关于 Signal Catcher 线程中对线程的理解

Thread* Thread::Attach(const char* thread_name, bool as_daemon, jobject thread_group,bool create_peer) {    Runtime* runtime = Runtime::Current();    ......    Thread* self;    {        MutexLock mu(nullptr, *Locks::runtime_shutdown_lock_);        if (runtime->IsShuttingDownLocked()) {        ......        } else {                Runtime::Current()->StartThreadBirth();                self = new Thread(as_daemon); //新建一个Thread对象                bool init_success = self->Init(runtime->GetThreadList(), runtime->GetJavaVM()); //调用init函数                Runtime::Current()->EndThreadBirth();                if (!init_success) {                    delete self;                    return nullptr;                }         }      }    ......    self->InitStringEntryPoints();      CHECK_NE(self->GetState(), kRunnable);    self->SetState(kNative);    ......    return self;}

inline ThreadState Thread::SetState(ThreadState new_state) {  // Cannot use this code to change into Runnable as changing to Runnable should fail if  // old_state_and_flags.suspend_request is true.  DCHECK_NE(new_state, kRunnable);  if (kIsDebugBuild && this != Thread::Current()) {    std::string name;    GetThreadName(name);    LOG(FATAL) << "Thread \"" << name << "\"(" << this << " != Thread::Current()="               << Thread::Current() << ") changing state to " << new_state;  }  union StateAndFlags old_state_and_flags;  old_state_and_flags.as_int = tls32_.state_and_flags.as_int;  tls32_.state_and_flags.as_struct.state = new_state;  return static_cast<ThreadState>(old_state_and_flags.as_struct.state);}

enum ThreadState {  //                                   Thread.State   JDWP state  kTerminated = 66,                 // TERMINATED     TS_ZOMBIE    Thread.run has returned, but Thread* still around  kRunnable,                        // RUNNABLE       TS_RUNNING   runnable  kTimedWaiting,                    // TIMED_WAITING  TS_WAIT      in Object.wait() with a timeout  kSleeping,                        // TIMED_WAITING  TS_SLEEPING  in Thread.sleep()  kBlocked,                         // BLOCKED        TS_MONITOR   blocked on a monitor  kWaiting,                         // WAITING        TS_WAIT      in Object.wait()  kWaitingForGcToComplete,          // WAITING        TS_WAIT      blocked waiting for GC  kWaitingForCheckPointsToRun,      // WAITING        TS_WAIT      GC waiting for checkpoints to run  kWaitingPerformingGc,             // WAITING        TS_WAIT      performing GC  kWaitingForDebuggerSend,          // WAITING        TS_WAIT      blocked waiting for events to be sent  kWaitingForDebuggerToAttach,      // WAITING        TS_WAIT      blocked waiting for debugger to attach  kWaitingInMainDebuggerLoop,       // WAITING        TS_WAIT      blocking/reading/processing debugger events  kWaitingForDebuggerSuspension,    // WAITING        TS_WAIT      waiting for debugger suspend all  kWaitingForJniOnLoad,             // WAITING        TS_WAIT      waiting for execution of dlopen and JNI on load code  kWaitingForSignalCatcherOutput,   // WAITING        TS_WAIT      waiting for signal catcher IO to complete  kWaitingInMainSignalCatcherLoop,  // WAITING        TS_WAIT      blocking/reading/processing signals  kWaitingForDeoptimization,        // WAITING        TS_WAIT      waiting for deoptimization suspend all  kWaitingForMethodTracingStart,    // WAITING        TS_WAIT      waiting for method tracing to start  kWaitingForVisitObjects,          // WAITING        TS_WAIT      waiting for visiting objects  kWaitingForGetObjectsAllocated,   // WAITING        TS_WAIT      waiting for getting the number of allocated objects  kStarting,                        // NEW            TS_WAIT      native thread started, not yet ready to run managed code  kNative,                          // RUNNABLE       TS_RUNNING   running in a JNI native method  kSuspended,                       // RUNNABLE       TS_RUNNING   suspended by GC or debugger};