Add infrastructure to run a function asynchronously.
[git/git.git] / run-command.h
1 #ifndef RUN_COMMAND_H
2 #define RUN_COMMAND_H
3
4 enum {
5 ERR_RUN_COMMAND_FORK = 10000,
6 ERR_RUN_COMMAND_EXEC,
7 ERR_RUN_COMMAND_PIPE,
8 ERR_RUN_COMMAND_WAITPID,
9 ERR_RUN_COMMAND_WAITPID_WRONG_PID,
10 ERR_RUN_COMMAND_WAITPID_SIGNAL,
11 ERR_RUN_COMMAND_WAITPID_NOEXIT,
12 };
13
14 struct child_process {
15 const char **argv;
16 pid_t pid;
17 int in;
18 int out;
19 int err;
20 const char *dir;
21 const char *const *env;
22 unsigned close_in:1;
23 unsigned close_out:1;
24 unsigned no_stdin:1;
25 unsigned no_stdout:1;
26 unsigned git_cmd:1; /* if this is to be git sub-command */
27 unsigned stdout_to_stderr:1;
28 };
29
30 int start_command(struct child_process *);
31 int finish_command(struct child_process *);
32 int run_command(struct child_process *);
33
34 #define RUN_COMMAND_NO_STDIN 1
35 #define RUN_GIT_CMD 2 /*If this is to be git sub-command */
36 #define RUN_COMMAND_STDOUT_TO_STDERR 4
37 int run_command_v_opt(const char **argv, int opt);
38 int run_command_v_opt_cd(const char **argv, int opt, const char *dir);
39
40 /*
41 * env (the environment) is to be formatted like environ: "VAR=VALUE".
42 * To unset an environment variable use just "VAR".
43 */
44 int run_command_v_opt_cd_env(const char **argv, int opt, const char *dir, const char *const *env);
45
46 /*
47 * The purpose of the following functions is to feed a pipe by running
48 * a function asynchronously and providing output that the caller reads.
49 *
50 * It is expected that no synchronization and mutual exclusion between
51 * the caller and the feed function is necessary so that the function
52 * can run in a thread without interfering with the caller.
53 */
54 struct async {
55 /*
56 * proc writes to fd and closes it;
57 * returns 0 on success, non-zero on failure
58 */
59 int (*proc)(int fd, void *data);
60 void *data;
61 int out; /* caller reads from here and closes it */
62 pid_t pid;
63 };
64
65 int start_async(struct async *async);
66 int finish_async(struct async *async);
67
68 #endif