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// Copyright 2017 The Abseil Authors.
//
// 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.
#include "absl/base/internal/malloc_extension.h"
#include <assert.h>
#include <string.h>
#include <atomic>
#include <string>
#include "absl/base/dynamic_annotations.h"
#include "absl/base/internal/malloc_extension_c.h"
namespace absl {
namespace base_internal {
// SysAllocator implementation
SysAllocator::~SysAllocator() {}
void SysAllocator::GetStats(char* buffer, int) { buffer[0] = 0; }
// Dummy key method to avoid weak vtable.
void MallocExtensionWriter::UnusedKeyMethod() {}
void StringMallocExtensionWriter::Write(const char* buf, int len) {
out_->append(buf, len);
}
// Default implementation -- does nothing
MallocExtension::~MallocExtension() { }
bool MallocExtension::VerifyAllMemory() { return true; }
bool MallocExtension::VerifyNewMemory(const void*) { return true; }
bool MallocExtension::VerifyArrayNewMemory(const void*) { return true; }
bool MallocExtension::VerifyMallocMemory(const void*) { return true; }
bool MallocExtension::GetNumericProperty(const char*, size_t*) {
return false;
}
bool MallocExtension::SetNumericProperty(const char*, size_t) {
return false;
}
void MallocExtension::GetStats(char* buffer, int length) {
assert(length > 0);
static_cast<void>(length);
buffer[0] = '\0';
}
bool MallocExtension::MallocMemoryStats(int* blocks, size_t* total,
int histogram[kMallocHistogramSize]) {
*blocks = 0;
*total = 0;
memset(histogram, 0, sizeof(*histogram) * kMallocHistogramSize);
return true;
}
void MallocExtension::MarkThreadIdle() {
// Default implementation does nothing
}
void MallocExtension::MarkThreadBusy() {
// Default implementation does nothing
}
SysAllocator* MallocExtension::GetSystemAllocator() {
return nullptr;
}
void MallocExtension::SetSystemAllocator(SysAllocator*) {
// Default implementation does nothing
}
void MallocExtension::ReleaseToSystem(size_t) {
// Default implementation does nothing
}
void MallocExtension::ReleaseFreeMemory() {
ReleaseToSystem(static_cast<size_t>(-1)); // SIZE_T_MAX
}
void MallocExtension::SetMemoryReleaseRate(double) {
// Default implementation does nothing
}
double MallocExtension::GetMemoryReleaseRate() {
return -1.0;
}
size_t MallocExtension::GetEstimatedAllocatedSize(size_t size) {
return size;
}
size_t MallocExtension::GetAllocatedSize(const void* p) {
assert(GetOwnership(p) != kNotOwned);
static_cast<void>(p);
return 0;
}
MallocExtension::Ownership MallocExtension::GetOwnership(const void*) {
return kUnknownOwnership;
}
void MallocExtension::GetProperties(MallocExtension::StatLevel,
std::map<std::string, Property>* result) {
result->clear();
}
size_t MallocExtension::ReleaseCPUMemory(int) {
return 0;
}
// The current malloc extension object.
std::atomic<MallocExtension*> MallocExtension::current_instance_;
MallocExtension* MallocExtension::InitModule() {
MallocExtension* ext = new MallocExtension;
current_instance_.store(ext, std::memory_order_release);
return ext;
}
void MallocExtension::Register(MallocExtension* implementation) {
InitModuleOnce();
// When running under valgrind, our custom malloc is replaced with
// valgrind's one and malloc extensions will not work. (Note:
// callers should be responsible for checking that they are the
// malloc that is really being run, before calling Register. This
// is just here as an extra sanity check.)
// Under compiler-based ThreadSanitizer RunningOnValgrind() returns true,
// but we still want to use malloc extensions.
#ifndef THREAD_SANITIZER
if (RunningOnValgrind()) {
return;
}
#endif // #ifndef THREAD_SANITIZER
current_instance_.store(implementation, std::memory_order_release);
}
void MallocExtension::GetHeapSample(MallocExtensionWriter*) {}
void MallocExtension::GetHeapGrowthStacks(MallocExtensionWriter*) {}
void MallocExtension::GetFragmentationProfile(MallocExtensionWriter*) {}
} // namespace base_internal
} // namespace absl
// These are C shims that work on the current instance.
#define C_SHIM(fn, retval, paramlist, arglist) \
extern "C" retval MallocExtension_##fn paramlist { \
return absl::base_internal::MallocExtension::instance()->fn arglist; \
}
C_SHIM(VerifyAllMemory, int, (void), ());
C_SHIM(VerifyNewMemory, int, (const void* p), (p));
C_SHIM(VerifyArrayNewMemory, int, (const void* p), (p));
C_SHIM(VerifyMallocMemory, int, (const void* p), (p));
C_SHIM(
MallocMemoryStats, int,
(int* blocks, size_t* total,
int histogram[absl::base_internal::MallocExtension::kMallocHistogramSize]),
(blocks, total, histogram));
C_SHIM(GetStats, void,
(char* buffer, int buffer_length), (buffer, buffer_length));
C_SHIM(GetNumericProperty, int,
(const char* property, size_t* value), (property, value));
C_SHIM(SetNumericProperty, int,
(const char* property, size_t value), (property, value));
C_SHIM(MarkThreadIdle, void, (void), ());
C_SHIM(MarkThreadBusy, void, (void), ());
C_SHIM(ReleaseFreeMemory, void, (void), ());
C_SHIM(ReleaseToSystem, void, (size_t num_bytes), (num_bytes));
C_SHIM(GetEstimatedAllocatedSize, size_t, (size_t size), (size));
C_SHIM(GetAllocatedSize, size_t, (const void* p), (p));
// Can't use the shim here because of the need to translate the enums.
extern "C"
MallocExtension_Ownership MallocExtension_GetOwnership(const void* p) {
return static_cast<MallocExtension_Ownership>(
absl::base_internal::MallocExtension::instance()->GetOwnership(p));
}
// Default implementation just returns size. The expectation is that
// the linked-in malloc implementation might provide an override of
// this weak function with a better implementation.
ABSL_ATTRIBUTE_WEAK ABSL_ATTRIBUTE_NOINLINE size_t nallocx(size_t size, int) {
return size;
}
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