#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)
{
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)
{
- const char **nargv = prepare_shell_cmd(argv);
- trace_argv_printf(nargv, "trace: exec:");
- sane_execvp(nargv[0], (char **)nargv);
- free(nargv);
+ struct argv_array nargv = ARGV_ARRAY_INIT;
+ prepare_shell_cmd(&nargv, argv);
+ trace_argv_printf(nargv.argv, "trace: exec:");
+ sane_execvp(nargv.argv[0], (char **)nargv.argv);
+ argv_array_clear(&nargv);
return -1;
}
#endif
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
{
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);
if (cmd->clean_on_exit && cmd->pid >= 0)
mark_child_for_cleanup(cmd->pid);
- if (cmd->git_cmd)
- free(cmd->argv);
-
+ argv_array_clear(&nargv);
cmd->argv = sargv;
if (fhin != 0)
close(fhin);
return !pthread_equal(main_thread, pthread_self());
}
+ void NORETURN async_exit(int code)
+ {
+ pthread_exit((void *)(intptr_t)code);
+ }
+
#else
static struct {
return process_is_async;
}
+ void NORETURN async_exit(int code)
+ {
+ exit(code);
+ }
+
#endif
int start_async(struct async *async)
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 child_process *cp,
+ struct strbuf *err,
+ void *pp_cb,
+ void *pp_task_cb)
+{
+ int i;
+
+ strbuf_addstr(err, "Starting a child failed:");
+ for (i = 0; cp->argv[i]; i++)
+ strbuf_addf(err, " %s", cp->argv[i]);
+
+ return 0;
+}
+
+static int default_task_finished(int result,
+ struct child_process *cp,
+ struct strbuf *err,
+ void *pp_cb,
+ void *pp_task_cb)
+{
+ int i;
+
+ if (!result)
+ return 0;
+
+ strbuf_addf(err, "A child failed with return code %d:", result);
+ for (i = 0; cp->argv[i]; i++)
+ strbuf_addf(err, " %s", cp->argv[i]);
+
+ 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.
+ */
+ fputs(pp->buffered_output.buf, 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].process,
+ &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) {
+ fputs(pp->children[i].err.buf, 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].process,
+ &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 {
+ fputs(pp->children[i].err.buf, stderr);
+ strbuf_reset(&pp->children[i].err);
+
+ /* Output all other finished child processes */
+ fputs(pp->buffered_output.buf, 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;
+}
int start_async(struct async *async);
int finish_async(struct async *async);
int in_async(void);
+ void NORETURN async_exit(int code);
+/**
+ * This callback should initialize the child process and preload the
+ * error channel if desired. The preloading of is useful if you want to
+ * have a message printed directly before the output of the child process.
+ * pp_cb is the callback cookie as passed to run_processes_parallel.
+ * You can store a child process specific callback cookie in pp_task_cb.
+ *
+ * Even after returning 0 to indicate that there are no more processes,
+ * this function will be called again until there are no more running
+ * child processes.
+ *
+ * Return 1 if the next child is ready to run.
+ * Return 0 if there are currently no more tasks to be processed.
+ * To send a signal to other child processes for abortion,
+ * return the negative signal number.
+ */
+typedef int (*get_next_task_fn)(struct child_process *cp,
+ struct strbuf *err,
+ void *pp_cb,
+ void **pp_task_cb);
+
+/**
+ * This callback is called whenever there are problems starting
+ * a new process.
+ *
+ * You must not write to stdout or stderr in this function. Add your
+ * message to the strbuf err instead, which will be printed without
+ * messing up the output of the other parallel processes.
+ *
+ * pp_cb is the callback cookie as passed into run_processes_parallel,
+ * pp_task_cb is the callback cookie as passed into get_next_task_fn.
+ *
+ * Return 0 to continue the parallel processing. To abort return non zero.
+ * To send a signal to other child processes for abortion, return
+ * the negative signal number.
+ */
+typedef int (*start_failure_fn)(struct child_process *cp,
+ struct strbuf *err,
+ void *pp_cb,
+ void *pp_task_cb);
+
+/**
+ * This callback is called on every child process that finished processing.
+ *
+ * You must not write to stdout or stderr in this function. Add your
+ * message to the strbuf err instead, which will be printed without
+ * messing up the output of the other parallel processes.
+ *
+ * pp_cb is the callback cookie as passed into run_processes_parallel,
+ * pp_task_cb is the callback cookie as passed into get_next_task_fn.
+ *
+ * Return 0 to continue the parallel processing. To abort return non zero.
+ * To send a signal to other child processes for abortion, return
+ * the negative signal number.
+ */
+typedef int (*task_finished_fn)(int result,
+ struct child_process *cp,
+ struct strbuf *err,
+ void *pp_cb,
+ void *pp_task_cb);
+
+/**
+ * Runs up to n processes at the same time. Whenever a process can be
+ * started, the callback get_next_task_fn is called to obtain the data
+ * required to start another child process.
+ *
+ * The children started via this function run in parallel. Their output
+ * (both stdout and stderr) is routed to stderr in a manner that output
+ * from different tasks does not interleave.
+ *
+ * If start_failure_fn or task_finished_fn are NULL, default handlers
+ * will be used. The default handlers will print an error message on
+ * error without issuing an emergency stop.
+ */
+int run_processes_parallel(int n,
+ get_next_task_fn,
+ start_failure_fn,
+ task_finished_fn,
+ void *pp_cb);
+
#endif