Handle signals differently in order to debug the issue with empty outputs

packet-exchange/src/client.c

@@ -56,7 +56,7 @@ typedef struct network_config {
 static void process_options(int argc, char *argv[]);
 static void do_tsn_task(struct thread_param *param, char * data, uint64_t next_txtime);
 static void print_histograms();
-static void sigint_handler(int sig_num);
+static void sighand(int sig_num);
 
 // Static variables
 
@@ -160,9 +160,6 @@ int main(int argc, char *argv[]) {
   pthread_t thread;
   thread_stat_t *stats;
 
-  // Catch breaks with sigint_handler
-  signal(SIGINT, sigint_handler);
-
   param = malloc(sizeof(thread_param_t));
   stats = &param->stats;
 
@@ -191,6 +188,9 @@ int main(int argc, char *argv[]) {
     memset((int64_t *)histograms, 0, NB_HISTOGRAMS * MAX_HIST_VAL);
   }
 
+  // Catch breaks with sighand to print the histograms
+  init_signals(sighand, enable_histograms);
+
   // Initialize the UDP packet sending socket
   init_udp_send(enable_etf, enable_timestamps,
                 network_config.packet_priority,
@@ -328,10 +328,9 @@ static void print_histograms() {
   printf(   "]}]}\n");
 }
 
-static void sigint_handler(int sig_num) {
+static void sighand(int sig_num) {
   (void)sig_num;
-  if (enable_histograms)
-    print_histograms();
+  print_histograms();
   exit(EXIT_SUCCESS);
 }
 

packet-exchange/src/server.c

@@ -60,7 +60,7 @@ typedef struct main_param {
 
 static void process_options(int argc, char *argv[]);
 static void print_histograms();
-static void sigint_handler(int sig_num);
+static void sighand(int sig_num);
 
 // Static variables
 
@@ -81,6 +81,7 @@ static enum TSNTask tsn_task;
 struct timespec measures_start;
 struct timespec measures_end;
 
+
 static void help(char *argv[]) {
   printf("Usage: %s [-aghtv] [-b CLIENT_IP] [-d BUF_LEN] [-f IF] [-i USEC] [-p PRIO] [-r USEC]\n\n", argv[0]);
   printf("       -a                    Run the real time thread on CPU1\n");
@@ -182,9 +183,6 @@ int main(int argc, char *argv[]) {
   thread_stat_t *stats;
   int64_t diff;
 
-  // Catch breaks with sigint_handler
-  signal(SIGINT, sigint_handler);
-
   param = malloc(sizeof(thread_param_t));
   stats = &param->stats;
 
@@ -210,6 +208,9 @@ int main(int argc, char *argv[]) {
     memset((int64_t *)histograms, 0, NB_HISTOGRAMS * MAX_HIST_VAL);
   }
 
+  // Catch breaks with sighand to print the histograms
+  init_signals(sighand, enable_histograms);
+
   // Initialize the UDP packet receiving socket
   init_udp_recv(enable_timestamps, network_config.network_if);
 
@@ -324,12 +325,10 @@ static void print_histograms() {
   printf(   "]]}]}\n");
 }
 
-
-static void sigint_handler(int sig_num) {
+static void sighand(int sig_num) {
   (void)sig_num;
 
-  if (enable_histograms)
-    print_histograms();
+  print_histograms();
 
   if(param->stats.lost_packets)
     fprintf(stderr, "%d packets were lost\n", param->stats.lost_packets);

packet-exchange/src/utilities.c

 #define _GNU_SOURCE
 #include <inttypes.h>
 #include <stdint.h>
+#include <signal.h>
 #include <time.h>
 #include <unistd.h>
 
 #include "utilities.h"
 
+(void)(*previous_handlers[NSIG])(int);
+static (void)(*sighand)(int);
+
 uint64_t ts_to_uint(struct timespec t) {
   return t.tv_sec * NSEC_PER_SEC + t.tv_nsec;
 }
@@ -28,3 +32,34 @@ uint64_t calcdiff_ns(struct timespec t1, struct timespec t2) {
 
 uint64_t max(uint64_t a, uint64_t b) { return a > b ? a : b; }
 uint64_t min(uint64_t a, uint64_t b) { return a < b ? a : b; }
+
+static void sighand_wrapper(int sig) {
+
+  // If we get un unexpected signal, report it, if not print the histogram
+  if(sig == SIGINT || sig == SIGTERM)
+    (*sighand)(sig); // Will print the histogram
+  else
+    printf("Uknown signal interrupt: %s (%d)\n", strsignal(sig), sig);
+
+  // Execute the default handler
+  if(previous_handlers[sig] == SIG_DFL) {
+    signal(sig, SIG_DFL);
+    raise(sig);
+  }
+  else if(previous_handlers[sig] == SIG_IGN) {
+    return;
+  }
+  else {
+    (*previous_handlers[sig])(sig);
+  }
+}
+
+void init_signals((void)(*_sighand(int)), int enable_histograms) {
+
+  sighand = _sighand;
+
+  if(enable_histograms)
+    for(int i = 0; i < NSIG; i++)
+      signal(i, sighand_wrapper);
+}
+

packet-exchange/src/utilities.h

@@ -4,6 +4,7 @@
 #define _GNU_SOURCE
 #include <inttypes.h>
 #include <stdint.h>
+#include <signal.h>
 #include <time.h>
 #include <unistd.h>
 
@@ -27,4 +28,9 @@ uint64_t calcdiff_ns(struct timespec t1, struct timespec t2);
 uint64_t max(uint64_t a, uint64_t b);
 uint64_t min(uint64_t a, uint64_t b);
 
+void init_signals((void)(*_sighand(int)), int enable_histograms);
+
+extern (void)(*previous_handlers[NSIG])(int);
+
+
 #endif