
+
if (pipe(notify_pipe))
notify_pipe[0] = notify_pipe[1] = -1;
+ if (cmd->no_stdin || cmd->no_stdout || cmd->no_stderr) {
+ null_fd = open("/dev/null", O_RDWR | O_CLOEXEC);
+ if (null_fd < 0)
+ die_errno(_("open /dev/null failed"));
+ set_cloexec(null_fd);
+ }
+
+ prepare_cmd(&argv, cmd);
+ childenv = prep_childenv(cmd->env);
+ atfork_prepare(&as);
+
+ /*
+ * NOTE: In order to prevent deadlocking when using threads special
+ * care should be taken with the function calls made in between the
+ * fork() and exec() calls. No calls should be made to functions which
+ * require acquiring a lock (e.g. malloc) as the lock could have been
+ * held by another thread at the time of forking, causing the lock to
+ * never be released in the child process. This means only
+ * Async-Signal-Safe functions are permitted in the child.
+ */
cmd->pid = fork();
failed_errno = errno;
if (!cmd->pid) {
+ int sig;
/*
- * Redirect the channel to write syscall error messages to
- * before redirecting the process's stderr so that all die()
- * in subsequent call paths use the parent's stderr.
+ * Ensure the default die/error/warn routines do not get
+ * called, they can take stdio locks and malloc.
*/
- if (cmd->no_stderr || need_err) {
- int child_err = dup(2);
- set_cloexec(child_err);
- set_error_handle(fdopen(child_err, "w"));
- }
+ set_die_routine(child_die_fn);
+ set_error_routine(child_error_fn);
+ set_warn_routine(child_warn_fn);
close(notify_pipe[0]);
set_cloexec(notify_pipe[1]);
child_notifier = notify_pipe[1];
- atexit(notify_parent);
if (cmd->no_stdin)
- dup_devnull(0);
+ child_dup2(null_fd, 0);
else if (need_in) {
- dup2(fdin[0], 0);
- close_pair(fdin);
+ child_dup2(fdin[0], 0);
+ child_close_pair(fdin);
} else if (cmd->in) {
- dup2(cmd->in, 0);
- close(cmd->in);
+ child_dup2(cmd->in, 0);
+ child_close(cmd->in);
}
if (cmd->no_stderr)
- dup_devnull(2);
+ child_dup2(null_fd, 2);
else if (need_err) {
- dup2(fderr[1], 2);
- close_pair(fderr);
+ child_dup2(fderr[1], 2);
+ child_close_pair(fderr);
} else if (cmd->err > 1) {
- dup2(cmd->err, 2);
- close(cmd->err);
+ child_dup2(cmd->err, 2);
+ child_close(cmd->err);
}
if (cmd->no_stdout)
- dup_devnull(1);
+ child_dup2(null_fd, 1);
else if (cmd->stdout_to_stderr)
- dup2(2, 1);
+ child_dup2(2, 1);
else if (need_out) {
- dup2(fdout[1], 1);
- close_pair(fdout);
+ child_dup2(fdout[1], 1);
+ child_close_pair(fdout);
} else if (cmd->out > 1) {
- dup2(cmd->out, 1);
- close(cmd->out);
+ child_dup2(cmd->out, 1);
+ child_close(cmd->out);
}
if (cmd->dir && chdir(cmd->dir))
- die_errno("exec '%s': cd to '%s' failed", cmd->argv[0],
- cmd->dir);
- if (cmd->env) {
- for (; *cmd->env; cmd->env++) {
- if (strchr(*cmd->env, '='))
- putenv((char *)*cmd->env);
- else
- unsetenv(*cmd->env);
- }
+ child_die(CHILD_ERR_CHDIR);
+
+ /*
+ * restore default signal handlers here, in case
+ * we catch a signal right before execve below
+ */
+ for (sig = 1; sig < NSIG; sig++) {
+ /* ignored signals get reset to SIG_DFL on execve */
+ if (signal(sig, SIG_DFL) == SIG_IGN)
+ signal(sig, SIG_IGN);
}
- if (cmd->git_cmd)
- execv_git_cmd(cmd->argv);
- else if (cmd->use_shell)
- execv_shell_cmd(cmd->argv);
- else
- sane_execvp(cmd->argv[0], (char *const*) cmd->argv);
+
+ if (sigprocmask(SIG_SETMASK, &as.old, NULL) != 0)
+ child_die(CHILD_ERR_SIGPROCMASK);
+
+ /*
+ * Attempt to exec using the command and arguments starting at
+ * argv.argv[1]. argv.argv[0] contains SHELL_PATH which will
+ * be used in the event exec failed with ENOEXEC at which point
+ * we will try to interpret the command using 'sh'.
