runtime/jit/profiling_info.cc - platform/art - Git at Google

 /*
  * Copyright (C) 2015 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.
  */

 #include "profiling_info.h"

 #include "art_method-inl.h"
 #include "dex/dex_instruction.h"
 #include "jit/jit.h"
 #include "jit/jit_code_cache.h"
 #include "scoped_thread_state_change-inl.h"
 #include "thread.h"

 namespace art HIDDEN {

 ProfilingInfo::ProfilingInfo(ArtMethod* method,
                              const std::vector<uint32_t>& inline_cache_entries,
                              const std::vector<uint32_t>& branch_cache_entries)
       : baseline_hotness_count_(GetOptimizeThreshold()),
         method_(method),
         number_of_inline_caches_(inline_cache_entries.size()),
         number_of_branch_caches_(branch_cache_entries.size()),
         current_inline_uses_(0) {
   InlineCache* inline_caches = GetInlineCaches();
   memset(inline_caches, 0, number_of_inline_caches_ * sizeof(InlineCache));
   for (size_t i = 0; i < number_of_inline_caches_; ++i) {
     inline_caches[i].dex_pc_ = inline_cache_entries[i];
   }

   BranchCache* branch_caches = GetBranchCaches();
   memset(branch_caches, 0, number_of_branch_caches_ * sizeof(BranchCache));
   for (size_t i = 0; i < number_of_branch_caches_; ++i) {
     branch_caches[i].dex_pc_ = branch_cache_entries[i];
   }
 }

 uint16_t ProfilingInfo::GetOptimizeThreshold() {
   return Runtime::Current()->GetJITOptions()->GetOptimizeThreshold();
 }

 ProfilingInfo* ProfilingInfo::Create(Thread* self,
                                      ArtMethod* method,
                                      const std::vector<uint32_t>& inline_cache_entries) {
   // Walk over the dex instructions of the method and keep track of
   // instructions we are interested in profiling.
   DCHECK(!method->IsNative());

   std::vector<uint32_t> branch_cache_entries;
   for (const DexInstructionPcPair& inst : method->DexInstructions()) {
     switch (inst->Opcode()) {
       case Instruction::IF_EQ:
       case Instruction::IF_EQZ:
       case Instruction::IF_NE:
       case Instruction::IF_NEZ:
       case Instruction::IF_LT:
       case Instruction::IF_LTZ:
       case Instruction::IF_LE:
       case Instruction::IF_LEZ:
       case Instruction::IF_GT:
       case Instruction::IF_GTZ:
       case Instruction::IF_GE:
       case Instruction::IF_GEZ:
         branch_cache_entries.push_back(inst.DexPc());
         break;

       default:
         break;
     }
   }

   // We always create a `ProfilingInfo` object, even if there is no instruction we are
   // interested in. The JIT code cache internally uses it for hotness counter.

   // Allocate the `ProfilingInfo` object int the JIT's data space.
   jit::JitCodeCache* code_cache = Runtime::Current()->GetJit()->GetCodeCache();
   return code_cache->AddProfilingInfo(self, method, inline_cache_entries, branch_cache_entries);
 }

 InlineCache* ProfilingInfo::GetInlineCache(uint32_t dex_pc) {
   // TODO: binary search if array is too long.
   InlineCache* caches = GetInlineCaches();
   for (size_t i = 0; i < number_of_inline_caches_; ++i) {
     if (caches[i].dex_pc_ == dex_pc) {
       return &caches[i];
     }
   }
   return nullptr;
 }

