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/*
* Copyright 2014 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 "jit_code_cache.h"
#include <sstream>
#include "art_method-inl.h"
#include "base/enums.h"
#include "base/stl_util.h"
#include "base/systrace.h"
#include "base/time_utils.h"
#include "debugger_interface.h"
#include "entrypoints/runtime_asm_entrypoints.h"
#include "gc/accounting/bitmap-inl.h"
#include "gc/scoped_gc_critical_section.h"
#include "jit/jit.h"
#include "jit/profiling_info.h"
#include "linear_alloc.h"
#include "mem_map.h"
#include "oat_file-inl.h"
#include "scoped_thread_state_change-inl.h"
#include "thread_list.h"
namespace art {
namespace jit {
static constexpr int kProtAll = PROT_READ | PROT_WRITE | PROT_EXEC;
static constexpr int kProtData = PROT_READ | PROT_WRITE;
static constexpr int kProtCode = PROT_READ | PROT_EXEC;
static constexpr size_t kCodeSizeLogThreshold = 50 * KB;
static constexpr size_t kStackMapSizeLogThreshold = 50 * KB;
#define CHECKED_MPROTECT(memory, size, prot) \
do { \
int rc = mprotect(memory, size, prot); \
if (UNLIKELY(rc != 0)) { \
errno = rc; \
PLOG(FATAL) << "Failed to mprotect jit code cache"; \
} \
} while (false) \
JitCodeCache* JitCodeCache::Create(size_t initial_capacity,
size_t max_capacity,
bool generate_debug_info,
std::string* error_msg) {
ScopedTrace trace(__PRETTY_FUNCTION__);
CHECK_GE(max_capacity, initial_capacity);
// Generating debug information is mostly for using the 'perf' tool, which does
// not work with ashmem.
bool use_ashmem = !generate_debug_info;
// With 'perf', we want a 1-1 mapping between an address and a method.
bool garbage_collect_code = !generate_debug_info;
// We need to have 32 bit offsets from method headers in code cache which point to things
// in the data cache. If the maps are more than 4G apart, having multiple maps wouldn't work.
// Ensure we're below 1 GB to be safe.
if (max_capacity > 1 * GB) {
std::ostringstream oss;
oss << "Maxium code cache capacity is limited to 1 GB, "
<< PrettySize(max_capacity) << " is too big";
*error_msg = oss.str();
return nullptr;
}
std::string error_str;
// Map name specific for android_os_Debug.cpp accounting.
MemMap* data_map = MemMap::MapAnonymous(
"data-code-cache", nullptr, max_capacity, kProtAll, false, false, &error_str, use_ashmem);
if (data_map == nullptr) {
std::ostringstream oss;
oss << "Failed to create read write execute cache: " << error_str << " size=" << max_capacity;
*error_msg = oss.str();
return nullptr;
}
// Align both capacities to page size, as that's the unit mspaces use.
initial_capacity = RoundDown(initial_capacity, 2 * kPageSize);
max_capacity = RoundDown(max_capacity, 2 * kPageSize);
// Data cache is 1 / 2 of the map.
// TODO: Make this variable?
size_t data_size = max_capacity / 2;
size_t code_size = max_capacity - data_size;
DCHECK_EQ(code_size + data_size, max_capacity);
uint8_t* divider = data_map->Begin() + data_size;
MemMap* code_map =
data_map->RemapAtEnd(divider, "jit-code-cache", kProtAll, &error_str, use_ashmem);
if (code_map == nullptr) {
std::ostringstream oss;
oss << "Failed to create read write execute cache: " << error_str << " size=" << max_capacity;
*error_msg = oss.str();
return nullptr;
}
DCHECK_EQ(code_map->Begin(), divider);
data_size = initial_capacity / 2;
code_size = initial_capacity - data_size;
DCHECK_EQ(code_size + data_size, initial_capacity);
return new JitCodeCache(
code_map, data_map, code_size, data_size, max_capacity, garbage_collect_code);
}
JitCodeCache::JitCodeCache(MemMap* code_map,
MemMap* data_map,
size_t initial_code_capacity,
size_t initial_data_capacity,
size_t max_capacity,
bool garbage_collect_code)
: lock_("Jit code cache", kJitCodeCacheLock),
lock_cond_("Jit code cache variable", lock_),
collection_in_progress_(false),
code_map_(code_map),
data_map_(data_map),
max_capacity_(max_capacity),
current_capacity_(initial_code_capacity + initial_data_capacity),
code_end_(initial_code_capacity),
data_end_(initial_data_capacity),
last_collection_increased_code_cache_(false),
