Fixed race in the rust kernel.

2 files changed, 10 insertions, 2 deletions

diff --git a/src/rt/sync/sync.cpp b/src/rt/sync/sync.cpp
index 70e5077cf98..fdfc065249d 100644
--- a/src/rt/sync/sync.cpp
+++ b/src/rt/sync/sync.cpp
@@ -11,6 +11,10 @@ void sync::yield() {
 #endif
 }
 
+rust_thread::rust_thread() : _is_running(false) {
+    // Nop.
+}
+
 #if defined(__WIN32__)
 static DWORD WINAPI
 #elif defined(__GNUC__)
@@ -36,6 +40,7 @@ rust_thread::start() {
    pthread_attr_setdetachstate(&attr, PTHREAD_CREATE_JOINABLE);
    pthread_create(&thread, &attr, rust_thread_start, (void *) this);
 #endif
+   _is_running = true;
 }
 
 void
@@ -46,10 +51,10 @@ rust_thread::join() {
    pthread_join(thread, NULL);
 #endif
    thread = 0;
+   _is_running = false;
 }
 
 bool
 rust_thread::is_running() {
-    // TODO: This may be broken because of possible races.
-    return thread;
+    return _is_running;
 }
diff --git a/src/rt/sync/sync.h b/src/rt/sync/sync.h
index 562d2a1b7cd..3829dafe650 100644
--- a/src/rt/sync/sync.h
+++ b/src/rt/sync/sync.h
@@ -15,12 +15,15 @@ public:
  * Thread utility class. Derive and implement your own run() method.
  */
 class rust_thread {
+private:
+    volatile bool _is_running;
 public:
 #if defined(__WIN32__)
     HANDLE thread;
 #else
     pthread_t thread;
 #endif
+    rust_thread();
     void start();
 
     virtual void run() {