 BranchCache* ProfilingInfo::GetBranchCache(uint32_t dex_pc) {
   // TODO: binary search if array is too long.
   BranchCache* caches = GetBranchCaches();
   for (size_t i = 0; i < number_of_branch_caches_; ++i) {
     if (caches[i].dex_pc_ == dex_pc) {
       return &caches[i];
     }
   }
   // Currently, only if instructions are profiled. The compiler will see other
   // branches, like switches.
   return nullptr;
 }

 void ProfilingInfo::AddInvokeInfo(uint32_t dex_pc, mirror::Class* cls) {
   InlineCache* cache = GetInlineCache(dex_pc);
   if (cache == nullptr) {
     return;
   }
   for (size_t i = 0; i < InlineCache::kIndividualCacheSize; ++i) {
     mirror::Class* existing = cache->classes_[i].Read<kWithoutReadBarrier>();
     mirror::Class* marked = ReadBarrier::IsMarked(existing);
     if (marked == cls) {
       // Receiver type is already in the cache, nothing else to do.
       return;
     } else if (marked == nullptr) {
       // Cache entry is empty, try to put `cls` in it.
       // Note: it's ok to spin on 'existing' here: if 'existing' is not null, that means
       // it is a stalled heap address, which will only be cleared during SweepSystemWeaks,
       // *after* this thread hits a suspend point.
       GcRoot<mirror::Class> expected_root(existing);
       GcRoot<mirror::Class> desired_root(cls);
       auto atomic_root = reinterpret_cast<Atomic<GcRoot<mirror::Class>>*>(&cache->classes_[i]);
       if (!atomic_root->CompareAndSetStrongSequentiallyConsistent(expected_root, desired_root)) {
         // Some other thread put a class in the cache, continue iteration starting at this
         // entry in case the entry contains `cls`.
         --i;
       } else {
         // We successfully set `cls`, just return.
         return;
       }
     }
   }
   // Unsuccessfull - cache is full, making it megamorphic. We do not DCHECK it though,
   // as the garbage collector might clear the entries concurrently.
 }

 ScopedProfilingInfoUse::ScopedProfilingInfoUse(jit::Jit* jit, ArtMethod* method, Thread* self)
     : jit_(jit),
       method_(method),
       self_(self),
       // Fetch the profiling info ahead of using it. If it's null when fetching,
       // we should not call JitCodeCache::DoneCompilerUse.
       profiling_info_(jit == nullptr
                           ? nullptr
                           : jit->GetCodeCache()->NotifyCompilerUse(method, self))
     {}

 ScopedProfilingInfoUse::~ScopedProfilingInfoUse() {
   if (profiling_info_ != nullptr) {
     jit_->GetCodeCache()->DoneCompilerUse(method_, self_);
   }
 }

 uint32_t InlineCache::EncodeDexPc(ArtMethod* method,
                                   const std::vector<uint32_t>& dex_pcs,
                                   uint32_t inline_max_code_units) {
   if (kIsDebugBuild) {
     // Make sure `inline_max_code_units` is always the same.
     static uint32_t global_max_code_units = inline_max_code_units;
     CHECK_EQ(global_max_code_units, inline_max_code_units);
   }
   if (dex_pcs.size() - 1 > MaxDexPcEncodingDepth(method, inline_max_code_units)) {
     return -1;
   }
   uint32_t size = dex_pcs.size();
   uint32_t insns_size = method->DexInstructions().InsnsSizeInCodeUnits();

   uint32_t dex_pc = dex_pcs[size - 1];
   uint32_t shift = MinimumBitsToStore(insns_size - 1);
   for (uint32_t i = size - 1; i > 0; --i) {
     DCHECK_LT(shift, BitSizeOf<uint32_t>());
     dex_pc += ((dex_pcs[i - 1] + 1) << shift);
     shift += MinimumBitsToStore(inline_max_code_units);
   }
   return dex_pc;
 }

 uint32_t InlineCache::MaxDexPcEncodingDepth(ArtMethod* method, uint32_t inline_max_code_units) {
   uint32_t insns_size = method->DexInstructions().InsnsSizeInCodeUnits();
   uint32_t num_bits = MinimumBitsToStore(insns_size - 1);
   uint32_t depth = 0;
   do {
     depth++;
     num_bits += MinimumBitsToStore(inline_max_code_units);
   } while (num_bits <= BitSizeOf<uint32_t>());
   return depth - 1;
 }