last_update_time_ns_(0),
garbage_collect_code_(garbage_collect_code),
used_memory_for_data_(0),
used_memory_for_code_(0),
number_of_compilations_(0),
number_of_osr_compilations_(0),
number_of_deoptimizations_(0),
number_of_collections_(0),
histogram_stack_map_memory_use_("Memory used for stack maps", 16),
histogram_code_memory_use_("Memory used for compiled code", 16),
histogram_profiling_info_memory_use_("Memory used for profiling info", 16) {
DCHECK_GE(max_capacity, initial_code_capacity + initial_data_capacity);
code_mspace_ = create_mspace_with_base(code_map_->Begin(), code_end_, false /*locked*/);
data_mspace_ = create_mspace_with_base(data_map_->Begin(), data_end_, false /*locked*/);
if (code_mspace_ == nullptr || data_mspace_ == nullptr) {
PLOG(FATAL) << "create_mspace_with_base failed";
}
SetFootprintLimit(current_capacity_);
CHECKED_MPROTECT(code_map_->Begin(), code_map_->Size(), kProtCode);
CHECKED_MPROTECT(data_map_->Begin(), data_map_->Size(), kProtData);
VLOG(jit) << "Created jit code cache: initial data size="
<< PrettySize(initial_data_capacity)
<< ", initial code size="
<< PrettySize(initial_code_capacity);
}
bool JitCodeCache::ContainsPc(const void* ptr) const {
return code_map_->Begin() <= ptr && ptr < code_map_->End();
}
bool JitCodeCache::ContainsMethod(ArtMethod* method) {
MutexLock mu(Thread::Current(), lock_);
for (auto& it : method_code_map_) {
if (it.second == method) {
return true;
}
}
return false;
}
class ScopedCodeCacheWrite : ScopedTrace {
public:
explicit ScopedCodeCacheWrite(MemMap* code_map)
: ScopedTrace("ScopedCodeCacheWrite"),
code_map_(code_map) {
ScopedTrace trace("mprotect all");
CHECKED_MPROTECT(code_map_->Begin(), code_map_->Size(), kProtAll);
}
~ScopedCodeCacheWrite() {
ScopedTrace trace("mprotect code");
CHECKED_MPROTECT(code_map_->Begin(), code_map_->Size(), kProtCode);
}
private:
MemMap* const code_map_;
DISALLOW_COPY_AND_ASSIGN(ScopedCodeCacheWrite);
};
uint8_t* JitCodeCache::CommitCode(Thread* self,
ArtMethod* method,
const uint8_t* vmap_table,
size_t frame_size_in_bytes,
size_t core_spill_mask,
size_t fp_spill_mask,
const uint8_t* code,
size_t code_size,
bool osr) {
uint8_t* result = CommitCodeInternal(self,
method,
vmap_table,
frame_size_in_bytes,
core_spill_mask,
fp_spill_mask,
code,
code_size,
osr);
if (result == nullptr) {
// Retry.
GarbageCollectCache(self);
result = CommitCodeInternal(self,
method,
vmap_table,
frame_size_in_bytes,
core_spill_mask,
fp_spill_mask,
code,
code_size,
osr);
}
return result;
}
bool JitCodeCache::WaitForPotentialCollectionToComplete(Thread* self) {
bool in_collection = false;
while (collection_in_progress_) {
in_collection = true;
lock_cond_.Wait(self);
}
return in_collection;
}
static uintptr_t FromCodeToAllocation(const void* code) {
size_t alignment = GetInstructionSetAlignment(kRuntimeISA);
return reinterpret_cast<uintptr_t>(code) - RoundUp(sizeof(OatQuickMethodHeader), alignment);
}
void JitCodeCache::FreeCode(const void* code_ptr, ArtMethod* method ATTRIBUTE_UNUSED) {
uintptr_t allocation = FromCodeToAllocation(code_ptr);
const OatQuickMethodHeader* method_header = OatQuickMethodHeader::FromCodePointer(code_ptr);
// Notify native debugger that we are about to remove the code.
// It does nothing if we are not using native debugger.
DeleteJITCodeEntryForAddress(reinterpret_cast<uintptr_t>(code_ptr));
// Use the offset directly to prevent sanity check that the method is
// compiled with optimizing.
// TODO(ngeoffray): Clean up.
if (method_header->vmap_table_offset_ != 0) {
const uint8_t* data = method_header->code_ - method_header->vmap_table_offset_;
FreeData(const_cast<uint8_t*>(data));
}
FreeCode(reinterpret_cast<uint8_t*>(allocation));
}
void JitCodeCache::RemoveMethodsIn(Thread* self, const LinearAlloc& alloc) {
ScopedTrace trace(__PRETTY_FUNCTION__);
MutexLock mu(self, lock_);
// We do not check if a code cache GC is in progress, as this method comes
// with the classlinker_classes_lock_ held, and suspending ourselves could
// lead to a deadlock.
