Remove lazy dequickening.
We removed quickening. Also one should not do that much work in a handler.
Test: test.py
Bug: 196414062
Change-Id: I6f88af8472ed4cd4fe313ef0a82b7d580b4d53c3
diff --git a/openjdkjvmti/ti_class_definition.cc b/openjdkjvmti/ti_class_definition.cc
index a480ac0..3d9d9e7 100644
--- a/openjdkjvmti/ti_class_definition.cc
+++ b/openjdkjvmti/ti_class_definition.cc
@@ -47,32 +47,6 @@
namespace openjdkjvmti {
-void ArtClassDefinition::InitializeMemory() const {
- DCHECK(art::MemMap::kCanReplaceMapping);
- VLOG(signals) << "Initializing de-quickened memory for dex file of " << name_;
- CHECK(dex_data_mmap_.IsValid());
- CHECK(temp_mmap_.IsValid());
- CHECK_EQ(dex_data_mmap_.GetProtect(), PROT_NONE);
- CHECK_EQ(temp_mmap_.GetProtect(), PROT_READ | PROT_WRITE);
-
- std::string desc = std::string("L") + name_ + ";";
- std::unique_ptr<FixedUpDexFile>
- fixed_dex_file(FixedUpDexFile::Create(*initial_dex_file_unquickened_, desc.c_str()));
- CHECK(fixed_dex_file.get() != nullptr);
- CHECK_LE(fixed_dex_file->Size(), temp_mmap_.Size());
- CHECK_EQ(temp_mmap_.Size(), dex_data_mmap_.Size());
- // Copy the data to the temp mmap.
- memcpy(temp_mmap_.Begin(), fixed_dex_file->Begin(), fixed_dex_file->Size());
-
- // Move the mmap atomically.
- art::MemMap source;
- source.swap(temp_mmap_);
- std::string error;
- CHECK(dex_data_mmap_.ReplaceWith(&source, &error)) << "Failed to replace mmap for "
- << name_ << " because " << error;
- CHECK(dex_data_mmap_.Protect(PROT_READ));
-}
-
bool ArtClassDefinition::IsModified() const {
// RedefineClasses calls always are 'modified' since they need to change the current_dex_file of
// the class.
@@ -86,27 +60,6 @@
return false;
}
- // The dex_data_ was never touched by the agents.
- if (dex_data_mmap_.IsValid() && dex_data_mmap_.GetProtect() == PROT_NONE) {
- if (current_dex_file_.data() == dex_data_mmap_.Begin()) {
- // the dex_data_ looks like it changed (not equal to current_dex_file_) but we never
- // initialized the dex_data_mmap_. This means the new_dex_data was filled in without looking
- // at the initial dex_data_.
- return true;
- } else if (dex_data_.data() == dex_data_mmap_.Begin()) {
- // The dex file used to have modifications but they were not added again.
- return true;
- } else {
- // It's not clear what happened. It's possible that the agent got the current dex file data
- // from some other source so we need to initialize everything to see if it is the same.
- VLOG(signals) << "Lazy dex file for " << name_ << " was never touched but the dex_data_ is "
- << "changed! Need to initialize the memory to see if anything changed";
- InitializeMemory();
- }
- }
-
- // We can definitely read current_dex_file_ and dex_file_ without causing page faults.
-
// Check if the dex file we want to set is the same as the current one.
// Unfortunately we need to do this check even if no modifications have been done since it could
// be that agents were removed in the mean-time so we still have a different dex file. The dex
@@ -241,44 +194,6 @@
const art::DexFile* quick_dex) {
art::Thread* self = art::Thread::Current();
DCHECK(quick_dex != nullptr);
- if (art::MemMap::kCanReplaceMapping && kEnableOnDemandDexDequicken) {
- size_t dequick_size = quick_dex->GetDequickenedSize();
- std::string mmap_name("anon-mmap-for-redefine: ");
- mmap_name += name_;
- std::string error;
- dex_data_mmap_ = art::MemMap::MapAnonymous(mmap_name.c_str(),
- dequick_size,
- PROT_NONE,
- /*low_4gb=*/ false,
- &error);
- mmap_name += "-TEMP";
- temp_mmap_ = art::MemMap::MapAnonymous(mmap_name.c_str(),
- dequick_size,
- PROT_READ | PROT_WRITE,
- /*low_4gb=*/ false,
- &error);
- if (UNLIKELY(dex_data_mmap_.IsValid() && temp_mmap_.IsValid())) {
- // Need to save the initial dexfile so we don't need to search for it in the fault-handler.
