这个属性值是定义在/system/build.prop文件中的 dalvik.vm.heapstartsize dalvik.vm.heapstartsize=8m它表示堆分配的初始大小,它会影响到整个系统对RAM的使用程度,和第一次使用应用时的流畅程度。它值越小,系统ram消耗越慢,但一些较大应用一开始不够用,需要调用gc和堆调整策略,导致应用反应较慢。它值越大,这个值...
/* Create a couple of list links to mark the start and end of the list. */ static BlockLink_t xStart, xEnd; 使用静态的xFreeBytesRemaining跟踪空闲区域的大小,注意这里没有碎片化,内存空闲区域初始值为configADJUSTED_HEAP_SIZE。参考代码如下: /* Keeps track of the number of free bytes remaining...
PFND3D12DDI_GET_GPU_DESCRIPTOR_HANDLE_FOR_HEAP_START Pfnd3d12ddiGetGpuDescriptorHandleForHeapStart;D3D12DDI_GPU_DESCRIPTOR_HANDLEPfnd3d12ddiGetGpuDescriptorHandleForHeapStart( D3D12DDI_HDEVICE unnamedParam1, D3D12DDI_HDESCRIPTORHEAP unnamedParam2 ){...} ...
5 调用dvmHeapSourceAllocAndGrow尝试分配,这个函数会扩张堆。所以heap startup的时候可以给一个比较小的初始堆,实在不够用再调用它进行扩张 6 进入回收软引用阶段,这里gcForMalloc的参数是ture,所以需要回收软引用。然后调用dvmHeapSourceAllocAndGrow尝试分配,如果失败则抛出OOM。 好了,教程到这里结束了,如果你坚持看...
/* A few bytes might be lost to byte aligning the heap start address. */ #define configADJUSTED_HEAP_SIZE ( configTOTAL_HEAP_SIZE - portBYTE_ALIGNMENT ) 在Heap_1模型中,堆的模型如下图所示: 由于分配出去的内存空间不需要回收,因此每一次分配空间的时候只需要按需要的内存大小在空闲空间上分割出来就...
('Z');// Fill in free entriesswitch( heapstatus ) {case_HEAPOK:printf("OK - heap is fine\n");break;case_HEAPEMPTY:printf("OK - heap is empty\n");break;case_HEAPBADBEGIN:printf("ERROR - bad start of heap\n");break;case_HEAPBADNODE:printf("ERROR - bad node in heap\n");...
main PostmasterMain ServerLoop BackendStartup BackendRun PostgresMain exec_simple_query # 词法解析/语法解析/优化器 PortalRun # 已经生产执行计划,开始执行 PortalRunSelect # 执行计划是 查询,这里和 insert的执行计划是不一样的 standard_ExecutorRun ExecutePlan ExecProcNode ExecScan ExecScanFetch SeqNext tabl...
at its start. *///返回给我们用地址,前面 heapSTRUCT_SIZE 保存链表节点数据pvReturn=(void*)(((uint8_t*)pxPreviousBlock->pxNextFreeBlock)+heapSTRUCT_SIZE);/* This block is being returned for use so must be taken out of the list of free blocks. */pxPreviousBlock->pxNextFreeBlock=pxBloc...
pxEnd->pxNextFreeBlock =NULL;/*To start with there is a single free block that is sized to take up the entire heap space, minus the space taken by pxEnd.*/pxFirstFreeBlock= (void*) pucAlignedHeap; pxFirstFreeBlock->xBlockSize = uxAddress -( size_t ) pxFirstFreeBlock; ...
int cur = start; int parent = (cur - 1) / 2; T temp = heap[cur]; while (cur>0) { if(heap[parent]<=temp) break; else { heap[cur] = heap[parent]; cur = parent; parent = (parent - 1) / 2; } } heap[cur] = temp; //回放temp中暂存的元素 ...