{
ScopedCodeCacheWrite scc(code_map_.get());
for (auto it = method_code_map_.begin(); it != method_code_map_.end();) {
if (alloc.ContainsUnsafe(it->second)) {
FreeCode(it->first, it->second);
it = method_code_map_.erase(it);
} else {
++it;
}
}
}
for (auto it = osr_code_map_.begin(); it != osr_code_map_.end();) {
if (alloc.ContainsUnsafe(it->first)) {
// Note that the code has already been removed in the loop above.
it = osr_code_map_.erase(it);
} else {
++it;
}
}
for (auto it = profiling_infos_.begin(); it != profiling_infos_.end();) {
ProfilingInfo* info = *it;
if (alloc.ContainsUnsafe(info->GetMethod())) {
info->GetMethod()->SetProfilingInfo(nullptr);
FreeData(reinterpret_cast<uint8_t*>(info));
it = profiling_infos_.erase(it);
} else {
++it;
}
}
}
void JitCodeCache::ClearGcRootsInInlineCaches(Thread* self) {
MutexLock mu(self, lock_);
for (ProfilingInfo* info : profiling_infos_) {
if (!info->IsInUseByCompiler()) {
info->ClearGcRootsInInlineCaches();
}
}
}
uint8_t* JitCodeCache::CommitCodeInternal(Thread* self,
ArtMethod* method,
const uint8_t* vmap_table,
size_t frame_size_in_bytes,
size_t core_spill_mask,
size_t fp_spill_mask,
const uint8_t* code,
size_t code_size,
bool osr) {
size_t alignment = GetInstructionSetAlignment(kRuntimeISA);
// Ensure the header ends up at expected instruction alignment.
size_t header_size = RoundUp(sizeof(OatQuickMethodHeader), alignment);
size_t total_size = header_size + code_size;
OatQuickMethodHeader* method_header = nullptr;
uint8_t* code_ptr = nullptr;
uint8_t* memory = nullptr;
{
ScopedThreadSuspension sts(self, kSuspended);
MutexLock mu(self, lock_);
WaitForPotentialCollectionToComplete(self);
{
ScopedCodeCacheWrite scc(code_map_.get());
memory = AllocateCode(total_size);
if (memory == nullptr) {
return nullptr;
}
code_ptr = memory + header_size;
std::copy(code, code + code_size, code_ptr);
method_header = OatQuickMethodHeader::FromCodePointer(code_ptr);
new (method_header) OatQuickMethodHeader(
(vmap_table == nullptr) ? 0 : code_ptr - vmap_table,
frame_size_in_bytes,
core_spill_mask,
fp_spill_mask,
code_size);
}
FlushInstructionCache(reinterpret_cast<char*>(code_ptr),
reinterpret_cast<char*>(code_ptr + code_size));
number_of_compilations_++;
}
// We need to update the entry point in the runnable state for the instrumentation.
{
MutexLock mu(self, lock_);
method_code_map_.Put(code_ptr, method);
if (osr) {
number_of_osr_compilations_++;
osr_code_map_.Put(method, code_ptr);
} else {
Runtime::Current()->GetInstrumentation()->UpdateMethodsCode(
method, method_header->GetEntryPoint());
}
if (collection_in_progress_) {
// We need to update the live bitmap if there is a GC to ensure it sees this new
// code.
GetLiveBitmap()->AtomicTestAndSet(FromCodeToAllocation(code_ptr));
}
last_update_time_ns_.StoreRelease(NanoTime());
VLOG(jit)
<< "JIT added (osr=" << std::boolalpha << osr << std::noboolalpha << ") "
<< PrettyMethod(method) << "@" << method
<< " ccache_size=" << PrettySize(CodeCacheSizeLocked()) << ": "
<< " dcache_size=" << PrettySize(DataCacheSizeLocked()) << ": "
<< reinterpret_cast<const void*>(method_header->GetEntryPoint()) << ","
<< reinterpret_cast<const void*>(method_header->GetEntryPoint() + method_header->code_size_);
histogram_code_memory_use_.AddValue(code_size);
if (code_size > kCodeSizeLogThreshold) {
LOG(INFO) << "JIT allocated "
<< PrettySize(code_size)
<< " for compiled code of "
<< PrettyMethod(method);
}
}
return reinterpret_cast<uint8_t*>(method_header);
}
size_t JitCodeCache::CodeCacheSize() {
MutexLock mu(Thread::Current(), lock_);
return CodeCacheSizeLocked();
}
size_t JitCodeCache::CodeCacheSizeLocked() {
return used_memory_for_code_;
}
size_t JitCodeCache::DataCacheSize() {
MutexLock mu(Thread::Current(), lock_);
return DataCacheSizeLocked();
}
size_t JitCodeCache::DataCacheSizeLocked() {
return used_memory_for_data_;
}
void JitCodeCache::ClearData(Thread* self, void* data) {
MutexLock mu(self, lock_);
FreeData(reinterpret_cast<uint8_t*>(data));
}
uint8_t* JitCodeCache::ReserveData(Thread* self, size_t size, ArtMethod* method) {
size = RoundUp(size, sizeof(void*));
uint8_t* result = nullptr;
{
ScopedThreadSuspension sts(self, kSuspended);
MutexLock mu(self, lock_);
WaitForPotentialCollectionToComplete(self);
result = AllocateData(size);
}
if (result == nullptr) {
// Retry.
