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b1bf95bb JW |
1 | #ifndef RUN_COMMAND_H |
2 | #define RUN_COMMAND_H | |
3 | ||
10bc232d | 4 | #include "thread-utils.h" |
200a76b7 | 5 | |
dbbcd44f | 6 | #include "strvec.h" |
c460c0ec | 7 | |
4c4066d9 HW |
8 | /** |
9 | * The run-command API offers a versatile tool to run sub-processes with | |
10 | * redirected input and output as well as with a modified environment | |
11 | * and an alternate current directory. | |
12 | * | |
13 | * A similar API offers the capability to run a function asynchronously, | |
14 | * which is primarily used to capture the output that the function | |
15 | * produces in the caller in order to process it. | |
16 | */ | |
17 | ||
18 | ||
19 | /** | |
20 | * This describes the arguments, redirections, and environment of a | |
21 | * command to run in a sub-process. | |
22 | * | |
23 | * The caller: | |
24 | * | |
25 | * 1. allocates and clears (using child_process_init() or | |
26 | * CHILD_PROCESS_INIT) a struct child_process variable; | |
27 | * 2. initializes the members; | |
28 | * 3. calls start_command(); | |
29 | * 4. processes the data; | |
30 | * 5. closes file descriptors (if necessary; see below); | |
31 | * 6. calls finish_command(). | |
32 | * | |
33 | * Special forms of redirection are available by setting these members | |
34 | * to 1: | |
35 | * | |
36 | * .no_stdin, .no_stdout, .no_stderr: The respective channel is | |
37 | * redirected to /dev/null. | |
38 | * | |
39 | * .stdout_to_stderr: stdout of the child is redirected to its | |
40 | * stderr. This happens after stderr is itself redirected. | |
41 | * So stdout will follow stderr to wherever it is | |
42 | * redirected. | |
43 | */ | |
f1000898 | 44 | struct child_process { |
4c4066d9 HW |
45 | |
46 | /** | |
d3b21597 ÆAB |
47 | * The .args is a `struct strvec', use that API to manipulate |
48 | * it, e.g. strvec_pushv() to add an existing "const char **" | |
49 | * vector. | |
4c4066d9 | 50 | * |
d3b21597 ÆAB |
51 | * If the command to run is a git command, set the first |
52 | * element in the strvec to the command name without the | |
53 | * 'git-' prefix and set .git_cmd = 1. | |
4c4066d9 | 54 | * |
d3b21597 ÆAB |
55 | * The memory in .args will be cleaned up automatically during |
56 | * `finish_command` (or during `start_command` when it is unsuccessful). | |
4c4066d9 | 57 | */ |
c972bf4c | 58 | struct strvec args; |
c7c4bdec ÆAB |
59 | |
60 | /** | |
61 | * Like .args the .env_array is a `struct strvec'. | |
62 | * | |
63 | * To modify the environment of the sub-process, specify an array of | |
64 | * environment settings. Each string in the array manipulates the | |
65 | * environment. | |
66 | * | |
67 | * - If the string is of the form "VAR=value", i.e. it contains '=' | |
68 | * the variable is added to the child process's environment. | |
69 | * | |
70 | * - If the string does not contain '=', it names an environment | |
71 | * variable that will be removed from the child process's environment. | |
72 | * | |
73 | * The memory in .env_array will be cleaned up automatically during | |
74 | * `finish_command` (or during `start_command` when it is unsuccessful). | |
75 | */ | |
c972bf4c | 76 | struct strvec env_array; |
ebcb5d16 | 77 | pid_t pid; |
ee4512ed JH |
78 | |
79 | int trace2_child_id; | |
80 | uint64_t trace2_child_us_start; | |
81 | const char *trace2_child_class; | |
82 | const char *trace2_hook_name; | |
83 | ||
c20181e3 JS |
84 | /* |
85 | * Using .in, .out, .err: | |
4c4066d9 HW |
86 | * - Specify 0 for no redirections. No new file descriptor is allocated. |
87 | * (child inherits stdin, stdout, stderr from parent). | |
c20181e3 JS |
88 | * - Specify -1 to have a pipe allocated as follows: |
89 | * .in: returns the writable pipe end; parent writes to it, | |
90 | * the readable pipe end becomes child's stdin | |
91 | * .out, .err: returns the readable pipe end; parent reads from | |
92 | * it, the writable pipe end becomes child's stdout/stderr | |
93 | * The caller of start_command() must close the returned FDs | |
94 | * after it has completed reading from/writing to it! | |
