Merge up to bleeding_edge r7201 to isolates branch.

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 24 matching lines @@
 #include <sys/resource.h>
 #include <sys/types.h>
 #include <sys/ucontext.h>
 #include <stdlib.h>
 
 #include <sys/types.h>  // mmap & munmap
 #include <sys/mman.h>   // mmap & munmap
 #include <sys/stat.h>   // open
 #include <sys/fcntl.h>  // open
 #include <unistd.h>     // getpagesize
+// If you don't have execinfo.h then you need devel/libexecinfo from ports.
 #include <execinfo.h>   // backtrace, backtrace_symbols
 #include <strings.h>    // index
 #include <errno.h>
 #include <stdarg.h>
 #include <limits.h>
 
 #undef MAP_TYPE
 
 #include "v8.h"
 
@@ skipping 468 matching lines @@
   virtual int Lock() {
     int result = pthread_mutex_lock(&mutex_);
     return result;
   }
 
   virtual int Unlock() {
     int result = pthread_mutex_unlock(&mutex_);
     return result;
   }
 
+  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_;   // Pthread mutex for POSIX platforms.
 };
 
 
 Mutex* OS::CreateMutex() {
   return new FreeBSDMutex();
 }
 
 
@@ skipping 49 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
+  };
+
+  explicit PlatformData(Sampler* sampler)
+      : sampler_(sampler),
+        signal_handler_installed_(false),
+        signal_sender_launched_(false) {
+  }
+
+  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_;
+};
+
 
 static void ProfilerSignalHandler(int signal, siginfo_t* info, void* context) {
   USE(info);
   if (signal != SIGPROF) return;
   if (active_sampler_ == NULL) return;
-
-  TickSample sample;
-
-  // We always sample the VM state.
-  sample.state = VMState::current_state();
-
-  // If profiling, we extract the current pc and sp.
-  if (active_sampler_->IsProfiling()) {
-    // Extracting the sample from the context is extremely machine dependent.
-    ucontext_t* ucontext = reinterpret_cast<ucontext_t*>(context);
-    mcontext_t& mcontext = ucontext->uc_mcontext;
-#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);
+  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;
+    }
+    return;
   }
 
-  active_sampler_->Tick(&sample);
+  if (vm_tid_ != GetThreadID()) return;
+
+  TickSample sample_obj;
+  TickSample* sample = CpuProfiler::TickSampleEvent();
+  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;
+#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);
 }
 
 
-class Sampler::PlatformData : public Malloced {
- public:
-  PlatformData() {
-    signal_handler_installed_ = false;
-  }
-
-  bool signal_handler_installed_;
-  struct sigaction old_signal_handler_;
-  struct itimerval old_timer_value_;
-};
+static void* SenderEntry(void* arg) {
+  Sampler::PlatformData* data =
+      reinterpret_cast<Sampler::PlatformData*>(arg);
+  data->SignalSender();
+  return 0;
+}
 
 
 Sampler::Sampler(Isolate* isolate, int interval)
     : isolate_(isolate),
       interval_(interval),
       profiling_(false),
       active_(false),
       samples_taken_(0) {
-  data_ = new PlatformData();
+  data_ = new PlatformData(this);
 }
 
 
 Sampler::~Sampler() {
   delete data_;
 }
 
 
 void Sampler::Start() {
   // There can only be one active sampler at the time on POSIX
   // platforms.
-  if (active_sampler_ != NULL) return;
+  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;
-  active_ = true;
+  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;
+  }
 }
 
 
 void Sampler::Stop() {
-  // Restore old signal handler
-  if (data_->signal_handler_installed_) {
-    setitimer(ITIMER_PROF, &data_->old_timer_value_, NULL);
-    sigaction(SIGPROF, &data_->old_signal_handler_, 0);
-    data_->signal_handler_installed_ = false;
-  }
-
   // This sampler is no longer the active sampler.
   active_sampler_ = NULL;
-  active_ = false;
+  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