CPU profiler: make code events handling scalable.

I changed the implementation of a queue between the VM and processor
thread to be unbounded and lock-free, using Herb Sutter's example from
DDJ article: http://www.ddj.com/high-performance-computing/210604448
This had brought back profiling overhead to a minimum for the page
from Chromium's issue 16184.

BUG=714

Review URL: http://codereview.chromium.org/2091019

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@4706 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

src/circular-queue-inl.h

@@ -34,54 +34,6 @@ namespace v8 {
 namespace internal {
 
 
-template<typename Record>
-CircularQueue<Record>::CircularQueue(int desired_buffer_size_in_bytes)
-    : buffer_(NewArray<Record>(desired_buffer_size_in_bytes / sizeof(Record))),
-      buffer_end_(buffer_ + desired_buffer_size_in_bytes / sizeof(Record)),
-      enqueue_semaphore_(
-          OS::CreateSemaphore(static_cast<int>(buffer_end_ - buffer_) - 1)),
-      enqueue_pos_(buffer_),
-      dequeue_pos_(buffer_) {
-  // To be able to distinguish between a full and an empty queue
-  // state, the queue must be capable of containing at least 2
-  // records.
-  ASSERT((buffer_end_ - buffer_) >= 2);
-}
-
-
-template<typename Record>
-CircularQueue<Record>::~CircularQueue() {
-  DeleteArray(buffer_);
-  delete enqueue_semaphore_;
-}
-
-
-template<typename Record>
-void CircularQueue<Record>::Dequeue(Record* rec) {
-  ASSERT(!IsEmpty());
-  *rec = *dequeue_pos_;
-  dequeue_pos_ = Next(dequeue_pos_);
-  // Tell we have a spare record.
-  enqueue_semaphore_->Signal();
-}
-
-
-template<typename Record>
-void CircularQueue<Record>::Enqueue(const Record& rec) {
-  // Wait until we have at least one spare record.
-  enqueue_semaphore_->Wait();
-  ASSERT(Next(enqueue_pos_) != dequeue_pos_);
-  *enqueue_pos_ = rec;
-  enqueue_pos_ = Next(enqueue_pos_);
-}
-
-
-template<typename Record>
-Record* CircularQueue<Record>::Next(Record* curr) {
-  return ++curr != buffer_end_ ? curr : buffer_;
-}
-
-
 void* SamplingCircularQueue::Enqueue() {
   WrapPositionIfNeeded(&producer_pos_->enqueue_pos);
   void* result = producer_pos_->enqueue_pos;

src/circular-queue.h

@@ -32,32 +32,6 @@ namespace v8 {
 namespace internal {
 
 
-// Lock-based blocking circular queue for small records.  Intended for
-// transfer of small records between a single producer and a single
-// consumer. Blocks on enqueue operation if the queue is full.
-template<typename Record>
-class CircularQueue {
- public:
-  inline explicit CircularQueue(int desired_buffer_size_in_bytes);
-  inline ~CircularQueue();
-
-  INLINE(void Dequeue(Record* rec));
-  INLINE(void Enqueue(const Record& rec));
-  INLINE(bool IsEmpty()) { return enqueue_pos_ == dequeue_pos_; }
-
- private:
-  INLINE(Record* Next(Record* curr));
-
-  Record* buffer_;
-  Record* const buffer_end_;
-  Semaphore* enqueue_semaphore_;
-  Record* enqueue_pos_;
-  Record* dequeue_pos_;
-
-  DISALLOW_COPY_AND_ASSIGN(CircularQueue);
-};
-
-
 // Lock-free cache-friendly sampling circular queue for large
 // records. Intended for fast transfer of large records between a
 // single producer and a single consumer. If the queue is full,

src/cpu-profiler-inl.h

@@ -34,6 +34,7 @@
 
 #include "circular-queue-inl.h"
 #include "profile-generator-inl.h"
+#include "unbound-queue-inl.h"
 
 namespace v8 {
 namespace internal {

src/cpu-profiler.cc

@@ -46,7 +46,6 @@ static const int kTickSamplesBufferChunksCount = 16;
 ProfilerEventsProcessor::ProfilerEventsProcessor(ProfileGenerator* generator)
     : generator_(generator),
       running_(false),
-      events_buffer_(kEventsBufferSize),
       ticks_buffer_(sizeof(TickSampleEventRecord),
                     kTickSamplesBufferChunkSize,
                     kTickSamplesBufferChunksCount),

src/cpu-profiler.h

@@ -31,6 +31,7 @@
 #ifdef ENABLE_LOGGING_AND_PROFILING
 
 #include "circular-queue.h"
+#include "unbound-queue.h"
 
 namespace v8 {
 namespace internal {
@@ -181,7 +182,7 @@ class ProfilerEventsProcessor : public Thread {
 
