Imported MaNGOS revision 6767 from http://mangos.svn.sourceforge.net/svnroot/mangos/trunk/

dep/src/zthread/Status.h

@@ -0,0 +1,179 @@
+/*
+ * Copyright (c) 2005, Eric Crahen
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is furnished
+ * to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
+ * WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
+ * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+ *
+ */
+
+#ifndef __ZTBLOCKINGSTATE_H__
+#define __ZTBLOCKINGSTATE_H__
+
+#include <assert.h>
+
+namespace ZThread {
+
+  /**
+   * @class Status
+   * @version 2.3.0
+   *
+   * A Status is associated with each Thread's Monitor. Monitors rely on a
+   * Status object for providing information that will affect a blocking operations.
+   */
+  class Status {
+  public:
+    //! Aggregate of pending status changes
+    volatile unsigned short _pending; 
+ 
+    //! Interest mask  
+    volatile unsigned short _mask;
+
+  public:
+ 
+    //! State for the monitor
+    typedef enum {
+    
+      // Default
+      INVALID      = 0x00,
+
+      // Valid states
+      SIGNALED     = 0x01,
+      INTERRUPTED  = 0x02, 
+      TIMEDOUT     = 0x04,
+      CANCELED     = 0x08,
+
+      // Mask
+      ANYTHING     = (~INVALID & ~CANCELED)
+
+    } STATE;
+
+    Status() : _pending((unsigned short)INVALID), _mask((unsigned short)ANYTHING) { }
+  
+    /**
+     * Set the mask for the STATE's that next() will report.
+     * STATE's not covered by the interest mask can still be 
+     * set, they just aren't reported until the mask is changed
+     * to cover that STATE.
+     *
+     * @param STATE
+     * @pre accessed ONLY by the owning thread.
+     */
+    void interest(STATE mask) {
+      _mask = static_cast<unsigned short>(mask);
+    }
+
+    bool masked(STATE mask) {
+      return (_mask & static_cast<unsigned short>(mask)) == 0;
+    }
+
+    /**
+     * Return true if next() will return a STATE covered
+     * by the current interest mask and by the mask given
+     * to this function.
+     *
+     * @param unsigned short
+     * @pre accessed ONLY by the owning thread.
+     */      
+    bool pending(unsigned short mask) {
+ 
+      assert(mask != INVALID);
+      return ((_pending & _mask) & mask) != INVALID;
+
+    }
+
+    /**
+     * Check the state without the interest mask. 
+     *
+     * @param state 
+     * @return true if the flag is set 
+     * @pre access must be serial
+     */
+    bool examine(STATE state) {
+      return (_pending & static_cast<unsigned short>(state)) != INVALID;
+    }
+
+    /**
+     * Add the flags to the current state.
+     *
+     * @param interest - the flags to add to the current state.
+     * @pre access must be serial
+     */
+    void push(STATE interest) {
+      _pending |= interest;  
+    }
+
+    /**
+     * Clear the flags from the current state
+     * 
+     * @param interest - the flags to clear from the current state.
+     * @pre access must be serial
+     */
+    void clear(STATE interest) {
+
+      assert(interest != INVALID);
+      assert(interest != ANYTHING);
+      assert(interest != CANCELED);
+
+      _pending &= ~interest;
+    
+    }
+
+    /**
+     * Get the next state from set that has accumulated. The order STATES are
+     * reported in is SIGNALED, TIMEOUT, or INTERRUPTED. Setting the 
+     * intrest mask allows certain state to be selectively ignored for 
+     * a time - but not lost. The states will become visible again as soon
+     * as the interest mask is changed appropriately. The interest mask is 
+     * generally used to create uninterruptable waits (waiting for threads 
+     * to start, reacquiring a conditions predicate lock, etc)
+     *
+     * @return STATE
+     * @pre access must be serial
+     */
+    STATE next() {
+
+      STATE state = INVALID;
+    
+      if(((_pending & _mask) & SIGNALED) != 0) {
+      
+        // Absorb the timeout if it happens when a signal
+        // is available at the same time
+        _pending &= ~(SIGNALED|TIMEDOUT);
+        state = SIGNALED;
+      
+      } else if(((_pending & _mask) & TIMEDOUT) != 0) {
+
+        _pending &= ~TIMEDOUT;
+        state = TIMEDOUT;
+
+      } else if(((_pending & _mask) & INTERRUPTED) != 0) {
+      
+        _pending &= ~INTERRUPTED;
+        state = INTERRUPTED;
+      
+      } 
+      
+      assert(state != INVALID);
+      return state;
+    
+    }
+
+  };
+
+}; // namespace ZThread
+
+#endif