git/sub-process.c
Stefan Beller 7663cdc86c hashmap.h: compare function has access to a data field
When using the hashmap a common need is to have access to caller provided
data in the compare function. A couple of times we abuse the keydata field
to pass in the data needed. This happens for example in patch-ids.c.

This patch changes the function signature of the compare function
to have one more void pointer available. The pointer given for each
invocation of the compare function must be defined in the init function
of the hashmap and is just passed through.

Documentation of this new feature is deferred to a later patch.
This is a rather mechanical conversion, just adding the new pass-through
parameter.  However while at it improve the naming of the fields of all
compare functions used by hashmaps by ensuring unused parameters are
prefixed with 'unused_' and naming the parameters what they are (instead
of 'unused' make it 'unused_keydata').

Signed-off-by: Stefan Beller <sbeller@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2017-06-30 12:49:28 -07:00

108 lines
2.4 KiB
C

/*
* Generic implementation of background process infrastructure.
*/
#include "sub-process.h"
#include "sigchain.h"
#include "pkt-line.h"
int cmd2process_cmp(const void *unused_cmp_data,
const struct subprocess_entry *e1,
const struct subprocess_entry *e2,
const void *unused_keydata)
{
return strcmp(e1->cmd, e2->cmd);
}
struct subprocess_entry *subprocess_find_entry(struct hashmap *hashmap, const char *cmd)
{
struct subprocess_entry key;
hashmap_entry_init(&key, strhash(cmd));
key.cmd = cmd;
return hashmap_get(hashmap, &key, NULL);
}
int subprocess_read_status(int fd, struct strbuf *status)
{
struct strbuf **pair;
char *line;
int len;
for (;;) {
len = packet_read_line_gently(fd, NULL, &line);
if ((len < 0) || !line)
break;
pair = strbuf_split_str(line, '=', 2);
if (pair[0] && pair[0]->len && pair[1]) {
/* the last "status=<foo>" line wins */
if (!strcmp(pair[0]->buf, "status=")) {
strbuf_reset(status);
strbuf_addbuf(status, pair[1]);
}
}
strbuf_list_free(pair);
}
return (len < 0) ? len : 0;
}
void subprocess_stop(struct hashmap *hashmap, struct subprocess_entry *entry)
{
if (!entry)
return;
entry->process.clean_on_exit = 0;
kill(entry->process.pid, SIGTERM);
finish_command(&entry->process);
hashmap_remove(hashmap, entry, NULL);
}
static void subprocess_exit_handler(struct child_process *process)
{
sigchain_push(SIGPIPE, SIG_IGN);
/* Closing the pipe signals the subprocess to initiate a shutdown. */
close(process->in);
close(process->out);
sigchain_pop(SIGPIPE);
/* Finish command will wait until the shutdown is complete. */
finish_command(process);
}
int subprocess_start(struct hashmap *hashmap, struct subprocess_entry *entry, const char *cmd,
subprocess_start_fn startfn)
{
int err;
struct child_process *process;
const char *argv[] = { cmd, NULL };
entry->cmd = cmd;
process = &entry->process;
child_process_init(process);
process->argv = argv;
process->use_shell = 1;
process->in = -1;
process->out = -1;
process->clean_on_exit = 1;
process->clean_on_exit_handler = subprocess_exit_handler;
err = start_command(process);
if (err) {
error("cannot fork to run subprocess '%s'", cmd);
return err;
}
hashmap_entry_init(entry, strhash(cmd));
err = startfn(entry);
if (err) {
error("initialization for subprocess '%s' failed", cmd);
subprocess_stop(hashmap, entry);
return err;
}
hashmap_add(hashmap, entry);
return 0;
}