   ProfileGenerator* generator_;
   bool running_;
-  CircularQueue<CodeEventsContainer> events_buffer_;
+  UnboundQueue<CodeEventsContainer> events_buffer_;
   SamplingCircularQueue ticks_buffer_;
   unsigned enqueue_order_;
 };

src/platform-linux.cc

@@ -165,6 +165,28 @@ int OS::ActivationFrameAlignment() {
 }
 
 
+#ifdef V8_TARGET_ARCH_ARM
+// 0xffff0fa0 is the hard coded address of a function provided by
+// the kernel which implements a memory barrier. On older
+// ARM architecture revisions (pre-v6) this may be implemented using
+// a syscall. This address is stable, and in active use (hard coded)
+// by at least glibc-2.7 and the Android C library.
+typedef void (*LinuxKernelMemoryBarrierFunc)(void);
+LinuxKernelMemoryBarrierFunc pLinuxKernelMemoryBarrier __attribute__((weak)) =
+    (LinuxKernelMemoryBarrierFunc) 0xffff0fa0;
+#endif
+
+void OS::ReleaseStore(volatile AtomicWord* ptr, AtomicWord value) {
+#ifdef V8_TARGET_ARCH_ARM
+  pLinuxKernelMemoryBarrier();
+#else
+  __asm__ __volatile__("" : : : "memory");
+  // An x86 store acts as a release barrier.
+#endif
+  *ptr = value;
+}
+
+
 const char* OS::LocalTimezone(double time) {
   if (isnan(time)) return "";
   time_t tv = static_cast<time_t>(floor(time/msPerSecond));

src/platform-macos.cc

@@ -39,6 +39,7 @@
 #include <pthread.h>
 #include <semaphore.h>
 #include <signal.h>
+#include <libkern/OSAtomic.h>
 #include <mach/mach.h>
 #include <mach/semaphore.h>
 #include <mach/task.h>
@@ -259,6 +260,12 @@ int OS::ActivationFrameAlignment() {
 }
 
 
+void OS::ReleaseStore(volatile AtomicWord* ptr, AtomicWord value) {
+  OSMemoryBarrier();
+  *ptr = value;
+}
+
+
 const char* OS::LocalTimezone(double time) {
   if (isnan(time)) return "";
   time_t tv = static_cast<time_t>(floor(time/msPerSecond));

src/platform-win32.cc

@@ -1340,6 +1340,12 @@ int OS::ActivationFrameAlignment() {
 }
 
 
+void OS::ReleaseStore(volatile AtomicWord* ptr, AtomicWord value) {
+  MemoryBarrier();
+  *ptr = value;
+}
+
+
 bool VirtualMemory::IsReserved() {
   return address_ != NULL;
 }

src/platform.h

@@ -277,6 +277,8 @@ class OS {
   // the platform doesn't care. Guaranteed to be a power of two.
   static int ActivationFrameAlignment();
 
+  static void ReleaseStore(volatile AtomicWord* ptr, AtomicWord value);
+
  private:
   static const int msPerSecond = 1000;
 

src/unbound-queue-inl.h

@@ -0,0 +1,87 @@
+// Copyright 2010 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
+//       with the distribution.
+//     * Neither the name of Google Inc. nor the names of its
+//       contributors may be used to endorse or promote products derived
+//       from this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+#ifndef V8_UNBOUND_QUEUE_INL_H_
+#define V8_UNBOUND_QUEUE_INL_H_
+
+#include "unbound-queue.h"
+
+namespace v8 {
+namespace internal {
+
+template<typename Record>
+struct UnboundQueue<Record>::Node: public Malloced {
+  explicit Node(const Record& value)
+      : value(value), next(NULL) {
+  }
+
+  Record value;
+  Node* next;
+};
+
+
+template<typename Record>
+UnboundQueue<Record>::UnboundQueue() {
+  first_ = new Node(Record());
+  divider_ = last_ = reinterpret_cast<AtomicWord>(first_);
+}
+
+
+template<typename Record>
+UnboundQueue<Record>::~UnboundQueue() {
+  while (first_ != NULL) DeleteFirst();
+}
+
+
+template<typename Record>
+void UnboundQueue<Record>::DeleteFirst() {
+  Node* tmp = first_;
+  first_ = tmp->next;
+  delete tmp;
+}
+
+
+template<typename Record>
+void UnboundQueue<Record>::Dequeue(Record* rec) {
+  ASSERT(divider_ != last_);
+  Node* next = reinterpret_cast<Node*>(divider_)->next;
+  *rec = next->value;
+  OS::ReleaseStore(&divider_, reinterpret_cast<AtomicWord>(next));
+}
+
+
+template<typename Record>
+void UnboundQueue<Record>::Enqueue(const Record& rec) {
+  Node*& next = reinterpret_cast<Node*>(last_)->next;
+  next = new Node(rec);
+  OS::ReleaseStore(&last_, reinterpret_cast<AtomicWord>(next));
+  while (first_ != reinterpret_cast<Node*>(divider_)) DeleteFirst();
+}
+
+} }  // namespace v8::internal
+
+#endif  // V8_UNBOUND_QUEUE_INL_H_

