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authorJohannes Sixt <johannes.sixt@telecom.at>2007-10-19 19:48:00 (GMT)
committerShawn O. Pearce <spearce@spearce.org>2007-10-21 05:30:41 (GMT)
commit2d22c208304156892fd6674e0055a3212c1e2d2e (patch)
tree48102e69b4db1fbd0b1513df225e05fd06bb1612 /run-command.c
parentcc41fa8da9b9e9d23221d3be47a80409a89732d4 (diff)
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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>
Diffstat (limited to 'run-command.c')
-rw-r--r--run-command.c51
1 files changed, 43 insertions, 8 deletions
diff --git a/run-command.c b/run-command.c
index d00c03b..d99a6c4 100644
--- a/run-command.c
+++ b/run-command.c
@@ -127,16 +127,11 @@ int start_command(struct child_process *cmd)
return 0;
}
-int finish_command(struct child_process *cmd)
+static int wait_or_whine(pid_t pid)
{
- if (cmd->close_in)
- close(cmd->in);
- if (cmd->close_out)
- close(cmd->out);
-
for (;;) {
int status, code;
- pid_t waiting = waitpid(cmd->pid, &status, 0);
+ pid_t waiting = waitpid(pid, &status, 0);
if (waiting < 0) {
if (errno == EINTR)
@@ -144,7 +139,7 @@ int finish_command(struct child_process *cmd)
error("waitpid failed (%s)", strerror(errno));
return -ERR_RUN_COMMAND_WAITPID;
}
- if (waiting != cmd->pid)
+ if (waiting != pid)
return -ERR_RUN_COMMAND_WAITPID_WRONG_PID;
if (WIFSIGNALED(status))
return -ERR_RUN_COMMAND_WAITPID_SIGNAL;
@@ -158,6 +153,15 @@ int finish_command(struct child_process *cmd)
}
}
+int finish_command(struct child_process *cmd)
+{
+ if (cmd->close_in)
+ close(cmd->in);
+ if (cmd->close_out)
+ close(cmd->out);
+ return wait_or_whine(cmd->pid);
+}
+
int run_command(struct child_process *cmd)
{
int code = start_command(cmd);
@@ -200,3 +204,34 @@ int run_command_v_opt_cd_env(const char **argv, int opt, const char *dir, const
cmd.env = env;
return run_command(&cmd);
}
+
+int start_async(struct async *async)
+{
+ int pipe_out[2];
+
+ if (pipe(pipe_out) < 0)
+ return error("cannot create pipe: %s", strerror(errno));
+
+ async->pid = fork();
+ if (async->pid < 0) {
+ error("fork (async) failed: %s", strerror(errno));
+ close_pair(pipe_out);
+ return -1;
+ }
+ if (!async->pid) {
+ close(pipe_out[0]);
+ exit(!!async->proc(pipe_out[1], async->data));
+ }
+ async->out = pipe_out[0];
+ close(pipe_out[1]);
+ return 0;
+}
+
+int finish_async(struct async *async)
+{
+ int ret = 0;
+
+ if (wait_or_whine(async->pid))
+ ret = error("waitpid (async) failed");
+ return ret;
+}