+ */
+ execve(argv.argv[1], (char *const *) argv.argv + 1,
+ (char *const *) childenv);
+ if (errno == ENOEXEC)
+ execve(argv.argv[0], (char *const *) argv.argv,
+ (char *const *) childenv);
+
if (errno == ENOENT) {
- if (!cmd->silent_exec_failure)
- error("cannot run %s: %s", cmd->argv[0],
- strerror(ENOENT));
- exit(127);
+ if (cmd->silent_exec_failure)
+ child_die(CHILD_ERR_SILENT);
+ child_die(CHILD_ERR_ENOENT);
} else {
- die_errno("cannot exec '%s'", cmd->argv[0]);
+ child_die(CHILD_ERR_ERRNO);
}
}
+ atfork_parent(&as);
if (cmd->pid < 0)
- error("cannot fork() for %s: %s", cmd->argv[0],
- strerror(errno));
+ error_errno("cannot fork() for %s", cmd->argv[0]);
else if (cmd->clean_on_exit)
- mark_child_for_cleanup(cmd->pid);
+ mark_child_for_cleanup(cmd->pid, cmd);
/*
- * Wait for child's execvp. If the execvp succeeds (or if fork()
+ * Wait for child's exec. If the exec succeeds (or if fork()
* failed), EOF is seen immediately by the parent. Otherwise, the
- * child process sends a single byte.
+ * child process sends a child_err struct.
* Note that use of this infrastructure is completely advisory,
* therefore, we keep error checks minimal.
*/
close(notify_pipe[1]);
- if (read(notify_pipe[0], ¬ify_pipe[1], 1) == 1) {
+ if (xread(notify_pipe[0], &cerr, sizeof(cerr)) == sizeof(cerr)) {
/*
- * At this point we know that fork() succeeded, but execvp()
+ * At this point we know that fork() succeeded, but exec()
* failed. Errors have been reported to our stderr.
*/
wait_or_whine(cmd->pid, cmd->argv[0], 0);
+ child_err_spew(cmd, &cerr);
failed_errno = errno;
cmd->pid = -1;
}
close(notify_pipe[0]);
+
+ if (null_fd >= 0)
+ close(null_fd);
+ argv_array_clear(&argv);
+ free(childenv);
}
#else
{
int fhin = 0, fhout = 1, fherr = 2;
const char **sargv = cmd->argv;
+ struct argv_array nargv = ARGV_ARRAY_INIT;
if (cmd->no_stdin)
fhin = open("/dev/null", O_RDWR);
fhout = dup(cmd->out);
if (cmd->git_cmd)
- cmd->argv = prepare_git_cmd(cmd->argv);
+ cmd->argv = prepare_git_cmd(&nargv, cmd->argv);
else if (cmd->use_shell)
- cmd->argv = prepare_shell_cmd(cmd->argv);
+ cmd->argv = prepare_shell_cmd(&nargv, cmd->argv);
cmd->pid = mingw_spawnvpe(cmd->argv[0], cmd->argv, (char**) cmd->env,
cmd->dir, fhin, fhout, fherr);
failed_errno = errno;
if (cmd->pid < 0 && (!cmd->silent_exec_failure || errno != ENOENT))
- error("cannot spawn %s: %s", cmd->argv[0], strerror(errno));
+ error_errno("cannot spawn %s", cmd->argv[0]);
if (cmd->clean_on_exit && cmd->pid >= 0)
- mark_child_for_cleanup(cmd->pid);
-
- if (cmd->git_cmd)
- free(cmd->argv);
+ mark_child_for_cleanup(cmd->pid, cmd);
+ argv_array_clear(&nargv);
cmd->argv = sargv;
if (fhin != 0)
close(fhin);
struct async *async = data;
intptr_t ret;
+ if (async->isolate_sigpipe) {
