Add notify watchdog

Add terminating threads
Remove clang warnings

Author: zielinsky

.gdb_history

@@ -10,3 +10,5 @@ run
 quit
 run
 quit
+run
+quit

.gitignore

@@ -8,3 +8,5 @@ cputracker.o
 cputracker
 analyzer.o
 printer.o
+out
+.gdb_history

Makefile

@@ -1,7 +1,7 @@
-CC = gcc -g
-CFLAGS = -O3 -Wall -Werror -pthread
-# CC = clang
-# CFLAGS = -Weverything -pthread
+# CC = gcc -g
+# CFLAGS = -O3 -Wall -Werror -pthread
+CC = clang
+CFLAGS = -Weverything -pthread
 
 OBJS = reader.o cputracker.o analyzer.o printer.o
 

analyzer.c

@@ -21,23 +21,26 @@ static unsigned long average_cpu_usage(struct proc_stat prev,
 }
 
 void *analyzer(void *arg) {
-  struct proc_stat *prev =
-      malloc((unsigned long)g_nproc * sizeof(struct proc_stat));
-  if (prev == NULL) {
+  struct proc_stat *prev;
+  unsigned long *avg;
+  unsigned long *bufforAvg;
+  struct proc_stat *stats;
+  
+  (void)arg;
+  
+  if ((prev = malloc((unsigned long)g_nproc * sizeof(struct proc_stat))) == NULL) {
     return NULL;
   }
-  unsigned long *avg = malloc((unsigned long)g_nproc * sizeof(unsigned long));
-  if (avg == NULL) {
+  if ((avg = malloc((unsigned long)g_nproc * sizeof(unsigned long))) == NULL) {
     free(prev);
     return NULL;
   }
-  unsigned long *bufforAvg;
-  struct proc_stat *stats = NULL;
-  pthread_cleanup_push(free, prev);
-  pthread_cleanup_push(free, avg);
+  pthread_cleanup_push(free, prev)
+  pthread_cleanup_push(free, avg)
   while (1) {
-    sem_wait(&g_dataFilledSpaceSemaphore);
+    notify_watchdog(Analyzer);
 
+    sem_wait(&g_dataFilledSpaceSemaphore);
     pthread_mutex_lock(&g_dataBufferMutex);
 
     stats = get_item_from_data_buffer();
@@ -47,23 +50,19 @@ void *analyzer(void *arg) {
     }
 
     pthread_mutex_unlock(&g_dataBufferMutex);
-
     sem_post(&g_dataLeftSpaceSemaphore);
 
     //
 
     sem_wait(&g_printLeftSpaceSemaphore);
-
     pthread_mutex_lock(&g_printBufferMutex);
 
     bufforAvg = get_item_from_print_buffer();
     memcpy(bufforAvg, avg, (unsigned long)g_nproc * sizeof(unsigned long));
 
     pthread_mutex_unlock(&g_printBufferMutex);
-
     sem_post(&g_printFilledSpaceSemaphore);
   }
   pthread_cleanup_pop(1);
   pthread_cleanup_pop(1);
-  return arg;
 }

cputracker.c

@@ -3,6 +3,7 @@
 #include "printer.h"
 #include "reader.h"
 
+
 int g_nproc = 0;
 static struct proc_stat *g_dataBuffer[BUFFER_SIZE];
 pthread_mutex_t g_dataBufferMutex = PTHREAD_MUTEX_INITIALIZER;
@@ -18,7 +19,12 @@ static pthread_t readerThreadId;
 static pthread_t analyzerThreadId;
 static pthread_t printerThreadId;
 
-void handler(int signum) {
+
+static int working[THREADS];
+static pthread_mutex_t watchdogMutex = PTHREAD_MUTEX_INITIALIZER;
+
+static void handler(int signum) {
+  (void)signum;
   pthread_cancel(readerThreadId);
   pthread_cancel(printerThreadId);
   pthread_cancel(analyzerThreadId);
@@ -48,7 +54,34 @@ unsigned long *get_item_from_print_buffer(void) {
   return g_printBuffer[index];
 }
 
+void notify_watchdog(int id){
+  pthread_mutex_lock(&watchdogMutex);
+  working[id] = 1;
+  pthread_mutex_unlock(&watchdogMutex);
+}
+
+static void watchdog(void) {
+  while (1) {
+    sleep(TIMEOUT);
+    pthread_mutex_lock(&watchdogMutex);
+    for (int i = 0; i < THREADS; i++) {
+      if (working[i] == 0) {
+        pthread_mutex_unlock(&watchdogMutex);
+        perror("Error: Thread not responding... Terminating\n");
+        handler(-1);
+        return;
+      }
+      working[i] = 0;
+    }
+    pthread_mutex_unlock(&watchdogMutex);
+  }
+}
+
+
 int main(void) {
+  struct sigaction action;
+  memset(&action, 0, sizeof(struct sigaction));
+
   if (get_nproc(&g_nproc) == -1) {
     exit(EXIT_FAILURE);
   }
@@ -76,11 +109,11 @@ 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);
 