95 | * - Specify > 0 to set a channel to a particular FD as follows: | |
96 | * .in: a readable FD, becomes child's stdin | |
97 | * .out: a writable FD, becomes child's stdout/stderr | |
4f41b611 | 98 | * .err: a writable FD, becomes child's stderr |
c20181e3 JS |
99 | * The specified FD is closed by start_command(), even in case |
100 | * of errors! | |
101 | */ | |
4919bf03 | 102 | int in; |
f4bba25b | 103 | int out; |
f3b33f1d | 104 | int err; |
4c4066d9 HW |
105 | |
106 | /** | |
107 | * To specify a new initial working directory for the sub-process, | |
108 | * specify it in the .dir member. | |
109 | */ | |
1568fea0 | 110 | const char *dir; |
4c4066d9 | 111 | |
f1000898 | 112 | unsigned no_stdin:1; |
e4507ae8 | 113 | unsigned no_stdout:1; |
b73a4397 | 114 | unsigned no_stderr:1; |
539052f4 | 115 | unsigned git_cmd:1; /* if this is to be git sub-command */ |
4c4066d9 HW |
116 | |
117 | /** | |
118 | * If the program cannot be found, the functions return -1 and set | |
119 | * errno to ENOENT. Normally, an error message is printed, but if | |
120 | * .silent_exec_failure is set to 1, no message is printed for this | |
121 | * special error condition. | |
122 | */ | |
c024beb5 | 123 | unsigned silent_exec_failure:1; |
4c4066d9 | 124 | |
ee4e2255 JK |
125 | /** |
126 | * Run the command from argv[0] using a shell (but note that we may | |
127 | * still optimize out the shell call if the command contains no | |
128 | * metacharacters). Note that further arguments to the command in | |
129 | * argv[1], etc, do not need to be shell-quoted. | |
130 | */ | |
8dba1e63 | 131 | unsigned use_shell:1; |
ee4e2255 | 132 | |
28d04e1e JS |
133 | /** |
134 | * Release any open file handles to the object store before running | |
135 | * the command; This is necessary e.g. when the spawned process may | |
136 | * want to repack because that would delete `.pack` files (and on | |
137 | * Windows, you cannot delete files that are still in use). | |
138 | */ | |
139 | unsigned close_object_store:1; | |
140 | ||
ee4e2255 | 141 | unsigned stdout_to_stderr:1; |
afe19ff7 | 142 | unsigned clean_on_exit:1; |
46df6906 | 143 | unsigned wait_after_clean:1; |
ac2fbaa6 LS |
144 | void (*clean_on_exit_handler)(struct child_process *process); |
145 | void *clean_on_exit_handler_cbdata; | |
f1000898 SP |
146 | }; |
147 | ||
3d97ea47 ÆAB |
148 | #define CHILD_PROCESS_INIT { \ |
149 | .args = STRVEC_INIT, \ | |
150 | .env_array = STRVEC_INIT, \ | |
151 | } | |
4c4066d9 HW |
152 | |
153 | /** | |
154 | * The functions: child_process_init, start_command, finish_command, | |
155 | * run_command, run_command_v_opt, run_command_v_opt_cd_env, child_process_clear | |
156 | * do the following: | |
157 | * | |
158 | * - If a system call failed, errno is set and -1 is returned. A diagnostic | |
159 | * is printed. | |
160 | * | |
161 | * - If the program was not found, then -1 is returned and errno is set to | |
162 | * ENOENT; a diagnostic is printed only if .silent_exec_failure is 0. | |
163 | * | |
164 | * - Otherwise, the program is run. If it terminates regularly, its exit | |
165 | * code is returned. No diagnostic is printed, even if the exit code is | |
166 | * non-zero. | |
167 | * | |
168 | * - If the program terminated due to a signal, then the return value is the | |
169 | * signal number + 128, ie. the same value that a POSIX shell's $? would | |
170 | * report. A diagnostic is printed. | |
171 | * | |
172 | */ | |
173 | ||
174 | /** | |
175 | * Initialize a struct child_process variable. | |
176 | */ | |
483bbd4e | 177 | void child_process_init(struct child_process *); |
4c4066d9 HW |
178 | |
179 | /** | |
180 | * Release the memory associated with the struct child_process. | |
181 | * Most users of the run-command API don't need to call this | |
182 | * function explicitly because `start_command` invokes it on | |
183 | * failure and `finish_command` calls it automatically already. | |
184 | */ | |
2d71608e | 185 | void child_process_clear(struct child_process *); |
4c4066d9 | 186 | |
55454427 | 187 | int is_executable(const char *name); |
d3180279 | 188 | |
3f36e6f3 PB |
189 | /** |
