improves signal handling & call monitoring

Change-Id: Ia37c70ffbb9122b2d53ec93baf203cd141613dc6
Signed-off-by: José Bollo <jose.bollo@iot.bzh>

5 files changed, 161 insertions, 95 deletions

diff --git a/src/CMakeLists.txt b/src/CMakeLists.txt
index 707b2e09..bad60b34 100644
--- a/src/CMakeLists.txt
+++ b/src/CMakeLists.txt
@@ -10,6 +10,7 @@ ADD_LIBRARY(src OBJECT
 	afb-hswitch.c
 	afb-method.c
 	afb-msg-json.c
+	afb-sig-handler.c
 	afb-websock.c
 	afb-ws-json.c
 	afb-ws.c
diff --git a/src/afb-api-so.c b/src/afb-api-so.c
index 07d0a5f2..6ac5070f 100644
--- a/src/afb-api-so.c
+++ b/src/afb-api-so.c
@@ -26,10 +26,6 @@
 #include <limits.h>
 #include <sys/types.h>
 #include <sys/stat.h>
-#include <signal.h>
-#include <time.h>
-#include <sys/syscall.h>
-#include <setjmp.h>
 
 #include "afb-plugin.h"
 #include "afb-req-itf.h"
@@ -40,10 +36,9 @@
 #include "afb-context.h"
 #include "afb-apis.h"
 #include "afb-api-so.h"
+#include "afb-sig-handler.h"
 #include "verbose.h"
 
-extern __thread sigjmp_buf *error_handler;
-
 struct api_so_desc {
 	struct AFB_plugin *plugin;	/* descriptor */
 	size_t apilength;
@@ -85,50 +80,23 @@ static const struct afb_daemon_itf daemon_itf = {
 	.get_system_bus = (void*)afb_common_get_system_bus
 };
 
+struct monitoring {
+	struct afb_req req;
+	void (*action)(struct afb_req);
+};
 
-static void trapping_call(struct afb_req req, void(*cb)(struct afb_req))
+static void monitored_call(int signum, struct monitoring *data)
 {
-	volatile int signum, timerset;
-	timer_t timerid;
-	sigjmp_buf jmpbuf, *older;
-	struct sigevent sevp;
-	struct itimerspec its;
-
-	timerset = 0;
-	older = error_handler;
-	signum = setjmp(jmpbuf);
-	if (signum != 0) {
-		afb_req_fail_f(req, "aborted", "signal %d caught", signum);
-	}
-	else {
-		error_handler = &jmpbuf;
-		if (api_timeout > 0) {
-			timerset = 1; /* TODO: check statuses */
-			sevp.sigev_notify = SIGEV_THREAD_ID;
-			sevp.sigev_signo = SIGALRM;
-			sevp.sigev_value.sival_ptr = NULL;
-#if defined(sigev_notify_thread_id)
-			sevp.sigev_notify_thread_id = (pid_t)syscall(SYS_gettid);
-#else
-			sevp._sigev_un._tid = (pid_t)syscall(SYS_gettid);
-#endif
-			timer_create(CLOCK_THREAD_CPUTIME_ID, &sevp, &timerid);
-			its.it_interval.tv_sec = 0;
-			its.it_interval.tv_nsec = 0;
-			its.it_value.tv_sec = api_timeout;
-			its.it_value.tv_nsec = 0;
-			timer_settime(timerid, 0, &its, NULL);
-		}
-
-		cb(req);
-	}
-	if (timerset)
-		timer_delete(timerid);
-	error_handler = older;
+	if (signum != 0)
+		afb_req_fail_f(data->req, "aborted", "signal %s(%d) caught", strsignal(signum), signum);
+	else
+		data->action(data->req);
 }
 
 static void call_check(struct afb_req req, struct afb_context *context, const struct AFB_restapi *verb)
 {
+	struct monitoring data;
+
 	int stag = (int)(verb->session & AFB_SESSION_MASK);
 
 	if (stag != AFB_SESSION_NONE) {
@@ -153,7 +121,9 @@ static void call_check(struct afb_req req, struct afb_context *context, const st
 	if ((stag & AFB_SESSION_CLOSE) != 0)
 		afb_context_close(context);
 
-	trapping_call(req, verb->callback);
+	data.req = req;
+	data.action = verb->callback;
+	afb_sig_monitor((void*)monitored_call, &data, api_timeout);
 }
 
