ART: Add option to ensure deterministic compilation
To ensure reliable stable generation of a boot image, add a flag
for forced determinism, trading compile time for a deterministic
output.
We have to run certain passes in the compiler-driver single-threaded.
It is also necessary to try to make the heap layout deterministic.
Switch to nonconcurrent GC, use the free-list implementation for LOS,
and try to allocate the main space at a known location. This is best
effort at the moment.
To allow the compiler phase to be parallelized, const-strings need
to be created beforehand.
The identity hashcode seed needs to be pinned.
Besides the Dex object we also need to null the DexFile pointer in
dex caches.
For classes, we need to remove the clinit thread ID.
Fix oatdump alignment padding accounting.
Bug: 26687569
Change-Id: Ia82120e8f715bb3691d861817b12778ac677355a
diff --git a/compiler/driver/compiler_driver.cc b/compiler/driver/compiler_driver.cc
index 818d50a..440fe95 100644
--- a/compiler/driver/compiler_driver.cc
+++ b/compiler/driver/compiler_driver.cc
@@ -39,6 +39,7 @@
#include "compiler_driver-inl.h"
#include "dex_compilation_unit.h"
#include "dex_file-inl.h"
+#include "dex_instruction-inl.h"
#include "dex/dex_to_dex_compiler.h"
#include "dex/verification_results.h"
#include "dex/verified_method.h"
@@ -365,7 +366,7 @@
classes_to_compile_(compiled_classes),
methods_to_compile_(compiled_methods),
had_hard_verifier_failure_(false),
- thread_count_(thread_count),
+ parallel_thread_count_(thread_count),
stats_(new AOTCompilationStats),
dump_stats_(dump_stats),
dump_passes_(dump_passes),
@@ -435,24 +436,27 @@
const std::vector<const DexFile*>& dex_files,
TimingLogger* timings) {
DCHECK(!Runtime::Current()->IsStarted());
- std::unique_ptr<ThreadPool> thread_pool(
- new ThreadPool("Compiler driver thread pool", thread_count_ - 1));
+
+ InitializeThreadPools();
+
VLOG(compiler) << "Before precompile " << GetMemoryUsageString(false);
// Precompile:
// 1) Load image classes
// 2) Resolve all classes
// 3) Attempt to verify all classes
// 4) Attempt to initialize image classes, and trivially initialized classes
- PreCompile(class_loader, dex_files, thread_pool.get(), timings);
+ PreCompile(class_loader, dex_files, timings);
// Compile:
// 1) Compile all classes and methods enabled for compilation. May fall back to dex-to-dex
// compilation.
if (!GetCompilerOptions().VerifyAtRuntime()) {
- Compile(class_loader, dex_files, thread_pool.get(), timings);
+ Compile(class_loader, dex_files, timings);
}
if (dump_stats_) {
stats_->Dump();
}
+
+ FreeThreadPools();
}
static optimizer::DexToDexCompilationLevel GetDexToDexCompilationLevel(
@@ -653,8 +657,9 @@
std::vector<const DexFile*> dex_files;
dex_files.push_back(dex_file);
- std::unique_ptr<ThreadPool> thread_pool(new ThreadPool("Compiler driver thread pool", 0U));
- PreCompile(jclass_loader, dex_files, thread_pool.get(), timings);
+ InitializeThreadPools();
+
+ PreCompile(jclass_loader, dex_files, timings);
// Can we run DEX-to-DEX compiler on this class ?
optimizer::DexToDexCompilationLevel dex_to_dex_compilation_level =
@@ -677,20 +682,147 @@
true,
dex_cache);
+ FreeThreadPools();
+
self->GetJniEnv()->DeleteGlobalRef(jclass_loader);
}
-void CompilerDriver::Resolve(jobject class_loader, const std::vector<const DexFile*>& dex_files,
- ThreadPool* thread_pool, TimingLogger* timings) {
+void CompilerDriver::Resolve(jobject class_loader,
+ const std::vector<const DexFile*>& dex_files,
+ TimingLogger* timings) {
+ // Resolution allocates classes and needs to run single-threaded to be deterministic.
