v8::internal::RuntimeProfiler Class Reference

#include <runtime-profiler.h>

Collaboration diagram for v8::internal::RuntimeProfiler:

Public Member Functions
	RuntimeProfiler (Isolate *isolate)
void	OptimizeNow ()
void	NotifyICChanged ()
void	AttemptOnStackReplacement (JSFunction *function, int nesting_levels=1)

Private Member Functions
void	Optimize (JSFunction *function, const char *reason)
bool	CodeSizeOKForOSR (Code *shared_code)

Private Attributes
Isolate *	isolate_
bool	any_ic_changed_

Detailed Description

Definition at line 22 of file runtime-profiler.h.

Constructor & Destructor Documentation

RuntimeProfiler()

v8::internal::RuntimeProfiler::RuntimeProfiler ( Isolate *  isolate )

explicit

Definition at line 54 of file runtime-profiler.cc.

    : isolate_(isolate),
      any_ic_changed_(false) {
}

Member Function Documentation

AttemptOnStackReplacement()

void v8::internal::RuntimeProfiler::AttemptOnStackReplacement	(	JSFunction *	function,
		int	nesting_levels = 1
	)

Definition at line 121 of file runtime-profiler.cc.

                                                                         {
  SharedFunctionInfo* shared = function->shared();
  // See AlwaysFullCompiler (in compiler.cc) comment on why we need
  // Debug::has_break_points().
  if (!FLAG_use_osr ||
      isolate_->DebuggerHasBreakPoints() ||
      function->IsBuiltin()) {
    return;
  }
 
  // If the code is not optimizable, don't try OSR.
  if (!shared->code()->optimizable()) return;
 
  // We are not prepared to do OSR for a function that already has an
  // allocated arguments object.  The optimized code would bypass it for
  // arguments accesses, which is unsound.  Don't try OSR.
  if (shared->uses_arguments()) return;
 
  // We're using on-stack replacement: patch the unoptimized code so that
  // any back edge in any unoptimized frame will trigger on-stack
  // replacement for that frame.
  if (FLAG_trace_osr) {
    PrintF("[OSR - patching back edges in ");
    function->PrintName();
    PrintF("]\n");
  }
 
  for (int i = 0; i < loop_nesting_levels; i++) {
    BackEdgeTable::Patch(isolate_, shared->code());
  }
}

References v8::internal::Isolate::DebuggerHasBreakPoints(), isolate_, v8::internal::BackEdgeTable::Patch(), and v8::internal::PrintF().

Referenced by OptimizeNow().

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CodeSizeOKForOSR()

bool v8::internal::RuntimeProfiler::CodeSizeOKForOSR ( Code *  shared_code )

private

NotifyICChanged()

void v8::internal::RuntimeProfiler::NotifyICChanged ( )

inline

Definition at line 28 of file runtime-profiler.h.

{ any_ic_changed_ = true; }

References any_ic_changed_.

Referenced by v8::internal::IC::OnTypeFeedbackChanged().

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Optimize()

void v8::internal::RuntimeProfiler::Optimize ( JSFunction *  function, const char *  reason  )

private

Definition at line 83 of file runtime-profiler.cc.

                                                                       {
  DCHECK(function->IsOptimizable());
 
  if (FLAG_trace_opt && function->PassesFilter(FLAG_hydrogen_filter)) {
    PrintF("[marking ");
    function->ShortPrint();
    PrintF(" for recompilation, reason: %s", reason);
    if (FLAG_type_info_threshold > 0) {
      int typeinfo, generic, total, type_percentage, generic_percentage;
      GetICCounts(function->shared()->code(), &typeinfo, &generic, &total,
                  &type_percentage, &generic_percentage);
      PrintF(", ICs with typeinfo: %d/%d (%d%%)", typeinfo, total,
             type_percentage);
      PrintF(", generic ICs: %d/%d (%d%%)", generic, total, generic_percentage);
    }
    PrintF("]\n");
  }
 
