##// END OF EJS Templates
rust-changelog: introducing an intermediate `ChangelogEntry`...
rust-changelog: introducing an intermediate `ChangelogEntry` Before this change, client code needing to extract, e.g, the Node ID and the description from a changeset had no other choice than calling both `entry_for_rev()` and `data_for_rev()`. This duplicates some (limited) computation, and more importantly imposes bad hygiene for client code: at some point of developement, the client code would have to pass over both entry and data in its internal layers, which at some point of development would raise the question whether they are consistent. We introduce the intermediate `ChangelogEntry` from which both conversion to the generic `RevlogEntry` and extraction of `ChangelogRevisionData` are possible. It might grow some convenience methods in the future. We keep the `data_for_rev()` method of `Changelog` for compatibility, pointing users at the more powerful alternative.

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sighandlers.c
175 lines | 3.7 KiB | text/x-c | CLexer
/*
* Signal handlers for cHg
*
* Copyright 2011, 2018 Yuya Nishihara <yuya@tcha.org>
*
* This software may be used and distributed according to the terms of the
* GNU General Public License version 2 or any later version.
*/
#include <assert.h>
#include <errno.h>
#include <signal.h>
#include <string.h>
#include <unistd.h>
static pid_t peerpgid = 0;
static pid_t peerpid = 0;
static void forwardsignal(int sig)
{
assert(peerpid > 0);
(void)kill(peerpid, sig);
}
static void forwardsignaltogroup(int sig)
{
/* prefer kill(-pgid, sig), fallback to pid if pgid is invalid */
pid_t killpid = peerpgid > 1 ? -peerpgid : peerpid;
(void)kill(killpid, sig);
}
static void handlestopsignal(int sig)
{
sigset_t unblockset, oldset;
struct sigaction sa, oldsa;
if (sigemptyset(&unblockset) < 0) {
return;
}
if (sigaddset(&unblockset, sig) < 0) {
return;
}
memset(&sa, 0, sizeof(sa));
sa.sa_handler = SIG_DFL;
sa.sa_flags = SA_RESTART;
if (sigemptyset(&sa.sa_mask) < 0) {
return;
}
forwardsignal(sig);
if (raise(sig) < 0) { /* resend to self */
return;
}
if (sigaction(sig, &sa, &oldsa) < 0) {
return;
}
if (sigprocmask(SIG_UNBLOCK, &unblockset, &oldset) < 0) {
return;
}
/* resent signal will be handled before sigprocmask() returns */
if (sigprocmask(SIG_SETMASK, &oldset, NULL) < 0) {
return;
}
if (sigaction(sig, &oldsa, NULL) < 0) {
return;
}
}
/*
* Installs signal handlers.
*
* Returns 0 on success, -1 on error and errno is set appropriately.
* Installed handlers wouldn't be cleaned up on error.
*/
int setupsignalhandler(pid_t pid, pid_t pgid)
{
if (pid <= 0) {
errno = EINVAL;
return -1;
}
peerpid = pid;
peerpgid = (pgid <= 1 ? 0 : pgid);
struct sigaction sa;
memset(&sa, 0, sizeof(sa));
/* deadly signals meant to be sent to a process group:
* - SIGHUP: usually generated by the kernel, when termination of a
* process causes that process group to become orphaned
* - SIGINT: usually generated by the terminal */
sa.sa_handler = forwardsignaltogroup;
sa.sa_flags = SA_RESTART;
if (sigemptyset(&sa.sa_mask) < 0) {
return -1;
}
if (sigaction(SIGHUP, &sa, NULL) < 0) {
return -1;
}
if (sigaction(SIGINT, &sa, NULL) < 0) {
return -1;
}
/* terminate frontend by double SIGTERM in case of server freeze */
sa.sa_handler = forwardsignal;
sa.sa_flags |= SA_RESETHAND;
if (sigaction(SIGTERM, &sa, NULL) < 0) {
return -1;
}
/* notify the worker about window resize events */
sa.sa_flags = SA_RESTART;
if (sigaction(SIGWINCH, &sa, NULL) < 0) {
return -1;
}
/* forward user-defined signals */
if (sigaction(SIGUSR1, &sa, NULL) < 0) {
return -1;
}
if (sigaction(SIGUSR2, &sa, NULL) < 0) {
return -1;
}
/* propagate job control requests to worker */
sa.sa_handler = forwardsignal;
sa.sa_flags = SA_RESTART;
if (sigaction(SIGCONT, &sa, NULL) < 0) {
return -1;
}
sa.sa_handler = handlestopsignal;
sa.sa_flags = SA_RESTART;
if (sigaction(SIGTSTP, &sa, NULL) < 0) {
return -1;
}
return 0;
}
/*
* Restores signal handlers to the default, and masks SIGINT.
*
* Returns 0 on success, -1 on error and errno is set appropriately.
*/
int restoresignalhandler(void)
{
struct sigaction sa;
memset(&sa, 0, sizeof(sa));
sa.sa_handler = SIG_DFL;
sa.sa_flags = SA_RESTART;
if (sigemptyset(&sa.sa_mask) < 0) {
return -1;
}
if (sigaction(SIGHUP, &sa, NULL) < 0) {
return -1;
}
if (sigaction(SIGTERM, &sa, NULL) < 0) {
return -1;
}
if (sigaction(SIGWINCH, &sa, NULL) < 0) {
return -1;
}
if (sigaction(SIGCONT, &sa, NULL) < 0) {
return -1;
}
if (sigaction(SIGTSTP, &sa, NULL) < 0) {
return -1;
}
/* ignore Ctrl+C while shutting down to make pager exits cleanly */
sa.sa_handler = SIG_IGN;
if (sigaction(SIGINT, &sa, NULL) < 0) {
return -1;
}
peerpid = 0;
return 0;
}