190 | * Check if the command exists on $PATH. This emulates the path search that | |
191 | * execvp would perform, without actually executing the command so it | |
192 | * can be used before fork() to prepare to run a command using | |
193 | * execve() or after execvp() to diagnose why it failed. | |
194 | * | |
195 | * The caller should ensure that command contains no directory separators. | |
196 | * | |
197 | * Returns 1 if it is found in $PATH or 0 if the command could not be found. | |
198 | */ | |
199 | int exists_in_PATH(const char *command); | |
200 | ||
4c4066d9 HW |
201 | /** |
202 | * Start a sub-process. Takes a pointer to a `struct child_process` | |
203 | * that specifies the details and returns pipe FDs (if requested). | |
204 | * See below for details. | |
205 | */ | |
ebcb5d16 | 206 | int start_command(struct child_process *); |
4c4066d9 HW |
207 | |
208 | /** | |
209 | * Wait for the completion of a sub-process that was started with | |
210 | * start_command(). | |
211 | */ | |
ebcb5d16 | 212 | int finish_command(struct child_process *); |
4c4066d9 | 213 | |
507d7804 | 214 | int finish_command_in_signal(struct child_process *); |
4c4066d9 HW |
215 | |
216 | /** | |
217 | * A convenience function that encapsulates a sequence of | |
218 | * start_command() followed by finish_command(). Takes a pointer | |
219 | * to a `struct child_process` that specifies the details. | |
220 | */ | |
f1000898 SP |
221 | int run_command(struct child_process *); |
222 | ||
850b6ede JH |
223 | /* |
224 | * Trigger an auto-gc | |
225 | */ | |
a95ce124 | 226 | int run_auto_maintenance(int quiet); |
850b6ede | 227 | |
3322a9d8 JS |
228 | #define RUN_COMMAND_NO_STDIN (1<<0) |
229 | #define RUN_GIT_CMD (1<<1) | |
230 | #define RUN_COMMAND_STDOUT_TO_STDERR (1<<2) | |
231 | #define RUN_SILENT_EXEC_FAILURE (1<<3) | |
232 | #define RUN_USING_SHELL (1<<4) | |
233 | #define RUN_CLEAN_ON_EXIT (1<<5) | |
234 | #define RUN_WAIT_AFTER_CLEAN (1<<6) | |
28d04e1e | 235 | #define RUN_CLOSE_OBJECT_STORE (1<<7) |
4c4066d9 HW |
236 | |
237 | /** | |
238 | * Convenience functions that encapsulate a sequence of | |
239 | * start_command() followed by finish_command(). The argument argv | |
240 | * specifies the program and its arguments. The argument opt is zero | |
241 | * or more of the flags `RUN_COMMAND_NO_STDIN`, `RUN_GIT_CMD`, | |
242 | * `RUN_COMMAND_STDOUT_TO_STDERR`, or `RUN_SILENT_EXEC_FAILURE` | |
243 | * that correspond to the members .no_stdin, .git_cmd, | |
244 | * .stdout_to_stderr, .silent_exec_failure of `struct child_process`. | |
245 | * The argument dir corresponds the member .dir. The argument env | |
246 | * corresponds to the member .env. | |
247 | */ | |
9b0b5093 | 248 | int run_command_v_opt(const char **argv, int opt); |
ee4512ed | 249 | int run_command_v_opt_tr2(const char **argv, int opt, const char *tr2_class); |
3427b375 AR |
250 | /* |
251 | * env (the environment) is to be formatted like environ: "VAR=VALUE". | |
252 | * To unset an environment variable use just "VAR". | |
253 | */ | |
ee493148 | 254 | int run_command_v_opt_cd_env(const char **argv, int opt, const char *dir, const char *const *env); |
ee4512ed JH |
255 | int run_command_v_opt_cd_env_tr2(const char **argv, int opt, const char *dir, |
256 | const char *const *env, const char *tr2_class); | |
b1bf95bb | 257 | |
911ec99b | 258 | /** |
96335bcf JK |
259 | * Execute the given command, sending "in" to its stdin, and capturing its |
260 | * stdout and stderr in the "out" and "err" strbufs. Any of the three may | |
261 | * be NULL to skip processing. | |
262 | * | |
911ec99b | 263 | * Returns -1 if starting the command fails or reading fails, and otherwise |
96335bcf JK |
264 | * returns the exit code of the command. Any output collected in the |
265 | * buffers is kept even if the command returns a non-zero exit. The hint fields | |
266 | * gives starting sizes for the strbuf allocations. | |
911ec99b JK |
267 | * |
268 | * The fields of "cmd" should be set up as they would for a normal run_command | |
96335bcf JK |
269 | * invocation. But note that there is no need to set the in, out, or err |
270 | * fields; pipe_command handles that automatically. | |