 
  if (isolate_->concurrent_recompilation_enabled() &&
      !isolate_->bootstrapper()->IsActive()) {
    if (isolate_->concurrent_osr_enabled() &&
        isolate_->optimizing_compiler_thread()->IsQueuedForOSR(function)) {
      // Do not attempt regular recompilation if we already queued this for OSR.
      // TODO(yangguo): This is necessary so that we don't install optimized
      // code on a function that is already optimized, since OSR and regular
      // recompilation race.  This goes away as soon as OSR becomes one-shot.
      return;
    }
    DCHECK(!function->IsInOptimizationQueue());
    function->MarkForConcurrentOptimization();
  } else {
    // The next call to the function will trigger optimization.
    function->MarkForOptimization();
  }
}

References v8::internal::Isolate::bootstrapper(), v8::internal::Isolate::concurrent_osr_enabled(), v8::internal::Isolate::concurrent_recompilation_enabled(), DCHECK, v8::internal::GetICCounts(), isolate_, v8::internal::OptimizingCompilerThread::IsQueuedForOSR(), v8::internal::Isolate::optimizing_compiler_thread(), and v8::internal::PrintF().

Referenced by OptimizeNow().

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OptimizeNow()

void v8::internal::RuntimeProfiler::OptimizeNow

(

)

Definition at line 155 of file runtime-profiler.cc.

                                  {
  HandleScope scope(isolate_);
 
  if (isolate_->DebuggerHasBreakPoints()) return;
 
  DisallowHeapAllocation no_gc;
 
  // Run through the JavaScript frames and collect them. If we already
  // have a sample of the function, we mark it for optimizations
  // (eagerly or lazily).
  int frame_count = 0;
  int frame_count_limit = FLAG_frame_count;
  for (JavaScriptFrameIterator it(isolate_);
       frame_count++ < frame_count_limit && !it.done();
       it.Advance()) {
    JavaScriptFrame* frame = it.frame();
    JSFunction* function = frame->function();
 
    SharedFunctionInfo* shared = function->shared();
    Code* shared_code = shared->code();
 
    List<JSFunction*> functions(4);
    frame->GetFunctions(&functions);
    for (int i = functions.length(); --i >= 0; ) {
      SharedFunctionInfo* shared_function_info = functions[i]->shared();
      int ticks = shared_function_info->profiler_ticks();
      if (ticks < Smi::kMaxValue) {
        shared_function_info->set_profiler_ticks(ticks + 1);
      }
    }
 
    if (shared_code->kind() != Code::FUNCTION) continue;
    if (function->IsInOptimizationQueue()) continue;
 
    if (FLAG_always_osr) {
      AttemptOnStackReplacement(function, Code::kMaxLoopNestingMarker);
      // Fall through and do a normal optimized compile as well.
    } else if (!frame->is_optimized() &&
        (function->IsMarkedForOptimization() ||
         function->IsMarkedForConcurrentOptimization() ||
         function->IsOptimized())) {
      // Attempt OSR if we are still running unoptimized code even though the
      // the function has long been marked or even already been optimized.
      int ticks = shared_code->profiler_ticks();
      int allowance = kOSRCodeSizeAllowanceBase +
                      ticks * kOSRCodeSizeAllowancePerTick;
      if (shared_code->CodeSize() > allowance) {
        if (ticks < 255) shared_code->set_profiler_ticks(ticks + 1);
      } else {
        AttemptOnStackReplacement(function);
      }
      continue;
    }
 
    // Only record top-level code on top of the execution stack and
    // avoid optimizing excessively large scripts since top-level code
    // will be executed only once.
    const int kMaxToplevelSourceSize = 10 * 1024;
    if (shared->is_toplevel() &&
        (frame_count > 1 || shared->SourceSize() > kMaxToplevelSourceSize)) {
      continue;
    }
 
