1 files changed, 197 insertions, 0 deletions
diff --git a/absl/base/internal/malloc_extension.cc b/absl/base/internal/malloc_extension.cc
new file mode 100644
index 00000000..daf4bc32
--- /dev/null
+++ b/absl/base/internal/malloc_extension.cc
@@ -0,0 +1,197 @@
+// 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 <stdint.h>
+#include <stdio.h>
+#include <string.h>
+#include <atomic>
+#include <string>
+
+#include "absl/base/dynamic_annotations.h"
+#include "absl/base/internal/malloc_extension_c.h"
+#include "absl/base/port.h"
+
+namespace absl {
+namespace base_internal {
+
+// SysAllocator implementation
+SysAllocator::~SysAllocator() {}
+void SysAllocator::GetStats(char* buffer, int) { buffer[0] = 0; }
+
+// 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;
+}