GarbageCollectCache(self);
ScopedThreadSuspension sts(self, kSuspended);
MutexLock mu(self, lock_);
WaitForPotentialCollectionToComplete(self);
result = AllocateData(size);
}
MutexLock mu(self, lock_);
histogram_stack_map_memory_use_.AddValue(size);
if (size > kStackMapSizeLogThreshold) {
LOG(INFO) << "JIT allocated "
<< PrettySize(size)
<< " for stack maps of "
<< PrettyMethod(method);
}
return result;
}
class MarkCodeVisitor FINAL : public StackVisitor {
public:
MarkCodeVisitor(Thread* thread_in, JitCodeCache* code_cache_in)
: StackVisitor(thread_in, nullptr, StackVisitor::StackWalkKind::kSkipInlinedFrames),
code_cache_(code_cache_in),
bitmap_(code_cache_->GetLiveBitmap()) {}
bool VisitFrame() OVERRIDE REQUIRES_SHARED(Locks::mutator_lock_) {
const OatQuickMethodHeader* method_header = GetCurrentOatQuickMethodHeader();
if (method_header == nullptr) {
return true;
}
const void* code = method_header->GetCode();
if (code_cache_->ContainsPc(code)) {
// Use the atomic set version, as multiple threads are executing this code.
bitmap_->AtomicTestAndSet(FromCodeToAllocation(code));
}
return true;
}
private:
JitCodeCache* const code_cache_;
CodeCacheBitmap* const bitmap_;
};
class MarkCodeClosure FINAL : public Closure {
public:
MarkCodeClosure(JitCodeCache* code_cache, Barrier* barrier)
: code_cache_(code_cache), barrier_(barrier) {}
void Run(Thread* thread) OVERRIDE REQUIRES_SHARED(Locks::mutator_lock_) {
ScopedTrace trace(__PRETTY_FUNCTION__);
DCHECK(thread == Thread::Current() || thread->IsSuspended());
MarkCodeVisitor visitor(thread, code_cache_);
visitor.WalkStack();
if (kIsDebugBuild) {
// The stack walking code queries the side instrumentation stack if it
// sees an instrumentation exit pc, so the JIT code of methods in that stack
// must have been seen. We sanity check this below.
for (const instrumentation::InstrumentationStackFrame& frame
: *thread->GetInstrumentationStack()) {
// The 'method_' in InstrumentationStackFrame is the one that has return_pc_ in
// its stack frame, it is not the method owning return_pc_. We just pass null to
// LookupMethodHeader: the method is only checked against in debug builds.
OatQuickMethodHeader* method_header =
code_cache_->LookupMethodHeader(frame.return_pc_, nullptr);
if (method_header != nullptr) {
const void* code = method_header->GetCode();
CHECK(code_cache_->GetLiveBitmap()->Test(FromCodeToAllocation(code)));
}
}
}
barrier_->Pass(Thread::Current());
}
private:
JitCodeCache* const code_cache_;
Barrier* const barrier_;
};
void JitCodeCache::NotifyCollectionDone(Thread* self) {
collection_in_progress_ = false;
lock_cond_.Broadcast(self);
}
void JitCodeCache::SetFootprintLimit(size_t new_footprint) {
size_t per_space_footprint = new_footprint / 2;
DCHECK(IsAlignedParam(per_space_footprint, kPageSize));
DCHECK_EQ(per_space_footprint * 2, new_footprint);
mspace_set_footprint_limit(data_mspace_, per_space_footprint);
{
ScopedCodeCacheWrite scc(code_map_.get());
mspace_set_footprint_limit(code_mspace_, per_space_footprint);
}
}
bool JitCodeCache::IncreaseCodeCacheCapacity() {
if (current_capacity_ == max_capacity_) {
return false;
}
// Double the capacity if we're below 1MB, or increase it by 1MB if
// we're above.
if (current_capacity_ < 1 * MB) {
current_capacity_ *= 2;
} else {
current_capacity_ += 1 * MB;
}
if (current_capacity_ > max_capacity_) {
current_capacity_ = max_capacity_;
}
if (!kIsDebugBuild || VLOG_IS_ON(jit)) {
LOG(INFO) << "Increasing code cache capacity to " << PrettySize(current_capacity_);
}
SetFootprintLimit(current_capacity_);
return true;
}
void JitCodeCache::MarkCompiledCodeOnThreadStacks(Thread* self) {
Barrier barrier(0);
size_t threads_running_checkpoint = 0;
MarkCodeClosure closure(this, &barrier);
threads_running_checkpoint = Runtime::Current()->GetThreadList()->RunCheckpoint(&closure);
// Now that we have run our checkpoint, move to a suspended state and wait
// for other threads to run the checkpoint.
