runtime/runtime.h

/*
 * Copyright (C) 2011 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.
 */

#ifndef ART_RUNTIME_RUNTIME_H_
#define ART_RUNTIME_RUNTIME_H_

#include <jni.h>
#include <stdio.h>

#include <iosfwd>
#include <string>
#include <utility>
#include <vector>

#include "base/macros.h"
#include "base/stringpiece.h"
#include "gc/collector_type.h"
#include "gc/heap.h"
#include "globals.h"
#include "instruction_set.h"
#include "instrumentation.h"
#include "jobject_comparator.h"
#include "locks.h"
#include "root_visitor.h"
#include "runtime_stats.h"
#include "safe_map.h"

namespace art {

namespace gc {
  class Heap;
}
namespace mirror {
  class ArtMethod;
  class ClassLoader;
  template<class T> class ObjectArray;
  template<class T> class PrimitiveArray;
  typedef PrimitiveArray<int8_t> ByteArray;
  class String;
  class Throwable;
}  // namespace mirror
namespace verifier {
class MethodVerifier;
}
class ClassLinker;
class CompilerCallbacks;
class DexFile;
class InternTable;
struct JavaVMExt;
class MonitorList;
class SignalCatcher;
class ThreadList;
class Trace;

class Runtime {
 public:
  typedef std::vector<std::pair<std::string, const void*> > Options;

  enum CompilerFilter {
    kInterpretOnly,       // Compile nothing.
    kSpace,               // Maximize space savings.
    kBalanced,            // Try to get the best performance return on compilation investment.
    kSpeed,               // Maximize runtime performance.
    kEverything           // Force compilation (Note: excludes compilaton of class initializers).
  };

  // Guide heuristics to determine whether to compile method if profile data not available.
#if ART_SMALL_MODE
  static const CompilerFilter kDefaultCompilerFilter = kInterpretOnly;
#else
  static const CompilerFilter kDefaultCompilerFilter = kSpeed;
#endif
  static const size_t kDefaultHugeMethodThreshold = 10000;
  static const size_t kDefaultLargeMethodThreshold = 600;
  static const size_t kDefaultSmallMethodThreshold = 60;
  static const size_t kDefaultTinyMethodThreshold = 20;
  static const size_t kDefaultNumDexMethodsThreshold = 900;

  class ParsedOptions {
   public:
    // returns null if problem parsing and ignore_unrecognized is false
    static ParsedOptions* Create(const Options& options, bool ignore_unrecognized);

    const std::vector<const DexFile*>* boot_class_path_;
    std::string boot_class_path_string_;
    std::string class_path_string_;
    std::string host_prefix_;
    std::string image_;
    bool check_jni_;
    std::string jni_trace_;
    CompilerCallbacks* compiler_callbacks_;
    bool is_zygote_;
    bool interpreter_only_;
    bool is_explicit_gc_disabled_;
    bool use_tlab_;
    size_t long_pause_log_threshold_;
    size_t long_gc_log_threshold_;
    bool dump_gc_performance_on_shutdown_;
    bool ignore_max_footprint_;
    size_t heap_initial_size_;
    size_t heap_maximum_size_;
    size_t heap_growth_limit_;
    size_t heap_min_free_;
    size_t heap_max_free_;
    double heap_target_utilization_;
    size_t parallel_gc_threads_;
    size_t conc_gc_threads_;
    gc::CollectorType collector_type_;
    size_t stack_size_;
    size_t max_spins_before_thin_lock_inflation_;
    bool low_memory_mode_;
    size_t lock_profiling_threshold_;
    std::string stack_trace_file_;
    bool method_trace_;
    std::string method_trace_file_;
    size_t method_trace_file_size_;
    bool (*hook_is_sensitive_thread_)();
    jint (*hook_vfprintf_)(FILE* stream, const char* format, va_list ap);
    void (*hook_exit_)(jint status);
    void (*hook_abort_)();
    std::vector<std::string> properties_;
    CompilerFilter compiler_filter_;
    size_t huge_method_threshold_;
    size_t large_method_threshold_;
    size_t small_method_threshold_;
    size_t tiny_method_threshold_;
    size_t num_dex_methods_threshold_;
    bool sea_ir_mode_;

   private:
    ParsedOptions() {}
  };