271 | */ | |
272 | int pipe_command(struct child_process *cmd, | |
273 | const char *in, size_t in_len, | |
274 | struct strbuf *out, size_t out_hint, | |
275 | struct strbuf *err, size_t err_hint); | |
276 | ||
277 | /** | |
278 | * Convenience wrapper around pipe_command for the common case | |
279 | * of capturing only stdout. | |
911ec99b | 280 | */ |
96335bcf JK |
281 | static inline int capture_command(struct child_process *cmd, |
282 | struct strbuf *out, | |
283 | size_t hint) | |
284 | { | |
285 | return pipe_command(cmd, NULL, 0, out, hint, NULL, 0); | |
286 | } | |
911ec99b | 287 | |
2d22c208 JS |
288 | /* |
289 | * The purpose of the following functions is to feed a pipe by running | |
290 | * a function asynchronously and providing output that the caller reads. | |
291 | * | |
292 | * It is expected that no synchronization and mutual exclusion between | |
293 | * the caller and the feed function is necessary so that the function | |
294 | * can run in a thread without interfering with the caller. | |
4c4066d9 HW |
295 | * |
296 | * The caller: | |
297 | * | |
298 | * 1. allocates and clears (memset(&asy, 0, sizeof(asy));) a | |
299 | * struct async variable; | |
300 | * 2. initializes .proc and .data; | |
301 | * 3. calls start_async(); | |
302 | * 4. processes communicates with proc through .in and .out; | |
303 | * 5. closes .in and .out; | |
304 | * 6. calls finish_async(). | |
305 | * | |
306 | * There are serious restrictions on what the asynchronous function can do | |
307 | * because this facility is implemented by a thread in the same address | |
308 | * space on most platforms (when pthreads is available), but by a pipe to | |
309 | * a forked process otherwise: | |
310 | * | |
311 | * - It cannot change the program's state (global variables, environment, | |
312 | * etc.) in a way that the caller notices; in other words, .in and .out | |
313 | * are the only communication channels to the caller. | |
314 | * | |
315 | * - It must not change the program's state that the caller of the | |
316 | * facility also uses. | |
317 | * | |
2d22c208 JS |
318 | */ |
319 | struct async { | |
4c4066d9 HW |
320 | |
321 | /** | |
322 | * The function pointer in .proc has the following signature: | |
323 | * | |
324 | * int proc(int in, int out, void *data); | |
325 | * | |
326 | * - in, out specifies a set of file descriptors to which the function | |
327 | * must read/write the data that it needs/produces. The function | |
328 | * *must* close these descriptors before it returns. A descriptor | |
329 | * may be -1 if the caller did not configure a descriptor for that | |
330 | * direction. | |
331 | * | |
332 | * - data is the value that the caller has specified in the .data member | |
333 | * of struct async. | |
334 | * | |
335 | * - The return value of the function is 0 on success and non-zero | |
336 | * on failure. If the function indicates failure, finish_async() will | |
337 | * report failure as well. | |
338 | * | |
2d22c208 | 339 | */ |
ae6a5609 | 340 | int (*proc)(int in, int out, void *data); |
4c4066d9 | 341 | |
2d22c208 | 342 | void *data; |
4c4066d9 HW |
343 | |
344 | /** | |
345 | * The members .in, .out are used to provide a set of fd's for | |
346 | * communication between the caller and the callee as follows: | |
347 | * | |
348 | * - Specify 0 to have no file descriptor passed. The callee will | |
349 | * receive -1 in the corresponding argument. | |
350 | * | |
351 | * - Specify < 0 to have a pipe allocated; start_async() replaces | |
352 | * with the pipe FD in the following way: | |
353 | * | |
354 | * .in: Returns the writable pipe end into which the caller | |
355 | * writes; the readable end of the pipe becomes the function's | |
356 | * in argument. | |
357 | * | |
358 | * .out: Returns the readable pipe end from which the caller | |
359 | * reads; the writable end of the pipe becomes the function's | |
360 | * out argument. | |
361 | * | |
362 | * The caller of start_async() must close the returned FDs after it | |
363 | * has completed reading from/writing from them. | |
364 | * | |
365 | * - Specify a file descriptor > 0 to be used by the function: | |
