Implement RetransformClasses
This CL implements basic support for the RetransformClasses function
and callbacks of the ClassFileLoadHook.
We do not yet support calling the ClassFileLoadHook events on first
load of class.
Bug: 32369913
Bug: 31684920
Test: mma -j40 test-art-host
Change-Id: I7959474f03f9903cc6f10ae3c06d9fd531ec7957
diff --git a/runtime/openjdkjvmti/ti_redefine.cc b/runtime/openjdkjvmti/ti_redefine.cc
index 6af51c4..28ea267 100644
--- a/runtime/openjdkjvmti/ti_redefine.cc
+++ b/runtime/openjdkjvmti/ti_redefine.cc
@@ -242,14 +242,12 @@
}
}
-// TODO This should handle doing multiple classes at once so we need to do less cleanup when things
-// go wrong.
jvmtiError Redefiner::RedefineClasses(ArtJvmTiEnv* env,
art::Runtime* runtime,
art::Thread* self,
jint class_count,
const jvmtiClassDefinition* definitions,
- std::string* error_msg) {
+ /*out*/std::string* error_msg) {
if (env == nullptr) {
*error_msg = "env was null!";
return ERR(INVALID_ENVIRONMENT);
@@ -263,46 +261,83 @@
*error_msg = "null definitions!";
return ERR(NULL_POINTER);
}
+ std::vector<ArtClassDefinition> def_vector;
+ def_vector.reserve(class_count);
+ for (jint i = 0; i < class_count; i++) {
+ ArtClassDefinition def;
+ def.dex_len = definitions[i].class_byte_count;
+ def.dex_data = MakeJvmtiUniquePtr(env, const_cast<unsigned char*>(definitions[i].class_bytes));
+ // We are definitely modified.
+ def.modified = true;
+ jvmtiError res = Transformer::FillInTransformationData(env, definitions[i].klass, &def);
+ if (res != OK) {
+ return res;
+ }
+ def_vector.push_back(std::move(def));
+ }
+ // Call all the transformation events.
+ jvmtiError res = Transformer::RetransformClassesDirect(env,
+ self,
+ &def_vector);
+ if (res != OK) {
+ // Something went wrong with transformation!
+ return res;
+ }
+ return RedefineClassesDirect(env, runtime, self, def_vector, error_msg);
+}
+
+jvmtiError Redefiner::RedefineClassesDirect(ArtJvmTiEnv* env,
+ art::Runtime* runtime,
+ art::Thread* self,
+ const std::vector<ArtClassDefinition>& definitions,
+ std::string* error_msg) {
+ DCHECK(env != nullptr);
+ if (definitions.size() == 0) {
+ // We don't actually need to do anything. Just return OK.
+ return OK;
+ }
// Stop JIT for the duration of this redefine since the JIT might concurrently compile a method we
// are going to redefine.
art::jit::ScopedJitSuspend suspend_jit;
// Get shared mutator lock so we can lock all the classes.
art::ScopedObjectAccess soa(self);
std::vector<Redefiner::ClassRedefinition> redefinitions;
- redefinitions.reserve(class_count);
+ redefinitions.reserve(definitions.size());
Redefiner r(runtime, self, error_msg);
- for (jint i = 0; i < class_count; i++) {
- jvmtiError res = r.AddRedefinition(env, definitions[i]);
- if (res != OK) {
- return res;
+ for (const ArtClassDefinition& def : definitions) {
+ // Only try to transform classes that have been modified.
+ if (def.modified) {
+ jvmtiError res = r.AddRedefinition(env, def);
+ if (res != OK) {
+ return res;
+ }
}
}
return r.Run();
}
-jvmtiError Redefiner::AddRedefinition(ArtJvmTiEnv* env, const jvmtiClassDefinition& def) {
+jvmtiError Redefiner::AddRedefinition(ArtJvmTiEnv* env, const ArtClassDefinition& def) {
std::string original_dex_location;
jvmtiError ret = OK;
if ((ret = GetClassLocation(env, def.klass, &original_dex_location))) {
*error_msg_ = "Unable to get original dex file location!";
return ret;
}
- std::unique_ptr<art::MemMap> map(MoveDataToMemMap(original_dex_location,
- def.class_byte_count,
- def.class_bytes,
- error_msg_));
- std::ostringstream os;
char* generic_ptr_unused = nullptr;
char* signature_ptr = nullptr;
- if (env->GetClassSignature(def.klass, &signature_ptr, &generic_ptr_unused) != OK) {
- *error_msg_ = "A jclass passed in does not seem to be valid";
- return ERR(INVALID_CLASS);
+ if ((ret = env->GetClassSignature(def.klass, &signature_ptr, &generic_ptr_unused)) != OK) {
+ *error_msg_ = "Unable to get class signature!";
+ return ret;
}
- // These will make sure we deallocate the signature.
- JvmtiUniquePtr sig_unique_ptr(MakeJvmtiUniquePtr(env, signature_ptr));
JvmtiUniquePtr generic_unique_ptr(MakeJvmtiUniquePtr(env, generic_ptr_unused));
+ JvmtiUniquePtr signature_unique_ptr(MakeJvmtiUniquePtr(env, signature_ptr));
+ std::unique_ptr<art::MemMap> map(MoveDataToMemMap(original_dex_location,
+ def.dex_len,
+ def.dex_data.get(),
+ error_msg_));
+ std::ostringstream os;
if (map.get() == nullptr) {
- os << "Failed to create anonymous mmap for modified dex file of class " << signature_ptr
+ os << "Failed to create anonymous mmap for modified dex file of class " << def.name
<< "in dex file " << original_dex_location << " because: " << *error_msg_;
*error_msg_ = os.str();
return ERR(OUT_OF_MEMORY);
@@ -319,7 +354,7 @@
/*verify_checksum*/true,
error_msg_));
if (dex_file.get() == nullptr) {
- os << "Unable to load modified dex file for " << signature_ptr << ": " << *error_msg_;
+ os << "Unable to load modified dex file for " << def.name << ": " << *error_msg_;
*error_msg_ = os.str();
return ERR(INVALID_CLASS_FORMAT);
}
@@ -989,17 +1024,16 @@
// Performs updates to class that will allow us to verify it.
void Redefiner::ClassRedefinition::UpdateClass(art::ObjPtr<art::mirror::Class> mclass,
art::ObjPtr<art::mirror::DexCache> new_dex_cache) {
- const art::DexFile::ClassDef* class_def = art::OatFile::OatDexFile::FindClassDef(
- *dex_file_, class_sig_.c_str(), art::ComputeModifiedUtf8Hash(class_sig_.c_str()));
- DCHECK(class_def != nullptr);
- UpdateMethods(mclass, new_dex_cache, *class_def);
+ DCHECK_EQ(dex_file_->NumClassDefs(), 1u);
+ const art::DexFile::ClassDef& class_def = dex_file_->GetClassDef(0);
+ UpdateMethods(mclass, new_dex_cache, class_def);
UpdateFields(mclass);
// Update the class fields.
// Need to update class last since the ArtMethod gets its DexFile from the class (which is needed
// to call GetReturnTypeDescriptor and GetParameterTypeList above).
mclass->SetDexCache(new_dex_cache.Ptr());
- mclass->SetDexClassDefIndex(dex_file_->GetIndexForClassDef(*class_def));
+ mclass->SetDexClassDefIndex(dex_file_->GetIndexForClassDef(class_def));
mclass->SetDexTypeIndex(dex_file_->GetIndexForTypeId(*dex_file_->FindTypeId(class_sig_.c_str())));
}