/** 
 * @file lltracethreadrecorder.cpp
 *
 * $LicenseInfo:firstyear=2001&license=viewerlgpl$
 * Second Life Viewer Source Code
 * Copyright (C) 2012, Linden Research, Inc.
 * 
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation;
 * version 2.1 of the License only.
 * 
 * This library is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * Lesser General Public License for more details.
 * 
 * You should have received a copy of the GNU Lesser General Public
 * License along with this library; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
 * 
 * Linden Research, Inc., 945 Battery Street, San Francisco, CA  94111  USA
 * $/LicenseInfo$
 */

#include "linden_common.h"

#include "lltracethreadrecorder.h"
#include "llfasttimer.h"
#include "lltrace.h"
#include "llstl.h"

namespace LLTrace
{
extern MemStatHandle gTraceMemStat;

static ThreadRecorder* sMasterThreadRecorder = NULL;

///////////////////////////////////////////////////////////////////////
// ThreadRecorder
///////////////////////////////////////////////////////////////////////

ThreadRecorder::ThreadRecorder()
:	mParentRecorder(NULL)
{
	init();
}

void ThreadRecorder::init()
{
#if LL_TRACE_ENABLED
	LLThreadLocalSingletonPointer<BlockTimerStackRecord>::setInstance(&mBlockTimerStackRecord);
	//NB: the ordering of initialization in this function is very fragile due to a large number of implicit dependencies
	set_thread_recorder(this);
	BlockTimerStatHandle& root_time_block = BlockTimer::getRootTimeBlock();

	BlockTimerStackRecord* timer_stack = LLThreadLocalSingletonPointer<BlockTimerStackRecord>::getInstance();
	timer_stack->mTimeBlock = &root_time_block;
	timer_stack->mActiveTimer = NULL;

	mNumTimeBlockTreeNodes = AccumulatorBuffer<TimeBlockAccumulator>::getDefaultBuffer()->size();

	mTimeBlockTreeNodes = new TimeBlockTreeNode[mNumTimeBlockTreeNodes];

	activate(&mThreadRecordingBuffers);

	// initialize time block parent pointers
	for (auto& base : BlockTimerStatHandle::instance_snapshot())
	{
		// because of indirect derivation from LLInstanceTracker, have to downcast
		BlockTimerStatHandle& time_block = static_cast<BlockTimerStatHandle&>(base);
		TimeBlockTreeNode& tree_node = mTimeBlockTreeNodes[time_block.getIndex()];
		tree_node.mBlock = &time_block;
		tree_node.mParent = &root_time_block;

		time_block.getCurrentAccumulator().mParent = &root_time_block;
	}

	mRootTimer = new BlockTimer(root_time_block);
	timer_stack->mActiveTimer = mRootTimer;

	BlockTimer::getRootTimeBlock().getCurrentAccumulator().mActiveCount = 1;

	claim_alloc(gTraceMemStat, this);
	claim_alloc(gTraceMemStat, mRootTimer);
	claim_alloc(gTraceMemStat, sizeof(TimeBlockTreeNode) * mNumTimeBlockTreeNodes);
#endif
}


ThreadRecorder::ThreadRecorder( ThreadRecorder& parent )
:	mParentRecorder(&parent)
{
	init();
	mParentRecorder->addChildRecorder(this);
}


ThreadRecorder::~ThreadRecorder()
{
#if LL_TRACE_ENABLED
	LLThreadLocalSingletonPointer<BlockTimerStackRecord>::setInstance(NULL);

	disclaim_alloc(gTraceMemStat, this);
	disclaim_alloc(gTraceMemStat, sizeof(BlockTimer));
	disclaim_alloc(gTraceMemStat, sizeof(TimeBlockTreeNode) * mNumTimeBlockTreeNodes);

	deactivate(&mThreadRecordingBuffers);

	delete mRootTimer;

	if (!mActiveRecordings.empty())
	{
		std::for_each(mActiveRecordings.begin(), mActiveRecordings.end(), DeletePointer());
		mActiveRecordings.clear();
	}

	set_thread_recorder(NULL);
	delete[] mTimeBlockTreeNodes;

	if (mParentRecorder)
	{
		mParentRecorder->removeChildRecorder(this);
	}
#endif
}

TimeBlockTreeNode* ThreadRecorder::getTimeBlockTreeNode( S32 index )
{
#if LL_TRACE_ENABLED
	if (0 <= index && index < mNumTimeBlockTreeNodes)
	{
		return &mTimeBlockTreeNodes[index];
	}
#endif
	return NULL;
}

AccumulatorBufferGroup* ThreadRecorder::activate( AccumulatorBufferGroup* recording)
{
#if LL_TRACE_ENABLED
	ActiveRecording* active_recording = new ActiveRecording(recording);
	if (!mActiveRecordings.empty())
	{
		AccumulatorBufferGroup& prev_active_recording = mActiveRecordings.back()->mPartialRecording;
		prev_active_recording.sync();
		BlockTimer::updateTimes();
		prev_active_recording.handOffTo(active_recording->mPartialRecording);
	}
	mActiveRecordings.push_back(active_recording);

	mActiveRecordings.back()->mPartialRecording.makeCurrent();
	return &active_recording->mPartialRecording;
#else
	return NULL;
#endif
}

