xref: /netbsd-src/external/bsd/tmux/dist/job.c (revision 9fb66d812c00ebfb445c0b47dea128f32aa6fe96)
1 /* $OpenBSD$ */
2 
3 /*
4  * Copyright (c) 2009 Nicholas Marriott <nicholas.marriott@gmail.com>
5  *
6  * Permission to use, copy, modify, and distribute this software for any
7  * purpose with or without fee is hereby granted, provided that the above
8  * copyright notice and this permission notice appear in all copies.
9  *
10  * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
11  * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
12  * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
13  * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
14  * WHATSOEVER RESULTING FROM LOSS OF MIND, USE, DATA OR PROFITS, WHETHER
15  * IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING
16  * OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
17  */
18 
19 #include <sys/types.h>
20 #include <sys/socket.h>
21 
22 #include <fcntl.h>
23 #include <signal.h>
24 #include <stdlib.h>
25 #include <string.h>
26 #include <unistd.h>
27 
28 #include "tmux.h"
29 
30 /*
31  * Job scheduling. Run queued commands in the background and record their
32  * output.
33  */
34 
35 static void	job_read_callback(struct bufferevent *, void *);
36 static void	job_write_callback(struct bufferevent *, void *);
37 static void	job_error_callback(struct bufferevent *, short, void *);
38 
39 /* A single job. */
40 struct job {
41 	enum {
42 		JOB_RUNNING,
43 		JOB_DEAD,
44 		JOB_CLOSED
45 	} state;
46 
47 	int			 flags;
48 
49 	char			*cmd;
50 	pid_t			 pid;
51 	int			 status;
52 
53 	int			 fd;
54 	struct bufferevent	*event;
55 
56 	job_update_cb		 updatecb;
57 	job_complete_cb		 completecb;
58 	job_free_cb		 freecb;
59 	void			*data;
60 
61 	LIST_ENTRY(job)		 entry;
62 };
63 
64 /* All jobs list. */
65 static LIST_HEAD(joblist, job) all_jobs = LIST_HEAD_INITIALIZER(all_jobs);
66 
67 /* Start a job running, if it isn't already. */
68 struct job *
69 job_run(const char *cmd, struct session *s, const char *cwd,
70     job_update_cb updatecb, job_complete_cb completecb, job_free_cb freecb,
71     void *data, int flags)
72 {
73 	struct job	*job;
74 	struct environ	*env;
75 	pid_t		 pid;
76 	int		 nullfd, out[2];
77 	const char	*home;
78 	sigset_t	 set, oldset;
79 
80 	if (socketpair(AF_UNIX, SOCK_STREAM, PF_UNSPEC, out) != 0)
81 		return (NULL);
82 	log_debug("%s: cmd=%s, cwd=%s", __func__, cmd, cwd == NULL ? "" : cwd);
83 
84 	/*
85 	 * Do not set TERM during .tmux.conf, it is nice to be able to use
86 	 * if-shell to decide on default-terminal based on outside TERM.
87 	 */
88 	env = environ_for_session(s, !cfg_finished);
89 
90 	sigfillset(&set);
91 	sigprocmask(SIG_BLOCK, &set, &oldset);
92 	switch (pid = fork()) {
93 	case -1:
94 		sigprocmask(SIG_SETMASK, &oldset, NULL);
95 		environ_free(env);
96 		close(out[0]);
97 		close(out[1]);
98 		return (NULL);
99 	case 0:
100 		proc_clear_signals(server_proc, 1);
101 		sigprocmask(SIG_SETMASK, &oldset, NULL);
102 
103 		if (cwd == NULL || chdir(cwd) != 0) {
104 			if ((home = find_home()) == NULL || chdir(home) != 0)
105 				chdir("/");
106 		}
107 
108 		environ_push(env);
109 		environ_free(env);
110 
111 		if (dup2(out[1], STDIN_FILENO) == -1)
112 			fatal("dup2 failed");
113 		if (dup2(out[1], STDOUT_FILENO) == -1)
114 			fatal("dup2 failed");
115 		if (out[1] != STDIN_FILENO && out[1] != STDOUT_FILENO)
116 			close(out[1]);
117 		close(out[0]);
118 
119 		nullfd = open(_PATH_DEVNULL, O_RDWR, 0);
120 		if (nullfd == -1)
121 			fatal("open failed");
122 		if (dup2(nullfd, STDERR_FILENO) == -1)
123 			fatal("dup2 failed");
124 		if (nullfd != STDERR_FILENO)
125 			close(nullfd);
126 
127 		closefrom(STDERR_FILENO + 1);
128 
129 		execl(_PATH_BSHELL, "sh", "-c", cmd, (char *) NULL);
130 		fatal("execl failed");
131 	}
132 
133 	sigprocmask(SIG_SETMASK, &oldset, NULL);
134 	environ_free(env);
135 	close(out[1]);
136 
137 	job = xmalloc(sizeof *job);
138 	job->state = JOB_RUNNING;
139 	job->flags = flags;
140 
141 	job->cmd = xstrdup(cmd);
142 	job->pid = pid;
143 	job->status = 0;
144 
145 	LIST_INSERT_HEAD(&all_jobs, job, entry);
146 
147 	job->updatecb = updatecb;