ScopedThreadSuspension sts(self, kSuspended);
if (threads_running_checkpoint != 0) {
barrier.Increment(self, threads_running_checkpoint);
}
}
bool JitCodeCache::ShouldDoFullCollection() {
if (current_capacity_ == max_capacity_) {
// Always do a full collection when the code cache is full.
return true;
} else if (current_capacity_ < kReservedCapacity) {
// Always do partial collection when the code cache size is below the reserved
// capacity.
return false;
} else if (last_collection_increased_code_cache_) {
// This time do a full collection.
return true;
} else {
// This time do a partial collection.
return false;
}
}
void JitCodeCache::GarbageCollectCache(Thread* self) {
ScopedTrace trace(__FUNCTION__);
if (!garbage_collect_code_) {
MutexLock mu(self, lock_);
IncreaseCodeCacheCapacity();
return;
}
// Wait for an existing collection, or let everyone know we are starting one.
{
ScopedThreadSuspension sts(self, kSuspended);
MutexLock mu(self, lock_);
if (WaitForPotentialCollectionToComplete(self)) {
return;
} else {
number_of_collections_++;
live_bitmap_.reset(CodeCacheBitmap::Create(
"code-cache-bitmap",
reinterpret_cast<uintptr_t>(code_map_->Begin()),
reinterpret_cast<uintptr_t>(code_map_->Begin() + current_capacity_ / 2)));
collection_in_progress_ = true;
}
}
TimingLogger logger("JIT code cache timing logger", true, VLOG_IS_ON(jit));
{
TimingLogger::ScopedTiming st("Code cache collection", &logger);
bool do_full_collection = false;
{
MutexLock mu(self, lock_);
do_full_collection = ShouldDoFullCollection();
}
if (!kIsDebugBuild || VLOG_IS_ON(jit)) {
LOG(INFO) << "Do "
<< (do_full_collection ? "full" : "partial")
<< " code cache collection, code="
<< PrettySize(CodeCacheSize())
<< ", data=" << PrettySize(DataCacheSize());
}
DoCollection(self, /* collect_profiling_info */ do_full_collection);
if (!kIsDebugBuild || VLOG_IS_ON(jit)) {
LOG(INFO) << "After code cache collection, code="
<< PrettySize(CodeCacheSize())
<< ", data=" << PrettySize(DataCacheSize());
}
{
MutexLock mu(self, lock_);
// Increase the code cache only when we do partial collections.
// TODO: base this strategy on how full the code cache is?
if (do_full_collection) {
last_collection_increased_code_cache_ = false;
} else {
last_collection_increased_code_cache_ = true;
IncreaseCodeCacheCapacity();
}
bool next_collection_will_be_full = ShouldDoFullCollection();
// Start polling the liveness of compiled code to prepare for the next full collection.
if (next_collection_will_be_full) {
// Save the entry point of methods we have compiled, and update the entry
// point of those methods to the interpreter. If the method is invoked, the
// interpreter will update its entry point to the compiled code and call it.
for (ProfilingInfo* info : profiling_infos_) {
const void* entry_point = info->GetMethod()->GetEntryPointFromQuickCompiledCode();
if (ContainsPc(entry_point)) {
info->SetSavedEntryPoint(entry_point);
Runtime::Current()->GetInstrumentation()->UpdateMethodsCode(
info->GetMethod(), GetQuickToInterpreterBridge());
}
}
DCHECK(CheckLiveCompiledCodeHasProfilingInfo());
}
live_bitmap_.reset(nullptr);
NotifyCollectionDone(self);
}
}
Runtime::Current()->GetJit()->AddTimingLogger(logger);
}
void JitCodeCache::RemoveUnmarkedCode(Thread* self) {
ScopedTrace trace(__FUNCTION__);
MutexLock mu(self, lock_);
ScopedCodeCacheWrite scc(code_map_.get());
// Iterate over all compiled code and remove entries that are not marked.
for (auto it = method_code_map_.begin(); it != method_code_map_.end();) {
const void* code_ptr = it->first;
ArtMethod* method = it->second;
uintptr_t allocation = FromCodeToAllocation(code_ptr);
if (GetLiveBitmap()->Test(allocation)) {
++it;
} else {
FreeCode(code_ptr, method);
it = method_code_map_.erase(it);
}
}
}
void JitCodeCache::DoCollection(Thread* self, bool collect_profiling_info) {
ScopedTrace trace(__FUNCTION__);
{
MutexLock mu(self, lock_);
if (collect_profiling_info) {
// Clear the profiling info of methods that do not have compiled code as entrypoint.
