4 Copyright (C) 1996, 1998, 1999, 2000, 2001, 2002, 2003, 2004, 2005, 2007
5 Free Software Foundation, Inc.
7 Written by: 1996 Miguel de Icaza
9 This program is free software; you can redistribute it and/or modify
10 it under the terms of the GNU General Public License as published by
11 the Free Software Foundation; either version 2 of the License, or
12 (at your option) any later version.
14 This program is distributed in the hope that it will be useful,
15 but WITHOUT ANY WARRANTY; without even the implied warranty of
16 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
17 GNU General Public License for more details.
19 You should have received a copy of the GNU General Public License
20 along with this program; if not, write to the Free Software
21 Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA. */
25 /** \file background.c
26 * \brief Source: Background support
31 #ifdef WITH_BACKGROUND
40 #include <sys/types.h>
42 #include <sys/wait.h> /* waitpid() */
46 #include "lib/global.h"
47 #include "background.h"
49 #include "layout.h" /* repaint_screen() */
50 #include "fileopctx.h" /* FileOpContext */
51 #include "lib/tty/key.h" /* add_select_channel(), delete_select_channel() */
58 /* If true, this is a background process */
59 int we_are_background
= 0;
61 /* File descriptor for talking to our parent */
64 /* File descriptor for messages from our parent */
65 static int from_parent_fd
;
67 #define MAXCALLARGS 4 /* Number of arguments supported */
69 struct TaskList
*task_list
= NULL
;
71 static int background_attention (int fd
, void *closure
);
74 register_task_running (FileOpContext
*ctx
, pid_t pid
, int fd
, int to_child
,
79 new = g_new (TaskList
, 1);
82 new->state
= Task_Running
;
83 new->next
= task_list
;
85 new->to_child_fd
= to_child
;
88 add_select_channel (fd
, background_attention
, ctx
);
92 destroy_task_and_return_fd (pid_t pid
)
94 TaskList
*p
= task_list
;
100 prev
->next
= p
->next
;
116 unregister_task_running (pid_t pid
, int fd
)
118 destroy_task_and_return_fd(pid
);
119 delete_select_channel (fd
);
123 unregister_task_with_pid (pid_t pid
)
125 int fd
= destroy_task_and_return_fd(pid
);
127 delete_select_channel (fd
);
131 * Try to make the Midnight Commander a background job
139 do_background (struct FileOpContext
*ctx
, char *info
)
141 int comm
[2]; /* control connection stream */
142 int back_comm
[2]; /* back connection */
145 if (pipe (comm
) == -1)
148 if (pipe (back_comm
) == -1)
151 if ((pid
= fork ()) == -1) {
152 int saved_errno
= errno
;
153 (void) close (comm
[0]);
154 (void) close (comm
[1]);
155 (void) close (back_comm
[0]);
156 (void) close (back_comm
[1]);
165 from_parent_fd
= back_comm
[0];
167 we_are_background
= 1;
170 /* Make stdin/stdout/stderr point somewhere */
175 if ((nullfd
= open ("/dev/null", O_RDWR
)) != -1) {
176 while (dup2 (nullfd
, 0) == -1 && errno
== EINTR
);
177 while (dup2 (nullfd
, 1) == -1 && errno
== EINTR
);
178 while (dup2 (nullfd
, 2) == -1 && errno
== EINTR
);
184 register_task_running (ctx
, pid
, comm
[0], back_comm
[1], info
);
189 /* {{{ Parent handlers */
191 /* Parent/child protocol
193 * the child (the background) process send the following:
194 * void *routine -- routine to be invoked in the parent
195 * int nargc -- number of arguments
196 * int type -- Return argument type.
198 * If the routine is zero, then it is a way to tell the parent
199 * that the process is dying.
201 * nargc arguments in the following format:
202 * int size of the coming block
203 * size bytes with the block
205 * Now, the parent loads all those and then invokes
206 * the routine with pointers to the information passed
207 * (we just support pointers).