+ sigset_t mask;
+ sigemptyset(&mask);
+ sigaddset(&mask, SIGPIPE);
+ if (pthread_sigmask(SIG_BLOCK, &mask, NULL) < 0) {
+ ret = error("unable to block SIGPIPE in async thread");
+ return (void *)ret;
+ }
+ }
+
pthread_setspecific(async_key, async);
ret = async->proc(async->proc_in, async->proc_out, async->data);
return (void *)ret;
return !pthread_equal(main_thread, pthread_self());
}
+static void NORETURN async_exit(int code)
+{
+ pthread_exit((void *)(intptr_t)code);
+}
+
#else
static struct {
return process_is_async;
}
+static void NORETURN async_exit(int code)
+{
+ exit(code);
+}
+
#endif
+void check_pipe(int err)
+{
+ if (err == EPIPE) {
+ if (in_async())
+ async_exit(141);
+
+ signal(SIGPIPE, SIG_DFL);
+ raise(SIGPIPE);
+ /* Should never happen, but just in case... */
+ exit(141);
+ }
+}
+
int start_async(struct async *async)
{
int need_in, need_out;
if (pipe(fdin) < 0) {
if (async->out > 0)
close(async->out);
- return error("cannot create pipe: %s", strerror(errno));
+ return error_errno("cannot create pipe");
}
async->in = fdin[1];
}
close_pair(fdin);
else if (async->in)
close(async->in);
- return error("cannot create pipe: %s", strerror(errno));
+ return error_errno("cannot create pipe");
}
async->out = fdout[0];
}
async->pid = fork();
if (async->pid < 0) {
- error("fork (async) failed: %s", strerror(errno));
+ error_errno("fork (async) failed");
goto error;
}
if (!async->pid) {
exit(!!async->proc(proc_in, proc_out, async->data));
}
- mark_child_for_cleanup(async->pid);
+ mark_child_for_cleanup(async->pid, NULL);
if (need_in)
close(fdin[0]);
{
int err = pthread_create(&async->tid, NULL, run_thread, async);
if (err) {
- error("cannot create thread: %s", strerror(err));
+ error_errno("cannot create thread");
goto error;
}
}
strbuf_reset(&path);
strbuf_git_path(&path, "hooks/%s", name);
- if (access(path.buf, X_OK) < 0)
+ if (access(path.buf, X_OK) < 0) {
+#ifdef STRIP_EXTENSION
+ strbuf_addstr(&path, STRIP_EXTENSION);
+ if (access(path.buf, X_OK) >= 0)
+ return path.buf;
+#endif
return NULL;
+ }
return path.buf;
}
return ret;
}
-int capture_command(struct child_process *cmd, struct strbuf *buf, size_t hint)
+struct io_pump {
+ /* initialized by caller */
+ int fd;
+ int type; /* POLLOUT or POLLIN */
+ union {
+ struct {
+ const char *buf;
+ size_t len;
+ } out;
+ struct {
+ struct strbuf *buf;
+ size_t hint;
+ } in;
+ } u;
+
+ /* returned by pump_io */
+ int error; /* 0 for success, otherwise errno */
+
+ /* internal use */
+ struct pollfd *pfd;
+};
+
+static int pump_io_round(struct io_pump *slots, int nr, struct pollfd *pfd)
{
- cmd->out = -1;
+ int pollsize = 0;
+ int i;
+
+ for (i = 0; i < nr; i++) {
+ struct io_pump *io = &slots[i];
+ if (io->fd < 0)
+ continue;
+ pfd[pollsize].fd = io->fd;