366 | * | |
367 | * .in: The FD must be readable; it becomes the function's in. | |
368 | * .out: The FD must be writable; it becomes the function's out. | |
369 | * | |
370 | * The specified FD is closed by start_async(), even if it fails to | |
371 | * run the function. | |
372 | */ | |
ae6a5609 | 373 | int in; /* caller writes here and closes it */ |
2d22c208 | 374 | int out; /* caller reads from here and closes it */ |
f6b60983 | 375 | #ifdef NO_PTHREADS |
2d22c208 | 376 | pid_t pid; |
618ebe9f | 377 | #else |
200a76b7 | 378 | pthread_t tid; |
ae6a5609 EFL |
379 | int proc_in; |
380 | int proc_out; | |
618ebe9f | 381 | #endif |
c792d7b6 | 382 | int isolate_sigpipe; |
2d22c208 JS |
383 | }; |
384 | ||
4c4066d9 HW |
385 | /** |
386 | * Run a function asynchronously. Takes a pointer to a `struct | |
387 | * async` that specifies the details and returns a set of pipe FDs | |
388 | * for communication with the function. See below for details. | |
389 | */ | |
2d22c208 | 390 | int start_async(struct async *async); |
4c4066d9 HW |
391 | |
392 | /** | |
393 | * Wait for the completion of an asynchronous function that was | |
394 | * started with start_async(). | |
395 | */ | |
2d22c208 | 396 | int finish_async(struct async *async); |
4c4066d9 | 397 | |
661a8cf4 | 398 | int in_async(void); |
c0e40a2d | 399 | int async_with_fork(void); |
b992fe10 | 400 | void check_pipe(int err); |
2d22c208 | 401 | |
c553c72e SB |
402 | /** |
403 | * This callback should initialize the child process and preload the | |
404 | * error channel if desired. The preloading of is useful if you want to | |
405 | * have a message printed directly before the output of the child process. | |
406 | * pp_cb is the callback cookie as passed to run_processes_parallel. | |
407 | * You can store a child process specific callback cookie in pp_task_cb. | |
408 | * | |
409 | * Even after returning 0 to indicate that there are no more processes, | |
410 | * this function will be called again until there are no more running | |
411 | * child processes. | |
412 | * | |
413 | * Return 1 if the next child is ready to run. | |
414 | * Return 0 if there are currently no more tasks to be processed. | |
415 | * To send a signal to other child processes for abortion, | |
416 | * return the negative signal number. | |
417 | */ | |
418 | typedef int (*get_next_task_fn)(struct child_process *cp, | |
aa710494 | 419 | struct strbuf *out, |
c553c72e SB |
420 | void *pp_cb, |
421 | void **pp_task_cb); | |
422 | ||
423 | /** | |
424 | * This callback is called whenever there are problems starting | |
425 | * a new process. | |
426 | * | |
427 | * You must not write to stdout or stderr in this function. Add your | |
aa710494 | 428 | * message to the strbuf out instead, which will be printed without |
c553c72e SB |
429 | * messing up the output of the other parallel processes. |
430 | * | |
431 | * pp_cb is the callback cookie as passed into run_processes_parallel, | |
432 | * pp_task_cb is the callback cookie as passed into get_next_task_fn. | |
433 | * | |
434 | * Return 0 to continue the parallel processing. To abort return non zero. | |
435 | * To send a signal to other child processes for abortion, return | |
436 | * the negative signal number. | |
437 | */ | |
aa710494 | 438 | typedef int (*start_failure_fn)(struct strbuf *out, |
c553c72e SB |
439 | void *pp_cb, |
440 | void *pp_task_cb); | |
441 | ||
442 | /** | |
443 | * This callback is called on every child process that finished processing. | |
444 | * | |
445 | * You must not write to stdout or stderr in this function. Add your | |
aa710494 | 446 | * message to the strbuf out instead, which will be printed without |
c553c72e SB |
447 | * messing up the output of the other parallel processes. |
448 | * | |
449 | * pp_cb is the callback cookie as passed into run_processes_parallel, | |
450 | * pp_task_cb is the callback cookie as passed into get_next_task_fn. | |
451 | * | |
452 | * Return 0 to continue the parallel processing. To abort return non zero. | |
453 | * To send a signal to other child processes for abortion, return | |
