Allocate the profiler sample buffer and zone segments with virtual memory instead of malloc.

runtime/vm/profiler.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/address_sanitizer.h"
 #include "platform/memory_sanitizer.h"
 #include "platform/utils.h"
 
 #include "vm/allocation.h"
 #include "vm/atomic.h"
@@ skipping 111 matching lines @@
 
 
 uword* Sample::GetPCArray() const {
   return reinterpret_cast<uword*>(reinterpret_cast<uintptr_t>(this) +
                                   sizeof(*this));
 }
 
 
 SampleBuffer::SampleBuffer(intptr_t capacity) {
   ASSERT(Sample::instance_size() > 0);
-  samples_ =
-      reinterpret_cast<Sample*>(calloc(capacity, Sample::instance_size()));
+
+  const intptr_t size = Utils::RoundUp(capacity * Sample::instance_size(),
+                                       VirtualMemory::PageSize());
+  const bool kNotExecutable = false;
+  memory_ = VirtualMemory::Reserve(size);
+  if ((memory_ == NULL) || !memory_->Commit(kNotExecutable, "dart-profiler")) {
+    OUT_OF_MEMORY();
+  }
+
+  samples_ = reinterpret_cast<Sample*>(memory_->address());
+  capacity_ = capacity;
+  cursor_ = 0;
+
   if (FLAG_trace_profiler) {
     OS::Print("Profiler holds %" Pd " samples\n", capacity);
     OS::Print("Profiler sample is %" Pd " bytes\n", Sample::instance_size());
-    OS::Print("Profiler memory usage = %" Pd " bytes\n",
-              capacity * Sample::instance_size());
+    OS::Print("Profiler memory usage = %" Pd " bytes\n", size);
   }
-  capacity_ = capacity;
-  cursor_ = 0;
 }
 
 
+SampleBuffer::~SampleBuffer() {
+  delete memory_;
+}
+
+
 Sample* SampleBuffer::At(intptr_t idx) const {
   ASSERT(idx >= 0);
   ASSERT(idx < capacity_);
   intptr_t offset = idx * Sample::instance_size();
   uint8_t* samples = reinterpret_cast<uint8_t*>(samples_);
   return reinterpret_cast<Sample*>(samples + offset);
 }
 
 
 intptr_t SampleBuffer::ReserveSampleSlot() {
@@ skipping 1453 matching lines @@
 
 
 ProcessedSampleBuffer::ProcessedSampleBuffer()
     : code_lookup_table_(new CodeLookupTable(Thread::Current())) {
   ASSERT(code_lookup_table_ != NULL);
 }
 
 #endif  // !PRODUCT
 
 }  // namespace dart