DartVMInitializer Class Reference

#include <dart_vm_initializer.h>

Static Public Member Functions
static void	Initialize (Dart_InitializeParams *params, bool enable_timeline_event_handler, bool trace_systrace)
static void	Cleanup ()

Detailed Description

Definition at line 11 of file dart_vm_initializer.h.

Member Function Documentation

Cleanup()

void DartVMInitializer::Cleanup ( )

static

Definition at line 112 of file dart_vm_initializer.cc.

                                {
  FML_DCHECK(gDartInitialized);
 
  // Dart_RecordTimelineEvent is unsafe during a concurrent call to Dart_Cleanup
  // because Dart_Cleanup will destroy the timeline recorder.  Clear the
  // initialized flag so that future calls to LogDartTimelineEvent will not
  // call Dart_RecordTimelineEvent.
  //
  // Note that this is inherently racy.  If a thread sees that gDartInitialized
  // is set and proceeds to call Dart_RecordTimelineEvent shortly before another
  // thread calls Dart_Cleanup, then the Dart_RecordTimelineEvent call may crash
  // if Dart_Cleanup deletes the timeline before Dart_RecordTimelineEvent
  // completes. In practice this is unlikely because Dart_Cleanup does
  // significant other work before deleting the timeline.
  //
  // The engine can not safely guard Dart_Cleanup and LogDartTimelineEvent with
  // a lock due to the risk of deadlocks.  Dart_Cleanup waits for various
  // Dart-owned threads to shut down.  If one of those threads invokes an engine
  // callback that calls LogDartTimelineEvent while the Dart_Cleanup thread owns
  // the lock, then Dart_Cleanup would deadlock.
  gDartInitialized = false;
 
  char* error = Dart_Cleanup();
  if (error) {
    FML_LOG(FATAL) << "Error while cleaning up the Dart VM: " << error;
    ::free(error);
  }
}

References error, FML_DCHECK, and FML_LOG.

Referenced by flutter::DartVM::~DartVM().

Initialize()

void DartVMInitializer::Initialize ( Dart_InitializeParams *  params, bool  enable_timeline_event_handler, bool  trace_systrace  )

static

Definition at line 81 of file dart_vm_initializer.cc.

                                                        {
  FML_DCHECK(!gDartInitialized);
 
  char* error = Dart_Initialize(params);
  if (error) {
    FML_LOG(FATAL) << "Error while initializing the Dart VM: " << error;
    ::free(error);
  } else {
    gDartInitialized = true;
  }
 
  if (enable_timeline_event_handler) {
    if (!trace_systrace) {
      // Systrace on all platforms except Fuchsia ignores the timestamp provided
      // here. On Android in particular, calls to get the system clock show up
      // in profiles.
      // Fuchsia does not use the TraceSetTimelineMicrosSource.
      fml::tracing::TraceSetTimelineMicrosSource(Dart_TimelineGetMicros);
    } else {
      fml::tracing::TraceSetTimelineMicrosSource(
          []() -> int64_t { return -1; });
    }
    fml::tracing::TraceSetTimelineEventHandler(LogDartTimelineEvent);
  }
 
  fml::TimePoint::SetClockSource(flutter::DartTimelineTicksSinceEpoch);
  tonic::SetUnhandledExceptionReporter(&ReportUnhandledException);
}

References flutter::DartTimelineTicksSinceEpoch(), error, FML_DCHECK, FML_LOG, params, fml::TimePoint::SetClockSource(), tonic::SetUnhandledExceptionReporter(), fml::tracing::TraceSetTimelineEventHandler(), and fml::tracing::TraceSetTimelineMicrosSource().

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The documentation for this class was generated from the following files:

• runtime/dart_vm_initializer.h
• runtime/dart_vm_initializer.cc