locks: running multiple threads at the same time

diff --git a/locks/locks.c b/locks/locks.c
index 734bb14..13661cd 100644 (file)
--- a/locks/locks.c
+++ b/locks/locks.c
@@ -19,8 +19,14 @@
 
 
 
+pthread_mutex_t gateMutex;
+pthread_cond_t gateBroadCast;
+bool isGateOpen = false;
+int threadsNumber = 20;
+
+
 struct sigaction sigintAction;  /*Stores the init SIGINT sigaction value*/
-char *fileName;
+char *fileName = "/tmp/locks";
 
 
 
@@ -32,10 +38,7 @@ int main (int argc, char *argv[])
        int c;                      /*Getopt parameter*/
        /*Default values*/
     struct sigaction sa;        /*sig actions values*/
-    bool isFileLock = false;
     bool isThread = false;
-    fileName = "/tmp/locks";
-
        
        opterr = 0;
        while ((c = getopt (argc, argv, "p:tf:")) != -1) {
@@ -44,7 +47,7 @@ int main (int argc, char *argv[])
             fileName = optarg;
             break;
                case 't':
-            isFileLock = true;
+            threadsNumber = atoi(optarg);
                        break;
                case 'f':
             isThread = true;
@@ -108,91 +111,67 @@ int main (int argc, char *argv[])
 
 int main_process ()
 {
-       pthread_t idThreadOne;                 /*Thread one identifier number*/
-    pthread_t idThreadTwo;                 /*Thread two identifier number*/
-       
+    int createIndex;
+    int joinIndex;
+       pthread_t threadIds [threadsNumber];                 /*Threads identifier numbers*/
        
-       if (pthread_create (&idThreadOne, NULL, thread_one, NULL) != 0 ) {
-        fprintf (stderr, "%s: %s\n", "thread one creation failed", strerror(errno));
-        fflush (stderr);
-
-        return -1;
-       }
+    pthread_mutex_init(&gateMutex, NULL);
+    pthread_cond_init(&gateBroadCast, NULL);
+    closeGate();
 
-    // Let other thread progress. Should be enough with sleep. This code is just for testing.
-    sleep(10);
 
-       if (pthread_create (&idThreadTwo, NULL, thread_two, NULL) != 0 ) {
-        fprintf (stderr, "%s: %s\n", "thread two creation failed", strerror(errno));
-        fflush (stderr);
-
-        return -1;
-       }
+    for (createIndex = 0; createIndex < threadsNumber; createIndex++) {
+        print_with_date (stdout, "Thread %d created\n", createIndex);
+       if (pthread_create (&threadIds[createIndex], NULL, &thread_lock, (void *) createIndex) != 0 ) {
+            print_with_date (stderr, "Thread %d creation failed\n", createIndex, strerror(errno));
+            break;
+       }
+    }
 
-    sleep(90);
+    sleep(5);
+    openGate();
 
+    for (joinIndex = createIndex; joinIndex --> 0; ) {
+        if (pthread_join(threadIds[joinIndex], NULL) != 0) {
+            print_with_date (stderr, "Thread %d join error\n", joinIndex, strerror(errno));   
+        }
+    }
+    
     return 0;
 }
 
-void *thread_one(void * arg) {
+void *thread_lock(void * arg) {
+    int threadNumber;
     int fd;
     int flockErr;
 
-    fd = open(fileName, O_CREAT | O_RDWR, 0664);
-    if (fd == -1) {
-        print_with_date (stderr, "%s\n", "ThreadOne, open file error", strerror(errno));
-    }
-   
-    print_with_date (stdout, "ThreadOne: before lock\n");
-    do {
-        flockErr = flock(fd, LOCK_EX);
-    } while(flockErr == -1 && errno == EINTR);
-
-
-    if (flockErr == -1) {
-        print_with_date (stderr, "%s: %s\n", "threadOne, flock error", strerror(errno));
-    }
-    print_with_date (stdout, "ThreadOne: after lock\n");
-
-    sleep(30);
+    threadNumber = (int) arg;
 
