* threaded_queue.h: New file.

winsup/cygserver/ChangeLog

@@ -1,3 +1,7 @@
+2003-08-30  Christopher Faylor  <cgf@redhat.com>
+
+	* threaded_queue.h: New file.
+
 2003-08-25  Christopher Faylor  <cgf@redhat.com>
 
 	* Makefile.in: Build libcygserver.a.

winsup/cygserver/threaded_queue.h

@@ -0,0 +1,127 @@
+/* threaded_queue.h
+
+   Copyright 2001, 2002 Red Hat Inc.
+
+   Written by Robert Collins <rbtcollins@hotmail.com>
+
+This file is part of Cygwin.
+
+This software is a copyrighted work licensed under the terms of the
+Cygwin license.  Please consult the file "CYGWIN_LICENSE" for
+details. */
+
+#ifndef _THREADED_QUEUE_
+#define _THREADED_QUEUE_
+
+/*****************************************************************************/
+
+/* a specific request */
+
+class queue_request
+{
+public:
+  queue_request *_next;
+
+  queue_request () : _next (NULL) {}
+  virtual ~queue_request ();
+
+  virtual void process () = 0;
+};
+
+/*****************************************************************************/
+
+/* a queue to allocate requests from n submission loops to x worker threads */
+
+class queue_submission_loop;
+
+class threaded_queue
+{
+public:
+  threaded_queue (size_t initial_workers = 1);
+  ~threaded_queue ();
+
+  void add_submission_loop (queue_submission_loop *);
+
+  bool running () const { return _running; }
+
+  bool start ();
+  bool stop ();
+
+  void add (queue_request *);
+
+private:
+  long _workers_count;
+  bool _running;
+
+  queue_submission_loop *_submitters_head;
+
+  long _requests_count;		// Informational only.
+  queue_request *_requests_head;
+
+  CRITICAL_SECTION _queue_lock;
+  HANDLE _requests_sem;		// == _requests_count
+
+  static DWORD WINAPI start_routine (LPVOID /* this */);
+
+  void create_workers (size_t initial_workers);
+  void worker_loop ();
+};
+
+/*****************************************************************************/
+
+/* parameters for a request finding and submitting loop */
+
+class queue_submission_loop
+{
+  friend class threaded_queue;
+
+public:
+  queue_submission_loop (threaded_queue *, bool ninterruptible);
+  virtual ~queue_submission_loop ();
+
+  bool start ();
+  bool stop ();
+
+  threaded_queue *queue () { return _queue; };
+
+protected:
+  bool _running;
+  HANDLE _interrupt_event;
+  threaded_queue *const _queue;
+
+private:
+  bool _interruptible;
+  HANDLE _hThread;
+  DWORD _tid;
+  queue_submission_loop *_next;
+
+  static DWORD WINAPI start_routine (LPVOID /* this */);
+  virtual void request_loop () = 0;
+};
+
+#ifdef __cplusplus
+
+/*---------------------------------------------------------------------------*
+ * Some type-safe versions of the various interlocked functions.
+ *---------------------------------------------------------------------------*/
+
+template <typename T> T *
+TInterlockedExchangePointer (T **lvalue, T *rvalue)
+{
+  return reinterpret_cast<T *>
+    (InterlockedExchangePointer (reinterpret_cast<void **> (lvalue),
+				 reinterpret_cast<void *> (rvalue)));
+}
+
+template <typename T> T *
+TInterlockedCompareExchangePointer (T **lvalue, T *rvalue1, T *rvalue2)
+{
+  return reinterpret_cast<T *>
+    (InterlockedCompareExchangePointer (reinterpret_cast<void **> (lvalue),
+					reinterpret_cast<void *> (rvalue1),
+					reinterpret_cast<void *> (rvalue2)));
+}
+
+#endif /* __cplusplus */
+
+#endif /* _THREADED_QUEUE_ */