git-commit-vandalism/run-command.h
Johannes Sixt 2d22c20830 Add infrastructure to run a function asynchronously.
This adds start_async() and finish_async(), which runs a function
asynchronously. Communication with the caller happens only via pipes.
For this reason, this implementation forks off a child process that runs
the function.

[sp: Style nit fixed by removing unnecessary block on if condition
     inside of start_async()]

Signed-off-by: Johannes Sixt <johannes.sixt@telecom.at>
Signed-off-by: Shawn O. Pearce <spearce@spearce.org>
2007-10-21 01:30:41 -04:00

69 lines
1.8 KiB
C

#ifndef RUN_COMMAND_H
#define RUN_COMMAND_H
enum {
ERR_RUN_COMMAND_FORK = 10000,
ERR_RUN_COMMAND_EXEC,
ERR_RUN_COMMAND_PIPE,
ERR_RUN_COMMAND_WAITPID,
ERR_RUN_COMMAND_WAITPID_WRONG_PID,
ERR_RUN_COMMAND_WAITPID_SIGNAL,
ERR_RUN_COMMAND_WAITPID_NOEXIT,
};
struct child_process {
const char **argv;
pid_t pid;
int in;
int out;
int err;
const char *dir;
const char *const *env;
unsigned close_in:1;
unsigned close_out:1;
unsigned no_stdin:1;
unsigned no_stdout:1;
unsigned git_cmd:1; /* if this is to be git sub-command */
unsigned stdout_to_stderr:1;
};
int start_command(struct child_process *);
int finish_command(struct child_process *);
int run_command(struct child_process *);
#define RUN_COMMAND_NO_STDIN 1
#define RUN_GIT_CMD 2 /*If this is to be git sub-command */
#define RUN_COMMAND_STDOUT_TO_STDERR 4
int run_command_v_opt(const char **argv, int opt);
int run_command_v_opt_cd(const char **argv, int opt, const char *dir);
/*
* env (the environment) is to be formatted like environ: "VAR=VALUE".
* To unset an environment variable use just "VAR".
*/
int run_command_v_opt_cd_env(const char **argv, int opt, const char *dir, const char *const *env);
/*
* The purpose of the following functions is to feed a pipe by running
* a function asynchronously and providing output that the caller reads.
*
* It is expected that no synchronization and mutual exclusion between
* the caller and the feed function is necessary so that the function
* can run in a thread without interfering with the caller.
*/
struct async {
/*
* proc writes to fd and closes it;
* returns 0 on success, non-zero on failure
*/
int (*proc)(int fd, void *data);
void *data;
int out; /* caller reads from here and closes it */
pid_t pid;
};
int start_async(struct async *async);
int finish_async(struct async *async);
#endif