+ bool force_determinism = GetCompilerOptions().IsForceDeterminism();
+ ThreadPool* resolve_thread_pool = force_determinism
+ ? single_thread_pool_.get()
+ : parallel_thread_pool_.get();
+ size_t resolve_thread_count = force_determinism ? 1U : parallel_thread_count_;
+
for (size_t i = 0; i != dex_files.size(); ++i) {
const DexFile* dex_file = dex_files[i];
CHECK(dex_file != nullptr);
- ResolveDexFile(class_loader, *dex_file, dex_files, thread_pool, timings);
+ ResolveDexFile(class_loader,
+ *dex_file,
+ dex_files,
+ resolve_thread_pool,
+ resolve_thread_count,
+ timings);
}
}
-void CompilerDriver::PreCompile(jobject class_loader, const std::vector<const DexFile*>& dex_files,
- ThreadPool* thread_pool, TimingLogger* timings) {
+// Resolve const-strings in the code. Done to have deterministic allocation behavior. Right now
+// this is single-threaded for simplicity.
+// TODO: Collect the relevant string indices in parallel, then allocate them sequentially in a
+// stable order.
+
+static void ResolveConstStrings(CompilerDriver* driver,
+ const DexFile& dex_file,
+ const DexFile::CodeItem* code_item) {
+ if (code_item == nullptr) {
+ // Abstract or native method.
+ return;
+ }
+
+ const uint16_t* code_ptr = code_item->insns_;
+ const uint16_t* code_end = code_item->insns_ + code_item->insns_size_in_code_units_;
+
+ while (code_ptr < code_end) {
+ const Instruction* inst = Instruction::At(code_ptr);
+ switch (inst->Opcode()) {
+ case Instruction::CONST_STRING: {
+ uint32_t string_index = inst->VRegB_21c();
+ driver->CanAssumeStringIsPresentInDexCache(dex_file, string_index);
+ break;
+ }
+ case Instruction::CONST_STRING_JUMBO: {
+ uint32_t string_index = inst->VRegB_31c();
+ driver->CanAssumeStringIsPresentInDexCache(dex_file, string_index);
+ break;
+ }
+
+ default:
+ break;
+ }
+
+ code_ptr += inst->SizeInCodeUnits();
+ }
+}
+
+static void ResolveConstStrings(CompilerDriver* driver,
+ const std::vector<const DexFile*>& dex_files,
+ TimingLogger* timings) {
+ for (const DexFile* dex_file : dex_files) {
+ TimingLogger::ScopedTiming t("Resolve const-string Strings", timings);
+
+ size_t class_def_count = dex_file->NumClassDefs();
+ for (size_t class_def_index = 0; class_def_index < class_def_count; ++class_def_index) {
+ const DexFile::ClassDef& class_def = dex_file->GetClassDef(class_def_index);
+
+ const uint8_t* class_data = dex_file->GetClassData(class_def);
+ if (class_data == nullptr) {
+ // empty class, probably a marker interface
+ continue;
+ }
+
+ ClassDataItemIterator it(*dex_file, class_data);
+ // Skip fields
+ while (it.HasNextStaticField()) {
+ it.Next();
+ }
+ while (it.HasNextInstanceField()) {
+ it.Next();
+ }
+
+ bool compilation_enabled = driver->IsClassToCompile(
+ dex_file->StringByTypeIdx(class_def.class_idx_));
+ if (!compilation_enabled) {
+ // Compilation is skipped, do not resolve const-string in code of this class.
+ // TODO: Make sure that inlining honors this.
+ continue;
+ }
+
+ // Direct methods.
+ int64_t previous_direct_method_idx = -1;
+ while (it.HasNextDirectMethod()) {
+ uint32_t method_idx = it.GetMemberIndex();
+ if (method_idx == previous_direct_method_idx) {
+ // smali can create dex files with two encoded_methods sharing the same method_idx
+ // http://code.google.com/p/smali/issues/detail?id=119
+ it.Next();
+ continue;
+ }
+ previous_direct_method_idx = method_idx;
+ ResolveConstStrings(driver, *dex_file, it.GetMethodCodeItem());
+ it.Next();
+ }
+ // Virtual methods.
