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![Elijah Newren](/assets/img/avatar_default.png)
We had several C files ignoring the rule to include one of the appropriate headers first; fix that. While at it, the rule in Documentation/CodingGuidelines about which header to include has also fallen out of sync, so update the wording to mention other allowed headers. Unfortunately, C files in reftable/ don't actually follow the previous or updated rule. If you follow the #include chain in its C files, reftable/system.h _tends_ to be first (i.e. record.c first includes record.h, which first includes basics.h, which first includees system.h), but not always (e.g. publicbasics.c includes another header first that does not include system.h). However, I'm going to punt on making actual changes to the C files in reftable/ since I do not want to risk bringing it out-of-sync with any version being used externally. Signed-off-by: Elijah Newren <newren@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
218 lines
5.6 KiB
C
218 lines
5.6 KiB
C
/*
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* Generic implementation of background process infrastructure.
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*/
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#include "git-compat-util.h"
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#include "sub-process.h"
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#include "sigchain.h"
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#include "pkt-line.h"
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int cmd2process_cmp(const void *cmp_data UNUSED,
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const struct hashmap_entry *eptr,
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const struct hashmap_entry *entry_or_key,
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const void *keydata UNUSED)
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{
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const struct subprocess_entry *e1, *e2;
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e1 = container_of(eptr, const struct subprocess_entry, ent);
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e2 = container_of(entry_or_key, const struct subprocess_entry, ent);
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return strcmp(e1->cmd, e2->cmd);
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}
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struct subprocess_entry *subprocess_find_entry(struct hashmap *hashmap, const char *cmd)
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{
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struct subprocess_entry key;
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hashmap_entry_init(&key.ent, strhash(cmd));
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key.cmd = cmd;
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return hashmap_get_entry(hashmap, &key, ent, NULL);
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}
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int subprocess_read_status(int fd, struct strbuf *status)
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{
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struct strbuf **pair;
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char *line;
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int len;
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for (;;) {
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len = packet_read_line_gently(fd, NULL, &line);
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if ((len < 0) || !line)
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break;
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pair = strbuf_split_str(line, '=', 2);
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if (pair[0] && pair[0]->len && pair[1]) {
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/* the last "status=<foo>" line wins */
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if (!strcmp(pair[0]->buf, "status=")) {
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strbuf_reset(status);
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strbuf_addbuf(status, pair[1]);
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}
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}
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strbuf_list_free(pair);
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}
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return (len < 0) ? len : 0;
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}
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void subprocess_stop(struct hashmap *hashmap, struct subprocess_entry *entry)
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{
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if (!entry)
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return;
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entry->process.clean_on_exit = 0;
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kill(entry->process.pid, SIGTERM);
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finish_command(&entry->process);
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hashmap_remove(hashmap, &entry->ent, NULL);
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}
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static void subprocess_exit_handler(struct child_process *process)
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{
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sigchain_push(SIGPIPE, SIG_IGN);
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/* Closing the pipe signals the subprocess to initiate a shutdown. */
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close(process->in);
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close(process->out);
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sigchain_pop(SIGPIPE);
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/* Finish command will wait until the shutdown is complete. */
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finish_command(process);
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}
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int subprocess_start(struct hashmap *hashmap, struct subprocess_entry *entry, const char *cmd,
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subprocess_start_fn startfn)
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{
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int err;
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struct child_process *process;
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entry->cmd = cmd;
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process = &entry->process;
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child_process_init(process);
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strvec_push(&process->args, cmd);
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process->use_shell = 1;
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process->in = -1;
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process->out = -1;
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process->clean_on_exit = 1;
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process->clean_on_exit_handler = subprocess_exit_handler;
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process->trace2_child_class = "subprocess";
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err = start_command(process);
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if (err) {
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error("cannot fork to run subprocess '%s'", cmd);
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return err;
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}
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hashmap_entry_init(&entry->ent, strhash(cmd));
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err = startfn(entry);
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if (err) {
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error("initialization for subprocess '%s' failed", cmd);
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subprocess_stop(hashmap, entry);
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return err;
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}
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hashmap_add(hashmap, &entry->ent);
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return 0;
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}
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static int handshake_version(struct child_process *process,
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const char *welcome_prefix, int *versions,
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int *chosen_version)
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{
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int version_scratch;
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int i;
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char *line;
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const char *p;
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if (!chosen_version)
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chosen_version = &version_scratch;
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if (packet_write_fmt_gently(process->in, "%s-client\n",
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welcome_prefix))
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return error("Could not write client identification");
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for (i = 0; versions[i]; i++) {
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if (packet_write_fmt_gently(process->in, "version=%d\n",
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versions[i]))
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return error("Could not write requested version");
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}
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if (packet_flush_gently(process->in))
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return error("Could not write flush packet");
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if (!(line = packet_read_line(process->out, NULL)) ||
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!skip_prefix(line, welcome_prefix, &p) ||
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strcmp(p, "-server"))
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return error("Unexpected line '%s', expected %s-server",
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line ? line : "<flush packet>", welcome_prefix);
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if (!(line = packet_read_line(process->out, NULL)) ||
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!skip_prefix(line, "version=", &p) ||
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strtol_i(p, 10, chosen_version))
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return error("Unexpected line '%s', expected version",
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line ? line : "<flush packet>");
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if ((line = packet_read_line(process->out, NULL)))
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return error("Unexpected line '%s', expected flush", line);
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/* Check to make sure that the version received is supported */
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for (i = 0; versions[i]; i++) {
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if (versions[i] == *chosen_version)
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break;
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}
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if (!versions[i])
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return error("Version %d not supported", *chosen_version);
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return 0;
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}
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static int handshake_capabilities(struct child_process *process,
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struct subprocess_capability *capabilities,
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unsigned int *supported_capabilities)
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{
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int i;
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char *line;
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for (i = 0; capabilities[i].name; i++) {
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if (packet_write_fmt_gently(process->in, "capability=%s\n",
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capabilities[i].name))
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return error("Could not write requested capability");
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}
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if (packet_flush_gently(process->in))
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return error("Could not write flush packet");
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while ((line = packet_read_line(process->out, NULL))) {
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const char *p;
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if (!skip_prefix(line, "capability=", &p))
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continue;
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for (i = 0;
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capabilities[i].name && strcmp(p, capabilities[i].name);
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i++)
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;
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if (capabilities[i].name) {
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if (supported_capabilities)
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*supported_capabilities |= capabilities[i].flag;
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} else {
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die("subprocess '%s' requested unsupported capability '%s'",
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process->args.v[0], p);
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}
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}
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return 0;
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}
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int subprocess_handshake(struct subprocess_entry *entry,
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const char *welcome_prefix,
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int *versions,
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int *chosen_version,
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struct subprocess_capability *capabilities,
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unsigned int *supported_capabilities)
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{
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int retval;
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struct child_process *process = &entry->process;
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sigchain_push(SIGPIPE, SIG_IGN);
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retval = handshake_version(process, welcome_prefix, versions,
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chosen_version) ||
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handshake_capabilities(process, capabilities,
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supported_capabilities);
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sigchain_pop(SIGPIPE);
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return retval;
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}
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