base/debug/thread_heap_usage_tracker.cc - chromium/src - Git at Google

 // Copyright 2016 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.

 #include "base/debug/thread_heap_usage_tracker.h"

 #include <stdint.h>
 #include <algorithm>
 #include <limits>
 #include <new>
 #include <type_traits>

 #include "base/allocator/allocator_shim.h"
 #include "base/allocator/features.h"
 #include "base/logging.h"
 #include "base/threading/thread_local_storage.h"
 #include "build/build_config.h"

 #if defined(OS_MACOSX) || defined(OS_IOS)
 #include <malloc/malloc.h>
 #else
 #include <malloc.h>
 #endif

 namespace base {
 namespace debug {

 namespace {

 using base::allocator::AllocatorDispatch;

 ThreadLocalStorage::StaticSlot g_thread_allocator_usage = TLS_INITIALIZER;

 const uintptr_t kSentinelMask = std::numeric_limits<uintptr_t>::max() - 1;
 ThreadHeapUsage* const kInitializationSentinel =
     reinterpret_cast<ThreadHeapUsage*>(kSentinelMask);
 ThreadHeapUsage* const kTeardownSentinel =
     reinterpret_cast<ThreadHeapUsage*>(kSentinelMask | 1);

 bool g_heap_tracking_enabled = false;

 // Forward declared as it needs to delegate memory allocation to the next
 // lower shim.
 ThreadHeapUsage* GetOrCreateThreadUsage();

 size_t GetAllocSizeEstimate(const AllocatorDispatch* next,
                             void* ptr,
                             void* context) {
   if (ptr == nullptr)
     return 0U;

   return next->get_size_estimate_function(next, ptr, context);
 }

 void RecordAlloc(const AllocatorDispatch* next,
                  void* ptr,
                  size_t size,
                  void* context) {
   ThreadHeapUsage* usage = GetOrCreateThreadUsage();
   if (usage == nullptr)
     return;

   usage->alloc_ops++;
   size_t estimate = GetAllocSizeEstimate(next, ptr, context);
   if (size && estimate) {
     // Only keep track of the net number of bytes allocated in the scope if the
     // size estimate function returns sane values, e.g. non-zero.
     usage->alloc_bytes += estimate;
     usage->alloc_overhead_bytes += estimate - size;

     // Record the max outstanding number of bytes, but only if the difference
     // is net positive (e.g. more bytes allocated than freed in the scope).
     if (usage->alloc_bytes > usage->free_bytes) {
       uint64_t allocated_bytes = usage->alloc_bytes - usage->free_bytes;
       if (allocated_bytes > usage->max_allocated_bytes)
         usage->max_allocated_bytes = allocated_bytes;
     }
   } else {
     usage->alloc_bytes += size;
   }
 }

 void RecordFree(const AllocatorDispatch* next, void* ptr, void* context) {
   ThreadHeapUsage* usage = GetOrCreateThreadUsage();
   if (usage == nullptr)
     return;

   size_t estimate = GetAllocSizeEstimate(next, ptr, context);
   usage->free_ops++;
   usage->free_bytes += estimate;
 }

 void* AllocFn(const AllocatorDispatch* self, size_t size, void* context) {
   void* ret = self->next->alloc_function(self->next, size, context);
   if (ret != nullptr)
     RecordAlloc(self->next, ret, size, context);

   return ret;
 }

 void* AllocZeroInitializedFn(const AllocatorDispatch* self,
                              size_t n,
                              size_t size,
                              void* context) {
   void* ret =
       self->next->alloc_zero_initialized_function(self->next, n, size, context);
   if (ret != nullptr)
     RecordAlloc(self->next, ret, size, context);

   return ret;
 }

 void* AllocAlignedFn(const AllocatorDispatch* self,
                      size_t alignment,
                      size_t size,
                      void* context) {
   void* ret =
       self->next->alloc_aligned_function(self->next, alignment, size, context);
   if (ret != nullptr)
     RecordAlloc(self->next, ret, size, context);

   return ret;
 }

 void* ReallocFn(const AllocatorDispatch* self,
                 void* address,
                 size_t size,
                 void* context) {
   if (address != nullptr)
     RecordFree(self->next, address, context);

