Merge branch 'ab/sha1dc-maint'
[git] / sub-process.c
1 /*
2  * Generic implementation of background process infrastructure.
3  */
4 #include "sub-process.h"
5 #include "sigchain.h"
6 #include "pkt-line.h"
7
8 int 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
15 struct 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
24 int 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
48 void 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
60 static 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
71 int 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 }