Merge

dlib/threads/threads_kernel_1.h

@@ -12,6 +12,9 @@
 #include "../windows_magic.h"
 #include <windows.h>
 #include "../algs.h"
+#include <condition_variable>
+#include <mutex>
+#include <chrono>
 
 
 namespace dlib
@@ -43,21 +46,22 @@ namespace dlib
         mutex (
         ) 
         {
-            InitializeCriticalSection(&cs);
         }
 
         ~mutex (
-        ) { DeleteCriticalSection(&cs); }
+        ) {  }
 
         void lock (
-        ) const { EnterCriticalSection(&cs); }
+        ) const { cs.lock(); }
 
         void unlock (
-        ) const { LeaveCriticalSection(&cs); }
+        ) const { cs.unlock(); }
 
     private:
 
-        mutable CRITICAL_SECTION cs;
+        friend class signaler;
+
+        mutable std::mutex cs;
 
         // restricted functions
         mutex(mutex&);        // copy constructor
@@ -77,147 +81,40 @@ namespace dlib
         signaler (
             const mutex& associated_mutex
         ) :
-            hSemaphore(CreateSemaphore (NULL, 0, 100000000, NULL)),
-            waiters(0),
-            hCountSema(CreateSemaphore (NULL,0,100000000,NULL)),
             m(associated_mutex)
         {           
-            if (hSemaphore == NULL || hCountSema == NULL)
-            {
-                if (hSemaphore != NULL)
-                {
-                    CloseHandle(hSemaphore); 
-                }
-
-                if (hCountSema != NULL)
-                {
-                    CloseHandle(hCountSema); 
-                }
 
-                throw dlib::thread_error(ECREATE_SIGNALER,
-        "in function signaler::signaler() an error occurred making the signaler"
-                );        
-            }
         }
 
         ~signaler (
-        ) { CloseHandle(hSemaphore); CloseHandle(hCountSema);}
+        ) { }
 
         void wait (
         ) const
         { 
-            // get a lock on the mutex for the waiters variable
-            waiters_mutex.lock();
-            // mark that one more thread will be waiting on this signaler
-            ++waiters;
-            // release the mutex for waiters
-            waiters_mutex.unlock();
-
-            // release the associated mutex
-            m.unlock();
-
-            // wait for the semaphore to be signaled
-            WaitForSingleObject (hSemaphore,INFINITE);
-
-            // signal that we are awake
-            ReleaseSemaphore(hCountSema,(LONG)1,NULL);
-
-            // relock the associated mutex 
-            m.lock();
+            std::unique_lock<std::mutex> cs(m.cs, std::defer_lock);
+            cv.wait(cs);
         }
 
         bool wait_or_timeout (
             unsigned long milliseconds
         ) const
         { 
-            // get a lock on the mutex for the waiters variable
-            waiters_mutex.lock();
-            // mark that one more thread will be waiting on this signaler
-            ++waiters;
-            // release the mutex for waiters
-            waiters_mutex.unlock();
-
-            // release the associated mutex
-            m.unlock();
-
-            bool value;
-
-            // wait for the semaphore to be signaled
-            if ( WaitForSingleObject (hSemaphore, milliseconds ) == WAIT_TIMEOUT )
-            {
-                // in this case we should decrement waiters because we are returning
-                // due to a timeout rather than because someone called signal() or 
-                // broadcast().
-                value = false;
-
-                // signal that we are awake
-                ReleaseSemaphore(hCountSema,(LONG)1,NULL);
-
-                // get a lock on the mutex for the waiters variable
-                waiters_mutex.lock();
-                // mark that one less thread will be waiting on this signaler. 
-                if (waiters != 0)
-                    --waiters;
-                // release the mutex for waiters
-                waiters_mutex.unlock();
-            }
-            else 
-            {
-                value = true;
-
-                // signal that we are awake
-                ReleaseSemaphore(hCountSema,(LONG)1,NULL);
-            }
-
-
-            // relock the associated mutex 
-            m.lock();
-
-            return value;
+            std::unique_lock<std::mutex> cs(m.cs, std::defer_lock);
+            auto status = cv.wait_until(cs, std::chrono::system_clock::now() + std::chrono::milliseconds(milliseconds));
+            return status == std::cv_status::no_timeout;
         }
 
         void signal (
         ) const 
         { 
-            // get a lock on the mutex for the waiters variable
-            waiters_mutex.lock();
-            
-            if (waiters > 0)
-            {
-                --waiters;
-                // make the semaphore release one waiting thread
-                ReleaseSemaphore(hSemaphore,1,NULL);
-
-                // wait for signaled thread to wake up
-                WaitForSingleObject(hCountSema,INFINITE);               
-            }
-
-            // release the mutex for waiters
-            waiters_mutex.unlock();
+            cv.notify_one();
         }
 
         void broadcast (
         ) const 
         { 
-            // get a lock on the mutex for the waiters variable
-            waiters_mutex.lock();
-            
-            if (waiters > 0)
-            {   
-                // make the semaphore release all the waiting threads
-                ReleaseSemaphore(hSemaphore,(LONG)waiters,NULL);
-
-                // wait for count to be zero
-                for (unsigned long i = 0; i < waiters; ++i)
-                {
-                    WaitForSingleObject(hCountSema,INFINITE);
-                }
-
-                waiters = 0;
-            }
-
-            // release the mutex for waiters
-            waiters_mutex.unlock();
+            cv.notify_all();
         }
 
         const mutex& get_mutex (
@@ -225,13 +122,7 @@ namespace dlib
 
     private:
 
-        mutable HANDLE hSemaphore;
-
-        mutable unsigned long waiters;
-        mutex waiters_mutex;
-        
-
-        mutable HANDLE hCountSema;
+        mutable std::condition_variable cv;
 
         const mutex& m;