Merge beast_basics to beast_core

modules/beast_core/thread/beast_ThreadWithCallQueue.cpp

@@ -0,0 +1,152 @@
+//------------------------------------------------------------------------------
+/*
+    This file is part of Beast: https://github.com/vinniefalco/Beast
+    Copyright 2013, Vinnie Falco <vinnie.falco@gmail.com>
+
+    Permission to use, copy, modify, and/or distribute this software for any
+    purpose  with  or without fee is hereby granted, provided that the above
+    copyright notice and this permission notice appear in all copies.
+
+    THE  SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+    WITH  REGARD  TO  THIS  SOFTWARE  INCLUDING  ALL  IMPLIED  WARRANTIES  OF
+    MERCHANTABILITY  AND  FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+    ANY  SPECIAL ,  DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+    WHATSOEVER  RESULTING  FROM  LOSS  OF USE, DATA OR PROFITS, WHETHER IN AN
+    ACTION  OF  CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+    OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+*/
+//==============================================================================
+
+ThreadWithCallQueue::ThreadWithCallQueue (String name)
+    : CallQueue (name)
+    , m_thread (name)
+    , m_entryPoints (nullptr)
+    , m_calledStart (false)
+    , m_calledStop (false)
+    , m_shouldStop (false)
+{
+}
+
+ThreadWithCallQueue::~ThreadWithCallQueue ()
+{
+    stop (true);
+}
+
+ThreadWithCallQueue::EntryPoints* ThreadWithCallQueue::getDefaultEntryPoints () noexcept
+{
+    static EntryPoints entryPoints;
+
+    return &entryPoints;
+}
+
+void ThreadWithCallQueue::start (EntryPoints* const entryPoints)
+{
+    {
+        // This is mostly for diagnostics
+        // TODO: Atomic flag for this whole thing
+        CriticalSection::ScopedLockType lock (m_mutex);
+
+        // start() MUST be called.
+        bassert (!m_calledStart);
+        m_calledStart = true;
+    }
+
+    m_entryPoints = entryPoints;
+
+    m_thread.start (this);
+}
+
+void ThreadWithCallQueue::stop (bool const wait)
+{
+    // can't call stop(true) from within a thread function
+    bassert (!wait || !m_thread.isTheCurrentThread ());
+
+    {
+        CriticalSection::ScopedLockType lock (m_mutex);
+
+        // start() MUST be called.
+        bassert (m_calledStart);
+
+        // TODO: Atomic for this
+        if (!m_calledStop)
+        {
+            m_calledStop = true;
+
+            {
+                CriticalSection::ScopedUnlockType unlock (m_mutex); // getting fancy
+
+                call (&ThreadWithCallQueue::doStop, this);
+
+                // in theory something could slip in here
+
+                close ();
+            }
+        }
+    }
+
+    if (wait)
+        m_thread.join ();
+}
+
+// Should be called periodically by the idle function.
+// There are three possible results:
+//
+// #1 Returns false. The idle function may continue or return.
+// #2 Returns true. The idle function should return as soon as possible.
+// #3 Throws a Thread::Interruption exception.
+//
+// If interruptionPoint returns true or throws, it must
+// not be called again before the thread has the opportunity to reset.
+//
+bool ThreadWithCallQueue::interruptionPoint ()
+{
+    return m_thread.interruptionPoint ();
+}
+
+// Interrupts the idle function by queueing a call that does nothing.
+void ThreadWithCallQueue::interrupt ()
+{
+    call (&ThreadWithCallQueue::doNothing);
+}
+
+void ThreadWithCallQueue::doNothing ()
+{
+    // Intentionally empty
+}
+
+void ThreadWithCallQueue::signal ()
+{
+    m_thread.interrupt ();
+}
+
+void ThreadWithCallQueue::reset ()
+{
+}
+
+void ThreadWithCallQueue::doStop ()
+{
+    m_shouldStop = true;
+}
+
+void ThreadWithCallQueue::threadRun ()
+{
+    m_entryPoints->threadInit ();
+
+    for (;;)
+    {
+        CallQueue::synchronize ();
+
+        if (m_shouldStop)
+            break;
+
+        bool interrupted = m_entryPoints->threadIdle ();
+
+        if (!interrupted)
+            interrupted = interruptionPoint ();
+
+        if (!interrupted)
+            m_thread.wait ();
+    }
+
+    m_entryPoints->threadExit ();
+}