/* Remove any hard limits, try to allocate, and shrink back down.
* Last resort when trying to allocate an object.
*/
static void* heapAllocAndGrow(HeapSource *hs, Heap *heap, size_t n)
{
/* Grow as much as possible, but don't let the real footprint
* go over the absolute max.
*/
size_t max = heap->maximumSize;
mspace_set_footprint_limit(heap->msp, max);
void* ptr = dvmHeapSourceAlloc(n);
/* Shrink back down as small as possible. Our caller may
* readjust max_allowed to a more appropriate value.
*/
mspace_set_footprint_limit(heap->msp,
mspace_footprint(heap->msp));
return ptr;
}
/*
* Adds an additional heap to the heap source. Returns false if there
* are too many heaps or insufficient free space to add another heap.
*/
static bool addNewHeap(HeapSource *hs)
{
Heap heap;
assert(hs != NULL);
if (hs->numHeaps >= HEAP_SOURCE_MAX_HEAP_COUNT) {
ALOGE("Attempt to create too many heaps (%zd >= %zd)",
hs->numHeaps, HEAP_SOURCE_MAX_HEAP_COUNT);
dvmAbort();
return false;
}
memset(&heap, 0, sizeof(heap));
/*
* Heap storage comes from a common virtual memory reservation.
* The new heap will start on the page after the old heap.
*/
char *base = hs->heaps[0].brk;
size_t overhead = base - hs->heaps[0].base;
assert(((size_t)hs->heaps[0].base & (SYSTEM_PAGE_SIZE - 1)) == 0);
if (overhead + hs->minFree >= hs->maximumSize) {
LOGE_HEAP("No room to create any more heaps "
"(%zd overhead, %zd max)",
overhead, hs->maximumSize);
return false;
}
size_t morecoreStart = SYSTEM_PAGE_SIZE;
heap.maximumSize = hs->growthLimit - overhead;
heap.concurrentStartBytes = hs->minFree - CONCURRENT_START;
heap.base = base;
heap.limit = heap.base + heap.maximumSize;
heap.brk = heap.base + morecoreStart;
if (!remapNewHeap(hs, &heap)) {
return false;
}
heap.msp = createMspace(base, morecoreStart, hs->minFree);
if (heap.msp == NULL) {
return false;
}
/* Don't let the soon-to-be-old heap grow any further.
*/
hs->heaps[0].maximumSize = overhead;
hs->heaps[0].limit = base;
mspace_set_footprint_limit(hs->heaps[0].msp, overhead);
/* Put the new heap in the list, at heaps[0].
* Shift existing heaps down.
*/
memmove(&hs->heaps[1], &hs->heaps[0], hs->numHeaps * sizeof(hs->heaps[0]));
hs->heaps[0] = heap;
hs->numHeaps++;
return true;
}
/*
* Sets the soft limit, handling any necessary changes to the allowed
* footprint of the active heap.
*/
static void setSoftLimit(HeapSource *hs, size_t softLimit)
{
/* Compare against the actual footprint, rather than the
* max_allowed, because the heap may not have grown all the
* way to the allowed size yet.
*/
mspace msp = hs->heaps[0].msp;
size_t currentHeapSize = mspace_footprint(msp);
if (softLimit < currentHeapSize) {
/* Don't let the heap grow any more, and impose a soft limit.
*/
mspace_set_footprint_limit(msp, currentHeapSize);
hs->softLimit = softLimit;
} else {
/* Let the heap grow to the requested max, and remove any
* soft limit, if set.
*/
mspace_set_footprint_limit(msp, softLimit);
hs->softLimit = SIZE_MAX;
}
}
static mspace createMspace(void* begin, size_t morecoreStart, size_t startingSize)
{
// Clear errno to allow strerror on error.
errno = 0;
// Allow access to inital pages that will hold mspace.
mprotect(begin, morecoreStart, PROT_READ | PROT_WRITE);
// Create mspace using our backing storage starting at begin and with a footprint of
// morecoreStart. Don't use an internal dlmalloc lock. When morecoreStart bytes of memory are
// exhausted morecore will be called.
mspace msp = create_mspace_with_base(begin, morecoreStart, false /*locked*/);
if (msp != NULL) {
// Do not allow morecore requests to succeed beyond the starting size of the heap.
mspace_set_footprint_limit(msp, startingSize);
} else {
ALOGE("create_mspace_with_base failed %s", strerror(errno));
}
return msp;
}
static mspace getMspace()
{
if (gExecutableStore == NULL) {
int fd = ashmem_create_region("CodeFlinger code cache",
kMaxCodeCacheCapacity);
LOG_ALWAYS_FATAL_IF(fd < 0,
"Creating code cache, ashmem_create_region "
"failed with error '%s'", strerror(errno));
gExecutableStore = mmap(NULL, kMaxCodeCacheCapacity,
PROT_READ | PROT_WRITE | PROT_EXEC,
MAP_PRIVATE, fd, 0);
LOG_ALWAYS_FATAL_IF(gExecutableStore == MAP_FAILED,
"Creating code cache, mmap failed with error "
"'%s'", strerror(errno));
close(fd);
gMspace = create_mspace_with_base(gExecutableStore, kMaxCodeCacheCapacity,
/*locked=*/ false);
mspace_set_footprint_limit(gMspace, kMaxCodeCacheCapacity);
}
return gMspace;
}
size_t
mm_mspace_setfootprint_limit(mm_mspace_t space, size_t size)
{
return mspace_set_footprint_limit(space.opaque, size);
}