209 * If the return type is integer:
211 * the parent then writes an int to the child with
212 * the return value from the routine and the values
213 * of any global variable that is modified in the parent
214 * currently: do_append and recursive_result.
216 * If the return type is a string:
218 * the parent writes the resulting string length
219 * if the result string was NULL or the empty string,
220 * then the length is zero.
221 * The parent then writes the string length and frees
225 * Receive requests from background process and invoke the
230 background_attention (int fd
, void *closure
)
236 int (*have_ctx0
)(int);
237 int (*have_ctx1
)(int, char *);
238 int (*have_ctx2
)(int, char *, char *);
239 int (*have_ctx3
)(int, char *, char *, char *);
240 int (*have_ctx4
)(int, char *, char *, char *, char *);
242 int (*non_have_ctx0
)(FileOpContext
*, int);
243 int (*non_have_ctx1
)(FileOpContext
*, int, char *);
244 int (*non_have_ctx2
)(FileOpContext
*, int, char *, char *);
245 int (*non_have_ctx3
)(FileOpContext
*, int, char *, char *, char *);
246 int (*non_have_ctx4
)(FileOpContext
*, int, char *, char *, char *, char *);
248 char * (*ret_str0
)();
249 char * (*ret_str1
)(char *);
250 char * (*ret_str2
)(char *, char *);
251 char * (*ret_str3
)(char *, char *, char *);
252 char * (*ret_str4
)(char *, char *, char *, char *);
257 int argc
, i
, result
, status
;
258 char *data
[MAXCALLARGS
];
261 int to_child_fd
= -1;
262 enum ReturnType type
;
266 bytes
= read (fd
, &routine
.pointer
, sizeof (routine
));
267 if (bytes
== -1 || (size_t) bytes
< (sizeof (routine
))) {
268 const char *background_process_error
= _(" Background process error ");
270 unregister_task_running (ctx
->pid
, fd
);
271 if (!waitpid (ctx
->pid
, &status
, WNOHANG
)) {
272 /* the process is still running, but it misbehaves - kill it */
273 kill (ctx
->pid
, SIGTERM
);
274 message (D_ERROR
, background_process_error
, _(" Unknown error in child "));
278 /* 0 means happy end */
279 if (WIFEXITED (status
) && (WEXITSTATUS (status
) == 0))
282 message (D_ERROR
, background_process_error
, _(" Child died unexpectedly "));
287 if ((read (fd
, &argc
, sizeof (argc
)) != sizeof (argc
)) ||
288 (read (fd
, &type
, sizeof (type
)) != sizeof (type
)) ||
289 (read (fd
, &have_ctx
, sizeof (have_ctx
)) != sizeof (have_ctx
)))
291 message (D_ERROR
, _(" Background protocol error "),_("Reading failed"));
295 if (argc
> MAXCALLARGS
){
296 message (D_ERROR
, _(" Background protocol error "),
297 _(" Background process sent us a request for more arguments \n"
298 " than we can handle. \n"));
303 if (read (fd
, ctx
, sizeof (FileOpContext
)) != sizeof (FileOpContext
))
305 message (D_ERROR
, _(" Background protocol error "),_("Reading failed"));
310 for (i
= 0; i
< argc
; i
++){
313 if (read (fd
, &size
, sizeof (size
)) != sizeof (size
)) {
314 message (D_ERROR
, _(" Background protocol error "),_("Reading failed"));
317 data
[i
] = g_malloc (size
+1);
318 if (read (fd
, data
[i
], size
) != size
) {
319 message (D_ERROR
, _(" Background protocol error "),_("Reading failed"));
322 data
[i
][size
] = 0; /* NULL terminate the blocks (they could be strings) */
325 /* Find child task info by descriptor */
326 /* Find before call, because process can destroy self after */
327 for (p
= task_list
; p
; p
= p
->next
) {
332 if (p
) to_child_fd
= p
->to_child_fd
;
334 if (to_child_fd