- initial_dex_file_unquickened_ = quick_dex;
- dex_data_ = art::ArrayRef<const unsigned char>(dex_data_mmap_.Begin(),
- dex_data_mmap_.Size());
- if (from_class_ext_) {
- // We got initial from class_ext so the current one must have undergone redefinition so no
- // cdex or quickening stuff.
- // We can only do this if it's not a first load.
- DCHECK(klass_ != nullptr);
- const art::DexFile& cur_dex = self->DecodeJObject(klass_)->AsClass()->GetDexFile();
- current_dex_file_ = art::ArrayRef<const unsigned char>(cur_dex.Begin(), cur_dex.Size());
- } else {
- // This class hasn't been redefined before. The dequickened current data is the same as the
- // dex_data_mmap_ when it's filled it. We don't need to copy anything because the mmap will
- // not be cleared until after everything is done.
- current_dex_file_ = art::ArrayRef<const unsigned char>(dex_data_mmap_.Begin(),
- dequick_size);
- }
- return;
- }
- }
dex_data_mmap_.Reset();
temp_mmap_.Reset();
// Failed to mmap a large enough area (or on-demand dequickening was disabled). This is
diff --git a/openjdkjvmti/ti_class_definition.h b/openjdkjvmti/ti_class_definition.h
index cb0853b..a914ec2 100644
--- a/openjdkjvmti/ti_class_definition.h
+++ b/openjdkjvmti/ti_class_definition.h
@@ -49,9 +49,6 @@
// redefinition/retransformation function that created it.
class ArtClassDefinition {
public:
- // If we support doing a on-demand dex-dequickening using signal handlers.
- static constexpr bool kEnableOnDemandDexDequicken = true;
-
ArtClassDefinition()
: klass_(nullptr),
loader_(nullptr),
@@ -135,13 +132,6 @@
return name_;
}
- bool IsLazyDefinition() const {
- DCHECK(IsInitialized());
- return dex_data_mmap_.IsValid() &&
- dex_data_.data() == dex_data_mmap_.Begin() &&
- dex_data_mmap_.GetProtect() == PROT_NONE;
- }
-
jobject GetProtectionDomain() const {
DCHECK(IsInitialized());
return protection_domain_;
@@ -166,8 +156,7 @@
std::string name_;
jobject protection_domain_;
- // Mmap that will be filled with the original-dex-file lazily if it needs to be de-quickened or
- // de-compact-dex'd
+ // Mmap that will be filled with the original-dex-file lazily if it needs to be de-compact-dex'd
mutable art::MemMap dex_data_mmap_;
// This is a temporary mmap we will use to be able to fill the dex file data atomically.
mutable art::MemMap temp_mmap_;
diff --git a/openjdkjvmti/transform.cc b/openjdkjvmti/transform.cc
index 9c440ef..753697d 100644
--- a/openjdkjvmti/transform.cc
+++ b/openjdkjvmti/transform.cc
@@ -70,185 +70,13 @@
namespace openjdkjvmti {
-// A FaultHandler that will deal with initializing ClassDefinitions when they are actually needed.