  // Creates and initializes a new runtime.
  static bool Create(const Options& options, bool ignore_unrecognized)
      SHARED_TRYLOCK_FUNCTION(true, Locks::mutator_lock_);

  bool IsCompiler() const {
    return compiler_callbacks_ != nullptr;
  }

  CompilerCallbacks* GetCompilerCallbacks() {
    return compiler_callbacks_;
  }

  bool IsZygote() const {
    return is_zygote_;
  }

  bool IsExplicitGcDisabled() const {
    return is_explicit_gc_disabled_;
  }

#ifdef ART_SEA_IR_MODE
  bool IsSeaIRMode() const {
    return sea_ir_mode_;
  }
#endif

  void SetSeaIRMode(bool sea_ir_mode) {
    sea_ir_mode_ = sea_ir_mode;
  }

  CompilerFilter GetCompilerFilter() const {
    return compiler_filter_;
  }

  void SetCompilerFilter(CompilerFilter compiler_filter) {
    compiler_filter_ = compiler_filter;
  }

  size_t GetHugeMethodThreshold() const {
    return huge_method_threshold_;
  }

  size_t GetLargeMethodThreshold() const {
    return large_method_threshold_;
  }

  size_t GetSmallMethodThreshold() const {
    return small_method_threshold_;
  }

  size_t GetTinyMethodThreshold() const {
    return tiny_method_threshold_;
  }

  size_t GetNumDexMethodsThreshold() const {
      return num_dex_methods_threshold_;
  }

  const std::string& GetHostPrefix() const {
    DCHECK(!IsStarted());
    return host_prefix_;
  }

  // Starts a runtime, which may cause threads to be started and code to run.
  bool Start() UNLOCK_FUNCTION(Locks::mutator_lock_);

  bool IsShuttingDown(Thread* self);
  bool IsShuttingDownLocked() const EXCLUSIVE_LOCKS_REQUIRED(Locks::runtime_shutdown_lock_) {
    return shutting_down_;
  }

  size_t NumberOfThreadsBeingBorn() const EXCLUSIVE_LOCKS_REQUIRED(Locks::runtime_shutdown_lock_) {
    return threads_being_born_;
  }

  void StartThreadBirth() EXCLUSIVE_LOCKS_REQUIRED(Locks::runtime_shutdown_lock_) {
    threads_being_born_++;
  }

  void EndThreadBirth() EXCLUSIVE_LOCKS_REQUIRED(Locks::runtime_shutdown_lock_);

  bool IsStarted() const {
    return started_;
  }

  bool IsFinishedStarting() const {
    return finished_starting_;
  }

  static Runtime* Current() {
    return instance_;
  }

  // Aborts semi-cleanly. Used in the implementation of LOG(FATAL), which most
  // callers should prefer.
  // This isn't marked ((noreturn)) because then gcc will merge multiple calls
  // in a single function together. This reduces code size slightly, but means
  // that the native stack trace we get may point at the wrong call site.
  static void Abort() LOCKS_EXCLUDED(Locks::abort_lock_);

  // Returns the "main" ThreadGroup, used when attaching user threads.
  jobject GetMainThreadGroup() const;

  // Returns the "system" ThreadGroup, used when attaching our internal threads.
  jobject GetSystemThreadGroup() const;

  // Returns the system ClassLoader which represents the CLASSPATH.
  jobject GetSystemClassLoader() const;

  // Attaches the calling native thread to the runtime.
  bool AttachCurrentThread(const char* thread_name, bool as_daemon, jobject thread_group,
                           bool create_peer);

  void CallExitHook(jint status);

  // Detaches the current native thread from the runtime.
  void DetachCurrentThread() LOCKS_EXCLUDED(Locks::mutator_lock_);

  void DumpForSigQuit(std::ostream& os)
      SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);
  void DumpLockHolders(std::ostream& os);

  ~Runtime();

  const std::string& GetBootClassPathString() const {
    return boot_class_path_string_;
  }

  const std::string& GetClassPathString() const {
    return class_path_string_;
  }

  ClassLinker* GetClassLinker() const {
    return class_linker_;
  }

  size_t GetDefaultStackSize() const {
    return default_stack_size_;
  }

  gc::Heap* GetHeap() const {
    return heap_;
  }

  InternTable* GetInternTable() const {
    DCHECK(intern_table_ != NULL);
    return intern_table_;
  }

  JavaVMExt* GetJavaVM() const {
    return java_vm_;
  }

  size_t GetMaxSpinsBeforeThinkLockInflation() const {
    return max_spins_before_thin_lock_inflation_;
  }

  MonitorList* GetMonitorList() const {
    return monitor_list_;
  }

  mirror::Throwable* GetPreAllocatedOutOfMemoryError() const
    SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);

  const std::vector<std::string>& GetProperties() const {
    return properties_;
  }

  ThreadList* GetThreadList() const {
    return thread_list_;
  }

  const char* GetVersion() const {
    return "2.0.0";
  }

  void DisallowNewSystemWeaks() EXCLUSIVE_LOCKS_REQUIRED(Locks::mutator_lock_);
  void AllowNewSystemWeaks() SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);

