From cb258d6fe7c84bd5f5896bd1a49a66b7197cb73b Mon Sep 17 00:00:00 2001
From: Saverio Proto <zioproto@gmail.com>
Date: Wed, 28 May 2014 21:49:23 +0200
Subject: [PATCH] Revert "Remove support for UNIX signals in the event
 library."

This reverts commit 12fd793a46d1695bedb96a5d9531dfd9f3efd7be.
---
 src/event.c | 50 +++++++++++++++++++++++++++++++++++++++++++++++++-
 src/event.h | 18 +++++++++++++++++-
 2 files changed, 66 insertions(+), 2 deletions(-)

diff --git a/src/event.c b/src/event.c
index cfc6d899..d23f43bb 100644
--- a/src/event.c
+++ b/src/event.c
@@ -1,5 +1,5 @@
 /*
-    event.c -- I/O and timeout event handling
+    event.c -- I/O, timeout and signal event handling
     Copyright (C) 2014 Guus Sliepen <guus@meshlink.io>
 
     This program is free software; you can redistribute it and/or modify
@@ -117,6 +117,49 @@ void timeout_del(event_loop_t *loop, timeout_t *timeout) {
 	timeout->tv = (struct timeval){0, 0};
 }
 
+static int signal_compare(const signal_t *a, const signal_t *b) {
+	return (int)a->signum - (int)b->signum;
+}
+
+static void signalio_handler(event_loop_t *loop, void *data, int flags) {
+	unsigned char signum;
+	if(read(loop->pipefd[0], &signum, 1) != 1)
+		return;
+
+	signal_t *sig = splay_search(&loop->signals, &((signal_t){.signum = signum}));
+	if(sig)
+		sig->cb(loop, sig->data);
+}
+
+static void pipe_init(event_loop_t *loop) {
+	if(!pipe(loop->pipefd))
+		io_add(loop, &loop->signalio, signalio_handler, NULL, loop->pipefd[0], IO_READ);
+}
+
+void signal_add(event_loop_t *loop, signal_t *sig, signal_cb_t cb, void *data, uint8_t signum) {
+	if(sig->cb)
+		return;
+
+	sig->cb = cb;
+	sig->data = data;
+	sig->signum = signum;
+	sig->node.data = sig;
+
+	if(loop->pipefd[0] == -1)
+		pipe_init(loop);
+
+	if(!splay_insert_node(&loop->signals, &sig->node))
+		abort();
+}
+
+void signal_del(event_loop_t *loop, signal_t *sig) {
+	if(!sig->cb)
+		return;
+
+	splay_unlink_node(&loop->signals, &sig->node);
+	sig->cb = NULL;
+}
+
 bool event_loop_run(event_loop_t *loop) {
 	loop->running = true;
 
@@ -187,6 +230,9 @@ void event_loop_stop(event_loop_t *loop) {
 void event_loop_init(event_loop_t *loop) {
 	loop->ios.compare = (splay_compare_t)io_compare;
 	loop->timeouts.compare = (splay_compare_t)timeout_compare;
+	loop->signals.compare = (splay_compare_t)signal_compare;
+	loop->pipefd[0] = -1;
+	loop->pipefd[1] = -1;
 	gettimeofday(&loop->now, NULL);
 }
 
@@ -195,4 +241,6 @@ void event_loop_exit(event_loop_t *loop) {
 		splay_free_node(&loop->ios, node);
 	for splay_each(timeout_t, timeout, &loop->timeouts)
 		splay_free_node(&loop->timeouts, node);
+	for splay_each(signal_t, signal, &loop->signals)
+		splay_free_node(&loop->signals, node);
 }
diff --git a/src/event.h b/src/event.h
index 272243ff..e49732af 100644
--- a/src/event.h
+++ b/src/event.h
@@ -1,5 +1,5 @@
 /*
-    event.h -- I/O and timeout event handling
+    event.h -- I/O, timeout and signal event handling
     Copyright (C) 2014 Guus Sliepen <guus@meshlink.io>
 
     This program is free software; you can redistribute it and/or modify
@@ -29,6 +29,7 @@ typedef struct event_loop_t event_loop_t;
 
 typedef void (*io_cb_t)(event_loop_t *loop, void *data, int flags);
 typedef void (*timeout_cb_t)(event_loop_t *loop, void *data);
+typedef void (*signal_cb_t)(event_loop_t *loop, void *data);
 
 typedef struct io_t {
 	int fd;
@@ -45,6 +46,13 @@ typedef struct timeout_t {
 	struct splay_node_t node;
 } timeout_t;
 
+typedef struct signal_t {
+	int signum;
+	signal_cb_t cb;
+	void *data;
+	struct splay_node_t node;
+} signal_t;
+
 struct event_loop_t {
 	fd_set readfds;
 	fd_set writefds;
@@ -54,6 +62,10 @@ struct event_loop_t {
 	
 	splay_tree_t ios;
 	splay_tree_t timeouts;
+	splay_tree_t signals;
+
+	io_t signalio;
+	int pipefd[2];
 
 	void *data;
 };
@@ -66,6 +78,10 @@ extern void timeout_add(event_loop_t *loop, timeout_t *timeout, timeout_cb_t cb,
 extern void timeout_del(event_loop_t *loop, timeout_t *timeout);
 extern void timeout_set(event_loop_t *loop, timeout_t *timeout, struct timeval *tv);
 
+extern void signal_add(event_loop_t *loop, signal_t *sig, signal_cb_t cb, void *data, uint8_t signum);
+extern void signal_trigger(event_loop_t *loop, signal_t *sig);
+extern void signal_del(event_loop_t *loop, signal_t *sig);
+
 extern void event_loop_init(event_loop_t *loop);
 extern void event_loop_exit(event_loop_t *loop);
 extern bool event_loop_run(event_loop_t *loop);
-- 
2.39.5