Andrew's git - gitweb.git/blob

   1/*
   2 * Generic implementation of background process infrastructure.
   3 */
   4#include "sub-process.h"
   5#include "sigchain.h"
   6#include "pkt-line.h"
   7
   8int cmd2process_cmp(const struct subprocess_entry *e1,
   9                           const struct subprocess_entry *e2,
  10                           const void *unused)
  11{
  12        return strcmp(e1->cmd, e2->cmd);
  13}
  14
  15struct subprocess_entry *subprocess_find_entry(struct hashmap *hashmap, const char *cmd)
  16{
  17        struct subprocess_entry key;
  18
  19        hashmap_entry_init(&key, strhash(cmd));
  20        key.cmd = cmd;
  21        return hashmap_get(hashmap, &key, NULL);
  22}
  23
  24int subprocess_read_status(int fd, struct strbuf *status)
  25{
  26        struct strbuf **pair;
  27        char *line;
  28        int len;
  29
  30        for (;;) {
  31                len = packet_read_line_gently(fd, NULL, &line);
  32                if ((len < 0) || !line)
  33                        break;
  34                pair = strbuf_split_str(line, '=', 2);
  35                if (pair[0] && pair[0]->len && pair[1]) {
  36                        /* the last "status=<foo>" line wins */
  37                        if (!strcmp(pair[0]->buf, "status=")) {
  38                                strbuf_reset(status);
  39                                strbuf_addbuf(status, pair[1]);
  40                        }
  41                }
  42                strbuf_list_free(pair);
  43        }
  44
  45        return (len < 0) ? len : 0;
  46}
  47
  48void subprocess_stop(struct hashmap *hashmap, struct subprocess_entry *entry)
  49{
  50        if (!entry)
  51                return;
  52
  53        entry->process.clean_on_exit = 0;
  54        kill(entry->process.pid, SIGTERM);
  55        finish_command(&entry->process);
  56
  57        hashmap_remove(hashmap, entry, NULL);
  58}
  59
  60static void subprocess_exit_handler(struct child_process *process)
  61{
  62        sigchain_push(SIGPIPE, SIG_IGN);
  63        /* Closing the pipe signals the subprocess to initiate a shutdown. */
  64        close(process->in);
  65        close(process->out);
  66        sigchain_pop(SIGPIPE);
  67        /* Finish command will wait until the shutdown is complete. */
  68        finish_command(process);
  69}
  70
  71int subprocess_start(struct hashmap *hashmap, struct subprocess_entry *entry, const char *cmd,
  72        subprocess_start_fn startfn)
  73{
  74        int err;
  75        struct child_process *process;
  76        const char *argv[] = { cmd, NULL };
  77
  78        entry->cmd = cmd;
  79        process = &entry->process;
  80
  81        child_process_init(process);
  82        process->argv = argv;
  83        process->use_shell = 1;
  84        process->in = -1;
  85        process->out = -1;
  86        process->clean_on_exit = 1;
  87        process->clean_on_exit_handler = subprocess_exit_handler;
  88
  89        err = start_command(process);
  90        if (err) {
  91                error("cannot fork to run subprocess '%s'", cmd);
  92                return err;
  93        }
  94
  95        hashmap_entry_init(entry, strhash(cmd));
  96
  97        err = startfn(entry);
  98        if (err) {
  99                error("initialization for subprocess '%s' failed", cmd);
 100                subprocess_stop(hashmap, entry);
 101                return err;
 102        }
 103
 104        hashmap_add(hashmap, entry);
 105        return 0;
 106}