Profiler fixes

runtime/vm/profiler_win.cc

 // Copyright (c) 2013, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 #include "platform/globals.h"
 #if defined(TARGET_OS_WINDOWS)
 
 #include "vm/isolate.h"
 #include "vm/profiler.h"
 
 namespace dart {
 
 #define kThreadError -1
 
 DECLARE_FLAG(bool, profile);
 
 static void CollectSample(IsolateProfilerData* profiler_data,
                           uintptr_t pc,
                           uintptr_t fp,
                           uintptr_t stack_lower,
                           uintptr_t stack_upper) {
   uintptr_t sp = stack_lower;
+  ASSERT(profiler_data != NULL);
   SampleBuffer* sample_buffer = profiler_data->sample_buffer();
+  ASSERT(sample_buffer != NULL);
   Sample* sample = sample_buffer->ReserveSample();
   ASSERT(sample != NULL);
   sample->timestamp = OS::GetCurrentTimeMicros();
   // TODO(johnmccutchan): Make real use of vm_tags and runtime_tags.
   // Issue # 14777
   sample->vm_tags = Sample::kExecuting;
   sample->runtime_tags = 0;
   int64_t cpu_usage;
   Thread::GetThreadCpuUsage(profiler_data->thread_id(), &cpu_usage);
   sample->cpu_usage = profiler_data->ComputeDeltaAndSetCpuUsage(cpu_usage);
@@ skipping 60 matching lines @@
 int64_t ProfilerManager::SampleAndRescheduleIsolates(int64_t current_time) {
   if (isolates_size_ == 0) {
     return 0;
   }
   static const int64_t max_time = 0x7fffffffffffffffLL;
   int64_t lowest = max_time;
   for (intptr_t i = 0; i < isolates_size_; i++) {
     Isolate* isolate = isolates_[i];
     ScopedMutex isolate_lock(isolate->profiler_data_mutex());
     IsolateProfilerData* profiler_data = isolate->profiler_data();
-    ASSERT(profiler_data != NULL);
+    if ((profiler_data == NULL) || !profiler_data->CanExpire() ||
+        (profiler_data->sample_buffer() == NULL)) {
+      // Descheduled.
+      continue;
+    }
     if (profiler_data->ShouldSample(current_time)) {
       SuspendAndSample(isolate, profiler_data);
       Reschedule(profiler_data);
     }
     if (profiler_data->CanExpire()) {
       int64_t isolate_time_left =
           profiler_data->TimeUntilExpiration(current_time);
       if (isolate_time_left < 0) {
         continue;
       }
@@ skipping 21 matching lines @@
   while (!shutdown_) {
     int64_t current_time = OS::GetCurrentTimeMicros();
     int64_t next_sample = SampleAndRescheduleIsolates(current_time);
     lock.WaitMicros(next_sample);
   }
 }
 
 }  // namespace dart
 
 #endif  // defined(TARGET_OS_WINDOWS)