platform-linux.cc in mustang-0.1.0

- old
+ new

@@ -56,11 +56,10 @@
 #undef MAP_TYPE
 
 #include "v8.h"
 
 #include "platform.h"
-#include "top.h"
 #include "v8threads.h"
 #include "vm-state-inl.h"
 
 
 namespace v8 {
@@ -74,28 +73,36 @@
 double ceiling(double x) {
   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();
 }
 
 
 uint64_t OS::CpuFeaturesImpliedByPlatform() {
 #if (defined(__VFP_FP__) && !defined(__SOFTFP__))
   // Here gcc is telling us that we are on an ARM and gcc is assuming that we
   // have VFP3 instructions.  If gcc can assume it then so can we.
   return 1u << VFP3;
 #elif CAN_USE_ARMV7_INSTRUCTIONS
   return 1u << ARMv7;
+#elif(defined(__mips_hard_float) && __mips_hard_float != 0)
+    // Here gcc is telling us that we are on an MIPS and gcc is assuming that we
+    // have FPU instructions.  If gcc can assume it then so can we.
+    return 1u << FPU;
 #else
   return 0;  // Linux runs on anything.
 #endif
 }
 
@@ -170,10 +177,62 @@
   return false;
 }
 #endif  // def __arm__
 
 
+#ifdef __mips__
+bool OS::MipsCpuHasFeature(CpuFeature feature) {
+  const char* search_string = NULL;
+  const char* file_name = "/proc/cpuinfo";
+  // Simple detection of FPU at runtime for Linux.
+  // It is based on /proc/cpuinfo, which reveals hardware configuration
+  // to user-space applications.  According to MIPS (early 2010), no similar
+  // facility is universally available on the MIPS architectures,
+  // so it's up to individual OSes to provide such.
+  //
+  // This is written as a straight shot one pass parser
+  // and not using STL string and ifstream because,
+  // on Linux, it's reading from a (non-mmap-able)
+  // character special device.
+
+  switch (feature) {
+    case FPU:
+      search_string = "FPU";
+      break;
+    default:
+      UNREACHABLE();
+  }
+
+  FILE* f = NULL;
+  const char* what = search_string;
+
+  if (NULL == (f = fopen(file_name, "r")))
+    return false;
+
+  int k;
+  while (EOF != (k = fgetc(f))) {
+    if (k == *what) {
+      ++what;
+      while ((*what != '\0') && (*what == fgetc(f))) {
+        ++what;
+      }
+      if (*what == '\0') {
+        fclose(f);
+        return true;
+      } else {
+        what = search_string;
+      }
+    }
+  }
+  fclose(f);
+
+  // Did not find string in the proc file.
+  return false;
+}
+#endif  // def __mips__
+
+
 int OS::ActivationFrameAlignment() {
 #ifdef V8_TARGET_ARCH_ARM
   // On EABI ARM targets this is required for fp correctness in the
   // runtime system.
   return 8;
@@ -185,12 +244,13 @@
   return 16;
 }
 
 
 void OS::ReleaseStore(volatile AtomicWord* ptr, AtomicWord value) {
-#if defined(V8_TARGET_ARCH_ARM) && defined(__arm__)
-  // Only use on ARM hardware.
+#if (defined(V8_TARGET_ARCH_ARM) && defined(__arm__)) || \
+    (defined(V8_TARGET_ARCH_MIPS) && defined(__mips__))
+  // Only use on ARM or MIPS hardware.
   MemoryBarrier();
 #else
   __asm__ __volatile__("" : : : "memory");
   // An x86 store acts as a release barrier.
 #endif
@@ -224,10 +284,13 @@
 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));
 }
@@ -249,11 +312,12 @@
   // TODO(805): Port randomization of allocated executable memory to Linux.
   const size_t msize = RoundUp(requested, sysconf(_SC_PAGESIZE));
   int prot = PROT_READ | PROT_WRITE | (is_executable ? PROT_EXEC : 0);
   void* mbase = mmap(NULL, msize, prot, MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);
   if (mbase == MAP_FAILED) {
-    LOG(StringEvent("OS::Allocate", "mmap failed"));
+    LOG(i::Isolate::Current(),
+        StringEvent("OS::Allocate", "mmap failed"));
     return NULL;
   }
   *allocated = msize;
   UpdateAllocatedSpaceLimits(mbase, msize);
   return mbase;
@@ -370,10 +434,11 @@
 
   // Allocate enough room to be able to store a full file name.
   const int kLibNameLen = FILENAME_MAX + 1;
   char* lib_name = reinterpret_cast<char*>(malloc(kLibNameLen));
 
