UI handling out of main loop

src/main.c

@@ -1,9 +1,34 @@
+#include <signal.h>
 #include <stdbool.h>
-#include <unistd.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <time.h>
+#include <sys/time.h>
 
 #include "emulator.h"
 #include "ui.h"
 
+#define SPEED_HZ_UI 64
+
+void signal_handler( int sig )
+{
+    switch ( sig ) {
+        /* case SIGINT: /\* Ctrl-C *\/ */
+        /*     enter_debugger |= USER_INTERRUPT; */
+        /*     break; */
+        case SIGALRM:
+            ui_get_event();
+            ui_update_display();
+            break;
+        case SIGPIPE:
+            ui_stop();
+            exit_emulator();
+            exit( 0 );
+        default:
+            break;
+    }
+}
+
 int main( int argc, char** argv )
 {
     config_t* config = config_init( argc, argv );
@@ -14,11 +39,33 @@ int main( int argc, char** argv )
     setup_ui( config );
     ui_start( config );
 
-    while ( true ) {
+    sigset_t set;
-        ui_get_event();
+    struct sigaction sa;
-        ui_update_display();
+    sigemptyset( &set );
+    sigaddset( &set, SIGALRM );
+    sa.sa_handler = signal_handler;
+    sa.sa_mask = set;
+#ifdef SA_RESTART
+    sa.sa_flags = SA_RESTART;
+#endif
+    sigaction( SIGALRM, &sa, ( struct sigaction* )0 );
 
-        usleep( 1000000 / 64 );
+    /************************************/
+    /* set the real time interval timer */
+    /************************************/
+    /*
+      Every <interval>µs setitimer will trigger a SIGALRM
+      which will getUI events and refresh UI in signal_handler
+     */
+    struct itimerval it;
+    it.it_interval.tv_sec = 0;
+    it.it_interval.tv_usec = 1000000 / SPEED_HZ_UI;
+    it.it_value.tv_sec = 0;
+    it.it_value.tv_usec = 1000000 / SPEED_HZ_UI;
+    setitimer( ITIMER_REAL, &it, ( struct itimerval* )0 );
+
+    while ( true ) {
+        // fprintf( stderr, "." );
     }
 
     /* Never reached */