   void* ret = self->next->realloc_function(self->next, address, size, context);
   if (ret != nullptr && size != 0)
     RecordAlloc(self->next, ret, size, context);

   return ret;
 }

 void FreeFn(const AllocatorDispatch* self, void* address, void* context) {
   if (address != nullptr)
     RecordFree(self->next, address, context);
   self->next->free_function(self->next, address, context);
 }

 size_t GetSizeEstimateFn(const AllocatorDispatch* self,
                          void* address,
                          void* context) {
   return self->next->get_size_estimate_function(self->next, address, context);
 }

 unsigned BatchMallocFn(const AllocatorDispatch* self,
                        size_t size,
                        void** results,
                        unsigned num_requested,
                        void* context) {
   unsigned count = self->next->batch_malloc_function(self->next, size, results,
                                                      num_requested, context);
   for (unsigned i = 0; i < count; ++i) {
     RecordAlloc(self->next, results[i], size, context);
   }
   return count;
 }

 void BatchFreeFn(const AllocatorDispatch* self,
                  void** to_be_freed,
                  unsigned num_to_be_freed,
                  void* context) {
   for (unsigned i = 0; i < num_to_be_freed; ++i) {
     if (to_be_freed[i] != nullptr) {
       RecordFree(self->next, to_be_freed[i], context);
     }
   }
   self->next->batch_free_function(self->next, to_be_freed, num_to_be_freed,
                                   context);
 }

 void FreeDefiniteSizeFn(const AllocatorDispatch* self,
                         void* ptr,
                         size_t size,
                         void* context) {
   if (ptr != nullptr)
     RecordFree(self->next, ptr, context);
   self->next->free_definite_size_function(self->next, ptr, size, context);
 }

 // The allocator dispatch used to intercept heap operations.
 AllocatorDispatch allocator_dispatch = {&AllocFn,
                                         &AllocZeroInitializedFn,
                                         &AllocAlignedFn,
                                         &ReallocFn,
                                         &FreeFn,
                                         &GetSizeEstimateFn,
                                         &BatchMallocFn,
                                         &BatchFreeFn,
                                         &FreeDefiniteSizeFn,
                                         nullptr};

 ThreadHeapUsage* GetOrCreateThreadUsage() {
   auto tls_ptr = reinterpret_cast<uintptr_t>(g_thread_allocator_usage.Get());
   if ((tls_ptr & kSentinelMask) == kSentinelMask)
     return nullptr;  // Re-entrancy case.

   auto* allocator_usage = reinterpret_cast<ThreadHeapUsage*>(tls_ptr);
   if (allocator_usage == nullptr) {
     // Prevent reentrancy due to the allocation below.
     g_thread_allocator_usage.Set(kInitializationSentinel);

     allocator_usage = new ThreadHeapUsage();
     static_assert(std::is_pod<ThreadHeapUsage>::value,
                   "AllocatorDispatch must be POD");
     memset(allocator_usage, 0, sizeof(*allocator_usage));
     g_thread_allocator_usage.Set(allocator_usage);
   }

   return allocator_usage;
 }

 }  // namespace

 ThreadHeapUsageTracker::ThreadHeapUsageTracker() : thread_usage_(nullptr) {
   static_assert(std::is_pod<ThreadHeapUsage>::value, "Must be POD.");
 }

 ThreadHeapUsageTracker::~ThreadHeapUsageTracker() {
   DCHECK(thread_checker_.CalledOnValidThread());

   if (thread_usage_ != nullptr) {
     // If this tracker wasn't stopped, make it inclusive so that the
     // usage isn't lost.
     Stop(false);
   }
 }

 void ThreadHeapUsageTracker::Start() {
   DCHECK(thread_checker_.CalledOnValidThread());
   DCHECK(g_thread_allocator_usage.initialized());

   thread_usage_ = GetOrCreateThreadUsage();
   usage_ = *thread_usage_;