454 | * the negative signal number. | |
455 | */ | |
456 | typedef int (*task_finished_fn)(int result, | |
aa710494 | 457 | struct strbuf *out, |
c553c72e SB |
458 | void *pp_cb, |
459 | void *pp_task_cb); | |
460 | ||
461 | /** | |
462 | * Runs up to n processes at the same time. Whenever a process can be | |
463 | * started, the callback get_next_task_fn is called to obtain the data | |
464 | * required to start another child process. | |
465 | * | |
466 | * The children started via this function run in parallel. Their output | |
467 | * (both stdout and stderr) is routed to stderr in a manner that output | |
468 | * from different tasks does not interleave. | |
469 | * | |
2a73b3da SB |
470 | * start_failure_fn and task_finished_fn can be NULL to omit any |
471 | * special handling. | |
c553c72e SB |
472 | */ |
473 | int run_processes_parallel(int n, | |
474 | get_next_task_fn, | |
475 | start_failure_fn, | |
476 | task_finished_fn, | |
477 | void *pp_cb); | |
ee4512ed JH |
478 | int run_processes_parallel_tr2(int n, get_next_task_fn, start_failure_fn, |
479 | task_finished_fn, void *pp_cb, | |
480 | const char *tr2_category, const char *tr2_label); | |
c553c72e | 481 | |
d1fa9435 JT |
482 | /** |
483 | * Convenience function which prepares env_array for a command to be run in a | |
484 | * new repo. This adds all GIT_* environment variables to env_array with the | |
485 | * exception of GIT_CONFIG_PARAMETERS and GIT_CONFIG_COUNT (which cause the | |
486 | * corresponding environment variables to be unset in the subprocess) and adds | |
487 | * an environment variable pointing to new_git_dir. See local_repo_env in | |
488 | * cache.h for more information. | |
489 | */ | |
490 | void prepare_other_repo_env(struct strvec *env_array, const char *new_git_dir); | |
491 | ||
fdb13226 JH |
492 | /** |
493 | * Possible return values for start_bg_command(). | |
494 | */ | |
495 | enum start_bg_result { | |
496 | /* child process is "ready" */ | |
497 | SBGR_READY = 0, | |
498 | ||
499 | /* child process could not be started */ | |
500 | SBGR_ERROR, | |
501 | ||
502 | /* callback error when testing for "ready" */ | |
503 | SBGR_CB_ERROR, | |
504 | ||
505 | /* timeout expired waiting for child to become "ready" */ | |
506 | SBGR_TIMEOUT, | |
507 | ||
508 | /* child process exited or was signalled before becomming "ready" */ | |
509 | SBGR_DIED, | |
510 | }; | |
511 | ||
512 | /** | |
513 | * Callback used by start_bg_command() to ask whether the | |
514 | * child process is ready or needs more time to become "ready". | |
515 | * | |
516 | * The callback will receive the cmd and cb_data arguments given to | |
517 | * start_bg_command(). | |
518 | * | |
519 | * Returns 1 is child needs more time (subject to the requested timeout). | |
520 | * Returns 0 if child is "ready". | |
521 | * Returns -1 on any error and cause start_bg_command() to also error out. | |
522 | */ | |
523 | typedef int(start_bg_wait_cb)(const struct child_process *cmd, void *cb_data); | |
524 | ||
525 | /** | |
526 | * Start a command in the background. Wait long enough for the child | |
527 | * to become "ready" (as defined by the provided callback). Capture | |
528 | * immediate errors (like failure to start) and any immediate exit | |
529 | * status (such as a shutdown/signal before the child became "ready") | |
530 | * and return this like start_command(). | |
531 | * | |
532 | * We run a custom wait loop using the provided callback to wait for | |
533 | * the child to start and become "ready". This is limited by the given | |
534 | * timeout value. | |
535 | * | |
536 | * If the child does successfully start and become "ready", we orphan | |
537 | * it into the background. | |
538 | * | |
539 | * The caller must not call finish_command(). | |
540 | * | |
541 | * The opaque cb_data argument will be forwarded to the callback for | |
542 | * any instance data that it might require. This may be NULL. | |
543 | */ | |
544 | enum start_bg_result start_bg_command(struct child_process *cmd, | |
545 | start_bg_wait_cb *wait_cb, | |
546 | void *cb_data, | |
547 | unsigned int timeout_sec); | |
548 | ||
b1bf95bb | 549 | #endif |