+ pfd[pollsize].events = io->type;
+ io->pfd = &pfd[pollsize++];
+ }
+
+ if (!pollsize)
+ return 0;
+
+ if (poll(pfd, pollsize, -1) < 0) {
+ if (errno == EINTR)
+ return 1;
+ die_errno("poll failed");
+ }
+
+ for (i = 0; i < nr; i++) {
+ struct io_pump *io = &slots[i];
+
+ if (io->fd < 0)
+ continue;
+
+ if (!(io->pfd->revents & (POLLOUT|POLLIN|POLLHUP|POLLERR|POLLNVAL)))
+ continue;
+
+ if (io->type == POLLOUT) {
+ ssize_t len = xwrite(io->fd,
+ io->u.out.buf, io->u.out.len);
+ if (len < 0) {
+ io->error = errno;
+ close(io->fd);
+ io->fd = -1;
+ } else {
+ io->u.out.buf += len;
+ io->u.out.len -= len;
+ if (!io->u.out.len) {
+ close(io->fd);
+ io->fd = -1;
+ }
+ }
+ }
+
+ if (io->type == POLLIN) {
+ ssize_t len = strbuf_read_once(io->u.in.buf,
+ io->fd, io->u.in.hint);
+ if (len < 0)
+ io->error = errno;
+ if (len <= 0) {
+ close(io->fd);
+ io->fd = -1;
+ }
+ }
+ }
+
+ return 1;
+}
+
+static int pump_io(struct io_pump *slots, int nr)
+{
+ struct pollfd *pfd;
+ int i;
+
+ for (i = 0; i < nr; i++)
+ slots[i].error = 0;
+
+ ALLOC_ARRAY(pfd, nr);
+ while (pump_io_round(slots, nr, pfd))
+ ; /* nothing */
+ free(pfd);
+
+ /* There may be multiple errno values, so just pick the first. */
+ for (i = 0; i < nr; i++) {
+ if (slots[i].error) {
+ errno = slots[i].error;
+ return -1;
+ }
+ }
+ return 0;
+}
+
+
+int pipe_command(struct child_process *cmd,
+ const char *in, size_t in_len,
+ struct strbuf *out, size_t out_hint,
+ struct strbuf *err, size_t err_hint)
+{
+ struct io_pump io[3];
+ int nr = 0;
+
+ if (in)
+ cmd->in = -1;
+ if (out)
+ cmd->out = -1;
+ if (err)
+ cmd->err = -1;
+
if (start_command(cmd) < 0)
return -1;
- if (strbuf_read(buf, cmd->out, hint) < 0) {
- close(cmd->out);
+ if (in) {
+ io[nr].fd = cmd->in;
+ io[nr].type = POLLOUT;
+ io[nr].u.out.buf = in;
+ io[nr].u.out.len = in_len;
+ nr++;
+ }
+ if (out) {
+ io[nr].fd = cmd->out;
+ io[nr].type = POLLIN;
+ io[nr].u.in.buf = out;
+ io[nr].u.in.hint = out_hint;
+ nr++;
+ }
+ if (err) {
+ io[nr].fd = cmd->err;
+ io[nr].type = POLLIN;
+ io[nr].u.in.buf = err;
+ io[nr].u.in.hint = err_hint;
+ nr++;
+ }
+
+ if (pump_io(io, nr) < 0) {
finish_command(cmd); /* throw away exit code */
return -1;
}
- close(cmd->out);
return finish_command(cmd);
}
+
+enum child_state {
+ GIT_CP_FREE,
+ GIT_CP_WORKING,
+ GIT_CP_WAIT_CLEANUP,
+};
+
+struct parallel_processes {
+ void *data;
+
+ int max_processes;
+ int nr_processes;
+
+ get_next_task_fn get_next_task;
+ start_failure_fn start_failure;
+ task_finished_fn task_finished;
+
+ struct {
+ enum child_state state;
+ struct child_process process;
+ struct strbuf err;
+ void *data;
+ } *children;
+ /*
+ * The struct pollfd is logically part of *children,
+ * but the system call expects it as its own array.