   // Reset the stats for our current scope.
   // The per-thread usage instance now tracks this scope's usage, while this
   // instance persists the outer scope's usage stats. On destruction, this
   // instance will restore the outer scope's usage stats with this scope's
   // usage added.
   memset(thread_usage_, 0, sizeof(*thread_usage_));
 }

 void ThreadHeapUsageTracker::Stop(bool usage_is_exclusive) {
   DCHECK(thread_checker_.CalledOnValidThread());
   DCHECK_NE(nullptr, thread_usage_);

   ThreadHeapUsage current = *thread_usage_;
   if (usage_is_exclusive) {
     // Restore the outer scope.
     *thread_usage_ = usage_;
   } else {
     // Update the outer scope with the accrued inner usage.
     if (thread_usage_->max_allocated_bytes) {
       uint64_t outer_net_alloc_bytes = usage_.alloc_bytes - usage_.free_bytes;

       thread_usage_->max_allocated_bytes =
           std::max(usage_.max_allocated_bytes,
                    outer_net_alloc_bytes + thread_usage_->max_allocated_bytes);
     }

     thread_usage_->alloc_ops += usage_.alloc_ops;
     thread_usage_->alloc_bytes += usage_.alloc_bytes;
     thread_usage_->alloc_overhead_bytes += usage_.alloc_overhead_bytes;
     thread_usage_->free_ops += usage_.free_ops;
     thread_usage_->free_bytes += usage_.free_bytes;
   }

   thread_usage_ = nullptr;
   usage_ = current;
 }

 ThreadHeapUsage ThreadHeapUsageTracker::GetUsageSnapshot() {
   DCHECK(g_thread_allocator_usage.initialized());

   ThreadHeapUsage* usage = GetOrCreateThreadUsage();
   DCHECK_NE(nullptr, usage);
   return *usage;
 }

 void ThreadHeapUsageTracker::EnableHeapTracking() {
   EnsureTLSInitialized();

   CHECK_EQ(false, g_heap_tracking_enabled) << "No double-enabling.";
   g_heap_tracking_enabled = true;
 #if BUILDFLAG(USE_ALLOCATOR_SHIM)
   base::allocator::InsertAllocatorDispatch(&allocator_dispatch);
 #else
   CHECK(false) << "Can't enable heap tracking without the shim.";
 #endif  // BUILDFLAG(USE_ALLOCATOR_SHIM)
 }

 bool ThreadHeapUsageTracker::IsHeapTrackingEnabled() {
   return g_heap_tracking_enabled;
 }

 void ThreadHeapUsageTracker::DisableHeapTrackingForTesting() {
 #if BUILDFLAG(USE_ALLOCATOR_SHIM)
   base::allocator::RemoveAllocatorDispatchForTesting(&allocator_dispatch);
 #else
   CHECK(false) << "Can't disable heap tracking without the shim.";
 #endif  // BUILDFLAG(USE_ALLOCATOR_SHIM)
   DCHECK_EQ(true, g_heap_tracking_enabled) << "Heap tracking not enabled.";
   g_heap_tracking_enabled = false;
 }

 base::allocator::AllocatorDispatch*
 ThreadHeapUsageTracker::GetDispatchForTesting() {
   return &allocator_dispatch;
 }

 void ThreadHeapUsageTracker::EnsureTLSInitialized() {
   if (!g_thread_allocator_usage.initialized()) {
     g_thread_allocator_usage.Initialize([](void* thread_heap_usage) {
       // This destructor will be called twice. Once to destroy the actual
       // ThreadHeapUsage instance and a second time, immediately after, for the
       // sentinel. Re-setting the TLS slow (below) does re-initialize the TLS
       // slot. The ThreadLocalStorage code is designed to deal with this use
       // case (see comments in ThreadHeapUsageTracker::EnsureTLSInitialized) and
       // will re-call the destructor with the kTeardownSentinel as arg.
       if (thread_heap_usage == kTeardownSentinel)
         return;
       DCHECK(thread_heap_usage != kInitializationSentinel);

       // Deleting the ThreadHeapUsage TLS object will re-enter the shim and hit
       // RecordFree() above. The sentinel prevents RecordFree() from re-creating
       // another ThreadHeapUsage object.
       g_thread_allocator_usage.Set(kTeardownSentinel);
       delete static_cast<ThreadHeapUsage*>(thread_heap_usage);
     });
   }
 }

 }  // namespace debug
 }  // namespace base
	// Copyright 2016 The Chromium Authors. All rights reserved.
	// Use of this source code is governed by a BSD-style license that can be
	// found in the LICENSE file.

