Removed _detached member from ThreadControl. Joining with a thread more

    than once or detaching a detached thread or joining with a detached
    thread now has undefined behavior (instead of throwing an exception).
Cleaned up a number of race conditions around the _id members of Thread and
    ThreadControl.
Explicitly hid the assignment operator and copy constructor of Thread so we
    get better diagnostics for that.

1 files changed, 15 insertions, 11 deletions

diff --git a/cpp/include/IceUtil/Thread.h b/cpp/include/IceUtil/Thread.h
index 73d0b7e70d9..bd411079baf 100644
--- a/cpp/include/IceUtil/Thread.h
+++ b/cpp/include/IceUtil/Thread.h
@@ -66,6 +66,9 @@ public:
     ThreadControl(pthread_t);
 #endif
 
+    ThreadControl(const ThreadControl&);
+    ThreadControl& operator=(const ThreadControl&);
+
     bool operator==(const ThreadControl&) const;
     bool operator!=(const ThreadControl&) const;
     bool operator<(const ThreadControl&) const;
@@ -80,19 +83,19 @@ public:
     // semantics.
     //
     // At most one thread can wait for the termination of a given
-    // thread.C alling join on a thread on which another thread is
-    // already waiting for termination results in undefined behaviour.
-    // Joining with a thread after having joined with it previously,
-    // or joining with a detached thread raises ThreadSyscallException.
+    // thread. Calling join on a thread on which another thread is
+    // already waiting for termination results in undefined behaviour,
+    // as does joining with a thread after having joined with it previously,
+    // or joining with a detached thread.
     //
     void join();
 
     //
     // Detach a thread. Once a thread is detached, it cannot be detached
-    // again, nor can it be joined with. Every thread must either be
-    // joined with or detached exactly once. Detaching a thread a second
-    // time, or detaching a thread that was previously joined with raises
-    // ThreadSyscallException.
+    // again, nor can it be joined with. Every thread that was created using
+    // the IceUtil::Thread class must either be joined with or detached
+    // exactly once. Detaching a thread a second time, or detaching a
+    // thread that was previously joined with results in undefined behavior.
     //
     void detach();
 
@@ -107,12 +110,11 @@ public:
 
 private:
 
+    Mutex _stateMutex;
 #ifdef _WIN32
     HandleWrapperPtr _handle;
 #endif
     ThreadId _id;
-
-    bool _detached;
 };
 
 class ICE_UTIL_API Thread : virtual public IceUtil::Shared
@@ -134,10 +136,12 @@ public:
     bool operator!=(const Thread&) const;
     bool operator<(const Thread&) const;
 
+    Thread(const Thread&);		// Copying is forbidden
+    void operator=(const Thread&);	// Assignment is forbidden
+
 private:
 
     Mutex _stateMutex;
-
     bool _started;
 #ifdef _WIN32
     HandleWrapperPtr _handle;