-class TransformationFaultHandler final : public art::FaultHandler {
- public:
- explicit TransformationFaultHandler(art::FaultManager* manager)
- : art::FaultHandler(manager),
- uninitialized_class_definitions_lock_("JVMTI Initialized class definitions lock",
- art::LockLevel::kSignalHandlingLock),
- class_definition_initialized_cond_("JVMTI Initialized class definitions condition",
- uninitialized_class_definitions_lock_) {
- manager->AddHandler(this, /* generated_code= */ false);
- }
-
- ~TransformationFaultHandler() {
- art::MutexLock mu(art::Thread::Current(), uninitialized_class_definitions_lock_);
- uninitialized_class_definitions_.clear();
- }
-
- bool Action(int sig, siginfo_t* siginfo, void* context ATTRIBUTE_UNUSED) override {
- DCHECK_EQ(sig, SIGSEGV);
- art::Thread* self = art::Thread::Current();
- uintptr_t ptr = reinterpret_cast<uintptr_t>(siginfo->si_addr);
- if (UNLIKELY(uninitialized_class_definitions_lock_.IsExclusiveHeld(self))) {
- // It's possible this is just some other unrelated segv that should be
- // handled separately, continue to later handlers. This is likely due to
- // running out of memory somewhere along the FixedUpDexFile pipeline and
- // is likely unrecoverable. By returning false here though we will get a
- // better, more accurate, stack-trace later that points to the actual
- // issue.
- LOG(WARNING) << "Recursive SEGV occurred during Transformation dequickening at 0x" << std::hex
- << ptr;
- return false;
- }
- ArtClassDefinition* res = nullptr;
-
- {
- // NB Technically using a mutex and condition variables here is non-posix compliant but
- // everything should be fine since both glibc and bionic implementations of mutexs and
- // condition variables work fine so long as the thread was not interrupted during a
- // lock/unlock (which it wasn't) on all architectures we care about.
- art::MutexLock mu(self, uninitialized_class_definitions_lock_);
- auto it = std::find_if(uninitialized_class_definitions_.begin(),
- uninitialized_class_definitions_.end(),
- [&](const auto op) { return op->ContainsAddress(ptr); });
- if (it != uninitialized_class_definitions_.end()) {
- res = *it;
- // Remove the class definition.
- uninitialized_class_definitions_.erase(it);
- // Put it in the initializing list
- initializing_class_definitions_.push_back(res);
- } else {
- // Wait for the ptr to be initialized (if it is currently initializing).
- while (DefinitionIsInitializing(ptr)) {
- WaitForClassInitializationToFinish();
- }
- // Return true (continue with user code) if we find that the definition has been
- // initialized. Return false (continue on to next signal handler) if the definition is not
- // initialized or found.
- return std::find_if(initialized_class_definitions_.begin(),
- initialized_class_definitions_.end(),
- [&](const auto op) { return op->ContainsAddress(ptr); }) !=
- initialized_class_definitions_.end();
- }
- }
-
- if (LIKELY(self != nullptr)) {
- CHECK_EQ(self->GetState(), art::ThreadState::kNative)
- << "Transformation fault handler occurred outside of native mode";
- }
-
- VLOG(signals) << "Lazy initialization of dex file for transformation of " << res->GetName()
- << " during SEGV";
- res->InitializeMemory();
-
- {
- art::MutexLock mu(self, uninitialized_class_definitions_lock_);
- // Move to initialized state and notify waiters.