== -1)
335 message (D_ERROR
, _(" Background process error "), _(" Unknown error in child "));
337 /* Handle the call */
338 if (type
== Return_Integer
){
342 result
= routine
.have_ctx0 (Background
);
345 result
= routine
.have_ctx1 (Background
, data
[0]);
348 result
= routine
.have_ctx2 (Background
, data
[0], data
[1]);
351 result
= routine
.have_ctx3 (Background
, data
[0], data
[1], data
[2]);
354 result
= routine
.have_ctx4 (Background
, data
[0], data
[1], data
[2], data
[3]);
360 result
= routine
.non_have_ctx0 (ctx
, Background
);
363 result
= routine
.non_have_ctx1 (ctx
, Background
, data
[0]);
366 result
= routine
.non_have_ctx2 (ctx
, Background
, data
[0], data
[1]);
369 result
= routine
.non_have_ctx3 (ctx
, Background
, data
[0], data
[1], data
[2]);
372 result
= routine
.non_have_ctx4 (ctx
, Background
, data
[0], data
[1], data
[2], data
[3]);
376 /* Send the result code and the value for shared variables */
377 ret
= write (to_child_fd
, &result
, sizeof (int));
378 if (have_ctx
&& to_child_fd
!= -1)
379 ret
= write (to_child_fd
, ctx
, sizeof (FileOpContext
));
380 } else if (type
== Return_String
) {
384 /* FIXME: string routines should also use the Foreground/Background
385 * parameter. Currently, this is not used here
389 resstr
= routine
.ret_str0 ();
392 resstr
= routine
.ret_str1 (data
[0]);
395 resstr
= routine
.ret_str2 (data
[0], data
[1]);
398 resstr
= routine
.ret_str3 (data
[0], data
[1], data
[2]);
401 resstr
= routine
.ret_str4 (data
[0], data
[1], data
[2], data
[3]);
403 default: g_assert_not_reached();
406 len
= strlen (resstr
);
407 ret
= write (to_child_fd
, &len
, sizeof (len
));
409 write (to_child_fd
, resstr
, len
);
414 ret
= write (to_child_fd
, &len
, sizeof (len
));
417 for (i
= 0; i
< argc
; i
++)
427 /* {{{ client RPC routines */
429 /* Sends the header for a call to a routine in the parent process. If the file
430 * operation context is not NULL, then it requests that the first parameter of
431 * the call be a file operation context.
434 parent_call_header (void *routine
, int argc
, enum ReturnType type
, FileOpContext
*ctx
)
439 have_ctx
= (ctx
!= NULL
);
441 ret
= write (parent_fd
, &routine
, sizeof (routine
));
442 ret
= write (parent_fd
, &argc
, sizeof (int));
443 ret
= write (parent_fd
, &type
, sizeof (type
));
444 ret
= write (parent_fd
, &have_ctx
, sizeof (have_ctx
));
447 ret
= write (parent_fd
, ctx
, sizeof (FileOpContext
));
451 parent_call (void *routine
, struct FileOpContext
*ctx
, int argc
, ...)
458 parent_call_header (routine
, argc
, Return_Integer
, ctx
);
459 for (i
= 0; i
< argc
; i
++) {
463 len
= va_arg (ap
, int);
464 value
= va_arg (ap
, void *);
465 ret
= write (parent_fd
, &len
, sizeof (int));
466 ret
= write (parent_fd
, value
, len
);
469 ret
= read (from_parent_fd
, &i
, sizeof (int));
471 ret
= read (from_parent_fd
, ctx
, sizeof (FileOpContext
));
477 parent_call_string (void *routine
, int argc
, ...)
484 parent_call_header (routine
, argc
, Return_String
, NULL
);
485 for (i
= 0; i
< argc
; i
++){
489 len
= va_arg (ap
, int);
490 value
= va_arg (ap
, void *);
491 if ((write (parent_fd
, &len
, sizeof (int)) != sizeof (int)) ||
492 (write (parent_fd
, value
, len
) != len
))
495 if (read (from_parent_fd
, &i
, sizeof (int)) != sizeof (int))
499 str
= g_malloc (i
+ 1);
500 if (read (from_parent_fd
, str
, i
) != i
)
509 #endif /* WITH_BACKGROUND */