Added exceptions to sys::Waitable.

Fixed client side deadlock involving client::Bounds.
Fixed incorrect exception messages during connection shutdown.


git-svn-id: https://svn.apache.org/repos/asf/incubator/qpid/trunk/qpid@664114 13f79535-47bb-0310-9956-ffa450edef68

2 files changed, 121 insertions, 9 deletions

diff --git a/cpp/src/qpid/sys/ExceptionHolder.h b/cpp/src/qpid/sys/ExceptionHolder.h
new file mode 100644
index 0000000000..cfb971411e
--- /dev/null
+++ b/cpp/src/qpid/sys/ExceptionHolder.h
@@ -0,0 +1,75 @@
+#ifndef QPID_EXCEPTIONHOLDER_H
+#define QPID_EXCEPTIONHOLDER_H
+
+/*
+ *
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License.  You may obtain a copy of the License at
+ * 
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ * 
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied.  See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ *
+ */
+
+#include "qpid/memory.h"
+#include <boost/shared_ptr.hpp>
+
+
+namespace qpid {
+namespace sys {
+
+struct Raisable {
+    virtual ~Raisable() {};
+    virtual void raise() const=0;
+    virtual std::string what() const=0;
+};
+
+/**
+ * Holder for exceptions. Allows the thread that notices an error condition to
+ * create an exception and store it to be thrown by another thread.
+ */
+class ExceptionHolder : public Raisable {
+  public:
+    ExceptionHolder() {}
+    // Use default copy & assign.
+    
+    /** Take ownership of ex */
+    template <class Ex> ExceptionHolder(Ex* ex) { wrap(ex); }
+    template <class Ex> ExceptionHolder(const boost::shared_ptr<Ex>& ex) { wrap(ex.release()); }
+
+    template <class Ex> ExceptionHolder& operator=(Ex* ex) { wrap(ex); return *this; }
+    template <class Ex> ExceptionHolder& operator=(boost::shared_ptr<Ex> ex) { wrap(ex.release()); return *this; }
+        
+    void raise() const { if (wrapper.get()) wrapper->raise() ; }
+    std::string what() const { return wrapper->what(); }
+    bool empty() const { return !wrapper.get(); }
+    operator bool() const { return !empty(); }
+    void reset() { wrapper.reset(); }
+
+  private:
+    template <class Ex> struct Wrapper : public Raisable {
+        Wrapper(Ex* ptr) : exception(ptr) {}
+        void raise() const { throw *exception; }
+        std::string what() const { return exception->what(); }
+        boost::shared_ptr<Ex> exception;
+    };
+    template <class Ex> void wrap(Ex* ex) { wrapper.reset(new Wrapper<Ex>(ex)); }
+    boost::shared_ptr<Raisable> wrapper;
+};
+    
+
+}} // namespace qpid::sys
+
+
+#endif  /*!QPID_EXCEPTIONHOLDER_H*/
diff --git a/cpp/src/qpid/sys/Waitable.h b/cpp/src/qpid/sys/Waitable.h
index 37392ed761..61b7e7d82b 100644
--- a/cpp/src/qpid/sys/Waitable.h
+++ b/cpp/src/qpid/sys/Waitable.h
@@ -21,8 +21,8 @@
  *
  */
 
-#include "Monitor.h"
-
+#include "qpid/sys/Monitor.h"
+#include "qpid/sys/ExceptionHolder.h"
 #include <assert.h>
 
 namespace qpid {
@@ -31,14 +31,18 @@ namespace sys {
 /**
  * A monitor that keeps track of waiting threads.  Threads declare a
  * ScopedWait around wait() inside a ScopedLock to be considered
- * waiters.
+ * waiters. 
+ *
+ * Allows waiting threads to be interrupted by an exception. 
  */
 class Waitable : public Monitor {
   public:
     Waitable() : waiters(0) {}
 
+    ~Waitable() { assert(waiters == 0); }
+
     /** Use this inside a scoped lock around the
-     * call to Monitor::wait to be counted as a waiter
+     * call to wait() to be counted as a waiter.
      */
     struct ScopedWait {
         Waitable& w;
@@ -46,22 +50,55 @@ class Waitable : public Monitor {
         ~ScopedWait() { if (--w.waiters==0) w.notifyAll(); }
     };
 
-    /** Block till there are no more ScopedWaits.
+    /** Block till there are no more waiters in ScopedWaits.
+     * waitWaiters() does not raise an exception even if waiters
+     * were interrupted by one.
      *@pre Must be called inside a ScopedLock but NOT a ScopedWait.
      */
     void waitWaiters() {
         while (waiters != 0) 
-            wait();
+            Monitor::wait();
     }
 
     /** Returns the number of outstanding ScopedWaits.
      * Must be called with the lock held.
      */
-    size_t hasWaiters() { return waiters; }
-    
+    size_t hasWaiters() const {
+        return waiters;
+    }
+
+    /** Set an execption to interrupt waiters in ScopedWait.
+     * Must be called with the lock held.
+     */
+    void setException(const ExceptionHolder& e) {
+        exception = e;
+        notifyAll();
+        
+    }
+
+    /** Throws an exception if one is set before or during the wait. */
+    void wait() {
+        ExCheck e(exception);
+        Monitor::wait();
+    }
+
+    /** Throws an exception if one is set before or during the wait. */
+    bool wait(const AbsTime& absoluteTime) {
+        ExCheck e(exception);
+        return Monitor::wait(absoluteTime);
+    }
+
+    ExceptionHolder exception;
+
   private:
-  friend struct ScopedWait;
+    struct ExCheck {
+        const ExceptionHolder& exception;
+        ExCheck(const ExceptionHolder& e) : exception(e) { e.raise(); }
+        ~ExCheck() { exception.raise(); }
+    };
+        
     size_t waiters;
+  friend struct ScopedWait;
 };
 
 }} // namespace qpid::sys