-    print_with_date (stdout, "ThreadOne: before release lock\n");
-    do {
-        flockErr = flock(fd, LOCK_UN);
-    } while(flockErr == -1 && errno == EINTR);
-    print_with_date (stdout, "ThreadOne: after release lock\n");
-
-    close (fd);
-
-    pthread_exit(0);
-}
-
-void *thread_two(void * arg) {
-    int fd;
-    int flockErr;
+    gate();
 
     fd = open(fileName, O_CREAT | O_RDWR, 0664);
     if (fd == -1) {
-        print_with_date (stderr, "%s: %s\n", "ThreadTwo, open file error", strerror(errno));
+        print_with_date (stderr, "Thread %d, open file error", threadNumber, strerror(errno));
     }
-    
-    print_with_date (stdout, "ThreadTwo: before lock\n");
+   
+    print_with_date (stdout, "Thread %d: before lock\n", threadNumber);
     do {
         flockErr = flock(fd, LOCK_EX);
     } while(flockErr == -1 && errno == EINTR);
 
 
     if (flockErr == -1) {
-        print_with_date (stderr, "%s: %s\n", "ThreadTwo, flock error", strerror(errno));
+        print_with_date (stderr, "Thread %d: flock error", threadNumber, strerror(errno));
     }
-    print_with_date (stdout, "ThreadTwo: after lock\n");
+    print_with_date (stdout, "Thread %d: after lock\n", threadNumber);
 
+    sleep(5);
 
-    print_with_date (stdout, "ThreadTwo: before release lock\n");
+    print_with_date (stdout, "Thread %d: before release lock\n", threadNumber);
     do {
         flockErr = flock(fd, LOCK_UN);
     } while(flockErr == -1 && errno == EINTR);
-    print_with_date (stdout, "ThreadTwo: after release lock\n");
+    print_with_date (stdout, "Thread %d: after release lock\n", threadNumber);
 
     close (fd);
 
@@ -225,6 +204,34 @@ int print_with_date(FILE *stream, const char *format, ...)
     }    
 }
 
+void gate() {
+    
+    pthread_mutex_lock(&gateMutex);
+
+    while(!isGateOpen) {
+        pthread_cond_wait(&gateBroadCast, &gateMutex);
+    }
+
+    pthread_mutex_unlock(&gateMutex);
+}
+
+void openGate() {
+    pthread_mutex_lock(&gateMutex);
+
+    isGateOpen = true;
+    pthread_cond_broadcast(&gateBroadCast);
+
+    pthread_mutex_unlock(&gateMutex);
+}
+
+void closeGate() {
+    pthread_mutex_lock(&gateMutex);
+
+    isGateOpen = false;
+
+    pthread_mutex_unlock(&gateMutex);
+}
+
 void sigint_handler(int sig)
 {
     /*TODO: kill child processes, finish threads and release allocate memory*/

diff --git a/locks/locks.h b/locks/locks.h
index a92c426..7fcdb4a 100644 (file)
--- a/locks/locks.h
+++ b/locks/locks.h
@@ -1,19 +1,13 @@
-/*System V IPC keys*/
-#define SHAREMEMKEY 1
-#define SHAREMEMSEM 2
 
 
 
-int print_with_date(FILE *stream, const char *format, ...);
+void gate();
 
-/****************************************************************************************/
-/* This method is used by pthread_create                                                */
-/*                                                                                      */
-/* INPUT PARAMETER: socket file descriptor                                              */
-/* RETURNS: void                                                                        */
-/****************************************************************************************/
-void *thread_one (void *arg);
+void openGate();
 
+void closeGate();
+
+int print_with_date(FILE *stream, const char *format, ...);
 
 /****************************************************************************************/
 /* This method is used by pthread_create                                                */
@@ -21,7 +15,7 @@ void *thread_one (void *arg);
 /* INPUT PARAMETER: socket file descriptor                                              */
 /* RETURNS: void                                                                        */
 /****************************************************************************************/
-void *thread_two (void *arg);
+void *thread_lock (void *arg);
 
 
 /****************************************************************************************/