+ int64_t previous_virtual_method_idx = -1;
+ while (it.HasNextVirtualMethod()) {
+ uint32_t method_idx = it.GetMemberIndex();
+ if (method_idx == previous_virtual_method_idx) {
+ // smali can create dex files with two encoded_methods sharing the same method_idx
+ // http://code.google.com/p/smali/issues/detail?id=119
+ it.Next();
+ continue;
+ }
+ previous_virtual_method_idx = method_idx;
+ ResolveConstStrings(driver, *dex_file, it.GetMethodCodeItem());
+ it.Next();
+ }
+ DCHECK(!it.HasNext());
+ }
+ }
+}
+
+inline void CompilerDriver::CheckThreadPools() {
+ DCHECK(parallel_thread_pool_ != nullptr);
+ DCHECK(single_thread_pool_ != nullptr);
+}
+
+void CompilerDriver::PreCompile(jobject class_loader,
+ const std::vector<const DexFile*>& dex_files,
+ TimingLogger* timings) {
+ CheckThreadPools();
+
LoadImageClasses(timings);
VLOG(compiler) << "LoadImageClasses: " << GetMemoryUsageString(false);
@@ -700,20 +832,26 @@
// We need to resolve for never_verify since it needs to run dex to dex to add the
// RETURN_VOID_NO_BARRIER.
if (never_verify || verification_enabled) {
- Resolve(class_loader, dex_files, thread_pool, timings);
+ Resolve(class_loader, dex_files, timings);
VLOG(compiler) << "Resolve: " << GetMemoryUsageString(false);
}
if (never_verify) {
VLOG(compiler) << "Verify none mode specified, skipping verification.";
- SetVerified(class_loader, dex_files, thread_pool, timings);
+ SetVerified(class_loader, dex_files, timings);
}
if (!verification_enabled) {
return;
}
- Verify(class_loader, dex_files, thread_pool, timings);
+ if (GetCompilerOptions().IsForceDeterminism() && IsBootImage()) {
+ // Resolve strings from const-string. Do this now to have a deterministic image.
+ ResolveConstStrings(this, dex_files, timings);
+ VLOG(compiler) << "Resolve const-strings: " << GetMemoryUsageString(false);
+ }
+
+ Verify(class_loader, dex_files, timings);
VLOG(compiler) << "Verify: " << GetMemoryUsageString(false);
if (had_hard_verifier_failure_ && GetCompilerOptions().AbortOnHardVerifierFailure()) {
@@ -721,7 +859,7 @@
<< "situations. Please check the log.";
}
- InitializeClasses(class_loader, dex_files, thread_pool, timings);
+ InitializeClasses(class_loader, dex_files, timings);
VLOG(compiler) << "InitializeClasses: " << GetMemoryUsageString(false);
UpdateImageClasses(timings);
@@ -1759,6 +1897,9 @@
// Wait for all the worker threads to finish.
thread_pool_->Wait(self, true, false);
+
+ // And stop the workers accepting jobs.
+ thread_pool_->StopWorkers(self);
}
size_t NextIndex() {
@@ -1995,9 +2136,12 @@
const ParallelCompilationManager* const manager_;
};
-void CompilerDriver::ResolveDexFile(jobject class_loader, const DexFile& dex_file,
+void CompilerDriver::ResolveDexFile(jobject class_loader,
+ const DexFile& dex_file,
const std::vector<const DexFile*>& dex_files,
- ThreadPool* thread_pool, TimingLogger* timings) {
+ ThreadPool* thread_pool,
+ size_t thread_count,
+ TimingLogger* timings) {
ClassLinker* class_linker = Runtime::Current()->GetClassLinker();
// TODO: we could resolve strings here, although the string table is largely filled with class
@@ -2010,27 +2154,43 @@
// classdefs are resolved by ResolveClassFieldsAndMethods.
TimingLogger::ScopedTiming t("Resolve Types", timings);
ResolveTypeVisitor visitor(&context);
- context.ForAll(0, dex_file.NumTypeIds(), &visitor, thread_count_);
+ context.ForAll(0, dex_file.NumTypeIds(), &visitor, thread_count);
}
TimingLogger::ScopedTiming t("Resolve MethodsAndFields", timings);
ResolveClassFieldsAndMethodsVisitor visitor(&context);
- context.ForAll(0, dex_file.NumClassDefs(), &visitor, thread_count_);
+ context.ForAll(0, dex_file.NumClassDefs(), &visitor, thread_count);
}
-void CompilerDriver::SetVerified(jobject class_loader, const std::vector<const DexFile*>& dex_files,
- ThreadPool* thread_pool, TimingLogger* timings) {
+void CompilerDriver::SetVerified(jobject class_loader,
+ const std::vector<const DexFile*>& dex_files,
+ TimingLogger* timings) {
+ // This can be run in parallel.