	#include "base/debug/thread_heap_usage_tracker.h"

	#include <stdint.h>
	#include <algorithm>
	#include <limits>
	#include <new>
	#include <type_traits>

	#include "base/allocator/allocator_shim.h"
	#include "base/allocator/features.h"
	#include "base/logging.h"
	#include "base/threading/thread_local_storage.h"
	#include "build/build_config.h"

	#if defined(OS_MACOSX) \|\| defined(OS_IOS)
	#include <malloc/malloc.h>
	#else
	#include <malloc.h>
	#endif

	namespace base {
	namespace debug {

	namespace {

	using base::allocator::AllocatorDispatch;

	ThreadLocalStorage::StaticSlot g_thread_allocator_usage = TLS_INITIALIZER;

	const uintptr_t kSentinelMask = std::numeric_limits<uintptr_t>::max() - 1;
	ThreadHeapUsage* const kInitializationSentinel =
	reinterpret_cast<ThreadHeapUsage*>(kSentinelMask);
	ThreadHeapUsage* const kTeardownSentinel =
	reinterpret_cast<ThreadHeapUsage*>(kSentinelMask \| 1);

	bool g_heap_tracking_enabled = false;

	// Forward declared as it needs to delegate memory allocation to the next
	// lower shim.
	ThreadHeapUsage* GetOrCreateThreadUsage();

	size_t GetAllocSizeEstimate(const AllocatorDispatch* next,
	void* ptr,
	void* context) {
	if (ptr == nullptr)
	return 0U;

	return next->get_size_estimate_function(next, ptr, context);
	}

	void RecordAlloc(const AllocatorDispatch* next,
	void* ptr,
	size_t size,
	void* context) {
	ThreadHeapUsage* usage = GetOrCreateThreadUsage();
	if (usage == nullptr)
	return;

	usage->alloc_ops++;
	size_t estimate = GetAllocSizeEstimate(next, ptr, context);
	if (size && estimate) {
	// Only keep track of the net number of bytes allocated in the scope if the
	// size estimate function returns sane values, e.g. non-zero.
	usage->alloc_bytes += estimate;
	usage->alloc_overhead_bytes += estimate - size;

	// Record the max outstanding number of bytes, but only if the difference
	// is net positive (e.g. more bytes allocated than freed in the scope).
	if (usage->alloc_bytes > usage->free_bytes) {
	uint64_t allocated_bytes = usage->alloc_bytes - usage->free_bytes;
	if (allocated_bytes > usage->max_allocated_bytes)
	usage->max_allocated_bytes = allocated_bytes;
	}
	} else {
	usage->alloc_bytes += size;
	}
	}

	void RecordFree(const AllocatorDispatch* next, void* ptr, void* context) {
	ThreadHeapUsage* usage = GetOrCreateThreadUsage();
	if (usage == nullptr)
	return;

	size_t estimate = GetAllocSizeEstimate(next, ptr, context);
	usage->free_ops++;
	usage->free_bytes += estimate;
	}

	void* AllocFn(const AllocatorDispatch* self, size_t size, void* context) {
	void* ret = self->next->alloc_function(self->next, size, context);
	if (ret != nullptr)
	RecordAlloc(self->next, ret, size, context);

	return ret;
	}

	void* AllocZeroInitializedFn(const AllocatorDispatch* self,
	size_t n,
	size_t size,
	void* context) {
	void* ret =
	self->next->alloc_zero_initialized_function(self->next, n, size, context);
	if (ret != nullptr)
	RecordAlloc(self->next, ret, size, context);

	return ret;
	}

	void* AllocAlignedFn(const AllocatorDispatch* self,
	size_t alignment,
	size_t size,
	void* context) {
	void* ret =
	self->next->alloc_aligned_function(self->next, alignment, size, context);
	if (ret != nullptr)
	RecordAlloc(self->next, ret, size, context);