ThreadRecorder::active_recording_list_t::iterator ThreadRecorder::bringUpToDate( AccumulatorBufferGroup* recording )
{
#if LL_TRACE_ENABLED
	if (mActiveRecordings.empty()) return mActiveRecordings.end();

	mActiveRecordings.back()->mPartialRecording.sync();
	BlockTimer::updateTimes();

	active_recording_list_t::reverse_iterator it, end_it;
	for (it = mActiveRecordings.rbegin(), end_it = mActiveRecordings.rend();
		it != end_it;
		++it)
	{
		ActiveRecording* cur_recording = *it;

		active_recording_list_t::reverse_iterator next_it = it;
		++next_it;

		// if we have another recording further down in the stack...
		if (next_it != mActiveRecordings.rend())
		{
			// ...push our gathered data down to it
			(*next_it)->mPartialRecording.append(cur_recording->mPartialRecording);
		}

		// copy accumulated measurements into result buffer and clear accumulator (mPartialRecording)
		cur_recording->movePartialToTarget();

		if (cur_recording->mTargetRecording == recording)
		{
			// found the recording, so return it
			break;
		}
	}

	if (it == end_it)
	{
		LL_WARNS() << "Recording not active on this thread" << LL_ENDL;
	}

	return (++it).base();
#else
	return ThreadRecorder::active_recording_list_t::iterator();
#endif
}

void ThreadRecorder::deactivate( AccumulatorBufferGroup* recording )
{
#if LL_TRACE_ENABLED
	active_recording_list_t::iterator recording_it = bringUpToDate(recording);
	// this method should only be called on a thread where the recorder is active
	llassert_always(recording_it != mActiveRecordings.end());

	ActiveRecording* recording_to_remove = *recording_it;
	bool was_current = recording_to_remove->mPartialRecording.isCurrent();
	llassert(recording_to_remove->mTargetRecording == recording);
	mActiveRecordings.erase(recording_it);
	if (was_current)
	{
		if (mActiveRecordings.empty())
		{
			AccumulatorBufferGroup::clearCurrent();
		}
		else
		{
			mActiveRecordings.back()->mPartialRecording.makeCurrent();
		}
	}
	delete recording_to_remove;
#endif
}

ThreadRecorder::ActiveRecording::ActiveRecording( AccumulatorBufferGroup* target ) 
:	mTargetRecording(target)
{}

void ThreadRecorder::ActiveRecording::movePartialToTarget()
{
#if LL_TRACE_ENABLED
	mTargetRecording->append(mPartialRecording);
	// reset based on self to keep history
	mPartialRecording.reset(&mPartialRecording);
#endif
}


// called by child thread
void ThreadRecorder::addChildRecorder( class ThreadRecorder* child )
{
#if LL_TRACE_ENABLED
	{ LLMutexLock lock(&mChildListMutex);
		mChildThreadRecorders.push_back(child);
	}
#endif
}

// called by child thread
void ThreadRecorder::removeChildRecorder( class ThreadRecorder* child )
{	
#if LL_TRACE_ENABLED
	{ LLMutexLock lock(&mChildListMutex);
		mChildThreadRecorders.remove(child);
	}
#endif
}

void ThreadRecorder::pushToParent()
{
#if LL_TRACE_ENABLED
	{ LLMutexLock lock(&mSharedRecordingMutex);	
		LLTrace::get_thread_recorder()->bringUpToDate(&mThreadRecordingBuffers);
		mSharedRecordingBuffers.append(mThreadRecordingBuffers);
		mThreadRecordingBuffers.reset();
	}
#endif
}


static LLTrace::BlockTimerStatHandle FTM_PULL_TRACE_DATA_FROM_CHILDREN("Pull child thread trace data");

void ThreadRecorder::pullFromChildren()
{
#if LL_TRACE_ENABLED
	LL_RECORD_BLOCK_TIME(FTM_PULL_TRACE_DATA_FROM_CHILDREN);
	if (mActiveRecordings.empty()) return;

	{ LLMutexLock child_list_lock(&mChildListMutex);

		AccumulatorBufferGroup& target_recording_buffers = mActiveRecordings.back()->mPartialRecording;
		target_recording_buffers.sync();
		for (child_thread_recorder_list_t::iterator it = mChildThreadRecorders.begin(), end_it = mChildThreadRecorders.end();
			it != end_it;
			++it)
		{ LLMutexLock shared_record_lock(&(*it)->mSharedRecordingMutex);

			target_recording_buffers.merge((*it)->mSharedRecordingBuffers);
			(*it)->mSharedRecordingBuffers.reset();
		}
	}
#endif
}


void set_master_thread_recorder( ThreadRecorder* recorder )
{
	sMasterThreadRecorder = recorder;
}


ThreadRecorder* get_master_thread_recorder()
{
	return sMasterThreadRecorder;
}

LLThreadLocalPointer<ThreadRecorder>& get_thread_recorder_ptr()
{
	static LLThreadLocalPointer<ThreadRecorder> s_thread_recorder;
	return s_thread_recorder;
}

const LLThreadLocalPointer<ThreadRecorder>& get_thread_recorder()
{
	return get_thread_recorder_ptr();
}

void set_thread_recorder( ThreadRecorder* recorder )
{
	get_thread_recorder_ptr() = recorder;
}

}
