Beispiel #1
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;
			}
		}
	}
}
/**
 * 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;
}