	return ret;
	}

	void* ReallocFn(const AllocatorDispatch* self,
	void* address,
	size_t size,
	void* context) {
	if (address != nullptr)
	RecordFree(self->next, address, context);

	void* ret = self->next->realloc_function(self->next, address, size, context);
	if (ret != nullptr && size != 0)
	RecordAlloc(self->next, ret, size, context);

	return ret;
	}

	void FreeFn(const AllocatorDispatch* self, void* address, void* context) {
	if (address != nullptr)
	RecordFree(self->next, address, context);
	self->next->free_function(self->next, address, context);
	}

	size_t GetSizeEstimateFn(const AllocatorDispatch* self,
	void* address,
	void* context) {
	return self->next->get_size_estimate_function(self->next, address, context);
	}

	unsigned BatchMallocFn(const AllocatorDispatch* self,
	size_t size,
	void** results,
	unsigned num_requested,
	void* context) {
	unsigned count = self->next->batch_malloc_function(self->next, size, results,
	num_requested, context);
	for (unsigned i = 0; i < count; ++i) {
	RecordAlloc(self->next, results[i], size, context);
	}
	return count;
	}

	void BatchFreeFn(const AllocatorDispatch* self,
	void** to_be_freed,
	unsigned num_to_be_freed,
	void* context) {
	for (unsigned i = 0; i < num_to_be_freed; ++i) {
	if (to_be_freed[i] != nullptr) {
	RecordFree(self->next, to_be_freed[i], context);
	}
	}
	self->next->batch_free_function(self->next, to_be_freed, num_to_be_freed,
	context);
	}

	void FreeDefiniteSizeFn(const AllocatorDispatch* self,
	void* ptr,
	size_t size,
	void* context) {
	if (ptr != nullptr)
	RecordFree(self->next, ptr, context);
	self->next->free_definite_size_function(self->next, ptr, size, context);
	}

	// The allocator dispatch used to intercept heap operations.
	AllocatorDispatch allocator_dispatch = {&AllocFn,
	&AllocZeroInitializedFn,
	&AllocAlignedFn,
	&ReallocFn,
	&FreeFn,
	&GetSizeEstimateFn,
	&BatchMallocFn,
	&BatchFreeFn,
	&FreeDefiniteSizeFn,
	nullptr};

	ThreadHeapUsage* GetOrCreateThreadUsage() {
	auto tls_ptr = reinterpret_cast<uintptr_t>(g_thread_allocator_usage.Get());
	if ((tls_ptr & kSentinelMask) == kSentinelMask)
	return nullptr; // Re-entrancy case.

	auto* allocator_usage = reinterpret_cast<ThreadHeapUsage*>(tls_ptr);
	if (allocator_usage == nullptr) {
	// Prevent reentrancy due to the allocation below.
	g_thread_allocator_usage.Set(kInitializationSentinel);

	allocator_usage = new ThreadHeapUsage();
	static_assert(std::is_pod<ThreadHeapUsage>::value,
	"AllocatorDispatch must be POD");
	memset(allocator_usage, 0, sizeof(*allocator_usage));
	g_thread_allocator_usage.Set(allocator_usage);
	}

	return allocator_usage;
	}

	} // namespace

	ThreadHeapUsageTracker::ThreadHeapUsageTracker() : thread_usage_(nullptr) {
	static_assert(std::is_pod<ThreadHeapUsage>::value, "Must be POD.");
	}

	ThreadHeapUsageTracker::~ThreadHeapUsageTracker() {
	DCHECK(thread_checker_.CalledOnValidThread());

	if (thread_usage_ != nullptr) {
	// If this tracker wasn't stopped, make it inclusive so that the
	// usage isn't lost.
	Stop(false);
	}
	}

	void ThreadHeapUsageTracker::Start() {
	DCHECK(thread_checker_.CalledOnValidThread());
	DCHECK(g_thread_allocator_usage.initialized());

	thread_usage_ = GetOrCreateThreadUsage();
	usage_ = *thread_usage_;

	// Reset the stats for our current scope.
	// The per-thread usage instance now tracks this scope's usage, while this
	// instance persists the outer scope's usage stats. On destruction, this
	// instance will restore the outer scope's usage stats with this scope's
	// usage added.
	memset(thread_usage_, 0, sizeof(*thread_usage_));
	}

	void ThreadHeapUsageTracker::Stop(bool usage_is_exclusive) {
	DCHECK(thread_checker_.CalledOnValidThread());
	DCHECK_NE(nullptr, thread_usage_);

