Move event loop to event.c

1 files changed, 123 insertions, 0 deletions

diff --git a/event.c b/event.c
new file mode 100644
index 0000000..4771aac
--- /dev/null
+++ b/event.c
@@ -0,0 +1,123 @@
+/* Copyright (C) 2018  Curtis McEnroe <june@causal.agency>
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include <err.h>
+#include <poll.h>
+#include <signal.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <sys/wait.h>
+#include <sysexits.h>
+#include <unistd.h>
+#include <errno.h>
+
+#include "chat.h"
+
+static union {
+	struct {
+		struct pollfd ui;
+		struct pollfd irc;
+		struct pollfd pipe;
+	};
+	struct pollfd fds[3];
+} fds;
+
+void eventSpawn(char *const argv[]) {
+	if (fds.pipe.events) {
+		uiLog(TagStatus, UIHot, L"eventSpawn: existing pipe");
+		return;
+	}
+
+	int rw[2];
+	int error = pipe(rw);
+	if (error) err(EX_OSERR, "pipe");
+
+	pid_t pid = fork();
+	if (pid < 0) err(EX_OSERR, "fork");
+	if (!pid) {
+		close(rw[0]);
+		close(STDIN_FILENO);
+		dup2(rw[1], STDOUT_FILENO);
+		dup2(rw[1], STDERR_FILENO);
+		close(rw[1]);
+		execvp(argv[0], argv);
+		perror(argv[0]);
+		exit(EX_CONFIG);
+	}
+
+	close(rw[1]);
+	fds.pipe.fd = rw[0];
+	fds.pipe.events = POLLIN;
+}
+
+static void pipeRead(void) {
+	char buf[256];
+	ssize_t len = read(fds.pipe.fd, buf, sizeof(buf) - 1);
+	if (len < 0) err(EX_IOERR, "read");
+	if (len) {
+		buf[len] = '\0';
+		len = strcspn(buf, "\n");
+		uiFmt(TagStatus, UIHot, "eventSpawn: %.*s", (int)len, buf);
+	} else {
+		close(fds.pipe.fd);
+		memset(&fds.pipe, 0, sizeof(fds.pipe));
+	}
+}
+
+static void sigchld(int sig) {
+	(void)sig;
+	int status;
+	pid_t pid = wait(&status);
+	if (pid < 0) err(EX_OSERR, "wait");
+	if (WIFEXITED(status) && WEXITSTATUS(status)) {
+		uiFmt(TagStatus, UIHot, "eventSpawn: exit %d", WEXITSTATUS(status));
+	} else if (WIFSIGNALED(status)) {
+		uiFmt(TagStatus, UIHot, "eventSpawn: singal %d", WTERMSIG(status));
+	}
+}
+
+static void sigint(int sig) {
+	(void)sig;
+	input(TagStatus, "/quit");
+	uiExit();
+	exit(EX_OK);
+}
+
+void eventLoop(int ui, int irc) {
+	signal(SIGINT, sigint);
+	signal(SIGCHLD, sigchld);
+
+	fds.ui.fd = ui;
+	fds.irc.fd = irc;
+	fds.ui.events = POLLIN;
+	fds.irc.events = POLLIN;
+
+	for (;;) {
+		uiDraw();
+
+		int ready = poll(fds.fds, (fds.pipe.events ? 3 : 2), -1);
+		if (ready < 0) {
+			if (errno != EINTR) err(EX_IOERR, "poll");
+			uiRead();
+			continue;
+		}
+
+		if (fds.ui.revents) uiRead();
+		if (fds.irc.revents) ircRead();
+		if (fds.pipe.revents) pipeRead();
+	}
+}