    // Do not record non-optimizable functions.
    if (shared->optimization_disabled()) {
      if (shared->deopt_count() >= FLAG_max_opt_count) {
        // If optimization was disabled due to many deoptimizations,
        // then check if the function is hot and try to reenable optimization.
        int ticks = shared_code->profiler_ticks();
        if (ticks >= kProfilerTicksBeforeReenablingOptimization) {
          shared_code->set_profiler_ticks(0);
          shared->TryReenableOptimization();
        } else {
          shared_code->set_profiler_ticks(ticks + 1);
        }
      }
      continue;
    }
    if (!function->IsOptimizable()) continue;
 
    int ticks = shared_code->profiler_ticks();
 
    if (ticks >= kProfilerTicksBeforeOptimization) {
      int typeinfo, generic, total, type_percentage, generic_percentage;
      GetICCounts(shared_code, &typeinfo, &generic, &total, &type_percentage,
                  &generic_percentage);
      if (type_percentage >= FLAG_type_info_threshold &&
          generic_percentage <= FLAG_generic_ic_threshold) {
        // If this particular function hasn't had any ICs patched for enough
        // ticks, optimize it now.
        Optimize(function, "hot and stable");
      } else if (ticks >= kTicksWhenNotEnoughTypeInfo) {
        Optimize(function, "not much type info but very hot");
      } else {
        shared_code->set_profiler_ticks(ticks + 1);
        if (FLAG_trace_opt_verbose) {
          PrintF("[not yet optimizing ");
          function->PrintName();
          PrintF(", not enough type info: %d/%d (%d%%)]\n", typeinfo, total,
                 type_percentage);
        }
      }
    } else if (!any_ic_changed_ &&
               shared_code->instruction_size() < kMaxSizeEarlyOpt) {
      // If no IC was patched since the last tick and this function is very
      // small, optimistically optimize it now.
      int typeinfo, generic, total, type_percentage, generic_percentage;
      GetICCounts(shared_code, &typeinfo, &generic, &total, &type_percentage,
                  &generic_percentage);
      if (type_percentage >= FLAG_type_info_threshold &&
          generic_percentage <= FLAG_generic_ic_threshold) {
        Optimize(function, "small function");
      } else {
        shared_code->set_profiler_ticks(ticks + 1);
      }
    } else {
      shared_code->set_profiler_ticks(ticks + 1);
    }
  }
  any_ic_changed_ = false;
}

References any_ic_changed_, AttemptOnStackReplacement(), v8::internal::Code::CodeSize(), v8::internal::Isolate::DebuggerHasBreakPoints(), v8::internal::SharedFunctionInfo::deopt_count(), v8::internal::JavaScriptFrame::function(), v8::internal::JavaScriptFrame::GetFunctions(), v8::internal::GetICCounts(), v8::internal::Code::instruction_size(), isolate_, v8::internal::Code::kind(), v8::internal::Code::kMaxLoopNestingMarker, v8::internal::kMaxSizeEarlyOpt, v8::internal::Smi::kMaxValue, v8::internal::kOSRCodeSizeAllowanceBase, v8::internal::kOSRCodeSizeAllowancePerTick, v8::internal::kProfilerTicksBeforeOptimization, v8::internal::kProfilerTicksBeforeReenablingOptimization, v8::internal::kTicksWhenNotEnoughTypeInfo, Optimize(), v8::internal::PrintF(), v8::internal::Code::profiler_ticks(), v8::internal::SharedFunctionInfo::profiler_ticks(), v8::internal::Code::set_profiler_ticks(), v8::internal::SharedFunctionInfo::set_profiler_ticks(), v8::internal::SharedFunctionInfo::SourceSize(), and v8::internal::SharedFunctionInfo::TryReenableOptimization().

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Member Data Documentation

any_ic_changed_

bool v8::internal::RuntimeProfiler::any_ic_changed_

private

Definition at line 39 of file runtime-profiler.h.

Referenced by NotifyICChanged(), and OptimizeNow().

isolate_

Isolate* v8::internal::RuntimeProfiler::isolate_

private

Definition at line 37 of file runtime-profiler.h.

Referenced by AttemptOnStackReplacement(), Optimize(), and OptimizeNow().

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

• /mnt/V8SourceCode/src/runtime-profiler.h
• /mnt/V8SourceCode/src/runtime-profiler.cc