+ */
+ struct pollfd *pfd;
+
+ unsigned shutdown : 1;
+
+ int output_owner;
+ struct strbuf buffered_output; /* of finished children */
+};
+
+static int default_start_failure(struct strbuf *out,
+ void *pp_cb,
+ void *pp_task_cb)
+{
+ return 0;
+}
+
+static int default_task_finished(int result,
+ struct strbuf *out,
+ void *pp_cb,
+ void *pp_task_cb)
+{
+ return 0;
+}
+
+static void kill_children(struct parallel_processes *pp, int signo)
+{
+ int i, n = pp->max_processes;
+
+ for (i = 0; i < n; i++)
+ if (pp->children[i].state == GIT_CP_WORKING)
+ kill(pp->children[i].process.pid, signo);
+}
+
+static struct parallel_processes *pp_for_signal;
+
+static void handle_children_on_signal(int signo)
+{
+ kill_children(pp_for_signal, signo);
+ sigchain_pop(signo);
+ raise(signo);
+}
+
+static void pp_init(struct parallel_processes *pp,
+ int n,
+ get_next_task_fn get_next_task,
+ start_failure_fn start_failure,
+ task_finished_fn task_finished,
+ void *data)
+{
+ int i;
+
+ if (n < 1)
+ n = online_cpus();
+
+ pp->max_processes = n;
+
+ trace_printf("run_processes_parallel: preparing to run up to %d tasks", n);
+
+ pp->data = data;
+ if (!get_next_task)
+ die("BUG: you need to specify a get_next_task function");
+ pp->get_next_task = get_next_task;
+
+ pp->start_failure = start_failure ? start_failure : default_start_failure;
+ pp->task_finished = task_finished ? task_finished : default_task_finished;
+
+ pp->nr_processes = 0;
+ pp->output_owner = 0;
+ pp->shutdown = 0;
+ pp->children = xcalloc(n, sizeof(*pp->children));
+ pp->pfd = xcalloc(n, sizeof(*pp->pfd));
+ strbuf_init(&pp->buffered_output, 0);
+
+ for (i = 0; i < n; i++) {
+ strbuf_init(&pp->children[i].err, 0);
+ child_process_init(&pp->children[i].process);
+ pp->pfd[i].events = POLLIN | POLLHUP;
+ pp->pfd[i].fd = -1;
+ }
+
+ pp_for_signal = pp;
+ sigchain_push_common(handle_children_on_signal);
+}
+
+static void pp_cleanup(struct parallel_processes *pp)
+{
+ int i;
+
+ trace_printf("run_processes_parallel: done");
+ for (i = 0; i < pp->max_processes; i++) {
+ strbuf_release(&pp->children[i].err);
+ child_process_clear(&pp->children[i].process);
+ }
+
+ free(pp->children);
+ free(pp->pfd);
+
+ /*
+ * When get_next_task added messages to the buffer in its last
+ * iteration, the buffered output is non empty.
+ */
+ strbuf_write(&pp->buffered_output, stderr);
+ strbuf_release(&pp->buffered_output);
+
+ sigchain_pop_common();
+}
+
+/* returns
+ * 0 if a new task was started.
+ * 1 if no new jobs was started (get_next_task ran out of work, non critical
+ * problem with starting a new command)
+ * <0 no new job was started, user wishes to shutdown early. Use negative code
+ * to signal the children.
+ */
+static int pp_start_one(struct parallel_processes *pp)
+{
+ int i, code;
+
+ for (i = 0; i < pp->max_processes; i++)
+ if (pp->children[i].state == GIT_CP_FREE)
+ break;
+ if (i == pp->max_processes)
+ die("BUG: bookkeeping is hard");
+
+ code = pp->get_next_task(&pp->children[i].process,
+ &pp->children[i].err,
+ pp->data,
+ &pp->children[i].data);
+ if (!code) {
+ strbuf_addbuf(&pp->buffered_output, &pp->children[i].err);
+ strbuf_reset(&pp->children[i].err);
+ return 1;
+ }
+ pp->children[i].process.err = -1;
+ pp->children[i].process.stdout_to_stderr = 1;
+ pp->children[i].process.no_stdin = 1;
+
+ if (start_command(&pp->children[i].process)) {
+ code = pp->start_failure(&pp->children[i].err,
+ pp->data,
+ pp->children[i].data);
+ strbuf_addbuf(&pp->buffered_output, &pp->children[i].err);