// Also remove the saved entry point from the ProfilingInfo objects.
for (ProfilingInfo* info : profiling_infos_) {
const void* ptr = info->GetMethod()->GetEntryPointFromQuickCompiledCode();
if (!ContainsPc(ptr) && !info->IsInUseByCompiler()) {
info->GetMethod()->SetProfilingInfo(nullptr);
}
if (info->GetSavedEntryPoint() != nullptr) {
info->SetSavedEntryPoint(nullptr);
// We are going to move this method back to interpreter. Clear the counter now to
// give it a chance to be hot again.
info->GetMethod()->ClearCounter();
}
}
} else if (kIsDebugBuild) {
// Sanity check that the profiling infos do not have a dangling entry point.
for (ProfilingInfo* info : profiling_infos_) {
DCHECK(info->GetSavedEntryPoint() == nullptr);
}
}
// Mark compiled code that are entrypoints of ArtMethods. Compiled code that is not
// an entry point is either:
// - an osr compiled code, that will be removed if not in a thread call stack.
// - discarded compiled code, that will be removed if not in a thread call stack.
for (const auto& it : method_code_map_) {
ArtMethod* method = it.second;
const void* code_ptr = it.first;
const OatQuickMethodHeader* method_header = OatQuickMethodHeader::FromCodePointer(code_ptr);
if (method_header->GetEntryPoint() == method->GetEntryPointFromQuickCompiledCode()) {
GetLiveBitmap()->AtomicTestAndSet(FromCodeToAllocation(code_ptr));
}
}
// Empty osr method map, as osr compiled code will be deleted (except the ones
// on thread stacks).
osr_code_map_.clear();
}
// Run a checkpoint on all threads to mark the JIT compiled code they are running.
MarkCompiledCodeOnThreadStacks(self);
// At this point, mutator threads are still running, and entrypoints of methods can
// change. We do know they cannot change to a code cache entry that is not marked,
// therefore we can safely remove those entries.
RemoveUnmarkedCode(self);
if (collect_profiling_info) {
ScopedThreadSuspension sts(self, kSuspended);
gc::ScopedGCCriticalSection gcs(
self, gc::kGcCauseJitCodeCache, gc::kCollectorTypeJitCodeCache);
MutexLock mu(self, lock_);
// Free all profiling infos of methods not compiled nor being compiled.
auto profiling_kept_end = std::remove_if(profiling_infos_.begin(), profiling_infos_.end(),
[this] (ProfilingInfo* info) NO_THREAD_SAFETY_ANALYSIS {
const void* ptr = info->GetMethod()->GetEntryPointFromQuickCompiledCode();
// We have previously cleared the ProfilingInfo pointer in the ArtMethod in the hope
// that the compiled code would not get revived. As mutator threads run concurrently,
// they may have revived the compiled code, and now we are in the situation where
// a method has compiled code but no ProfilingInfo.
// We make sure compiled methods have a ProfilingInfo object. It is needed for
// code cache collection.
if (ContainsPc(ptr) &&
info->GetMethod()->GetProfilingInfo(kRuntimePointerSize) == nullptr) {
// We clear the inline caches as classes in it might be stalled.
info->ClearGcRootsInInlineCaches();
// Do a fence to make sure the clearing is seen before attaching to the method.
QuasiAtomic::ThreadFenceRelease();
info->GetMethod()->SetProfilingInfo(info);
} else if (info->GetMethod()->GetProfilingInfo(kRuntimePointerSize) != info) {
// No need for this ProfilingInfo object anymore.
FreeData(reinterpret_cast<uint8_t*>(info));
return true;
}
return false;
});
profiling_infos_.erase(profiling_kept_end, profiling_infos_.end());
DCHECK(CheckLiveCompiledCodeHasProfilingInfo());
}
}
bool JitCodeCache::CheckLiveCompiledCodeHasProfilingInfo() {
ScopedTrace trace(__FUNCTION__);
// Check that methods we have compiled do have a ProfilingInfo object. We would
// have memory leaks of compiled code otherwise.
for (const auto& it : method_code_map_) {
ArtMethod* method = it.second;
if (method->GetProfilingInfo(kRuntimePointerSize) == nullptr) {
const void* code_ptr = it.first;
const OatQuickMethodHeader* method_header = OatQuickMethodHeader::FromCodePointer(code_ptr);
if (method_header->GetEntryPoint() == method->GetEntryPointFromQuickCompiledCode()) {
// If the code is not dead, then we have a problem. Note that this can even
// happen just after a collection, as mutator threads are running in parallel
// and could deoptimize an existing compiled code.
return false;
}
}
}
return true;
}
OatQuickMethodHeader* JitCodeCache::LookupMethodHeader(uintptr_t pc, ArtMethod* method) {
static_assert(kRuntimeISA != kThumb2, "kThumb2 cannot be a runtime ISA");
if (kRuntimeISA == kArm) {
// On Thumb-2, the pc is offset by one.
