Add signal handler

Author: zielinsky

.gdb_history

@@ -0,0 +1,12 @@
+run
+next
+next
+quit
+quit
+run
+quit
+quit
+run
+quit
+run
+quit

analyzer.c

@@ -2,7 +2,7 @@
 #include "cputracker.h"
 
 static unsigned long average_cpu_usage(struct proc_stat prev,
-                                struct proc_stat current) {
+                                       struct proc_stat current) {
   unsigned long prevIdle = prev.idle + prev.iowait;
   unsigned long idle = current.idle + current.iowait;
 
@@ -20,11 +20,13 @@ static unsigned long average_cpu_usage(struct proc_stat prev,
   return (total - idle) * 100 / total;
 }
 
-void *analyzer(void) {
+void *analyzer(void *arg) {
   struct proc_stat *prev = malloc((unsigned long)g_nproc * sizeof(struct proc_stat));
   unsigned long *avg = malloc((unsigned long)g_nproc * sizeof(unsigned long));
   unsigned long *bufforAvg;
   struct proc_stat *stats = NULL;
+  pthread_cleanup_push(free, prev);
+  pthread_cleanup_push(free, avg);
   while (1) {
     sem_wait(&g_dataFilledSpaceSemaphore);
 
@@ -53,6 +55,7 @@ void *analyzer(void) {
 
     sem_post(&g_printFilledSpaceSemaphore);
   }
-  free(prev);
-  free(avg);
+  pthread_cleanup_pop(1);
+  pthread_cleanup_pop(1);
+  return arg;
 }

analyzer.h

@@ -2,5 +2,5 @@
 #define ANALYZER_H
 #include "cputracker.h"
 
-void *analyzer(void);
+void *analyzer(void *arg);
 #endif

cputracker.c

@@ -3,8 +3,6 @@
 #include "printer.h"
 #include "reader.h"
 
-volatile sig_atomic_t done = 0;
-
 int g_nproc = 0;
 static struct proc_stat *g_dataBuffer[BUFFER_SIZE];
 pthread_mutex_t g_dataBufferMutex = PTHREAD_MUTEX_INITIALIZER;
@@ -20,6 +18,12 @@ static pthread_t readerThreadId;
 static pthread_t analyzerThreadId;
 static pthread_t printerThreadId;
 
+void handler(int signum) {
+  pthread_cancel(readerThreadId);
+  pthread_cancel(printerThreadId);
+  pthread_cancel(analyzerThreadId);
+}
+
 static int get_nproc(int *nproc) {
   *nproc = (int)sysconf(_SC_NPROCESSORS_ONLN);
   if (*nproc == -1) {
@@ -72,6 +76,11 @@ int main(void) {
   pthread_create(&analyzerThreadId, NULL, analyzer, NULL);
   pthread_create(&printerThreadId, NULL, printer, NULL);
 
+  struct sigaction action;
+  memset(&action, 0, sizeof(struct sigaction));
+  action.sa_handler = handler;
+  sigaction(SIGTERM, &action, NULL);
+
   pthread_join(readerThreadId, NULL);
   pthread_join(analyzerThreadId, NULL);
   pthread_join(printerThreadId, NULL);

printer.c

@@ -1,6 +1,6 @@
 #include "printer.h"
 
-void *printer(void) {
+void *printer(void *arg) {
   unsigned long *avg = NULL;
   while (1) {
     sem_wait(&g_printFilledSpaceSemaphore);
@@ -22,4 +22,5 @@ void *printer(void) {
     sem_post(&g_printLeftSpaceSemaphore);
     sleep(1);
   }
+  return arg;
 }

printer.h

@@ -2,5 +2,5 @@
 #define PRINTER_H
 #include "cputracker.h"
 
-void *printer(void);
+void *printer(void *arg);
 #endif

reader.c

@@ -20,7 +20,7 @@ static int get_proc_stats(struct proc_stat *stats) {
   return 0;
 }
 
-void *reader(void) {
+void *reader(void *arg) {
   struct proc_stat *stats = NULL;
   while (1) {
 
@@ -32,6 +32,7 @@ void *reader(void) {
 
     if (get_proc_stats(stats) == -1) {
       pthread_mutex_unlock(&g_dataBufferMutex);
+      sem_post(&g_dataLeftSpaceSemaphore);
       continue;
     }
 
@@ -40,4 +41,5 @@ void *reader(void) {
     sem_post(&g_dataFilledSpaceSemaphore);
     usleep(READ_DELAY);
   }
+  return arg;
 }

reader.h

@@ -4,5 +4,5 @@
 
 #define READ_DELAY 50000
 
-void *reader(void);
+void *reader(void *arg);
 #endif