--- old/src/os/windows/vm/os_windows.cpp	2015-06-12 14:46:29.512172460 +0200
+++ new/src/os/windows/vm/os_windows.cpp	2015-06-12 14:46:29.352167230 +0200
@@ -70,6 +70,7 @@
 #include "utilities/defaultStream.hpp"
 #include "utilities/events.hpp"
 #include "utilities/growableArray.hpp"
+#include "utilities/semaphore.hpp"
 #include "utilities/vmError.hpp"
 
 #ifdef _DEBUG
@@ -1895,6 +1896,43 @@
   return (int)error;
 }
 
+Semaphore::Semaphore(uint value, uint max) {
+  _semaphore = ::CreateSemaphore(NULL, value, max, NULL);
+
+  guarantee(_semaphore != NULL, err_msg("CreateSemaphore failed: %ld", GetLastError()));
+}
+
+Semaphore::~Semaphore() {
+  if (_semaphore != NULL) {
+    ::CloseHandle(_semaphore);
+  }
+}
+
+void Semaphore::signal(uint count) {
+  BOOL ret = ::ReleaseSemaphore(_semaphore, count, NULL);
+
+  guarantee(ret != 0, err_msg("ReleaseSemaphore failed: %d", GetLastError()));
+}
+
+void Semaphore::signal() {
+  signal(1);
+}
+
+void Semaphore::wait() {
+  DWORD ret = ::WaitForSingleObject(_semaphore, INFINITE);
+  guarantee(ret == WAIT_OBJECT_0, err_msg("WaitForSingleObject failed: %d", GetLastError()));
+}
+
+bool Semaphore::trywait() {
+  Unimplemented();
+  return false;
+}
+
+bool Semaphore::timedwait(unsigned int sec, int nsec) {
+  Unimplemented();
+  return false;
+}
+
 // sun.misc.Signal
 // NOTE that this is a workaround for an apparent kernel bug where if
 // a signal handler for SIGBREAK is installed then that signal handler