+  watchdog();
+
   pthread_join(readerThreadId, NULL);
   pthread_join(analyzerThreadId, NULL);
   pthread_join(printerThreadId, NULL);
@@ -92,6 +125,8 @@ int main(void) {
   pthread_mutex_destroy(&g_printBufferMutex);
   sem_destroy(&g_printFilledSpaceSemaphore);
   sem_destroy(&g_printLeftSpaceSemaphore);
+
+  pthread_mutex_destroy(&watchdogMutex);
   for (int i = 0; i < BUFFER_SIZE; i++) {
     free(g_dataBuffer[i]);
     free(g_printBuffer[i]);

cputracker.h

@@ -15,6 +15,11 @@
 #define EXIT_FAILURE 1
 #define EXIT_SUCCESS 0
 
+#define TIMEOUT 2
+#define THREADS 3
+
+enum State {Reader = 0, Printer = 1, Analyzer = 2};
+
 struct proc_stat {
   char name[256];
   unsigned long user, // Time spent with normal processing in user mode.
@@ -33,7 +38,6 @@ struct proc_stat {
                   // operating systems under the control of the Linux kernel).
 };
 
-extern volatile sig_atomic_t done;
 
 extern int g_nproc;
 extern pthread_mutex_t g_dataBufferMutex;
@@ -46,4 +50,5 @@ extern sem_t g_printLeftSpaceSemaphore;
 
 unsigned long *get_item_from_print_buffer(void);
 struct proc_stat *get_item_from_data_buffer(void);
+void notify_watchdog(int id);
 #endif

printer.c

@@ -1,26 +1,23 @@
 #include "printer.h"
 
 void *printer(void *arg) {
-  unsigned long *avg = NULL;
+  unsigned long *avg;
+  (void)arg;
   while (1) {
+    notify_watchdog(Printer);
     sem_wait(&g_printFilledSpaceSemaphore);
-
     pthread_mutex_lock(&g_printBufferMutex);
 
     system("clear");
-
     avg = get_item_from_print_buffer();
-
     printf("CORE\t%%\n");
     for (int i = 0; i < g_nproc; i++) {
       printf("[%2d]: \033[38;2;%lu;%lu;0m%3lu\033[0m\n", i, avg[i] * 5 / 2,
              255 - avg[i] * 5 / 2, avg[i]);
     }
-
+    
     pthread_mutex_unlock(&g_printBufferMutex);
-
     sem_post(&g_printLeftSpaceSemaphore);
     sleep(1);
   }
-  return arg;
 }

reader.c

@@ -1,5 +1,5 @@
 #include "reader.h"
-#include <pthread.h>
+#include "cputracker.h"
 
 static int get_proc_stats(struct proc_stat *stats) {
   FILE *file = fopen("/proc/stat", "r");
@@ -10,7 +10,6 @@ static int get_proc_stats(struct proc_stat *stats) {
       fclose(file);
       return -1;
     }
-
     sscanf(line, "%s %lu %lu %lu %lu %lu %lu %lu %lu %lu %lu",
            stats[thread].name, &stats[thread].user, &stats[thread].nice,
            &stats[thread].system, &stats[thread].idle, &stats[thread].iowait,
@@ -22,25 +21,20 @@ static int get_proc_stats(struct proc_stat *stats) {
 }
 
 void *reader(void *arg) {
-  struct proc_stat *stats = NULL;
+  (void)arg;
   while (1) {
-
+    notify_watchdog(Reader);
     sem_wait(&g_dataLeftSpaceSemaphore);
-
     pthread_mutex_lock(&g_dataBufferMutex);
 
-    stats = get_item_from_data_buffer();
-
-    if (get_proc_stats(stats) == -1) {
+    if (get_proc_stats(get_item_from_data_buffer()) == -1) {
       pthread_mutex_unlock(&g_dataBufferMutex);
       sem_post(&g_dataLeftSpaceSemaphore);
       continue;
     }
-
+    
     pthread_mutex_unlock(&g_dataBufferMutex);
-
     sem_post(&g_dataFilledSpaceSemaphore);
     usleep(READ_DELAY);
   }
-  return arg;
 }