- initializing_class_definitions_.erase(std::find(initializing_class_definitions_.begin(),
- initializing_class_definitions_.end(),
- res));
- initialized_class_definitions_.push_back(res);
- class_definition_initialized_cond_.Broadcast(self);
- }
-
- return true;
- }
-
- void RemoveDefinition(ArtClassDefinition* def) REQUIRES(!uninitialized_class_definitions_lock_) {
- art::MutexLock mu(art::Thread::Current(), uninitialized_class_definitions_lock_);
- auto it = std::find(uninitialized_class_definitions_.begin(),
- uninitialized_class_definitions_.end(),
- def);
- if (it != uninitialized_class_definitions_.end()) {
- uninitialized_class_definitions_.erase(it);
- return;
- }
- while (std::find(initializing_class_definitions_.begin(),
- initializing_class_definitions_.end(),
- def) != initializing_class_definitions_.end()) {
- WaitForClassInitializationToFinish();
- }
- it = std::find(initialized_class_definitions_.begin(),
- initialized_class_definitions_.end(),
- def);
- CHECK(it != initialized_class_definitions_.end()) << "Could not find class definition for "
- << def->GetName();
- initialized_class_definitions_.erase(it);
- }
-
- void AddArtDefinition(ArtClassDefinition* def) REQUIRES(!uninitialized_class_definitions_lock_) {
- DCHECK(def->IsLazyDefinition());
- art::MutexLock mu(art::Thread::Current(), uninitialized_class_definitions_lock_);
- uninitialized_class_definitions_.push_back(def);
- }
-
- private:
- bool DefinitionIsInitializing(uintptr_t ptr) REQUIRES(uninitialized_class_definitions_lock_) {
- return std::find_if(initializing_class_definitions_.begin(),
- initializing_class_definitions_.end(),
- [&](const auto op) { return op->ContainsAddress(ptr); }) !=
- initializing_class_definitions_.end();
- }
-
- void WaitForClassInitializationToFinish() REQUIRES(uninitialized_class_definitions_lock_) {
- class_definition_initialized_cond_.Wait(art::Thread::Current());
- }
-
- art::Mutex uninitialized_class_definitions_lock_ ACQUIRED_BEFORE(art::Locks::abort_lock_);
- art::ConditionVariable class_definition_initialized_cond_
- GUARDED_BY(uninitialized_class_definitions_lock_);
-
- // A list of the class definitions that have a non-readable map.
- std::vector<ArtClassDefinition*> uninitialized_class_definitions_
- GUARDED_BY(uninitialized_class_definitions_lock_);
-
- // A list of class definitions that are currently undergoing unquickening. Threads should wait
- // until the definition is no longer in this before returning.
- std::vector<ArtClassDefinition*> initializing_class_definitions_
- GUARDED_BY(uninitialized_class_definitions_lock_);
-
- // A list of class definitions that are already unquickened. Threads should immediately return if
- // it is here.
- std::vector<ArtClassDefinition*> initialized_class_definitions_
- GUARDED_BY(uninitialized_class_definitions_lock_);
-};
-
-static TransformationFaultHandler* gTransformFaultHandler = nullptr;
static EventHandler* gEventHandler = nullptr;
void Transformer::Register(EventHandler* eh) {
- // Although we create this the fault handler is actually owned by the 'art::fault_manager' which
- // will take care of destroying it.
- if (art::MemMap::kCanReplaceMapping && ArtClassDefinition::kEnableOnDemandDexDequicken) {
- gTransformFaultHandler = new TransformationFaultHandler(&art::fault_manager);
- }
gEventHandler = eh;
}
-// Simple helper to add and remove the class definition from the fault handler.
-class ScopedDefinitionHandler {
- public:
- explicit ScopedDefinitionHandler(ArtClassDefinition* def)
- : def_(def), is_lazy_(def_->IsLazyDefinition()) {
- if (is_lazy_) {
- gTransformFaultHandler->AddArtDefinition(def_);
- }
- }
-
- ~ScopedDefinitionHandler() {
- if (is_lazy_) {
- gTransformFaultHandler->RemoveDefinition(def_);
- }
- }
-
- private:
- ArtClassDefinition* def_;
- bool is_lazy_;
-};
-
// Initialize templates.
template
void Transformer::TransformSingleClassDirect<ArtJvmtiEvent::kClassFileLoadHookNonRetransformable>(
@@ -272,7 +100,6 @@
// native state early. This also avoids any problems that the FaultHandler might have in
// determining if an access to the dex_data is from generated code or not.
art::ScopedThreadStateChange stsc(self, art::ThreadState::kNative);
- ScopedDefinitionHandler handler(def);
jint new_len = -1;
unsigned char* new_data = nullptr;
art::ArrayRef<const unsigned char> dex_data = def->GetDexData();