  // Visit all the roots. If only_dirty is true then non-dirty roots won't be visited. If
  // clean_dirty is true then dirty roots will be marked as non-dirty after visiting.
  void VisitRoots(RootVisitor* visitor, void* arg, bool only_dirty, bool clean_dirty)
      SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);

  // Visit all of the roots we can do safely do concurrently.
  void VisitConcurrentRoots(RootVisitor* visitor, void* arg, bool only_dirty, bool clean_dirty)
      SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);

  // Visit all of the non thread roots, we can do this with mutators unpaused.
  void VisitNonThreadRoots(RootVisitor* visitor, void* arg)
      SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);

  // Visit all other roots which must be done with mutators suspended.
  void VisitNonConcurrentRoots(RootVisitor* visitor, void* arg)
      SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);

  // Sweep system weaks, the system weak is deleted if the visitor return nullptr. Otherwise, the
  // system weak is updated to be the visitor's returned value.
  void SweepSystemWeaks(RootVisitor* visitor, void* arg)
      SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);

  // Returns a special method that calls into a trampoline for runtime method resolution
  mirror::ArtMethod* GetResolutionMethod() const {
    CHECK(HasResolutionMethod());
    return resolution_method_;
  }

  bool HasResolutionMethod() const {
    return resolution_method_ != NULL;
  }

  void SetResolutionMethod(mirror::ArtMethod* method) {
    resolution_method_ = method;
  }

  mirror::ArtMethod* CreateResolutionMethod() SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);

  // Returns a special method that calls into a trampoline for runtime imt conflicts
  mirror::ArtMethod* GetImtConflictMethod() const {
    CHECK(HasImtConflictMethod());
    return imt_conflict_method_;
  }

  bool HasImtConflictMethod() const {
    return imt_conflict_method_ != NULL;
  }

  void SetImtConflictMethod(mirror::ArtMethod* method) {
    imt_conflict_method_ = method;
  }

  mirror::ArtMethod* CreateImtConflictMethod() SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);

  // Returns an imt with every entry set to conflict, used as default imt for all classes.
  mirror::ObjectArray<mirror::ArtMethod>* GetDefaultImt() const {
    CHECK(HasDefaultImt());
    return default_imt_;
  }

  bool HasDefaultImt() const {
    return default_imt_ != NULL;
  }

  void SetDefaultImt(mirror::ObjectArray<mirror::ArtMethod>* imt) {
    default_imt_ = imt;
  }

  mirror::ObjectArray<mirror::ArtMethod>* CreateDefaultImt(ClassLinker* cl)
      SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);

  // Returns a special method that describes all callee saves being spilled to the stack.
  enum CalleeSaveType {
    kSaveAll,
    kRefsOnly,
    kRefsAndArgs,
    kLastCalleeSaveType  // Value used for iteration
  };

  bool HasCalleeSaveMethod(CalleeSaveType type) const {
    return callee_save_methods_[type] != NULL;
  }

  mirror::ArtMethod* GetCalleeSaveMethod(CalleeSaveType type) const {
    DCHECK(HasCalleeSaveMethod(type));
    return callee_save_methods_[type];
  }

  void SetCalleeSaveMethod(mirror::ArtMethod* method, CalleeSaveType type);

  mirror::ArtMethod* CreateCalleeSaveMethod(InstructionSet instruction_set,
                                                 CalleeSaveType type)
      SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);

  mirror::ArtMethod* CreateRefOnlyCalleeSaveMethod(InstructionSet instruction_set)
      SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);

  mirror::ArtMethod* CreateRefAndArgsCalleeSaveMethod(InstructionSet instruction_set)
      SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);

  int32_t GetStat(int kind);

  RuntimeStats* GetStats() {
    return &stats_;
  }

  bool HasStatsEnabled() const {
    return stats_enabled_;
  }

  void ResetStats(int kinds);

  void SetStatsEnabled(bool new_state);

  bool PreZygoteFork();
  bool InitZygote();
  void DidForkFromZygote();

  instrumentation::Instrumentation* GetInstrumentation() {
    return &instrumentation_;
  }

  bool UseCompileTimeClassPath() const {
    return use_compile_time_class_path_;
  }

  void AddMethodVerifier(verifier::MethodVerifier* verifier);
  void RemoveMethodVerifier(verifier::MethodVerifier* verifier);

  const std::vector<const DexFile*>& GetCompileTimeClassPath(jobject class_loader);
  void SetCompileTimeClassPath(jobject class_loader, std::vector<const DexFile*>& class_path);

 private:
  static void InitPlatformSignalHandlers();