 static void call(struct api_so_desc *desc, struct afb_req req, struct afb_context *context, const char *verb, size_t lenverb)
diff --git a/src/afb-sig-handler.c b/src/afb-sig-handler.c
new file mode 100644
index 00000000..127bf0c9
--- /dev/null
+++ b/src/afb-sig-handler.c
@@ -0,0 +1,118 @@
+/* 
+ * Copyright (C) 2015 "IoT.bzh"
+ * Author "Fulup Ar Foll"
+ * Author José Bollo <jose.bollo@iot.bzh>
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#define _GNU_SOURCE
+
+#include <stdlib.h>
+#include <signal.h>
+#include <string.h>
+#include <unistd.h>
+#include <time.h>
+#include <sys/syscall.h>
+#include <setjmp.h>
+
+#include "afb-sig-handler.h"
+#include "verbose.h"
+
+static _Thread_local sigjmp_buf *error_handler;
+
+static void on_signal_terminate (int signum)
+{
+	ERROR("Terminating signal received %s", strsignal(signum));
+	exit(1);
+}
+
+static void on_signal_error(int signum)
+{
+	sigset_t sigset;
+
+	// unlock signal to allow a new signal to come
+	if (error_handler != NULL) {
+		sigemptyset(&sigset);
+		sigaddset(&sigset, signum);
+		sigprocmask(SIG_UNBLOCK, &sigset, 0);
+		longjmp(*error_handler, signum);
+	}
+	if (signum == SIGALRM)
+		return;
+	ERROR("Unmonitored signal received %s", strsignal(signum));
+	exit(2);
+}
+
+static int install(void (*handler)(int), int *signals)
+{
+	int result = 1;
+	while(*signals > 0) {
+		if (signal(*signals, handler) == SIG_ERR) {
+			ERROR("failed to install signal handler for signal %s", strsignal(*signals));
+			result = 0;
+		}
+		signals++;
+	}
+	return result;
+}
+
+int afb_sig_handler_init()
+{
+	static int sigerr[] = { SIGALRM, SIGSEGV, SIGFPE, 0 };
+	static int sigterm[] = { SIGINT, SIGABRT, 0 };
+
+	return (install(on_signal_error, sigerr) & install(on_signal_terminate, sigterm)) - 1;
+}
+
+void afb_sig_monitor(void (*function)(int sig, void*), void *closure, int timeout)
+{
+	volatile int signum, timerset;
+	timer_t timerid;
+	sigjmp_buf jmpbuf, *older;
+	struct sigevent sevp;
+	struct itimerspec its;
+
+	timerset = 0;
+	older = error_handler;
+	signum = setjmp(jmpbuf);
+	if (signum != 0) {
+		function(signum, closure);
+	}
+	else {
+		error_handler = &jmpbuf;
+		if (timeout > 0) {
+			timerset = 1; /* TODO: check statuses */
+			sevp.sigev_notify = SIGEV_THREAD_ID;
+			sevp.sigev_signo = SIGALRM;
+			sevp.sigev_value.sival_ptr = NULL;
+#if defined(sigev_notify_thread_id)
+			sevp.sigev_notify_thread_id = (pid_t)syscall(SYS_gettid);
+#else
+			sevp._sigev_un._tid = (pid_t)syscall(SYS_gettid);
+#endif
+			timer_create(CLOCK_THREAD_CPUTIME_ID, &sevp, &timerid);
+			its.it_interval.tv_sec = 0;
+			its.it_interval.tv_nsec = 0;
+			its.it_value.tv_sec = timeout;
+			its.it_value.tv_nsec = 0;
+			timer_settime(timerid, 0, &its, NULL);
+		}
+
+		function(0, closure);
+	}
+	if (timerset)
+		timer_delete(timerid);
+	error_handler = older;
+}
+
diff --git a/src/afb-sig-handler.h b/src/afb-sig-handler.h
new file mode 100644
index 00000000..3d0249a2
--- /dev/null
+++ b/src/afb-sig-handler.h
@@ -0,0 +1,24 @@
+/* 
+ * Copyright (C) 2015 "IoT.bzh"
+ * Author "Fulup Ar Foll"
+ * Author José Bollo <jose.bollo@iot.bzh>
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#pragma once
+
+extern int afb_sig_handler_init();
+
+extern void afb_sig_monitor(void (*function)(int sig, void*), void *closure, int timeout);
+
diff --git a/src/main.c b/src/main.c
index 81f891b3..0c4e42f7 100644
--- a/src/main.c
+++ b/src/main.c
@@ -42,6 +42,7 @@
 #include "afb-hsrv.h"
 #include "afb-context.h"
 #include "afb-hreq.h"
+#include "afb-sig-handler.h"
 #include "session.h"
 #include "verbose.h"
 #include "afb-common.h"
@@ -127,8 +128,6 @@ static  AFB_options cliOptions [] = {
   {0, 0, NULL, NULL}
  };
 
-
-
 /*----------------------------------------------------------
  | printversion
  |   print version and copyright
@@ -429,49 +428,6 @@ static void closeSession (int status, void *data) {
 }
 
 /*----------------------------------------------------------
- | timeout signalQuit
- +--------------------------------------------------------- */
-void signalQuit (int signum)
-{
-	ERROR("Terminating signal received %s", strsignal(signum));
-	exit(1);
-}
-
-/*----------------------------------------------------------
- | Error signals
- |
- +--------------------------------------------------------- */
-__thread sigjmp_buf *error_handler;
-static void signalError(int signum)
-{
-	sigset_t sigset;
-
-	// unlock signal to allow a new signal to come
-	if (error_handler != NULL) {
-		sigemptyset(&sigset);
-		sigaddset(&sigset, signum);
-		sigprocmask(SIG_UNBLOCK, &sigset, 0);
-		longjmp(*error_handler, signum);
-	}
-	if (signum == SIGALRM)
-		return;
-	ERROR("Unmonitored signal received %s", strsignal(signum));
-	exit(2);
-}
-
-static void install_error_handlers()
-{
-	int i, signals[] = { SIGALRM, SIGSEGV, SIGFPE, 0 };
-
-	for (i = 0; signals[i] != 0; i++) {
-		if (signal(signals[i], signalError) == SIG_ERR) {
-			ERROR("Signal handler error");
-			exit(1);
-		}
-	}
-}
-
-/*----------------------------------------------------------
  | daemonize
  |   set the process in background
  +--------------------------------------------------------- */
@@ -647,11 +603,8 @@ int main(int argc, char *argv[])  {
      exit (1);
   }
 
-  install_error_handlers();
-
-  // ------------------ clean exit on CTR-C signal ------------------------
-  if (signal (SIGINT, signalQuit) == SIG_ERR || signal (SIGABRT, signalQuit) == SIG_ERR) {
-     ERROR("main fail to install Signal handler");
+  if (afb_sig_handler_init() < 0) {
+     ERROR("main fail to initialise signal handlers");
      return 1;
   }