 }  // namespace art
	/*
	* Copyright (C) 2015 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.
	*/

	#include "profiling_info.h"

	#include "art_method-inl.h"
	#include "dex/dex_instruction.h"
	#include "jit/jit.h"
	#include "jit/jit_code_cache.h"
	#include "scoped_thread_state_change-inl.h"
	#include "thread.h"

	namespace art HIDDEN {

	ProfilingInfo::ProfilingInfo(ArtMethod* method,
	const std::vector<uint32_t>& inline_cache_entries,
	const std::vector<uint32_t>& branch_cache_entries)
	: baseline_hotness_count_(GetOptimizeThreshold()),
	method_(method),
	number_of_inline_caches_(inline_cache_entries.size()),
	number_of_branch_caches_(branch_cache_entries.size()),
	current_inline_uses_(0) {
	InlineCache* inline_caches = GetInlineCaches();
	memset(inline_caches, 0, number_of_inline_caches_ * sizeof(InlineCache));
	for (size_t i = 0; i < number_of_inline_caches_; ++i) {
	inline_caches[i].dex_pc_ = inline_cache_entries[i];
	}

	BranchCache* branch_caches = GetBranchCaches();
	memset(branch_caches, 0, number_of_branch_caches_ * sizeof(BranchCache));
	for (size_t i = 0; i < number_of_branch_caches_; ++i) {
	branch_caches[i].dex_pc_ = branch_cache_entries[i];
	}
	}

	uint16_t ProfilingInfo::GetOptimizeThreshold() {
	return Runtime::Current()->GetJITOptions()->GetOptimizeThreshold();
	}

	ProfilingInfo* ProfilingInfo::Create(Thread* self,
	ArtMethod* method,
	const std::vector<uint32_t>& inline_cache_entries) {
	// Walk over the dex instructions of the method and keep track of
	// instructions we are interested in profiling.
	DCHECK(!method->IsNative());

	std::vector<uint32_t> branch_cache_entries;
	for (const DexInstructionPcPair& inst : method->DexInstructions()) {
	switch (inst->Opcode()) {
	case Instruction::IF_EQ:
	case Instruction::IF_EQZ:
	case Instruction::IF_NE:
	case Instruction::IF_NEZ:
	case Instruction::IF_LT:
	case Instruction::IF_LTZ:
	case Instruction::IF_LE:
	case Instruction::IF_LEZ:
	case Instruction::IF_GT:
	case Instruction::IF_GTZ:
	case Instruction::IF_GE:
	case Instruction::IF_GEZ:
	branch_cache_entries.push_back(inst.DexPc());
	break;

	default:
	break;
	}
	}

	// We always create a `ProfilingInfo` object, even if there is no instruction we are
	// interested in. The JIT code cache internally uses it for hotness counter.

	// Allocate the `ProfilingInfo` object int the JIT's data space.
	jit::JitCodeCache* code_cache = Runtime::Current()->GetJit()->GetCodeCache();
	return code_cache->AddProfilingInfo(self, method, inline_cache_entries, branch_cache_entries);
	}

	InlineCache* ProfilingInfo::GetInlineCache(uint32_t dex_pc) {
	// TODO: binary search if array is too long.
	InlineCache* caches = GetInlineCaches();
	for (size_t i = 0; i < number_of_inline_caches_; ++i) {
	if (caches[i].dex_pc_ == dex_pc) {
	return &caches[i];
	}
	}
	return nullptr;
	}