for (const DexFile* dex_file : dex_files) {
CHECK(dex_file != nullptr);
- SetVerifiedDexFile(class_loader, *dex_file, dex_files, thread_pool, timings);
+ SetVerifiedDexFile(class_loader,
+ *dex_file,
+ dex_files,
+ parallel_thread_pool_.get(),
+ parallel_thread_count_,
+ timings);
}
}
-void CompilerDriver::Verify(jobject class_loader, const std::vector<const DexFile*>& dex_files,
- ThreadPool* thread_pool, TimingLogger* timings) {
+void CompilerDriver::Verify(jobject class_loader,
+ const std::vector<const DexFile*>& dex_files,
+ TimingLogger* timings) {
+ // Note: verification should not be pulling in classes anymore when compiling the boot image,
+ // as all should have been resolved before. As such, doing this in parallel should still
+ // be deterministic.
for (const DexFile* dex_file : dex_files) {
CHECK(dex_file != nullptr);
- VerifyDexFile(class_loader, *dex_file, dex_files, thread_pool, timings);
+ VerifyDexFile(class_loader,
+ *dex_file,
+ dex_files,
+ parallel_thread_pool_.get(),
+ parallel_thread_count_,
+ timings);
}
}
@@ -2104,15 +2264,18 @@
const ParallelCompilationManager* const manager_;
};
-void CompilerDriver::VerifyDexFile(jobject class_loader, const DexFile& dex_file,
+void CompilerDriver::VerifyDexFile(jobject class_loader,
+ const DexFile& dex_file,
const std::vector<const DexFile*>& dex_files,
- ThreadPool* thread_pool, TimingLogger* timings) {
+ ThreadPool* thread_pool,
+ size_t thread_count,
+ TimingLogger* timings) {
TimingLogger::ScopedTiming t("Verify Dex File", timings);
ClassLinker* class_linker = Runtime::Current()->GetClassLinker();
ParallelCompilationManager context(class_linker, class_loader, this, &dex_file, dex_files,
thread_pool);
VerifyClassVisitor visitor(&context);
- context.ForAll(0, dex_file.NumClassDefs(), &visitor, thread_count_);
+ context.ForAll(0, dex_file.NumClassDefs(), &visitor, thread_count);
}
class SetVerifiedClassVisitor : public CompilationVisitor {
@@ -2162,15 +2325,18 @@
const ParallelCompilationManager* const manager_;
};
-void CompilerDriver::SetVerifiedDexFile(jobject class_loader, const DexFile& dex_file,
+void CompilerDriver::SetVerifiedDexFile(jobject class_loader,
+ const DexFile& dex_file,
const std::vector<const DexFile*>& dex_files,
- ThreadPool* thread_pool, TimingLogger* timings) {
+ ThreadPool* thread_pool,
+ size_t thread_count,
+ TimingLogger* timings) {
TimingLogger::ScopedTiming t("Verify Dex File", timings);
ClassLinker* class_linker = Runtime::Current()->GetClassLinker();
ParallelCompilationManager context(class_linker, class_loader, this, &dex_file, dex_files,
thread_pool);
SetVerifiedClassVisitor visitor(&context);
- context.ForAll(0, dex_file.NumClassDefs(), &visitor, thread_count_);
+ context.ForAll(0, dex_file.NumClassDefs(), &visitor, thread_count);
}
class InitializeClassVisitor : public CompilationVisitor {
@@ -2271,31 +2437,37 @@
const ParallelCompilationManager* const manager_;
};
-void CompilerDriver::InitializeClasses(jobject jni_class_loader, const DexFile& dex_file,
+void CompilerDriver::InitializeClasses(jobject jni_class_loader,
+ const DexFile& dex_file,
const std::vector<const DexFile*>& dex_files,
- ThreadPool* thread_pool, TimingLogger* timings) {
+ TimingLogger* timings) {
TimingLogger::ScopedTiming t("InitializeNoClinit", timings);
+
+ // Initialization allocates objects and needs to run single-threaded to be deterministic.
