tmux/job.c

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C
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2011-07-09 09:42:33 +00:00
/* $Id$ */
/*
* Copyright (c) 2009 Nicholas Marriott <nicm@users.sourceforge.net>
*
* Permission to use, copy, modify, and distribute this software for any
* purpose with or without fee is hereby granted, provided that the above
* copyright notice and this permission notice appear in all copies.
*
* THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
* WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
* MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
* ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
* WHATSOEVER RESULTING FROM LOSS OF MIND, USE, DATA OR PROFITS, WHETHER
* IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING
* OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
*/
#include <sys/types.h>
#include <sys/socket.h>
#include <fcntl.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include "tmux.h"
/*
* Job scheduling. Run queued commands in the background and record their
* output.
*/
void job_callback(struct bufferevent *, short, void *);
void job_write_callback(struct bufferevent *, void *);
/* All jobs list. */
struct joblist all_jobs = LIST_HEAD_INITIALIZER(all_jobs);
/* Start a job running, if it isn't already. */
struct job *
job_run(const char *cmd, struct session *s,
void (*callbackfn)(struct job *), void (*freefn)(void *), void *data)
{
struct job *job;
struct environ env;
pid_t pid;
int nullfd, out[2];
if (socketpair(AF_UNIX, SOCK_STREAM, PF_UNSPEC, out) != 0)
return (NULL);
environ_init(&env);
environ_copy(&global_environ, &env);
if (s != NULL)
environ_copy(&s->environ, &env);
server_fill_environ(s, &env);
switch (pid = fork()) {
case -1:
environ_free(&env);
return (NULL);
case 0: /* child */
clear_signals(1);
environ_push(&env);
environ_free(&env);
if (dup2(out[1], STDIN_FILENO) == -1)
fatal("dup2 failed");
if (dup2(out[1], STDOUT_FILENO) == -1)
fatal("dup2 failed");
if (out[1] != STDIN_FILENO && out[1] != STDOUT_FILENO)
close(out[1]);
close(out[0]);
nullfd = open(_PATH_DEVNULL, O_RDWR, 0);
if (nullfd < 0)
fatal("open failed");
if (dup2(nullfd, STDERR_FILENO) == -1)
fatal("dup2 failed");
if (nullfd != STDERR_FILENO)
close(nullfd);
closefrom(STDERR_FILENO + 1);
execl(_PATH_BSHELL, "sh", "-c", cmd, (char *) NULL);
fatal("execl failed");
}
/* parent */
environ_free(&env);
close(out[1]);
job = xmalloc(sizeof *job);
job->cmd = xstrdup(cmd);
job->pid = pid;
job->status = 0;
LIST_INSERT_HEAD(&all_jobs, job, lentry);
job->callbackfn = callbackfn;
job->freefn = freefn;
job->data = data;
job->fd = out[0];
setblocking(job->fd, 0);
job->event = bufferevent_new(job->fd, NULL, job_write_callback,
job_callback, job);
bufferevent_enable(job->event, EV_READ);
log_debug("run job %p: %s, pid %ld", job, job->cmd, (long) job->pid);
return (job);
}
/* Kill and free an individual job. */
void
job_free(struct job *job)
{
log_debug("free job %p: %s", job, job->cmd);
LIST_REMOVE(job, lentry);
free(job->cmd);
if (job->freefn != NULL && job->data != NULL)
job->freefn(job->data);
if (job->pid != -1)
kill(job->pid, SIGTERM);
if (job->event != NULL)
bufferevent_free(job->event);
if (job->fd != -1)
close(job->fd);
free(job);
}
/* Called when output buffer falls below low watermark (default is 0). */
void
job_write_callback(unused struct bufferevent *bufev, void *data)
{
struct job *job = data;
size_t len = EVBUFFER_LENGTH(EVBUFFER_OUTPUT(job->event));
log_debug("job write %p: %s, pid %ld, output left %lu", job, job->cmd,
(long) job->pid, (unsigned long) len);
if (len == 0) {
shutdown(job->fd, SHUT_WR);
bufferevent_disable(job->event, EV_WRITE);
}
}
/* Job buffer error callback. */
void
job_callback(unused struct bufferevent *bufev, unused short events, void *data)
{
struct job *job = data;
log_debug("job error %p: %s, pid %ld", job, job->cmd, (long) job->pid);
if (job->pid == -1) {
if (job->callbackfn != NULL)
job->callbackfn(job);
job_free(job);
} else {
bufferevent_disable(job->event, EV_READ);
close(job->fd);
job->fd = -1;
}
}
/* Job died (waitpid() returned its pid). */
void
job_died(struct job *job, int status)
{
log_debug("job died %p: %s, pid %ld", job, job->cmd, (long) job->pid);
job->status = status;
if (job->fd == -1) {
if (job->callbackfn != NULL)
job->callbackfn(job);
job_free(job);
} else
job->pid = -1;
}