Esempio n. 1
0
/**
 * Walk all objects in the heap in a single threaded linear fashion.
 */
void
MM_HeapWalker::allObjectsDo(MM_EnvironmentBase *env, MM_HeapWalkerObjectFunc function, void *userData, uintptr_t walkFlags, bool parallel, bool prepareHeapForWalk)
{
	uintptr_t typeFlags = 0;

	GC_OMRVMInterface::flushCachesForWalk(env->getOmrVM());

	if (walkFlags & J9_MU_WALK_NEW_AND_REMEMBERED_ONLY) {
		typeFlags |= MEMORY_TYPE_NEW;
	}

	MM_GCExtensionsBase *extensions = env->getExtensions();
	MM_HeapRegionManager *regionManager = extensions->heap->getHeapRegionManager();
	GC_HeapRegionIterator regionIterator(regionManager);
	MM_HeapRegionDescriptor *region = NULL;
	OMR_VMThread *omrVMThread = env->getOmrVMThread();
	
	while (NULL != (region = regionIterator.nextRegion())) {
		if (typeFlags == (region->getTypeFlags() & typeFlags)) {
			/* Optimization to avoid virtual dispatch for every slot in the system */
			omrobjectptr_t object = NULL;
			GC_ObjectHeapIteratorAddressOrderedList liveObjectIterator(extensions, region, false);

			while (NULL != (object = liveObjectIterator.nextObject())) {
				function(omrVMThread, region, object, userData);
			}
		}
	}
}
/**
 * Walk all segments and calculate the maximum number of chunks needed to represent the current heap.
 * The chunk calculation is done on a per segment basis (no segment can represent memory from more than 1 chunk),
 * and partial sized chunks (ie: less than the chunk size) are reserved for any remaining space at the end of a
 * segment.
 * @return number of chunks required to represent the current heap memory.
 */
uintptr_t
MM_SweepHeapSectioningSegmented::calculateActualChunkNumbers() const
{
	uintptr_t totalChunkCount = 0;

	MM_HeapRegionDescriptor *region;
	MM_Heap *heap = _extensions->heap;
	MM_HeapRegionManager *regionManager = heap->getHeapRegionManager();
	GC_HeapRegionIterator regionIterator(regionManager);

	while((region = regionIterator.nextRegion()) != NULL) {
		if ((region)->isCommitted()) {
			/* TODO:  this must be rethought for Tarok since it treats all regions identically but some might require different sweep logic */
			MM_MemorySubSpace *subspace = region->getSubSpace();
			/* if this is a committed region, it requires a non-NULL subspace */
			Assert_MM_true(NULL != subspace);
			uintptr_t poolCount = subspace->getMemoryPoolCount();

			totalChunkCount += MM_Math::roundToCeiling(_extensions->parSweepChunkSize, region->getSize()) / _extensions->parSweepChunkSize;

			/* Add extra chunks if more than one memory pool */
			totalChunkCount += (poolCount - 1);
		}
	}

	return totalChunkCount;
}
Esempio n. 3
0
void
MM_MarkMap::initializeMarkMap(MM_EnvironmentBase *env)
{
	/* TODO: The multiplier should really be some constant defined globally */
	const uintptr_t MODRON_PARALLEL_MULTIPLIER = 32;
	uintptr_t heapAlignment = _extensions->heapAlignment;

	/* Determine the size of heap that a work unit of mark map clearing corresponds to */
	uintptr_t heapClearUnitFactor = env->_currentTask->getThreadCount();
	heapClearUnitFactor = ((heapClearUnitFactor == 1) ? 1 : heapClearUnitFactor * MODRON_PARALLEL_MULTIPLIER);
	uintptr_t heapClearUnitSize = _extensions->heap->getMemorySize() / heapClearUnitFactor;
	heapClearUnitSize = MM_Math::roundToCeiling(heapAlignment, heapClearUnitSize);

	/* Walk all object segments to determine what ranges of the mark map should be cleared */
	MM_HeapRegionDescriptor *region;
	MM_Heap *heap = _extensions->getHeap();
	MM_HeapRegionManager *regionManager = heap->getHeapRegionManager();
	GC_HeapRegionIterator regionIterator(regionManager);
	while(NULL != (region = regionIterator.nextRegion())) {
		if (region->isCommitted()) {
			/* Walk the segment in chunks the size of the heapClearUnit size, checking if the corresponding mark map
			 * range should  be cleared.
			 */
			uint8_t* heapClearAddress = (uint8_t*)region->getLowAddress();
			uintptr_t heapClearSizeRemaining = region->getSize();

			while(0 != heapClearSizeRemaining) {
				/* Calculate the size of heap that is to be processed */
				uintptr_t heapCurrentClearSize = (heapClearUnitSize > heapClearSizeRemaining) ? heapClearSizeRemaining : heapClearUnitSize;
				Assert_MM_true(heapCurrentClearSize > 0);