+ bool force_determinism = GetCompilerOptions().IsForceDeterminism();
+ ThreadPool* init_thread_pool = force_determinism
+ ? single_thread_pool_.get()
+ : parallel_thread_pool_.get();
+ size_t init_thread_count = force_determinism ? 1U : parallel_thread_count_;
+
ClassLinker* class_linker = Runtime::Current()->GetClassLinker();
ParallelCompilationManager context(class_linker, jni_class_loader, this, &dex_file, dex_files,
- thread_pool);
- size_t thread_count;
+ init_thread_pool);
if (IsBootImage()) {
// TODO: remove this when transactional mode supports multithreading.
- thread_count = 1U;
- } else {
- thread_count = thread_count_;
+ init_thread_count = 1U;
}
InitializeClassVisitor visitor(&context);
- context.ForAll(0, dex_file.NumClassDefs(), &visitor, thread_count);
+ context.ForAll(0, dex_file.NumClassDefs(), &visitor, init_thread_count);
}
void CompilerDriver::InitializeClasses(jobject class_loader,
const std::vector<const DexFile*>& dex_files,
- ThreadPool* thread_pool, TimingLogger* timings) {
+ TimingLogger* timings) {
for (size_t i = 0; i != dex_files.size(); ++i) {
const DexFile* dex_file = dex_files[i];
CHECK(dex_file != nullptr);
- InitializeClasses(class_loader, *dex_file, dex_files, thread_pool, timings);
+ InitializeClasses(class_loader, *dex_file, dex_files, timings);
}
if (IsBootImage()) {
// Prune garbage objects created during aborted transactions.
@@ -2303,8 +2475,9 @@
}
}
-void CompilerDriver::Compile(jobject class_loader, const std::vector<const DexFile*>& dex_files,
- ThreadPool* thread_pool, TimingLogger* timings) {
+void CompilerDriver::Compile(jobject class_loader,
+ const std::vector<const DexFile*>& dex_files,
+ TimingLogger* timings) {
if (kDebugProfileGuidedCompilation) {
LOG(INFO) << "[ProfileGuidedCompilation] " <<
((profile_compilation_info_ == nullptr)
@@ -2314,7 +2487,12 @@
for (size_t i = 0; i != dex_files.size(); ++i) {
const DexFile* dex_file = dex_files[i];
CHECK(dex_file != nullptr);
- CompileDexFile(class_loader, *dex_file, dex_files, thread_pool, timings);
+ CompileDexFile(class_loader,
+ *dex_file,
+ dex_files,
+ parallel_thread_pool_.get(),
+ parallel_thread_count_,
+ timings);
}
VLOG(compiler) << "Compile: " << GetMemoryUsageString(false);
}
@@ -2421,14 +2599,17 @@
const ParallelCompilationManager* const manager_;
};
-void CompilerDriver::CompileDexFile(jobject class_loader, const DexFile& dex_file,
+void CompilerDriver::CompileDexFile(jobject class_loader,
+ const DexFile& dex_file,
const std::vector<const DexFile*>& dex_files,
- ThreadPool* thread_pool, TimingLogger* timings) {
+ ThreadPool* thread_pool,
+ size_t thread_count,
+ TimingLogger* timings) {
TimingLogger::ScopedTiming t("Compile Dex File", timings);
ParallelCompilationManager context(Runtime::Current()->GetClassLinker(), class_loader, this,
&dex_file, dex_files, thread_pool);
CompileClassVisitor visitor(&context);
- context.ForAll(0, dex_file.NumClassDefs(), &visitor, thread_count_);
+ context.ForAll(0, dex_file.NumClassDefs(), &visitor, thread_count);
}
void CompilerDriver::AddCompiledMethod(const MethodReference& method_ref,
@@ -2589,4 +2770,16 @@
return true;
}
+void CompilerDriver::InitializeThreadPools() {
+ size_t parallel_count = parallel_thread_count_ > 0 ? parallel_thread_count_ - 1 : 0;
+ parallel_thread_pool_.reset(
+ new ThreadPool("Compiler driver thread pool", parallel_count));
+ single_thread_pool_.reset(new ThreadPool("Single-threaded Compiler driver thread pool", 0));
+}
+
+void CompilerDriver::FreeThreadPools() {
+ parallel_thread_pool_.reset();
+ single_thread_pool_.reset();
+}
+
} // namespace art