--pc;
}
if (!ContainsPc(reinterpret_cast<const void*>(pc))) {
return nullptr;
}
MutexLock mu(Thread::Current(), lock_);
if (method_code_map_.empty()) {
return nullptr;
}
auto it = method_code_map_.lower_bound(reinterpret_cast<const void*>(pc));
--it;
const void* code_ptr = it->first;
OatQuickMethodHeader* method_header = OatQuickMethodHeader::FromCodePointer(code_ptr);
if (!method_header->Contains(pc)) {
return nullptr;
}
if (kIsDebugBuild && method != nullptr) {
DCHECK_EQ(it->second, method)
<< PrettyMethod(method) << " " << PrettyMethod(it->second) << " " << std::hex << pc;
}
return method_header;
}
OatQuickMethodHeader* JitCodeCache::LookupOsrMethodHeader(ArtMethod* method) {
MutexLock mu(Thread::Current(), lock_);
auto it = osr_code_map_.find(method);
if (it == osr_code_map_.end()) {
return nullptr;
}
return OatQuickMethodHeader::FromCodePointer(it->second);
}
ProfilingInfo* JitCodeCache::AddProfilingInfo(Thread* self,
ArtMethod* method,
const std::vector<uint32_t>& entries,
bool retry_allocation)
// No thread safety analysis as we are using TryLock/Unlock explicitly.
NO_THREAD_SAFETY_ANALYSIS {
ProfilingInfo* info = nullptr;
if (!retry_allocation) {
// If we are allocating for the interpreter, just try to lock, to avoid
// lock contention with the JIT.
if (lock_.ExclusiveTryLock(self)) {
info = AddProfilingInfoInternal(self, method, entries);
lock_.ExclusiveUnlock(self);
}
} else {
{
MutexLock mu(self, lock_);
info = AddProfilingInfoInternal(self, method, entries);
}
if (info == nullptr) {
GarbageCollectCache(self);
MutexLock mu(self, lock_);
info = AddProfilingInfoInternal(self, method, entries);
}
}
return info;
}
ProfilingInfo* JitCodeCache::AddProfilingInfoInternal(Thread* self ATTRIBUTE_UNUSED,
ArtMethod* method,
const std::vector<uint32_t>& entries) {
size_t profile_info_size = RoundUp(
sizeof(ProfilingInfo) + sizeof(InlineCache) * entries.size(),
sizeof(void*));
// Check whether some other thread has concurrently created it.
ProfilingInfo* info = method->GetProfilingInfo(kRuntimePointerSize);
if (info != nullptr) {
return info;
}
uint8_t* data = AllocateData(profile_info_size);
if (data == nullptr) {
return nullptr;
}
info = new (data) ProfilingInfo(method, entries);
// Make sure other threads see the data in the profiling info object before the
// store in the ArtMethod's ProfilingInfo pointer.
QuasiAtomic::ThreadFenceRelease();
method->SetProfilingInfo(info);
profiling_infos_.push_back(info);
histogram_profiling_info_memory_use_.AddValue(profile_info_size);
return info;
}
// NO_THREAD_SAFETY_ANALYSIS as this is called from mspace code, at which point the lock
// is already held.
void* JitCodeCache::MoreCore(const void* mspace, intptr_t increment) NO_THREAD_SAFETY_ANALYSIS {
if (code_mspace_ == mspace) {
size_t result = code_end_;
code_end_ += increment;
return reinterpret_cast<void*>(result + code_map_->Begin());
} else {
DCHECK_EQ(data_mspace_, mspace);
size_t result = data_end_;
data_end_ += increment;
return reinterpret_cast<void*>(result + data_map_->Begin());
}
}
void JitCodeCache::GetProfiledMethods(const std::set<std::string>& dex_base_locations,
std::vector<MethodReference>& methods) {
ScopedTrace trace(__FUNCTION__);
MutexLock mu(Thread::Current(), lock_);
for (const ProfilingInfo* info : profiling_infos_) {
ArtMethod* method = info->GetMethod();
const DexFile* dex_file = method->GetDexFile();
if (ContainsElement(dex_base_locations, dex_file->GetBaseLocation())) {
methods.emplace_back(dex_file, method->GetDexMethodIndex());
}
}
}
uint64_t JitCodeCache::GetLastUpdateTimeNs() const {
return last_update_time_ns_.LoadAcquire();
}
bool JitCodeCache::IsOsrCompiled(ArtMethod* method) {
MutexLock mu(Thread::Current(), lock_);
return osr_code_map_.find(method) != osr_code_map_.end();
}
bool JitCodeCache::NotifyCompilationOf(ArtMethod* method, Thread* self, bool osr) {
if (!osr && ContainsPc(method->GetEntryPointFromQuickCompiledCode())) {
return false;
}
MutexLock mu(self, lock_);
if (osr && (osr_code_map_.find(method) != osr_code_map_.end())) {
return false;
}
ProfilingInfo* info = method->GetProfilingInfo(kRuntimePointerSize);
if (info == nullptr) {
VLOG(jit) << PrettyMethod(method) << " needs a ProfilingInfo to be compiled";
// Because the counter is not atomic, there are some rare cases where we may not
// hit the threshold for creating the ProfilingInfo. Reset the counter now to
// "correct" this.