				/* Check if the thread should clear the corresponding mark map range for the current heap range */
				if(J9MODRON_HANDLE_NEXT_WORK_UNIT(env)) {
					/* Convert the heap address/size to its corresponding mark map address/size */
					/* NOTE: We calculate the low and high heap offsets, and build the mark map index and size values
					 * from these to avoid rounding errors (if we use the size, the conversion routine could get a different
					 * rounding result then the actual end address)
					 */
					uintptr_t heapClearOffset = ((uintptr_t)heapClearAddress) - _heapMapBaseDelta;
					uintptr_t heapMapClearIndex = convertHeapIndexToHeapMapIndex(env, heapClearOffset, sizeof(uintptr_t));
					uintptr_t heapMapClearSize =
						convertHeapIndexToHeapMapIndex(env, heapClearOffset + heapCurrentClearSize, sizeof(uintptr_t))
						- heapMapClearIndex;

					/* And clear the mark map */
					OMRZeroMemory((void *) (((uintptr_t)_heapMapBits) + heapMapClearIndex), heapMapClearSize);
				}

				/* Move to the next address range in the segment */
				heapClearAddress += heapCurrentClearSize;
				heapClearSizeRemaining -= heapCurrentClearSize;
			}
		}
	}
}
Esempio n. 4
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void *
MM_HeapRegionManagerTarok::findHighestValidAddressBelow(MM_HeapRegionDescriptor *targetRegion)
{
	void *lowValidAddress = _lowTableEdge;
	uintptr_t targetIndex = mapDescriptorToRegionTableIndex(targetRegion);
	uintptr_t cursorIndex = 0;

	while (cursorIndex < targetIndex) {
		MM_HeapRegionDescriptor *cursorRegion = mapRegionTableIndexToDescriptor(cursorIndex);
		if (cursorRegion->_isAllocated) {
			lowValidAddress = cursorRegion->getHighAddress();
		}
		cursorIndex++;
	}
	return lowValidAddress;
}
Esempio n. 5
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void *
MM_HeapRegionManagerTarok::findLowestValidAddressAbove(MM_HeapRegionDescriptor *targetRegion)
{
	void *highValidAddress = _highTableEdge;
	uintptr_t targetIndex = mapDescriptorToRegionTableIndex(targetRegion);
	uintptr_t cursorIndex = targetIndex + 1;

	while (cursorIndex < _tableRegionCount) {
		MM_HeapRegionDescriptor *cursorRegion = mapRegionTableIndexToDescriptor(cursorIndex);
		if (cursorRegion->_isAllocated) {
			highValidAddress = cursorRegion->getLowAddress();
			break;
		}
		cursorIndex++;
	}
	return highValidAddress;
}
Esempio n. 6
0
MM_HeapRegionDescriptor *
MM_HeapRegionManagerTarok::internalAcquireSingleTableRegion(MM_EnvironmentBase *env, MM_MemorySubSpace *subSpace, uintptr_t freeListIndex)
{
	Assert_MM_true(NULL != _freeRegionTable[freeListIndex]);

	/*since we only need one region, always return the first free region */
	MM_HeapRegionDescriptor *toReturn = _freeRegionTable[freeListIndex];

	_freeRegionTable[freeListIndex] = toReturn->_nextInSet;

	toReturn->_nextInSet = NULL;
	toReturn->_isAllocated = true;
	toReturn->associateWithSubSpace(subSpace);
	_totalHeapSize += toReturn->getSize();

	return toReturn;
}
Esempio n. 7
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void
MM_HeapRegionManagerTarok::setNodeAndLinkRegions(MM_EnvironmentBase *env, void *lowHeapEdge, void *highHeapEdge, uintptr_t numaNode)
{
	uintptr_t regionCount = 0;
	MM_HeapRegionDescriptor *firstRegion = NULL;

	Trc_MM_HeapRegionManager_enableRegionsInTable_Entry(env->getLanguageVMThread(), lowHeapEdge, highHeapEdge, numaNode);
	if (highHeapEdge > lowHeapEdge) {
		for (uint8_t* address = (uint8_t*)lowHeapEdge; address < highHeapEdge; address += getRegionSize()) {
			MM_HeapRegionDescriptor *region = tableDescriptorForAddress(address);
			region->setNumaNode(numaNode);
			regionCount += 1;
		}

		firstRegion = tableDescriptorForAddress(lowHeapEdge);
		firstRegion->_nextInSet = _freeRegionTable[numaNode];
		_freeRegionTable[numaNode] = firstRegion;
		internalLinkRegions(env, firstRegion, regionCount);
	}
	Trc_MM_HeapRegionManager_enableRegionsInTable_Exit(env->getLanguageVMThread(), regionCount, firstRegion, numaNode);
}
Esempio n. 8
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void
MM_ConcurrentOverflow::handleOverflow(MM_EnvironmentBase *env)
{
	MM_EnvironmentStandard *envStandard = MM_EnvironmentStandard::getEnvironment(env);
	if (envStandard->_currentTask->synchronizeGCThreadsAndReleaseMaster(env, UNIQUE_ID)) {
		_overflow = false;
		envStandard->_currentTask->releaseSynchronizedGCThreads(envStandard);
	}

