Bug 698002. Add MacOS port of the v8 profiler. r=bgirard

This uses a separate thread that will pause the main thread
and read the registers out of it.

--HG--
extra : rebase_source : bb8174320728b6c4976047fd25e6e93280ea444a

tools/profiler/Makefile.in

@@ -86,6 +86,16 @@ CPPSRCS += \
   TableTicker.cpp \
   $(NULL)
 endif
+ifeq ($(OS_TARGET),Darwin)
+
+DEFINES += -DMOZ_ENABLE_PROFILER_SPS
+
+CPPSRCS += \
+  platform-macos.cc \
+  TableTicker.cpp \
+  $(NULL)
+endif
+
 
 include $(topsrcdir)/config/rules.mk
 

tools/profiler/sampler.h

@@ -94,7 +94,7 @@
 #define SAMPLE_MARKER(info)
 
 // Redefine the macros for platforms where SPS is supported.
-#if defined(ANDROID) || defined(__linux__)
+#if defined(ANDROID) || defined(__linux__) || defined(XP_MACOSX)
 
 #include "sps_sampler.h"
 

tools/profiler/sps/platform-macos.cc

@@ -0,0 +1,301 @@
+#include <dlfcn.h>
+#include <unistd.h>
+#include <sys/mman.h>
+#include <mach/mach_init.h>
+#include <mach-o/dyld.h>
+#include <mach-o/getsect.h>
+
+#include <AvailabilityMacros.h>
+
+#include <pthread.h>
+#include <semaphore.h>
+#include <signal.h>
+#include <libkern/OSAtomic.h>
+#include <mach/mach.h>
+#include <mach/semaphore.h>
+#include <mach/task.h>
+#include <mach/vm_statistics.h>
+#include <sys/time.h>
+#include <sys/resource.h>
+#include <sys/types.h>
+#include <sys/sysctl.h>
+#include <stdarg.h>
+#include <stdlib.h>
+#include <string.h>
+#include <errno.h>
+
+
+#include "v8-support.h"
+#include "platform.h"
+
+// this port is based off of v8 svn revision 9837
+
+// XXX: this is a very stubbed out implementation
+// that only supports a single Sampler
+struct SamplerRegistry {
+  static void AddActiveSampler(Sampler *sampler) {
+    ASSERT(!SamplerRegistry::sampler);
+    SamplerRegistry::sampler = sampler;
+  }
+  static void RemoveActiveSampler(Sampler *sampler) {
+  }
+  static Sampler *sampler;
+};
+
+Sampler *SamplerRegistry::sampler = NULL;
+
+// 0 is never a valid thread id on MacOSX since a ptread_t is
+// a pointer.
+static const pthread_t kNoThread = (pthread_t) 0;
+
+class MacOSMutex : public Mutex {
+ public:
+  MacOSMutex() {
+    pthread_mutexattr_t attr;
+    pthread_mutexattr_init(&attr);
+    pthread_mutexattr_settype(&attr, PTHREAD_MUTEX_RECURSIVE);
+    pthread_mutex_init(&mutex_, &attr);
+  }
+
+  virtual ~MacOSMutex() { pthread_mutex_destroy(&mutex_); }
+
+  virtual int Lock() { return pthread_mutex_lock(&mutex_); }
+  virtual int Unlock() { return pthread_mutex_unlock(&mutex_); }
+
+  virtual bool TryLock() {
+    int result = pthread_mutex_trylock(&mutex_);
+    // Return false if the lock is busy and locking failed.
+    if (result == EBUSY) {
+      return false;
+    }
+    ASSERT(result == 0);  // Verify no other errors.
+    return true;
+  }
+
+ private:
+  pthread_mutex_t mutex_;
+};
+
+
+Mutex* OS::CreateMutex() {
+  return new MacOSMutex();
+}
+
+void OS::Sleep(int milliseconds) {
+  usleep(1000 * milliseconds);
+}
+
+class Thread::PlatformData : public Malloced {
+ public:
+  PlatformData() : thread_(kNoThread) {}
+  pthread_t thread_;  // Thread handle for pthread.
+};
+
+Thread::Thread(const char* name)
+    : data_(new PlatformData),
+      stack_size_(0) {
+  set_name(name);
+}
+
+
+Thread::~Thread() {
+  delete data_;
+}
+
+
+static void SetThreadName(const char* name) {
+  // pthread_setname_np is only available in 10.6 or later, so test
+  // for it at runtime.
+  int (*dynamic_pthread_setname_np)(const char*);
+  *reinterpret_cast<void**>(&dynamic_pthread_setname_np) =
+    dlsym(RTLD_DEFAULT, "pthread_setname_np");
+  if (!dynamic_pthread_setname_np)
+    return;
+
+  // Mac OS X does not expose the length limit of the name, so hardcode it.
+  static const int kMaxNameLength = 63;
+  USE(kMaxNameLength);
+  ASSERT(Thread::kMaxThreadNameLength <= kMaxNameLength);
+  dynamic_pthread_setname_np(name);
+}
+
+
+static void* ThreadEntry(void* arg) {
+  Thread* thread = reinterpret_cast<Thread*>(arg);
+  // This is also initialized by the first argument to pthread_create() but we
+  // don't know which thread will run first (the original thread or the new
+  // one) so we initialize it here too.
+  thread->data()->thread_ = pthread_self();
+  SetThreadName(thread->name());
+  ASSERT(thread->data()->thread_ != kNoThread);
+  thread->Run();
+  return NULL;
+}
+
+
+void Thread::set_name(const char* name) {
+  strncpy(name_, name, sizeof(name_));
+  name_[sizeof(name_) - 1] = '\0';
+}
+
+
+void Thread::Start() {
+  pthread_attr_t* attr_ptr = NULL;
+  pthread_attr_t attr;
+  if (stack_size_ > 0) {
+    pthread_attr_init(&attr);
+    pthread_attr_setstacksize(&attr, static_cast<size_t>(stack_size_));
+    attr_ptr = &attr;
+  }
+  pthread_create(&data_->thread_, attr_ptr, ThreadEntry, this);
+  ASSERT(data_->thread_ != kNoThread);
+}
+
+
+class Sampler::PlatformData : public Malloced {
+ public:
+  PlatformData() : profiled_thread_(mach_thread_self()) {}
+
+  ~PlatformData() {
+    // Deallocate Mach port for thread.
+    mach_port_deallocate(mach_task_self(), profiled_thread_);
+  }
+
+  thread_act_t profiled_thread() { return profiled_thread_; }
+
+ private:
+  // Note: for profiled_thread_ Mach primitives are used instead of PThread's
+  // because the latter doesn't provide thread manipulation primitives required.
+  // For details, consult "Mac OS X Internals" book, Section 7.3.
+  thread_act_t profiled_thread_;
+};
+
+
+class SamplerThread : public Thread {
+ public:
+  explicit SamplerThread(int interval)
+      : Thread("SamplerThread"),
+        interval_(interval) {}
+
+  static void AddActiveSampler(Sampler* sampler) {
+    ScopedLock lock(mutex_);
+    SamplerRegistry::AddActiveSampler(sampler);
+    if (instance_ == NULL) {
+      instance_ = new SamplerThread(sampler->interval());
+      instance_->Start();
+    } else {
+      ASSERT(instance_->interval_ == sampler->interval());
+    }
+  }
+
+  static void RemoveActiveSampler(Sampler* sampler) {
+    ScopedLock lock(mutex_);
+    SamplerRegistry::RemoveActiveSampler(sampler);
+    /*
+    if (SamplerRegistry::GetState() == SamplerRegistry::HAS_NO_SAMPLERS) {
+      RuntimeProfiler::StopRuntimeProfilerThreadBeforeShutdown(instance_);
+      delete instance_;
+      instance_ = NULL;
+    }
+    */
+  }
+
+  // Implement Thread::Run().
+  virtual void Run() {
+    while (SamplerRegistry::sampler->IsActive()) {
+      SampleContext(SamplerRegistry::sampler);
+      OS::Sleep(interval_);
+    }
+  }
+
+  void SampleContext(Sampler* sampler) {
+    thread_act_t profiled_thread = sampler->platform_data()->profiled_thread();
+    TickSample sample_obj;
+    TickSample* sample = &sample_obj;
+    //TickSample* sample = CpuProfiler::TickSampleEvent(sampler->isolate());
+    //if (sample == NULL) sample = &sample_obj;
+
+    if (KERN_SUCCESS != thread_suspend(profiled_thread)) return;
+
+#if V8_HOST_ARCH_X64
+    thread_state_flavor_t flavor = x86_THREAD_STATE64;
+    x86_thread_state64_t state;
+    mach_msg_type_number_t count = x86_THREAD_STATE64_COUNT;
+#if __DARWIN_UNIX03
+#define REGISTER_FIELD(name) __r ## name
+#else
+#define REGISTER_FIELD(name) r ## name
+#endif  // __DARWIN_UNIX03
+#elif V8_HOST_ARCH_IA32
+    thread_state_flavor_t flavor = i386_THREAD_STATE;
+    i386_thread_state_t state;
+    mach_msg_type_number_t count = i386_THREAD_STATE_COUNT;
+#if __DARWIN_UNIX03
+#define REGISTER_FIELD(name) __e ## name
+#else
+#define REGISTER_FIELD(name) e ## name
+#endif  // __DARWIN_UNIX03
+#else
+#error Unsupported Mac OS X host architecture.
+#endif  // V8_HOST_ARCH
+
+    if (thread_get_state(profiled_thread,
+                         flavor,
+                         reinterpret_cast<natural_t*>(&state),
+                         &count) == KERN_SUCCESS) {
+      //sample->state = sampler->isolate()->current_vm_state();
+      sample->pc = reinterpret_cast<Address>(state.REGISTER_FIELD(ip));
+      sample->sp = reinterpret_cast<Address>(state.REGISTER_FIELD(sp));
+      sample->fp = reinterpret_cast<Address>(state.REGISTER_FIELD(bp));
+      sampler->SampleStack(sample);
+      sampler->Tick(sample);
+    }
+    thread_resume(profiled_thread);
+  }
+
+  const int interval_;
+  //RuntimeProfilerRateLimiter rate_limiter_;
+
+  // Protects the process wide state below.
+  static Mutex* mutex_;
+  static SamplerThread* instance_;
+
+  DISALLOW_COPY_AND_ASSIGN(SamplerThread);
+};
+
+#undef REGISTER_FIELD
+
+
+Mutex* SamplerThread::mutex_ = OS::CreateMutex();
+SamplerThread* SamplerThread::instance_ = NULL;
+
+
+Sampler::Sampler(int interval, bool profiling)
+    : // isolate_(isolate),
+      interval_(interval),
+      profiling_(profiling),
+      synchronous_(profiling),
+      active_(false) /*,
+      samples_taken_(0)*/ {
+  data_ = new PlatformData;
+}
+
+
+Sampler::~Sampler() {
+  ASSERT(!IsActive());
+  delete data_;
+}
+
+
+void Sampler::Start() {
+  ASSERT(!IsActive());
+  SetActive(true);
+  SamplerThread::AddActiveSampler(this);
+}
+
+
+void Sampler::Stop() {
+  ASSERT(IsActive());
+  SamplerThread::RemoveActiveSampler(this);
+  SetActive(false);
+}

tools/profiler/sps/platform.h

@@ -10,6 +10,7 @@
 
 #include "mozilla/Util.h"
 #include "mozilla/unused.h"
+#include "v8-support.h"
 #include <vector>
 #define ASSERT(a) MOZ_ASSERT(a)
 #ifdef ANDROID
@@ -80,6 +81,122 @@ private:
 #ifdef ENABLE_SPS_LEAF_DATA
 struct MapInfo getmaps(pid_t pid);
 #endif
+// ----------------------------------------------------------------------------
+// Mutex
+//
+// Mutexes are used for serializing access to non-reentrant sections of code.
+// The implementations of mutex should allow for nested/recursive locking.
+
+class Mutex {
+ public:
+  virtual ~Mutex() {}
+
+  // Locks the given mutex. If the mutex is currently unlocked, it becomes
+  // locked and owned by the calling thread, and immediately. If the mutex
+  // is already locked by another thread, suspends the calling thread until
+  // the mutex is unlocked.
+  virtual int Lock() = 0;
+
+  // Unlocks the given mutex. The mutex is assumed to be locked and owned by
+  // the calling thread on entrance.
+  virtual int Unlock() = 0;
+
+  // Tries to lock the given mutex. Returns whether the mutex was
+  // successfully locked.
+  virtual bool TryLock() = 0;
+};
+
+// ----------------------------------------------------------------------------
+// ScopedLock
+//
+// Stack-allocated ScopedLocks provide block-scoped locking and
+// unlocking of a mutex.
+class ScopedLock {
+ public:
+  explicit ScopedLock(Mutex* mutex): mutex_(mutex) {
+    ASSERT(mutex_ != NULL);
+    mutex_->Lock();
+  }
+  ~ScopedLock() {
+    mutex_->Unlock();
+  }
+
+ private:
+  Mutex* mutex_;
+  DISALLOW_COPY_AND_ASSIGN(ScopedLock);
+};
+
+
+
+// ----------------------------------------------------------------------------
+// OS
+//
+// This class has static methods for the different platform specific
+// functions. Add methods here to cope with differences between the
+// supported platforms.
+
+class OS {
+ public:
+
+  // Sleep for a number of milliseconds.
+  static void Sleep(const int milliseconds);
+
+  // Factory method for creating platform dependent Mutex.
+  // Please use delete to reclaim the storage for the returned Mutex.
+  static Mutex* CreateMutex();
+
+ private:
+  static const int msPerSecond = 1000;
+
+};
+
+
+
+
+// ----------------------------------------------------------------------------
+// Thread
+//
+// Thread objects are used for creating and running threads. When the start()
+// method is called the new thread starts running the run() method in the new
+// thread. The Thread object should not be deallocated before the thread has
+// terminated.
+
+class Thread {
+ public:
+
+  // Create new thread.
+  explicit Thread(const char* name);
+  virtual ~Thread();
+
+  // Start new thread by calling the Run() method in the new thread.
+  void Start();
+
+  inline const char* name() const {
+    return name_;
+  }
+
+  // Abstract method for run handler.
+  virtual void Run() = 0;
+
+  // The thread name length is limited to 16 based on Linux's implementation of
+  // prctl().
+  static const int kMaxThreadNameLength = 16;
+
+  class PlatformData;
+  PlatformData* data() { return data_; }
+
+ private:
+  void set_name(const char *name);
+
+  PlatformData* data_;
+
+  char name_[kMaxThreadNameLength];
+  int stack_size_;
+
+  DISALLOW_COPY_AND_ASSIGN(Thread);
+};
+
+
 
 // ----------------------------------------------------------------------------
 // Sampler
@@ -113,6 +230,8 @@ class Sampler {
   explicit Sampler(int interval, bool profiling);
   virtual ~Sampler();
 
+  int interval() const { return interval_; }
+
   // Performs stack sampling.
   virtual void SampleStack(TickSample* sample) = 0;
 
@@ -132,17 +251,13 @@ class Sampler {
   // Is the sampler used for profiling?
   bool IsProfiling() const { return profiling_; }
 
-  // Is the sampler running in sync with the JS thread? On platforms
-  // where the sampler is implemented with a thread that wakes up
-  // every now and then, having a synchronous sampler implies
-  // suspending/resuming the JS thread.
-  bool IsSynchronous() const { return synchronous_; }
-
   // Whether the sampler is running (that is, consumes resources).
   bool IsActive() const { return active_; }
 
   class PlatformData;
 
+  PlatformData* platform_data() { return data_; }
+
  private:
   void SetActive(bool value) { NoBarrier_Store(&active_, value); }