Merge pull request #6 from nuertey/master

Multithreading Issues and Memory Leaks

Author: Deepika Bhavnani

main.cpp

@@ -16,11 +16,15 @@
 */
 #include "mbed.h"
 
-#if !defined(MBED_CONF_NSAPI_SOCKET_STATS_ENABLE)
+#if !defined(MBED_CONF_NSAPI_SOCKET_STATS_ENABLE) 
 #error [NOT_SUPPORTED] Socket Statistics not supported
 #endif
 
 #define SAMPLE_TIME     10 // milli-sec
+#define COMPLETED_FLAG (1UL << 0)
+
+PlatformMutex stdio_mutex;
+EventFlags threadFlag;
 
 void print_stats()
 {
@@ -30,10 +34,10 @@ void print_stats()
 
     memset(&stats[0], 0, sizeof(mbed_stats_socket_t) * MBED_CONF_NSAPI_SOCKET_STATS_MAX_COUNT);
     printf("%-15s%-15s%-15s%-15s%-15s%-15s%-15s\n", "Num", "ID", "State", "Proto", "Sent", "Recv", "Time");
-    while (1) {
-
+    while (COMPLETED_FLAG != threadFlag.get()) {
         count = SocketStats::mbed_stats_socket_get_each(&stats[0], MBED_CONF_NSAPI_SOCKET_STATS_MAX_COUNT);
         for (int i = 0; i < count; i++) {
+            stdio_mutex.lock();
             printf("\n%-15d", num);
             printf("%-15p", stats[i].reference_id);
 
@@ -63,40 +67,33 @@ void print_stats()
             printf("%-15d", stats[i].sent_bytes);
             printf("%-15d", stats[i].recv_bytes);
             printf("%-15lld\n", stats[i].last_change_tick);
+            stdio_mutex.unlock();
         }
         num++;
         ThisThread::sleep_for(SAMPLE_TIME);
     }
+    // Now allow the stats thread to simply exit by itself gracefully.
 }
 
 // Network interface
 NetworkInterface *net;
 
 int main()
 {
-    Thread *thread = new Thread(osPriorityNormal1, 2048);
-    int remaining;
-    int rcount;
-    char *p;
-    char *buffer = new char[256];
-    nsapi_size_or_error_t result;
-
-    thread->start(print_stats);
     // Bring up the ethernet interface
     printf("Mbed OS Socket statistics example\n");
 
 #ifdef MBED_MAJOR_VERSION
     printf("Mbed OS version: %d.%d.%d\n\n", MBED_MAJOR_VERSION, MBED_MINOR_VERSION, MBED_PATCH_VERSION);
 #endif
-
     net = NetworkInterface::get_default_instance();
 
     if (!net) {
-        printf("Error! No network inteface found.\n");
+        printf("Error! No network interface found.\n");
         return 0;
     }
 
-    result = net->connect();
+    nsapi_size_or_error_t result = net->connect();
     if (result != 0) {
         printf("Error! net->connect() returned: %d\n", result);
         return result;
@@ -110,6 +107,9 @@ int main()
     printf("Netmask: %s\n", netmask ? netmask : "None");
     printf("Gateway: %s\n", gateway ? gateway : "None");
 
+    Thread *thread = new Thread(osPriorityNormal1, 2048);
+    thread->start(print_stats);
+
     // Open a socket on the network interface, and create a TCP connection to api.ipify.org
     TCPSocket socket;
     // Send a simple http request
@@ -118,54 +118,72 @@ int main()
 
     result = socket.open(net);
     if (result != 0) {
+        stdio_mutex.lock();
         printf("Error! socket.open() returned: %d\n", result);
+        stdio_mutex.unlock();
     }
 
+    int remaining = 256;
+    int rcount = 0;
+    char *buffer = new char[256];
+    char *p = buffer;
+
     result = socket.connect("api.ipify.org", 80);
     if (result != 0) {
+        stdio_mutex.lock();
         printf("Error! socket.connect() returned: %d\n", result);
+        stdio_mutex.unlock();
         goto DISCONNECT;
     }
 
     // Loop until whole request sent
     while (size) {
         result = socket.send(sbuffer + result, size);
         if (result < 0) {
+            stdio_mutex.lock();
             printf("Error! socket.send() returned: %d\n", result);
+            stdio_mutex.unlock();
             goto DISCONNECT;
         }
         size -= result;
+        stdio_mutex.lock();
         printf("sent %d [%.*s]\n", result, strstr(sbuffer, "\r\n") - sbuffer, sbuffer);
+        stdio_mutex.unlock();
     }
 
-    // Receieve an HTTP response and print out the response line
-    remaining = 256;
-    rcount = 0;
-    p = buffer;
+    // Receive an HTTP response and print out the response line
     while (0 < (result = socket.recv(p, remaining))) {
         p += result;
         rcount += result;
         remaining -= result;
     }
     if (result < 0) {
+        stdio_mutex.lock();
         printf("Error! socket.recv() returned: %d\n", result);
+        stdio_mutex.unlock();
         goto DISCONNECT;
     }
     // the HTTP response code
+    stdio_mutex.lock();
     printf("recv %d [%.*s]\n", rcount, strstr(buffer, "\r\n") - buffer, buffer);
+    stdio_mutex.unlock();
 
     // The api.ipify.org service also gives us the device's external IP address
     p = strstr(buffer, "\r\n\r\n") + 4;
+    stdio_mutex.lock();
     printf("External IP address: %.*s\n", rcount - (p - buffer), p);
-    delete[] buffer;
+    stdio_mutex.unlock();
 
 DISCONNECT:
+    delete[] buffer;
+
     // Close the socket to return its memory and bring down the network interface
     socket.close();
 
-    ThisThread::sleep_for(SAMPLE_TIME);
     // Bring down the ethernet interface
     net->disconnect();
-    thread->terminate();
+    threadFlag.set(COMPLETED_FLAG);
+    thread->join();
+    delete thread;
     printf("Done\n");
 }