148 	job->completecb = completecb;
149 	job->freecb = freecb;
150 	job->data = data;
151 
152 	job->fd = out[0];
153 	setblocking(job->fd, 0);
154 
155 	job->event = bufferevent_new(job->fd, job_read_callback,
156 	    job_write_callback, job_error_callback, job);
157 	if (job->event == NULL)
158 		fatalx("out of memory");
159 	bufferevent_enable(job->event, EV_READ|EV_WRITE);
160 
161 	log_debug("run job %p: %s, pid %ld", job, job->cmd, (long) job->pid);
162 	return (job);
163 }
164 
165 /* Kill and free an individual job. */
166 void
167 job_free(struct job *job)
168 {
169 	log_debug("free job %p: %s", job, job->cmd);
170 
171 	LIST_REMOVE(job, entry);
172 	free(job->cmd);
173 
174 	if (job->freecb != NULL && job->data != NULL)
175 		job->freecb(job->data);
176 
177 	if (job->pid != -1)
178 		kill(job->pid, SIGTERM);
179 	if (job->event != NULL)
180 		bufferevent_free(job->event);
181 	if (job->fd != -1)
182 		close(job->fd);
183 
184 	free(job);
185 }
186 
187 /* Job buffer read callback. */
188 static void
189 job_read_callback(__unused struct bufferevent *bufev, void *data)
190 {
191 	struct job	*job = data;
192 
193 	if (job->updatecb != NULL)
194 		job->updatecb(job);
195 }
196 
197 /*
198  * Job buffer write callback. Fired when the buffer falls below watermark
199  * (default is empty). If all the data has been written, disable the write
200  * event.
201  */
202 static void
203 job_write_callback(__unused struct bufferevent *bufev, void *data)
204 {
205 	struct job	*job = data;
206 	size_t		 len = EVBUFFER_LENGTH(EVBUFFER_OUTPUT(job->event));
207 
208 	log_debug("job write %p: %s, pid %ld, output left %zu", job, job->cmd,
209 	    (long) job->pid, len);
210 
211 	if (len == 0) {
212 		shutdown(job->fd, SHUT_WR);
213 		bufferevent_disable(job->event, EV_WRITE);
214 	}
215 }
216 
217 /* Job buffer error callback. */
218 static void
219 job_error_callback(__unused struct bufferevent *bufev, __unused short events,
220     void *data)
221 {
222 	struct job	*job = data;
223 
224 	log_debug("job error %p: %s, pid %ld", job, job->cmd, (long) job->pid);
225 
226 	if (job->state == JOB_DEAD) {
227 		if (job->completecb != NULL)
228 			job->completecb(job);
229 		job_free(job);
230 	} else {
231 		bufferevent_disable(job->event, EV_READ);
232 		job->state = JOB_CLOSED;
233 	}
234 }
235 
236 /* Job died (waitpid() returned its pid). */
237 void
238 job_check_died(pid_t pid, int status)
239 {
240 	struct job	*job;
241 
242 	LIST_FOREACH(job, &all_jobs, entry) {
243 		if (pid == job->pid)
244 			break;
245 	}
246 	if (job == NULL)
247 		return;
248 	log_debug("job died %p: %s, pid %ld", job, job->cmd, (long) job->pid);
249 
250 	job->status = status;
251 
252 	if (job->state == JOB_CLOSED) {
253 		if (job->completecb != NULL)
254 			job->completecb(job);
255 		job_free(job);
256 	} else {
257 		job->pid = -1;
258 		job->state = JOB_DEAD;
259 	}
260 }
261 
262 /* Get job status. */
263 int
264 job_get_status(struct job *job)
265 {
266 	return (job->status);
267 }
268 
269 /* Get job data. */
270 void *
271 job_get_data(struct job *job)
272 {
273 	return (job->data);
274 }
275 
276 /* Get job event. */
277 struct bufferevent *
278 job_get_event(struct job *job)
279 {
280 	return (job->event);
281 }
282 
283 /* Kill all jobs. */
284 void
285 job_kill_all(void)
286 {
287 	struct job	*job;
288 
289 	LIST_FOREACH(job, &all_jobs, entry) {
290 		if (job->pid != -1)
291 			kill(job->pid, SIGTERM);
292 	}
293 }
294 
295 /* Are any jobs still running? */
296 int
297 job_still_running(void)
298 {
299 	struct job	*job;
300 
301 	LIST_FOREACH(job, &all_jobs, entry) {
302 		if ((~job->flags & JOB_NOWAIT) && job->state == JOB_RUNNING)
303 			return (1);
304 	}
305 	return (0);
306 }
307 
308 /* Print job summary. */
309 void
310 job_print_summary(struct cmdq_item *item, int blank)
311 {
312 	struct job	*job;
313 	u_int		 n = 0;
314 
315 	LIST_FOREACH(job, &all_jobs, entry) {
316 		if (blank) {
317 			cmdq_print(item, "%s", "");
318 			blank = 0;
319 		}
320 		cmdq_print(item, "Job %u: %s [fd=%d, pid=%ld, status=%d]",
321 		    n, job->cmd, job->fd, (long)job->pid, job->status);
322 		n++;
323 	}
324 }
325