+  i::Isolate* isolate = ISOLATE;
   // This loop will terminate once the scanning hits an EOF.
   while (true) {
     uintptr_t start, end;
     char attr_r, attr_w, attr_x, attr_p;
     // Parse the addresses and permission bits at the beginning of the line.
@@ -403,11 +468,11 @@
       } else {
         // No library name found, just record the raw address range.
         snprintf(lib_name, kLibNameLen,
                  "%08" V8PRIxPTR "-%08" V8PRIxPTR, start, end);
       }
-      LOG(SharedLibraryEvent(lib_name, start, end));
+      LOG(isolate, SharedLibraryEvent(lib_name, start, end));
     } else {
       // Entry not describing executable data. Skip to end of line to setup
       // reading the next entry.
       do {
         c = getc(fp);
@@ -563,16 +628,22 @@
 bool ThreadHandle::IsValid() const {
   return data_->thread_ != kNoThread;
 }
 
 
-Thread::Thread() : ThreadHandle(ThreadHandle::INVALID) {
-  set_name("v8:<unknown>");
+Thread::Thread(Isolate* isolate, const Options& options)
+    : ThreadHandle(ThreadHandle::INVALID),
+      isolate_(isolate),
+      stack_size_(options.stack_size) {
+  set_name(options.name);
 }
 
 
-Thread::Thread(const char* name) : ThreadHandle(ThreadHandle::INVALID) {
+Thread::Thread(Isolate* isolate, const char* name)
+    : ThreadHandle(ThreadHandle::INVALID),
+      isolate_(isolate),
+      stack_size_(0) {
   set_name(name);
 }
 
 
 Thread::~Thread() {
@@ -582,13 +653,16 @@
 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.
-  prctl(PR_SET_NAME, thread->name(), 0, 0, 0);
+  prctl(PR_SET_NAME,
+        reinterpret_cast<unsigned long>(thread->name()),  // NOLINT
+        0, 0, 0);
   thread->thread_handle_data()->thread_ = pthread_self();
   ASSERT(thread->IsValid());
+  Thread::SetThreadLocal(Isolate::isolate_key(), thread->isolate());
   thread->Run();
   return NULL;
 }
 
 
@@ -597,11 +671,18 @@
   name_[sizeof(name_) - 1] = '\0';
 }
 
 
 void Thread::Start() {
-  pthread_create(&thread_handle_data()->thread_, NULL, ThreadEntry, this);
+  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(&thread_handle_data()->thread_, attr_ptr, ThreadEntry, this);
   ASSERT(IsValid());
 }
 
 
 void Thread::Join() {
@@ -758,14 +839,10 @@
 }
 
 
 #ifdef ENABLE_LOGGING_AND_PROFILING
 
-static Sampler* active_sampler_ = NULL;
-static int vm_tid_ = 0;
-
-
 #if !defined(__GLIBC__) && (defined(__arm__) || defined(__thumb__))
 // Android runs a fairly new Linux kernel, so signal info is there,
 // but the C library doesn't have the structs defined.
 
 struct sigcontext {
@@ -790,29 +867,38 @@
 #endif
 
 
 static int GetThreadID() {
   // Glibc doesn't provide a wrapper for gettid(2).
+#if defined(ANDROID)
+  return syscall(__NR_gettid);
+#else
   return syscall(SYS_gettid);
+#endif
 }
 
 
 static void ProfilerSignalHandler(int signal, siginfo_t* info, void* context) {
 #ifndef V8_HOST_ARCH_MIPS
   USE(info);
   if (signal != SIGPROF) return;
-  if (active_sampler_ == NULL || !active_sampler_->IsActive()) return;
-  if (vm_tid_ != GetThreadID()) return;
+  Isolate* isolate = Isolate::UncheckedCurrent();
+  if (isolate == NULL || !isolate->IsInitialized() || !isolate->IsInUse()) {
+    // We require a fully initialized and entered isolate.
+    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 = Top::current_vm_state();
+  sample->state = isolate->current_vm_state();
 #if V8_HOST_ARCH_IA32
   sample->pc = reinterpret_cast<Address>(mcontext.gregs[REG_EIP]);
   sample->sp = reinterpret_cast<Address>(mcontext.gregs[REG_ESP]);
   sample->fp = reinterpret_cast<Address>(mcontext.gregs[REG_EBP]);
 #elif V8_HOST_ARCH_X64
@@ -829,58 +915,145 @@
   sample->pc = reinterpret_cast<Address>(mcontext.arm_pc);
   sample->sp = reinterpret_cast<Address>(mcontext.arm_sp);
   sample->fp = reinterpret_cast<Address>(mcontext.arm_fp);
 #endif
 #elif V8_HOST_ARCH_MIPS
-  // Implement this on MIPS.
-  UNIMPLEMENTED();
+  sample.pc = reinterpret_cast<Address>(mcontext.pc);
+  sample.sp = reinterpret_cast<Address>(mcontext.gregs[29]);
+  sample.fp = reinterpret_cast<Address>(mcontext.gregs[30]);
 #endif
-  active_sampler_->SampleStack(sample);
-  active_sampler_->Tick(sample);
+  sampler->SampleStack(sample);
+  sampler->Tick(sample);
 #endif
 }
 
 
 class Sampler::PlatformData : public Malloced {
  public:
+  PlatformData() : vm_tid_(GetThreadID()) {}
+
+  int vm_tid() const { return vm_tid_; }
+
+ private:
+  const int vm_tid_;
+};
+
+
+class SignalSender : public Thread {
+ public:
   enum SleepInterval {
-    FULL_INTERVAL,
-    HALF_INTERVAL
+    HALF_INTERVAL,
+    FULL_INTERVAL
   };
 