	BranchCache* ProfilingInfo::GetBranchCache(uint32_t dex_pc) {
	// TODO: binary search if array is too long.
	BranchCache* caches = GetBranchCaches();
	for (size_t i = 0; i < number_of_branch_caches_; ++i) {
	if (caches[i].dex_pc_ == dex_pc) {
	return &caches[i];
	}
	}
	// Currently, only if instructions are profiled. The compiler will see other
	// branches, like switches.
	return nullptr;
	}

	void ProfilingInfo::AddInvokeInfo(uint32_t dex_pc, mirror::Class* cls) {
	InlineCache* cache = GetInlineCache(dex_pc);
	if (cache == nullptr) {
	return;
	}
	for (size_t i = 0; i < InlineCache::kIndividualCacheSize; ++i) {
	mirror::Class* existing = cache->classes_[i].Read<kWithoutReadBarrier>();
	mirror::Class* marked = ReadBarrier::IsMarked(existing);
	if (marked == cls) {
	// Receiver type is already in the cache, nothing else to do.
	return;
	} else if (marked == nullptr) {
	// Cache entry is empty, try to put `cls` in it.
	// Note: it's ok to spin on 'existing' here: if 'existing' is not null, that means
	// it is a stalled heap address, which will only be cleared during SweepSystemWeaks,
	// after this thread hits a suspend point.
	GcRoot<mirror::Class> expected_root(existing);
	GcRoot<mirror::Class> desired_root(cls);
	auto atomic_root = reinterpret_cast<Atomic<GcRoot<mirror::Class>>*>(&cache->classes_[i]);
	if (!atomic_root->CompareAndSetStrongSequentiallyConsistent(expected_root, desired_root)) {
	// Some other thread put a class in the cache, continue iteration starting at this
	// entry in case the entry contains `cls`.
	--i;
	} else {
	// We successfully set `cls`, just return.
	return;
	}
	}
	}
	// Unsuccessfull - cache is full, making it megamorphic. We do not DCHECK it though,
	// as the garbage collector might clear the entries concurrently.
	}

	ScopedProfilingInfoUse::ScopedProfilingInfoUse(jit::Jit* jit, ArtMethod* method, Thread* self)
	: jit_(jit),
	method_(method),
	self_(self),
	// Fetch the profiling info ahead of using it. If it's null when fetching,
	// we should not call JitCodeCache::DoneCompilerUse.
	profiling_info_(jit == nullptr
	? nullptr
	: jit->GetCodeCache()->NotifyCompilerUse(method, self))
	{}

	ScopedProfilingInfoUse::~ScopedProfilingInfoUse() {
	if (profiling_info_ != nullptr) {
	jit_->GetCodeCache()->DoneCompilerUse(method_, self_);
	}
	}

	uint32_t InlineCache::EncodeDexPc(ArtMethod* method,
	const std::vector<uint32_t>& dex_pcs,
	uint32_t inline_max_code_units) {
	if (kIsDebugBuild) {
	// Make sure `inline_max_code_units` is always the same.
	static uint32_t global_max_code_units = inline_max_code_units;
	CHECK_EQ(global_max_code_units, inline_max_code_units);
	}
	if (dex_pcs.size() - 1 > MaxDexPcEncodingDepth(method, inline_max_code_units)) {
	return -1;
	}
	uint32_t size = dex_pcs.size();
	uint32_t insns_size = method->DexInstructions().InsnsSizeInCodeUnits();

	uint32_t dex_pc = dex_pcs[size - 1];
	uint32_t shift = MinimumBitsToStore(insns_size - 1);
	for (uint32_t i = size - 1; i > 0; --i) {
	DCHECK_LT(shift, BitSizeOf<uint32_t>());
	dex_pc += ((dex_pcs[i - 1] + 1) << shift);
	shift += MinimumBitsToStore(inline_max_code_units);
	}
	return dex_pc;
	}

	uint32_t InlineCache::MaxDexPcEncodingDepth(ArtMethod* method, uint32_t inline_max_code_units) {
	uint32_t insns_size = method->DexInstructions().InsnsSizeInCodeUnits();
	uint32_t num_bits = MinimumBitsToStore(insns_size - 1);
	uint32_t depth = 0;
	do {
	depth++;
	num_bits += MinimumBitsToStore(inline_max_code_units);
	} while (num_bits <= BitSizeOf<uint32_t>());
	return depth - 1;
	}

	} // namespace art