+ strbuf_reset(&pp->children[i].err);
+ if (code)
+ pp->shutdown = 1;
+ return code;
+ }
+
+ pp->nr_processes++;
+ pp->children[i].state = GIT_CP_WORKING;
+ pp->pfd[i].fd = pp->children[i].process.err;
+ return 0;
+}
+
+static void pp_buffer_stderr(struct parallel_processes *pp, int output_timeout)
+{
+ int i;
+
+ while ((i = poll(pp->pfd, pp->max_processes, output_timeout)) < 0) {
+ if (errno == EINTR)
+ continue;
+ pp_cleanup(pp);
+ die_errno("poll");
+ }
+
+ /* Buffer output from all pipes. */
+ for (i = 0; i < pp->max_processes; i++) {
+ if (pp->children[i].state == GIT_CP_WORKING &&
+ pp->pfd[i].revents & (POLLIN | POLLHUP)) {
+ int n = strbuf_read_once(&pp->children[i].err,
+ pp->children[i].process.err, 0);
+ if (n == 0) {
+ close(pp->children[i].process.err);
+ pp->children[i].state = GIT_CP_WAIT_CLEANUP;
+ } else if (n < 0)
+ if (errno != EAGAIN)
+ die_errno("read");
+ }
+ }
+}
+
+static void pp_output(struct parallel_processes *pp)
+{
+ int i = pp->output_owner;
+ if (pp->children[i].state == GIT_CP_WORKING &&
+ pp->children[i].err.len) {
+ strbuf_write(&pp->children[i].err, stderr);
+ strbuf_reset(&pp->children[i].err);
+ }
+}
+
+static int pp_collect_finished(struct parallel_processes *pp)
+{
+ int i, code;
+ int n = pp->max_processes;
+ int result = 0;
+
+ while (pp->nr_processes > 0) {
+ for (i = 0; i < pp->max_processes; i++)
+ if (pp->children[i].state == GIT_CP_WAIT_CLEANUP)
+ break;
+ if (i == pp->max_processes)
+ break;
+
+ code = finish_command(&pp->children[i].process);
+
+ code = pp->task_finished(code,
+ &pp->children[i].err, pp->data,
+ pp->children[i].data);
+
+ if (code)
+ result = code;
+ if (code < 0)
+ break;
+
+ pp->nr_processes--;
+ pp->children[i].state = GIT_CP_FREE;
+ pp->pfd[i].fd = -1;
+ child_process_init(&pp->children[i].process);
+
+ if (i != pp->output_owner) {
+ strbuf_addbuf(&pp->buffered_output, &pp->children[i].err);
+ strbuf_reset(&pp->children[i].err);
+ } else {
+ strbuf_write(&pp->children[i].err, stderr);
+ strbuf_reset(&pp->children[i].err);
+
+ /* Output all other finished child processes */
+ strbuf_write(&pp->buffered_output, stderr);
+ strbuf_reset(&pp->buffered_output);
+
+ /*
+ * Pick next process to output live.
+ * NEEDSWORK:
+ * For now we pick it randomly by doing a round
+ * robin. Later we may want to pick the one with
+ * the most output or the longest or shortest
+ * running process time.
+ */
+ for (i = 0; i < n; i++)
+ if (pp->children[(pp->output_owner + i) % n].state == GIT_CP_WORKING)
+ break;
+ pp->output_owner = (pp->output_owner + i) % n;
+ }
+ }
+ return result;
+}
+
+int run_processes_parallel(int n,
+ get_next_task_fn get_next_task,
+ start_failure_fn start_failure,
+ task_finished_fn task_finished,
+ void *pp_cb)
+{
+ int i, code;
+ int output_timeout = 100;
+ int spawn_cap = 4;
+ struct parallel_processes pp;
+
+ pp_init(&pp, n, get_next_task, start_failure, task_finished, pp_cb);
+ while (1) {
+ for (i = 0;
+ i < spawn_cap && !pp.shutdown &&
+ pp.nr_processes < pp.max_processes;
+ i++) {
+ code = pp_start_one(&pp);
+ if (!code)
+ continue;
+ if (code < 0) {
+ pp.shutdown = 1;
+ kill_children(&pp, -code);
+ }
+ break;
+ }
+ if (!pp.nr_processes)
+ break;
+ pp_buffer_stderr(&pp, output_timeout);
+ pp_output(&pp);
+ code = pp_collect_finished(&pp);
+ if (code) {
+ pp.shutdown = 1;
+ if (code < 0)
+ kill_children(&pp, -code);
+ }
+ }
+
+ pp_cleanup(&pp);
+ return 0;
+}
projects / platform / upstream / git.git / blobdiff