	ThreadHeapUsage current = *thread_usage_;
	if (usage_is_exclusive) {
	// Restore the outer scope.
	*thread_usage_ = usage_;
	} else {
	// Update the outer scope with the accrued inner usage.
	if (thread_usage_->max_allocated_bytes) {
	uint64_t outer_net_alloc_bytes = usage_.alloc_bytes - usage_.free_bytes;

	thread_usage_->max_allocated_bytes =
	std::max(usage_.max_allocated_bytes,
	outer_net_alloc_bytes + thread_usage_->max_allocated_bytes);
	}

	thread_usage_->alloc_ops += usage_.alloc_ops;
	thread_usage_->alloc_bytes += usage_.alloc_bytes;
	thread_usage_->alloc_overhead_bytes += usage_.alloc_overhead_bytes;
	thread_usage_->free_ops += usage_.free_ops;
	thread_usage_->free_bytes += usage_.free_bytes;
	}

	thread_usage_ = nullptr;
	usage_ = current;
	}

	ThreadHeapUsage ThreadHeapUsageTracker::GetUsageSnapshot() {
	DCHECK(g_thread_allocator_usage.initialized());

	ThreadHeapUsage* usage = GetOrCreateThreadUsage();
	DCHECK_NE(nullptr, usage);
	return *usage;
	}

	void ThreadHeapUsageTracker::EnableHeapTracking() {
	EnsureTLSInitialized();

	CHECK_EQ(false, g_heap_tracking_enabled) << "No double-enabling.";
	g_heap_tracking_enabled = true;
	#if BUILDFLAG(USE_ALLOCATOR_SHIM)
	base::allocator::InsertAllocatorDispatch(&allocator_dispatch);
	#else
	CHECK(false) << "Can't enable heap tracking without the shim.";
	#endif // BUILDFLAG(USE_ALLOCATOR_SHIM)
	}

	bool ThreadHeapUsageTracker::IsHeapTrackingEnabled() {
	return g_heap_tracking_enabled;
	}

	void ThreadHeapUsageTracker::DisableHeapTrackingForTesting() {
	#if BUILDFLAG(USE_ALLOCATOR_SHIM)
	base::allocator::RemoveAllocatorDispatchForTesting(&allocator_dispatch);
	#else
	CHECK(false) << "Can't disable heap tracking without the shim.";
	#endif // BUILDFLAG(USE_ALLOCATOR_SHIM)
	DCHECK_EQ(true, g_heap_tracking_enabled) << "Heap tracking not enabled.";
	g_heap_tracking_enabled = false;
	}

	base::allocator::AllocatorDispatch*
	ThreadHeapUsageTracker::GetDispatchForTesting() {
	return &allocator_dispatch;
	}

	void ThreadHeapUsageTracker::EnsureTLSInitialized() {
	if (!g_thread_allocator_usage.initialized()) {
	g_thread_allocator_usage.Initialize([](void* thread_heap_usage) {
	// This destructor will be called twice. Once to destroy the actual
	// ThreadHeapUsage instance and a second time, immediately after, for the
	// sentinel. Re-setting the TLS slow (below) does re-initialize the TLS
	// slot. The ThreadLocalStorage code is designed to deal with this use
	// case (see comments in ThreadHeapUsageTracker::EnsureTLSInitialized) and
	// will re-call the destructor with the kTeardownSentinel as arg.
	if (thread_heap_usage == kTeardownSentinel)
	return;
	DCHECK(thread_heap_usage != kInitializationSentinel);

	// Deleting the ThreadHeapUsage TLS object will re-enter the shim and hit
	// RecordFree() above. The sentinel prevents RecordFree() from re-creating
	// another ThreadHeapUsage object.
	g_thread_allocator_usage.Set(kTeardownSentinel);
	delete static_cast<ThreadHeapUsage*>(thread_heap_usage);
	});
	}
	}

	} // namespace debug
	} // namespace base