Imported existing code

indra/llcommon/llqueuedthread.h

@@ -0,0 +1,217 @@
+/** 
+ * @file llqueuedthread.h
+ * @brief
+ *
+ * $LicenseInfo:firstyear=2004&license=viewergpl$
+ * 
+ * Copyright (c) 2004-2009, Linden Research, Inc.
+ * 
+ * Second Life Viewer Source Code
+ * The source code in this file ("Source Code") is provided by Linden Lab
+ * to you under the terms of the GNU General Public License, version 2.0
+ * ("GPL"), unless you have obtained a separate licensing agreement
+ * ("Other License"), formally executed by you and Linden Lab.  Terms of
+ * the GPL can be found in doc/GPL-license.txt in this distribution, or
+ * online at http://secondlifegrid.net/programs/open_source/licensing/gplv2
+ * 
+ * There are special exceptions to the terms and conditions of the GPL as
+ * it is applied to this Source Code. View the full text of the exception
+ * in the file doc/FLOSS-exception.txt in this software distribution, or
+ * online at
+ * http://secondlifegrid.net/programs/open_source/licensing/flossexception
+ * 
+ * By copying, modifying or distributing this software, you acknowledge
+ * that you have read and understood your obligations described above,
+ * and agree to abide by those obligations.
+ * 
+ * ALL LINDEN LAB SOURCE CODE IS PROVIDED "AS IS." LINDEN LAB MAKES NO
+ * WARRANTIES, EXPRESS, IMPLIED OR OTHERWISE, REGARDING ITS ACCURACY,
+ * COMPLETENESS OR PERFORMANCE.
+ * $/LicenseInfo$
+ */
+
+#ifndef LL_LLQUEUEDTHREAD_H
+#define LL_LLQUEUEDTHREAD_H
+
+#include <queue>
+#include <string>
+#include <map>
+#include <set>
+
+#include "llapr.h"
+
+#include "llthread.h"
+#include "llsimplehash.h"
+
+//============================================================================
+// Note: ~LLQueuedThread is O(N) N=# of queued threads, assumed to be small
+//   It is assumed that LLQueuedThreads are rarely created/destroyed.
+
+class LLQueuedThread : public LLThread
+{
+	//------------------------------------------------------------------------
+public:
+	enum priority_t {
+		PRIORITY_IMMEDIATE = 0x7FFFFFFF,
+		PRIORITY_URGENT =    0x40000000,
+		PRIORITY_HIGH =      0x30000000,
+		PRIORITY_NORMAL =    0x20000000,
+		PRIORITY_LOW =       0x10000000,
+		PRIORITY_LOWBITS =   0x0FFFFFFF,
+		PRIORITY_HIGHBITS =  0x70000000
+	};
+	enum status_t {
+		STATUS_EXPIRED = -1,
+		STATUS_UNKNOWN = 0,
+		STATUS_QUEUED = 1,
+		STATUS_INPROGRESS = 2,
+		STATUS_COMPLETE = 3,
+		STATUS_ABORTED = 4,
+		STATUS_DELETE = 5
+	};
+	enum flags_t {
+		FLAG_AUTO_COMPLETE = 1,
+		FLAG_AUTO_DELETE = 2, // child-class dependent
+		FLAG_ABORT = 4
+	};
+
+	typedef U32 handle_t;
+	
+	//------------------------------------------------------------------------
+public:
+
+	class QueuedRequest : public LLSimpleHashEntry<handle_t>
+	{
+		friend class LLQueuedThread;
+		
+	protected:
+		virtual ~QueuedRequest(); // use deleteRequest()
+		
+	public:
+		QueuedRequest(handle_t handle, U32 priority, U32 flags = 0);
+
+		status_t getStatus()
+		{
+			return mStatus;
+		}
+		U32 getPriority() const
+		{
+			return mPriority;
+		}
+		U32 getFlags() const
+		{
+			return mFlags;
+		}
+		bool higherPriority(const QueuedRequest& second) const
+		{
+			if ( mPriority == second.mPriority)
+				return mHashKey < second.mHashKey;
+			else
+				return mPriority > second.mPriority;
+		}
+
+	protected:
+		status_t setStatus(status_t newstatus)
+		{
+			status_t oldstatus = mStatus;
+			mStatus = newstatus;
+			return oldstatus;
+		}
+		void setFlags(U32 flags)
+		{
+			// NOTE: flags are |'d
+			mFlags |= flags;
+		}
+		
+		virtual bool processRequest() = 0; // Return true when request has completed
+		virtual void finishRequest(bool completed); // Always called from thread after request has completed or aborted
+		virtual void deleteRequest(); // Only method to delete a request
+
+		void setPriority(U32 pri)
+		{
+			// Only do this on a request that is not in a queued list!
+			mPriority = pri;
+		};
+		
+	protected:
+		LLAtomic32<status_t> mStatus;
+		U32 mPriority;
+		U32 mFlags;
+	};
+
+protected:
+	struct queued_request_less
+	{
+		bool operator()(const QueuedRequest* lhs, const QueuedRequest* rhs) const
+		{
+			return lhs->higherPriority(*rhs); // higher priority in front of queue (set)
+		}
+	};
+
+	//------------------------------------------------------------------------
+	
+public:
+	static handle_t nullHandle() { return handle_t(0); }
+	
+public:
+	LLQueuedThread(const std::string& name, bool threaded = true);
+	virtual ~LLQueuedThread();	
+	virtual void shutdown();
+	
+private:
+	// No copy constructor or copy assignment
+	LLQueuedThread(const LLQueuedThread&);
+	LLQueuedThread& operator=(const LLQueuedThread&);
+
+	virtual bool runCondition(void);
+	virtual void run(void);
+	virtual void startThread(void);
+	virtual void endThread(void);
+	virtual void threadedUpdate(void);
+
+protected:
+	handle_t generateHandle();
+	bool addRequest(QueuedRequest* req);
+	S32  processNextRequest(void);
+	void incQueue();
+
+public:
+	bool waitForResult(handle_t handle, bool auto_complete = true);
+
+	virtual S32 update(U32 max_time_ms);
+	S32 updateQueue(U32 max_time_ms);
+	
+	void waitOnPending();
+	void printQueueStats();
+
+	S32 getPending();
+	bool getThreaded() { return mThreaded ? true : false; }
+
+	// Request accessors
+	status_t getRequestStatus(handle_t handle);
+	void abortRequest(handle_t handle, bool autocomplete);
+	void setFlags(handle_t handle, U32 flags);
+	void setPriority(handle_t handle, U32 priority);
+	bool completeRequest(handle_t handle);
+	// This is public for support classes like LLWorkerThread,
+	// but generally the methods above should be used.
+	QueuedRequest* getRequest(handle_t handle);
+
+	// debug (see source)
+	bool check();
+	
+protected:
+	BOOL mThreaded;  // if false, run on main thread and do updates during update()
+	LLAtomic32<BOOL> mIdleThread; // request queue is empty (or we are quitting) and the thread is idle
+	
+	typedef std::set<QueuedRequest*, queued_request_less> request_queue_t;
+	request_queue_t mRequestQueue;
+
+	enum { REQUEST_HASH_SIZE = 512 }; // must be power of 2
+	typedef LLSimpleHash<handle_t, REQUEST_HASH_SIZE> request_hash_t;
+	request_hash_t mRequestHash;
+
+	handle_t mNextHandle;
+};
+
+#endif // LL_LLQUEUEDTHREAD_H