Graduate

Signed-off-by: Matt Strapp <matt@mattstrapp.net>

1 files changed, 42 insertions, 0 deletions

diff --git a/csci4061/110920_breakout/chap8/pgm_8_1.c b/csci4061/110920_breakout/chap8/pgm_8_1.c
new file mode 100644
index 0000000..a979bb6
--- /dev/null
+++ b/csci4061/110920_breakout/chap8/pgm_8_1.c
@@ -0,0 +1,42 @@
+// Program 8.1
+
+#include <math.h>
+#include <signal.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <unistd.h>
+ 
+int main(int argc,  char *argv[]) {
+   int i;
+   sigset_t intmask;
+   int repeatfactor;
+   double y = 0.0;
+ 
+   if (argc != 2) {
+      fprintf(stderr, "Usage: %s repeatfactor\n", argv[0]);
+      return 1; 
+   }   
+   repeatfactor = atoi(argv[1]);
+   if ((sigemptyset(&intmask) == -1) || (sigaddset(&intmask, SIGINT) == -1)){
+      perror("Failed to initialize the signal mask");
+      return 1;
+   }
+   for ( ; ; ) {
+      if (sigprocmask(SIG_BLOCK, &intmask, NULL) == -1)
+         break; 
+      fprintf(stderr, "SIGINT signal blocked\n");
+      for (i = 0; i < repeatfactor; i++) 
+         y += sin((double)i);
+      fprintf(stderr, "Blocked calculation is finished, y = %f\n", y);
+      sleep(3);
+      if (sigprocmask(SIG_UNBLOCK, &intmask, NULL) == -1)
+         break;
+      fprintf(stderr, "SIGINT signal unblocked\n");
+      for (i = 0; i < repeatfactor; i++) 
+         y += sin((double)i);
+      fprintf(stderr, "Unblocked calculation is finished, y=%f\n", y);
+      sleep(3);
+   }    
+   perror("Failed to change signal mask");
+   return 1;
+}
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