  Runtime();

  void BlockSignals();

  bool Init(const Options& options, bool ignore_unrecognized)
      SHARED_TRYLOCK_FUNCTION(true, Locks::mutator_lock_);
  void InitNativeMethods() LOCKS_EXCLUDED(Locks::mutator_lock_);
  void InitThreadGroups(Thread* self);
  void RegisterRuntimeNativeMethods(JNIEnv* env);

  void StartDaemonThreads();
  void StartSignalCatcher();

  // A pointer to the active runtime or NULL.
  static Runtime* instance_;

  CompilerCallbacks* compiler_callbacks_;
  bool is_zygote_;
  bool is_concurrent_gc_enabled_;
  bool is_explicit_gc_disabled_;

  CompilerFilter compiler_filter_;
  size_t huge_method_threshold_;
  size_t large_method_threshold_;
  size_t small_method_threshold_;
  size_t tiny_method_threshold_;
  size_t num_dex_methods_threshold_;

  bool sea_ir_mode_;

  // The host prefix is used during cross compilation. It is removed
  // from the start of host paths such as:
  //    $ANDROID_PRODUCT_OUT/system/framework/boot.oat
  // to produce target paths such as
  //    /system/framework/boot.oat
  // Similarly it is prepended to target paths to arrive back at a
  // host past. In both cases this is necessary because image and oat
  // files embedded expect paths of dependent files (an image points
  // to an oat file and an oat files to one or more dex files). These
  // files contain the expected target path.
  std::string host_prefix_;

  std::string boot_class_path_string_;
  std::string class_path_string_;
  std::vector<std::string> properties_;

  // The default stack size for managed threads created by the runtime.
  size_t default_stack_size_;

  gc::Heap* heap_;

  // The number of spins that are done before thread suspension is used to forcibly inflate.
  size_t max_spins_before_thin_lock_inflation_;
  MonitorList* monitor_list_;

  ThreadList* thread_list_;

  InternTable* intern_table_;

  ClassLinker* class_linker_;

  SignalCatcher* signal_catcher_;
  std::string stack_trace_file_;

  JavaVMExt* java_vm_;

  mirror::Throwable* pre_allocated_OutOfMemoryError_;

  mirror::ArtMethod* callee_save_methods_[kLastCalleeSaveType];

  mirror::ArtMethod* resolution_method_;

  mirror::ArtMethod* imt_conflict_method_;

  mirror::ObjectArray<mirror::ArtMethod>* default_imt_;

  // Method verifier set, used so that we can update their GC roots.
  Mutex method_verifiers_lock_;
  std::set<verifier::MethodVerifier*> method_verifiers_;

  // A non-zero value indicates that a thread has been created but not yet initialized. Guarded by
  // the shutdown lock so that threads aren't born while we're shutting down.
  size_t threads_being_born_ GUARDED_BY(Locks::runtime_shutdown_lock_);

  // Waited upon until no threads are being born.
  UniquePtr<ConditionVariable> shutdown_cond_ GUARDED_BY(Locks::runtime_shutdown_lock_);

  // Set when runtime shutdown is past the point that new threads may attach.
  bool shutting_down_ GUARDED_BY(Locks::runtime_shutdown_lock_);

  // The runtime is starting to shutdown but is blocked waiting on shutdown_cond_.
  bool shutting_down_started_ GUARDED_BY(Locks::runtime_shutdown_lock_);

  bool started_;

  // New flag added which tells us if the runtime has finished starting. If
  // this flag is set then the Daemon threads are created and the class loader
  // is created. This flag is needed for knowing if its safe to request CMS.
  bool finished_starting_;

  // Hooks supported by JNI_CreateJavaVM
  jint (*vfprintf_)(FILE* stream, const char* format, va_list ap);
  void (*exit_)(jint status);
  void (*abort_)();

  bool stats_enabled_;
  RuntimeStats stats_;

  bool method_trace_;
  std::string method_trace_file_;
  size_t method_trace_file_size_;
  instrumentation::Instrumentation instrumentation_;

  typedef SafeMap<jobject, std::vector<const DexFile*>, JobjectComparator> CompileTimeClassPaths;
  CompileTimeClassPaths compile_time_class_paths_;
  bool use_compile_time_class_path_;

  jobject main_thread_group_;
  jobject system_thread_group_;

  // As returned by ClassLoader.getSystemClassLoader().
  jobject system_class_loader_;

  // If true, then we dump the GC cumulative timings on shutdown.
  bool dump_gc_performance_on_shutdown_;

  DISALLOW_COPY_AND_ASSIGN(Runtime);
};

}  // namespace art

#endif  // ART_RUNTIME_RUNTIME_H_