method->ClearCounter();
return false;
}
if (info->IsMethodBeingCompiled(osr)) {
return false;
}
info->SetIsMethodBeingCompiled(true, osr);
return true;
}
ProfilingInfo* JitCodeCache::NotifyCompilerUse(ArtMethod* method, Thread* self) {
MutexLock mu(self, lock_);
ProfilingInfo* info = method->GetProfilingInfo(kRuntimePointerSize);
if (info != nullptr) {
info->IncrementInlineUse();
}
return info;
}
void JitCodeCache::DoneCompilerUse(ArtMethod* method, Thread* self) {
MutexLock mu(self, lock_);
ProfilingInfo* info = method->GetProfilingInfo(kRuntimePointerSize);
DCHECK(info != nullptr);
info->DecrementInlineUse();
}
void JitCodeCache::DoneCompiling(ArtMethod* method, Thread* self ATTRIBUTE_UNUSED, bool osr) {
ProfilingInfo* info = method->GetProfilingInfo(kRuntimePointerSize);
DCHECK(info->IsMethodBeingCompiled(osr));
info->SetIsMethodBeingCompiled(false, osr);
}
size_t JitCodeCache::GetMemorySizeOfCodePointer(const void* ptr) {
MutexLock mu(Thread::Current(), lock_);
return mspace_usable_size(reinterpret_cast<const void*>(FromCodeToAllocation(ptr)));
}
void JitCodeCache::InvalidateCompiledCodeFor(ArtMethod* method,
const OatQuickMethodHeader* header) {
ProfilingInfo* profiling_info = method->GetProfilingInfo(kRuntimePointerSize);
if ((profiling_info != nullptr) &&
(profiling_info->GetSavedEntryPoint() == header->GetEntryPoint())) {
// Prevent future uses of the compiled code.
profiling_info->SetSavedEntryPoint(nullptr);
}
if (method->GetEntryPointFromQuickCompiledCode() == header->GetEntryPoint()) {
// The entrypoint is the one to invalidate, so we just update
// it to the interpreter entry point and clear the counter to get the method
// Jitted again.
Runtime::Current()->GetInstrumentation()->UpdateMethodsCode(
method, GetQuickToInterpreterBridge());
method->ClearCounter();
} else {
MutexLock mu(Thread::Current(), lock_);
auto it = osr_code_map_.find(method);
if (it != osr_code_map_.end() && OatQuickMethodHeader::FromCodePointer(it->second) == header) {
// Remove the OSR method, to avoid using it again.
osr_code_map_.erase(it);
}
}
MutexLock mu(Thread::Current(), lock_);
number_of_deoptimizations_++;
}
uint8_t* JitCodeCache::AllocateCode(size_t code_size) {
size_t alignment = GetInstructionSetAlignment(kRuntimeISA);
uint8_t* result = reinterpret_cast<uint8_t*>(
mspace_memalign(code_mspace_, alignment, code_size));
size_t header_size = RoundUp(sizeof(OatQuickMethodHeader), alignment);
// Ensure the header ends up at expected instruction alignment.
DCHECK_ALIGNED_PARAM(reinterpret_cast<uintptr_t>(result + header_size), alignment);
used_memory_for_code_ += mspace_usable_size(result);
return result;
}
void JitCodeCache::FreeCode(uint8_t* code) {
used_memory_for_code_ -= mspace_usable_size(code);
mspace_free(code_mspace_, code);
}
uint8_t* JitCodeCache::AllocateData(size_t data_size) {
void* result = mspace_malloc(data_mspace_, data_size);
used_memory_for_data_ += mspace_usable_size(result);
return reinterpret_cast<uint8_t*>(result);
}
void JitCodeCache::FreeData(uint8_t* data) {
used_memory_for_data_ -= mspace_usable_size(data);
mspace_free(data_mspace_, data);
}
void JitCodeCache::Dump(std::ostream& os) {
MutexLock mu(Thread::Current(), lock_);
os << "Current JIT code cache size: " << PrettySize(used_memory_for_code_) << "\n"
<< "Current JIT data cache size: " << PrettySize(used_memory_for_data_) << "\n"
<< "Current JIT capacity: " << PrettySize(current_capacity_) << "\n"
<< "Current number of JIT code cache entries: " << method_code_map_.size() << "\n"
<< "Total number of JIT compilations: " << number_of_compilations_ << "\n"
<< "Total number of JIT compilations for on stack replacement: "
<< number_of_osr_compilations_ << "\n"
<< "Total number of deoptimizations: " << number_of_deoptimizations_ << "\n"
<< "Total number of JIT code cache collections: " << number_of_collections_ << std::endl;
histogram_stack_map_memory_use_.PrintMemoryUse(os);
histogram_code_memory_use_.PrintMemoryUse(os);
histogram_profiling_info_memory_use_.PrintMemoryUse(os);
}
} // namespace jit
} // namespace art