	MM_Heap *heap = _extensions->heap;
	MM_HeapRegionManager *regionManager = heap->getHeapRegionManager();
	GC_HeapRegionIterator regionIterator(regionManager);
	MM_HeapRegionDescriptor *region = NULL;
	MM_ConcurrentGC *collector = (MM_ConcurrentGC *)_extensions->getGlobalCollector();
	MM_CardCleanerForMarking cardCleanerForMarking(collector->getMarkingScheme());
	MM_ConcurrentCardTable *cardTable = collector->getCardTable();

	while((region = regionIterator.nextRegion()) != NULL) {
		cardTable->cleanCardTableForRange(envStandard, &cardCleanerForMarking, region->getLowAddress(), region->getHighAddress());
	}

	envStandard->_currentTask->synchronizeGCThreads(env, UNIQUE_ID);
}
/**
 * Reset and reassign each chunk to a range of heap memory.
 * Given the current updated listed of chunks and the corresponding heap memory, walk the chunk
 * list reassigning each chunk to an appropriate range of memory.  This will clear each chunk
 * structure and then assign its basic values that connect it to a range of memory (base/top,
 * pool, segment, etc).
 * @return the total number of chunks in the system.
 */
uintptr_t
MM_SweepHeapSectioningSegmented::reassignChunks(MM_EnvironmentBase *env)
{
	MM_ParallelSweepChunk *chunk; /* Sweep table chunk (global) */
	MM_ParallelSweepChunk *previousChunk;
	uintptr_t totalChunkCount;  /* Total chunks in system */

	MM_SweepHeapSectioningIterator sectioningIterator(this);

	totalChunkCount = 0;
	previousChunk = NULL;

	MM_HeapRegionManager *regionManager = _extensions->getHeap()->getHeapRegionManager();
	GC_HeapRegionIterator regionIterator(regionManager);
	MM_HeapRegionDescriptor *region = NULL;

	while (NULL != (region = regionIterator.nextRegion())) {
		if (region->isCommitted()) {
			/* TODO:  this must be rethought for Tarok since it treats all regions identically but some might require different sweep logic */
			uintptr_t *heapChunkBase = (uintptr_t *)region->getLowAddress();  /* Heap chunk base pointer */
			uintptr_t *regionHighAddress = (uintptr_t *)region->getHighAddress();

			while (heapChunkBase < regionHighAddress) {
				void *poolHighAddr;
				uintptr_t *heapChunkTop;
				MM_MemoryPool *pool;

				chunk = sectioningIterator.nextChunk();
				Assert_MM_true(chunk != NULL);  /* Should never return NULL */
				totalChunkCount += 1;

				/* Clear all data in the chunk (including sweep implementation specific information) */
				chunk->clear();

				if(((uintptr_t)regionHighAddress - (uintptr_t)heapChunkBase) < _extensions->parSweepChunkSize) {
					/* corner case - we will wrap our address range */
					heapChunkTop = regionHighAddress;
				} else {
					/* normal case - just increment by the chunk size */
					heapChunkTop = (uintptr_t *)((uintptr_t)heapChunkBase + _extensions->parSweepChunkSize);
				}

				/* Find out if the range of memory we are considering spans 2 different pools.  If it does,
				 * the current chunk can only be attributed to one, so we limit the upper range of the chunk
				 * to the first pool and will continue the assignment at the upper address range.
				 */
				pool = region->getSubSpace()->getMemoryPool(env, heapChunkBase, heapChunkTop, poolHighAddr);
				if (NULL == poolHighAddr) {
					heapChunkTop = (heapChunkTop > regionHighAddress ? regionHighAddress : heapChunkTop);
				} else {
					/* Yes ..so adjust chunk boundaries */
					assume0(poolHighAddr > heapChunkBase && poolHighAddr < heapChunkTop);
					heapChunkTop = (uintptr_t *) poolHighAddr;
				}

				/* All values for the chunk have been calculated - assign them */
				chunk->chunkBase = (void *)heapChunkBase;
				chunk->chunkTop = (void *)heapChunkTop;
				chunk->memoryPool = pool;
				chunk->_coalesceCandidate = (heapChunkBase != region->getLowAddress());
				chunk->_previous= previousChunk;
				if(NULL != previousChunk) {
					previousChunk->_next = chunk;
				}

				/* Move to the next chunk */
				heapChunkBase = heapChunkTop;

				/* and remember address of previous chunk */
				previousChunk = chunk;

				assume0((uintptr_t)heapChunkBase == MM_Math::roundToCeiling(_extensions->heapAlignment,(uintptr_t)heapChunkBase));
			}
		}
	}

	if(NULL != previousChunk) {
		previousChunk->_next = NULL;
	}

	return totalChunkCount;
}