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/*
* Copyright (C) 2013 The Android Open Source Project
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
#ifndef ART_RUNTIME_GC_SPACE_MALLOC_SPACE_H_
#define ART_RUNTIME_GC_SPACE_MALLOC_SPACE_H_
#include "space.h"
#include <iosfwd>
#include "base/memory_tool.h"
#include "base/mutex.h"
namespace art {
namespace gc {
namespace collector {
class MarkSweep;
} // namespace collector
namespace space {
class ZygoteSpace;
// A common parent of DlMallocSpace and RosAllocSpace.
class MallocSpace : public ContinuousMemMapAllocSpace {
public:
typedef void(*WalkCallback)(void *start, void *end, size_t num_bytes, void* callback_arg);
SpaceType GetType() const override {
return kSpaceTypeMallocSpace;
}
// Allocate num_bytes allowing the underlying space to grow.
virtual mirror::Object* AllocWithGrowth(Thread* self, size_t num_bytes,
size_t* bytes_allocated, size_t* usable_size,
size_t* bytes_tl_bulk_allocated) = 0;
// Allocate num_bytes without allowing the underlying space to grow.
mirror::Object* Alloc(Thread* self, size_t num_bytes, size_t* bytes_allocated,
size_t* usable_size, size_t* bytes_tl_bulk_allocated) override = 0;
// Return the storage space required by obj. If usable_size isn't null then it is set to the
// amount of the storage space that may be used by obj.
size_t AllocationSize(mirror::Object* obj, size_t* usable_size) override = 0;
size_t Free(Thread* self, mirror::Object* ptr) override
REQUIRES_SHARED(Locks::mutator_lock_) = 0;
size_t FreeList(Thread* self, size_t num_ptrs, mirror::Object** ptrs) override
REQUIRES_SHARED(Locks::mutator_lock_) = 0;
// Returns the maximum bytes that could be allocated for the given
// size in bulk, that is the maximum value for the
// bytes_allocated_bulk out param returned by MallocSpace::Alloc().
virtual size_t MaxBytesBulkAllocatedFor(size_t num_bytes) = 0;
#ifndef NDEBUG
virtual void CheckMoreCoreForPrecondition() {} // to be overridden in the debug build.
#else
void CheckMoreCoreForPrecondition() {} // no-op in the non-debug build.
#endif
void* MoreCore(intptr_t increment);
// Hands unused pages back to the system.
virtual size_t Trim() = 0;
// Perform a mspace_inspect_all which calls back for each allocation chunk. The chunk may not be
// in use, indicated by num_bytes equaling zero.
virtual void Walk(WalkCallback callback, void* arg) = 0;
// Returns the number of bytes that the space has currently obtained from the system. This is
// greater or equal to the amount of live data in the space.
virtual size_t GetFootprint() = 0;
// Returns the number of bytes that the heap is allowed to obtain from the system via MoreCore.
virtual size_t GetFootprintLimit() = 0;
// Set the maximum number of bytes that the heap is allowed to obtain from the system via
// MoreCore. Note this is used to stop the mspace growing beyond the limit to Capacity. When
// allocations fail we GC before increasing the footprint limit and allowing the mspace to grow.
virtual void SetFootprintLimit(size_t limit) = 0;
// Removes the fork time growth limit on capacity, allowing the application to allocate up to the
// maximum reserved size of the heap.
void ClearGrowthLimit() {
growth_limit_ = NonGrowthLimitCapacity();
}
// Override capacity so that we only return the possibly limited capacity
size_t Capacity() const override {
return growth_limit_;
}
// The total amount of memory reserved for the alloc space.
size_t NonGrowthLimitCapacity() const override {
return GetMemMap()->Size();
}
// Change the non growth limit capacity by shrinking or expanding the map. Currently, only
// shrinking is supported.
void ClampGrowthLimit();
void Dump(std::ostream& os) const override;
void SetGrowthLimit(size_t growth_limit);
virtual MallocSpace* CreateInstance(MemMap&& mem_map,
const std::string& name,
void* allocator,
uint8_t* begin,
uint8_t* end,
uint8_t* limit,
size_t growth_limit,
bool can_move_objects) = 0;
// Splits ourself into a zygote space and new malloc space which has our unused memory. When true,
// the low memory mode argument specifies that the heap wishes the created space to be more
// aggressive in releasing unused pages. Invalidates the space its called on.
ZygoteSpace* CreateZygoteSpace(const char* alloc_space_name, bool low_memory_mode,
MallocSpace** out_malloc_space) NO_THREAD_SAFETY_ANALYSIS;
uint64_t GetBytesAllocated() override = 0;
uint64_t GetObjectsAllocated() override = 0;
// Returns the class of a recently freed object.
mirror::Class* FindRecentFreedObject(const mirror::Object* obj);
bool CanMoveObjects() const override {
return can_move_objects_;
}
void DisableMovingObjects() {
can_move_objects_ = false;
}
protected:
MallocSpace(const std::string& name,
MemMap&& mem_map,
uint8_t* begin,
uint8_t* end,
uint8_t* limit,
size_t growth_limit,
bool create_bitmaps,
bool can_move_objects,
size_t starting_size,
size_t initial_size);
static MemMap CreateMemMap(const std::string& name,
size_t starting_size,
size_t* initial_size,
size_t* growth_limit,
size_t* capacity);
// When true the low memory mode argument specifies that the heap wishes the created allocator to
// be more aggressive in releasing unused pages.
virtual void* CreateAllocator(void* base, size_t morecore_start, size_t initial_size,
size_t maximum_size, bool low_memory_mode) = 0;
virtual void RegisterRecentFree(mirror::Object* ptr)
REQUIRES_SHARED(Locks::mutator_lock_)
REQUIRES(lock_);
accounting::ContinuousSpaceBitmap::SweepCallback* GetSweepCallback() override {
return &SweepCallback;
}
// Recent allocation buffer.
static constexpr size_t kRecentFreeCount = kDebugSpaces ? (1 << 16) : 0;
static constexpr size_t kRecentFreeMask = kRecentFreeCount - 1;
std::pair<const mirror::Object*, mirror::Class*> recent_freed_objects_[kRecentFreeCount];
size_t recent_free_pos_;
static size_t bitmap_index_;
// Used to ensure mutual exclusion when the allocation spaces data structures are being modified.
Mutex lock_ DEFAULT_MUTEX_ACQUIRED_AFTER;
// The capacity of the alloc space until such time that ClearGrowthLimit is called.
// The underlying mem_map_ controls the maximum size we allow the heap to grow to. The growth
// limit is a value <= to the mem_map_ capacity used for ergonomic reasons because of the zygote.
// Prior to forking the zygote the heap will have a maximally sized mem_map_ but the growth_limit_
// will be set to a lower value. The growth_limit_ is used as the capacity of the alloc_space_,
// however, capacity normally can't vary. In the case of the growth_limit_ it can be cleared
// one time by a call to ClearGrowthLimit.
size_t growth_limit_;
// True if objects in the space are movable.
bool can_move_objects_;
// Starting and initial sized, used when you reset the space.
const size_t starting_size_;
const size_t initial_size_;
private:
static void SweepCallback(size_t num_ptrs, mirror::Object** ptrs, void* arg)
REQUIRES_SHARED(Locks::mutator_lock_);
DISALLOW_COPY_AND_ASSIGN(MallocSpace);
};
} // namespace space
} // namespace gc
} // namespace art
#endif // ART_RUNTIME_GC_SPACE_MALLOC_SPACE_H_