1.1 --- a/src/share/vm/utilities/ostream.hpp Wed Feb 09 15:02:23 2011 -0800
1.2 +++ b/src/share/vm/utilities/ostream.hpp Tue Feb 22 15:26:36 2011 -0800
1.3 @@ -123,18 +123,36 @@
1.4
1.5 // advisory locking for the shared tty stream:
1.6 class ttyLocker: StackObj {
1.7 + friend class ttyUnlocker;
1.8 private:
1.9 intx _holder;
1.10
1.11 public:
1.12 static intx hold_tty(); // returns a "holder" token
1.13 static void release_tty(intx holder); // must witness same token
1.14 + static bool release_tty_if_locked(); // returns true if lock was released
1.15 static void break_tty_lock_for_safepoint(intx holder);
1.16
1.17 ttyLocker() { _holder = hold_tty(); }
1.18 ~ttyLocker() { release_tty(_holder); }
1.19 };
1.20
1.21 +// Release the tty lock if it's held and reacquire it if it was
1.22 +// locked. Used to avoid lock ordering problems.
1.23 +class ttyUnlocker: StackObj {
1.24 + private:
1.25 + bool _was_locked;
1.26 + public:
1.27 + ttyUnlocker() {
1.28 + _was_locked = ttyLocker::release_tty_if_locked();
1.29 + }
1.30 + ~ttyUnlocker() {
1.31 + if (_was_locked) {
1.32 + ttyLocker::hold_tty();
1.33 + }
1.34 + }
1.35 +};
1.36 +
1.37 // for writing to strings; buffer will expand automatically
1.38 class stringStream : public outputStream {
1.39 protected:
