Version 3.2.6

src/platform-freebsd.cc

 // Copyright 2006-2008 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 57 matching lines @@
 double ceiling(double x) {
     // Correct as on OS X
     if (-1.0 < x && x < 0.0) {
         return -0.0;
     } else {
         return ceil(x);
     }
 }
 
 
+static Mutex* limit_mutex = NULL;
+
+
 void OS::Setup() {
   // Seed the random number generator.
   // Convert the current time to a 64-bit integer first, before converting it
   // to an unsigned. Going directly can cause an overflow and the seed to be
   // set to all ones. The seed will be identical for different instances that
   // call this setup code within the same millisecond.
   uint64_t seed = static_cast<uint64_t>(TimeCurrentMillis());
   srandom(static_cast<unsigned int>(seed));
+  limit_mutex = CreateMutex();
 }
 
 
 void OS::ReleaseStore(volatile AtomicWord* ptr, AtomicWord value) {
   __asm__ __volatile__("" : : : "memory");
   *ptr = value;
 }
 
 
 uint64_t OS::CpuFeaturesImpliedByPlatform() {
@@ skipping 28 matching lines @@
 // We keep the lowest and highest addresses mapped as a quick way of
 // determining that pointers are outside the heap (used mostly in assertions
 // and verification).  The estimate is conservative, ie, not all addresses in
 // 'allocated' space are actually allocated to our heap.  The range is
 // [lowest, highest), inclusive on the low and and exclusive on the high end.
 static void* lowest_ever_allocated = reinterpret_cast<void*>(-1);
 static void* highest_ever_allocated = reinterpret_cast<void*>(0);
 
 
 static void UpdateAllocatedSpaceLimits(void* address, int size) {
+  ASSERT(limit_mutex != NULL);
+  ScopedLock lock(limit_mutex);
+
   lowest_ever_allocated = Min(lowest_ever_allocated, address);
   highest_ever_allocated =
       Max(highest_ever_allocated,
           reinterpret_cast<void*>(reinterpret_cast<char*>(address) + size));
 }
 
 
 bool OS::IsOutsideAllocatedSpace(void* address) {
   return address < lowest_ever_allocated || address >= highest_ever_allocated;
 }
@@ skipping 149 matching lines @@
       result = read(fd, buffer + bytes_read, 1);
       if (result < 1) break;
     } while (buffer[bytes_read] != '\n');
     buffer[bytes_read] = 0;
     // Ignore mappings that are not executable.
     if (buffer[3] != 'x') continue;
     char* start_of_path = index(buffer, '/');
     // There may be no filename in this line.  Skip to next.
     if (start_of_path == NULL) continue;
     buffer[bytes_read] = 0;
-    LOG(SharedLibraryEvent(start_of_path, start, end));
+    LOG(i::Isolate::Current(), SharedLibraryEvent(start_of_path, start, end));
   }
   close(fd);
 #endif
 }
 
 
 void OS::SignalCodeMovingGC() {
 }
 
 
@@ skipping 298 matching lines @@
 }
 
 
 Semaphore* OS::CreateSemaphore(int count) {
   return new FreeBSDSemaphore(count);
 }
 
 
 #ifdef ENABLE_LOGGING_AND_PROFILING
 
-static Sampler* active_sampler_ = NULL;
-static pthread_t vm_tid_ = NULL;
-
-
 static pthread_t GetThreadID() {
   pthread_t thread_id = pthread_self();
   return thread_id;
 }
 
 
 class Sampler::PlatformData : public Malloced {
  public:
-  enum SleepInterval {
-    FULL_INTERVAL,
-    HALF_INTERVAL
-  };
+  PlatformData() : vm_tid_(GetThreadID()) {}
 
-  explicit PlatformData(Sampler* sampler)
-      : sampler_(sampler),
-        signal_handler_installed_(false),
-        signal_sender_launched_(false) {
-  }
+  pthread_t vm_tid() const { return vm_tid_; }
 
-  void SignalSender() {
-    while (sampler_->IsActive()) {
-      if (rate_limiter_.SuspendIfNecessary()) continue;
-      if (sampler_->IsProfiling() && RuntimeProfiler::IsEnabled()) {
-        Sleep(FULL_INTERVAL);
-        RuntimeProfiler::NotifyTick();
-      } else {
-        if (RuntimeProfiler::IsEnabled()) RuntimeProfiler::NotifyTick();
-        Sleep(FULL_INTERVAL);
-      }
-    }
-  }
-
-  void Sleep(SleepInterval full_or_half) {
-    // Convert ms to us and subtract 100 us to compensate delays
-    // occuring during signal delivery.
-    useconds_t interval = sampler_->interval_ * 1000 - 100;
-    if (full_or_half == HALF_INTERVAL) interval /= 2;
-    int result = usleep(interval);
-#ifdef DEBUG
-    if (result != 0 && errno != EINTR) {
-      fprintf(stderr,
-              "SignalSender usleep error; interval = %u, errno = %d\n",
-              interval,
-              errno);
-      ASSERT(result == 0 || errno == EINTR);
-    }
-#endif
-    USE(result);
-  }
-
-  Sampler* sampler_;
-  bool signal_handler_installed_;
-  struct sigaction old_signal_handler_;
-  struct itimerval old_timer_value_;
-  bool signal_sender_launched_;
-  pthread_t signal_sender_thread_;
-  RuntimeProfilerRateLimiter rate_limiter_;
+ private:
+  pthread_t vm_tid_;
 };
 
 
 static void ProfilerSignalHandler(int signal, siginfo_t* info, void* context) {
   USE(info);
   if (signal != SIGPROF) return;
-  if (active_sampler_ == NULL) return;
-  if (!active_sampler_->IsActive()) {
-    // Restore old signal handler
-    Sampler::PlatformData* data = active_sampler_->data();
-    if (data->signal_handler_installed_) {
-      sigaction(SIGPROF, &data->old_signal_handler_, 0);
-      data->signal_handler_installed_ = false;
-    }
+  Isolate* isolate = Isolate::UncheckedCurrent();
+  if (isolate == NULL || !isolate->IsInitialized() || !isolate->IsInUse()) {
+    // We require a fully initialized and entered isolate.
     return;
   }
-
-  if (vm_tid_ != GetThreadID()) return;
+  Sampler* sampler = isolate->logger()->sampler();
+  if (sampler == NULL || !sampler->IsActive()) return;
 
   TickSample sample_obj;
-  TickSample* sample = CpuProfiler::TickSampleEvent();
+  TickSample* sample = CpuProfiler::TickSampleEvent(isolate);
   if (sample == NULL) sample = &sample_obj;
 
   // Extracting the sample from the context is extremely machine dependent.
   ucontext_t* ucontext = reinterpret_cast<ucontext_t*>(context);
   mcontext_t& mcontext = ucontext->uc_mcontext;
+  sample->state = isolate->current_vm_state();
 #if V8_HOST_ARCH_IA32
   sample->pc = reinterpret_cast<Address>(mcontext.mc_eip);
   sample->sp = reinterpret_cast<Address>(mcontext.mc_esp);
   sample->fp = reinterpret_cast<Address>(mcontext.mc_ebp);
 #elif V8_HOST_ARCH_X64
   sample->pc = reinterpret_cast<Address>(mcontext.mc_rip);
   sample->sp = reinterpret_cast<Address>(mcontext.mc_rsp);
   sample->fp = reinterpret_cast<Address>(mcontext.mc_rbp);
 #elif V8_HOST_ARCH_ARM
   sample->pc = reinterpret_cast<Address>(mcontext.mc_r15);
   sample->sp = reinterpret_cast<Address>(mcontext.mc_r13);
   sample->fp = reinterpret_cast<Address>(mcontext.mc_r11);
 #endif
-  active_sampler_->SampleStack(sample);
-  active_sampler_->Tick(sample);
+  sampler->SampleStack(sample);
+  sampler->Tick(sample);
 }
 
 
-static void* SenderEntry(void* arg) {
-  Sampler::PlatformData* data =
-      reinterpret_cast<Sampler::PlatformData*>(arg);
-  data->SignalSender();
-  return 0;
-}
+class SignalSender : public Thread {
+ public:
+  enum SleepInterval {
+    HALF_INTERVAL,
+    FULL_INTERVAL
+  };
+
+  explicit SignalSender(int interval)
+      : Thread(NULL, "SignalSender"),
+        interval_(interval) {}
+
+  static void AddActiveSampler(Sampler* sampler) {
+    ScopedLock lock(mutex_);
+    SamplerRegistry::AddActiveSampler(sampler);
+    if (instance_ == NULL) {
+      // Install a signal handler.
+      struct sigaction sa;
+      sa.sa_sigaction = ProfilerSignalHandler;
+      sigemptyset(&sa.sa_mask);
+      sa.sa_flags = SA_RESTART | SA_SIGINFO;
+      signal_handler_installed_ =
+          (sigaction(SIGPROF, &sa, &old_signal_handler_) == 0);
+
+      // Start a thread that sends SIGPROF signal to VM threads.
+      instance_ = new SignalSender(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::WakeUpRuntimeProfilerThreadBeforeShutdown();
+      instance_->Join();
+      delete instance_;
+      instance_ = NULL;
+
+      // Restore the old signal handler.
+      if (signal_handler_installed_) {
+        sigaction(SIGPROF, &old_signal_handler_, 0);
+        signal_handler_installed_ = false;
+      }
+    }
+  }
+
+  // Implement Thread::Run().
+  virtual void Run() {
+    SamplerRegistry::State state;
+    while ((state = SamplerRegistry::GetState()) !=
+           SamplerRegistry::HAS_NO_SAMPLERS) {
+      bool cpu_profiling_enabled =
+          (state == SamplerRegistry::HAS_CPU_PROFILING_SAMPLERS);
+      bool runtime_profiler_enabled = RuntimeProfiler::IsEnabled();
+      // When CPU profiling is enabled both JavaScript and C++ code is
+      // profiled. We must not suspend.
+      if (!cpu_profiling_enabled) {
+        if (rate_limiter_.SuspendIfNecessary()) continue;
+      }
+      if (cpu_profiling_enabled && runtime_profiler_enabled) {
+        if (!SamplerRegistry::IterateActiveSamplers(&DoCpuProfile, this)) {
+          return;
+        }
+        Sleep(HALF_INTERVAL);
+        if (!SamplerRegistry::IterateActiveSamplers(&DoRuntimeProfile, NULL)) {
+          return;
+        }
+        Sleep(HALF_INTERVAL);
+      } else {
+        if (cpu_profiling_enabled) {
+          if (!SamplerRegistry::IterateActiveSamplers(&DoCpuProfile,
+                                                      this)) {
+            return;
+          }
+        }
+        if (runtime_profiler_enabled) {
+          if (!SamplerRegistry::IterateActiveSamplers(&DoRuntimeProfile,
+                                                      NULL)) {
+            return;
+          }
+        }
+        Sleep(FULL_INTERVAL);
+      }
+    }
+  }
+
+  static void DoCpuProfile(Sampler* sampler, void* raw_sender) {
+    if (!sampler->IsProfiling()) return;
+    SignalSender* sender = reinterpret_cast<SignalSender*>(raw_sender);
+    sender->SendProfilingSignal(sampler->platform_data()->vm_tid());
+  }
+
+  static void DoRuntimeProfile(Sampler* sampler, void* ignored) {
+    if (!sampler->isolate()->IsInitialized()) return;
+    sampler->isolate()->runtime_profiler()->NotifyTick();
+  }
+
+  void SendProfilingSignal(pthread_t tid) {
+    if (!signal_handler_installed_) return;
+    pthread_kill(tid, SIGPROF);
+  }
+
+  void Sleep(SleepInterval full_or_half) {
+    // Convert ms to us and subtract 100 us to compensate delays
+    // occuring during signal delivery.
+    useconds_t interval = interval_ * 1000 - 100;
+    if (full_or_half == HALF_INTERVAL) interval /= 2;
+    int result = usleep(interval);
+#ifdef DEBUG
+    if (result != 0 && errno != EINTR) {
+      fprintf(stderr,
+              "SignalSender usleep error; interval = %u, errno = %d\n",
+              interval,
+              errno);
+      ASSERT(result == 0 || errno == EINTR);
+    }
+#endif
+    USE(result);
+  }
+
+  const int interval_;
+  RuntimeProfilerRateLimiter rate_limiter_;
+
+  // Protects the process wide state below.
+  static Mutex* mutex_;
+  static SignalSender* instance_;
+  static bool signal_handler_installed_;
+  static struct sigaction old_signal_handler_;
+
+  DISALLOW_COPY_AND_ASSIGN(SignalSender);
+};
+
+Mutex* SignalSender::mutex_ = OS::CreateMutex();
+SignalSender* SignalSender::instance_ = NULL;
+struct sigaction SignalSender::old_signal_handler_;
+bool SignalSender::signal_handler_installed_ = false;
 
 
 Sampler::Sampler(Isolate* isolate, int interval)
     : isolate_(isolate),
       interval_(interval),
       profiling_(false),
       active_(false),
       samples_taken_(0) {
-  data_ = new PlatformData(this);
+  data_ = new PlatformData;
 }
 
 
 Sampler::~Sampler() {
+  ASSERT(!IsActive());
   delete data_;
 }
 
 
 void Sampler::Start() {
-  // There can only be one active sampler at the time on POSIX
-  // platforms.
   ASSERT(!IsActive());
-  vm_tid_ = GetThreadID();
-
-  // Request profiling signals.
-  struct sigaction sa;
-  sa.sa_sigaction = ProfilerSignalHandler;
-  sigemptyset(&sa.sa_mask);
-  sa.sa_flags = SA_SIGINFO;
-  if (sigaction(SIGPROF, &sa, &data_->old_signal_handler_) != 0) return;
-  data_->signal_handler_installed_ = true;
-
-  // Set the itimer to generate a tick for each interval.
-  itimerval itimer;
-  itimer.it_interval.tv_sec = interval_ / 1000;
-  itimer.it_interval.tv_usec = (interval_ % 1000) * 1000;
-  itimer.it_value.tv_sec = itimer.it_interval.tv_sec;
-  itimer.it_value.tv_usec = itimer.it_interval.tv_usec;
-  setitimer(ITIMER_PROF, &itimer, &data_->old_timer_value_);
-
-  // Set this sampler as the active sampler.
-  active_sampler_ = this;
   SetActive(true);
-
-  // There's no way to send a signal to a thread on FreeBSD, but we can
-  // start a thread that uses the stack guard to interrupt the JS thread.
-  if (pthread_create(
-          &data_->signal_sender_thread_, NULL, SenderEntry, data_) == 0) {
-    data_->signal_sender_launched_ = true;
-  }
+  SignalSender::AddActiveSampler(this);
 }
 
 
 void Sampler::Stop() {
-  // This sampler is no longer the active sampler.
-  active_sampler_ = NULL;
+  ASSERT(IsActive());
+  SignalSender::RemoveActiveSampler(this);
   SetActive(false);
-
-  // Wait for signal sender termination (it will exit after setting
-  // active_ to false).
-  if (data_->signal_sender_launched_) {
-    Top::WakeUpRuntimeProfilerThreadBeforeShutdown();
-    pthread_join(data_->signal_sender_thread_, NULL);
-    data_->signal_sender_launched_ = false;
-  }
 }
 
 #endif  // ENABLE_LOGGING_AND_PROFILING
 
 } }  // namespace v8::internal