-  explicit PlatformData(Sampler* sampler)
-      : sampler_(sampler),
-        signal_handler_installed_(false),
+  explicit SignalSender(int interval)
+      : Thread(NULL, "SignalSender"),
         vm_tgid_(getpid()),
-        signal_sender_launched_(false) {
+        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());
+    }
   }
 
-  void SignalSender() {
-    while (sampler_->IsActive()) {
-      if (rate_limiter_.SuspendIfNecessary()) continue;
-      if (sampler_->IsProfiling() && RuntimeProfiler::IsEnabled()) {
-        SendProfilingSignal();
+  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);
-        RuntimeProfiler::NotifyTick();
+        if (!SamplerRegistry::IterateActiveSamplers(&DoRuntimeProfile, NULL)) {
+          return;
+        }
         Sleep(HALF_INTERVAL);
       } else {
-        if (sampler_->IsProfiling()) SendProfilingSignal();
-        if (RuntimeProfiler::IsEnabled()) RuntimeProfiler::NotifyTick();
+        if (cpu_profiling_enabled) {
+          if (!SamplerRegistry::IterateActiveSamplers(&DoCpuProfile,
+                                                      this)) {
+            return;
+          }
+        }
+        if (runtime_profiler_enabled) {
+          if (!SamplerRegistry::IterateActiveSamplers(&DoRuntimeProfile,
+                                                      NULL)) {
+            return;
+          }
+        }
         Sleep(FULL_INTERVAL);
       }
     }
   }
 
-  void SendProfilingSignal() {
+  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(int tid) {
+    if (!signal_handler_installed_) return;
     // Glibc doesn't provide a wrapper for tgkill(2).
-    syscall(SYS_tgkill, vm_tgid_, vm_tid_, SIGPROF);
+#if defined(ANDROID)
+    syscall(__NR_tgkill, vm_tgid_, tid, SIGPROF);
+#else
+    syscall(SYS_tgkill, vm_tgid_, tid, SIGPROF);
+#endif
   }
 
   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;
+    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,
@@ -891,91 +1064,57 @@
     }
 #endif
     USE(result);
   }
 
-  Sampler* sampler_;
-  bool signal_handler_installed_;
-  struct sigaction old_signal_handler_;
-  int vm_tgid_;
-  bool signal_sender_launched_;
-  pthread_t signal_sender_thread_;
+  const int vm_tgid_;
+  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);
 };
 
 
-static void* SenderEntry(void* arg) {
-  Sampler::PlatformData* data =
-      reinterpret_cast<Sampler::PlatformData*>(arg);
-  data->SignalSender();
-  return 0;
-}
+Mutex* SignalSender::mutex_ = OS::CreateMutex();
+SignalSender* SignalSender::instance_ = NULL;
+struct sigaction SignalSender::old_signal_handler_;
+bool SignalSender::signal_handler_installed_ = false;
 
 
-Sampler::Sampler(int interval)
-    : interval_(interval),
+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(!data_->signal_sender_launched_);
+  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_RESTART | SA_SIGINFO;
-  if (sigaction(SIGPROF, &sa, &data_->old_signal_handler_) != 0) return;
-  data_->signal_handler_installed_ = true;
-
-  // Start a thread that sends SIGPROF signal to VM thread.
-  // Sending the signal ourselves instead of relying on itimer provides
-  // much better accuracy.
   SetActive(true);
-  if (pthread_create(
-          &data_->signal_sender_thread_, NULL, SenderEntry, data_) == 0) {
-    data_->signal_sender_launched_ = true;
-  }
-
-  // Set this sampler as the active sampler.
-  active_sampler_ = this;
+  SignalSender::AddActiveSampler(this);
 }
 
 
 void Sampler::Stop() {
+  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;
-  }
-
-  // Restore old signal handler
-  if (data_->signal_handler_installed_) {
-    sigaction(SIGPROF, &data_->old_signal_handler_, 0);
-    data_->signal_handler_installed_ = false;
-  }
-
-  // This sampler is no longer the active sampler.
-  active_sampler_ = NULL;
 }
-
 
 #endif  // ENABLE_LOGGING_AND_PROFILING
 
 } }  // namespace v8::internal