src/unbound-queue.h

@@ -0,0 +1,66 @@
+// Copyright 2010 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
+//       with the distribution.
+//     * Neither the name of Google Inc. nor the names of its
+//       contributors may be used to endorse or promote products derived
+//       from this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+#ifndef V8_UNBOUND_QUEUE_
+#define V8_UNBOUND_QUEUE_
+
+namespace v8 {
+namespace internal {
+
+
+// Lock-free unbound queue for small records.  Intended for
+// transferring small records between a Single producer and a Single
+// consumer. Doesn't have restrictions on the number of queued
+// elements, so producer never blocks.  Implemented after Herb
+// Sutter's article:
+// http://www.ddj.com/high-performance-computing/210604448
+template<typename Record>
+class UnboundQueue BASE_EMBEDDED {
+ public:
+  inline UnboundQueue();
+  inline ~UnboundQueue();
+
+  INLINE(void Dequeue(Record* rec));
+  INLINE(void Enqueue(const Record& rec));
+  INLINE(bool IsEmpty()) { return divider_ == last_; }
+
+ private:
+  INLINE(void DeleteFirst());
+
+  struct Node;
+
+  Node* first_;
+  AtomicWord divider_;  // Node*
+  AtomicWord last_;     // Node*
+
+  DISALLOW_COPY_AND_ASSIGN(UnboundQueue);
+};
+
+
+} }  // namespace v8::internal
+
+#endif  // V8_UNBOUND_QUEUE_

src/v8.cc

@@ -149,10 +149,10 @@ void V8::TearDown() {
 
   Top::TearDown();
 
-  CpuProfiler::TearDown();
-
   Heap::TearDown();
 
+  CpuProfiler::TearDown();
+
   Logger::TearDown();
 
   is_running_ = false;

test/cctest/SConscript

@@ -71,6 +71,7 @@ SOURCES = {
     'test-strings.cc',
     'test-threads.cc',
     'test-thread-termination.cc',
+    'test-unbound-queue.cc',
     'test-utils.cc',
     'test-version.cc'
   ],

test/cctest/test-circular-queue.cc

@@ -1,6 +1,6 @@
 // Copyright 2010 the V8 project authors. All rights reserved.
 //
-// Tests of circular queues.
+// Tests of the circular queue.
 
 #include "v8.h"
 #include "circular-queue-inl.h"
@@ -8,53 +8,9 @@
 
 namespace i = v8::internal;
 
-using i::CircularQueue;
 using i::SamplingCircularQueue;
 
 
-TEST(SingleRecordCircularQueue) {
-  typedef int Record;
-  CircularQueue<Record> cq(sizeof(Record) * 2);
-  CHECK(cq.IsEmpty());
-  cq.Enqueue(1);
-  CHECK(!cq.IsEmpty());
-  Record rec = 0;
-  cq.Dequeue(&rec);
-  CHECK_EQ(1, rec);
-  CHECK(cq.IsEmpty());
-}
-
-
-TEST(MultipleRecordsCircularQueue) {
-  typedef int Record;
-  const int kQueueSize = 10;
-  CircularQueue<Record> cq(sizeof(Record) * (kQueueSize + 1));
-  CHECK(cq.IsEmpty());
-  cq.Enqueue(1);
-  CHECK(!cq.IsEmpty());
-  for (int i = 2; i <= 5; ++i) {
-    cq.Enqueue(i);
-    CHECK(!cq.IsEmpty());
-  }
-  Record rec = 0;
-  for (int i = 1; i <= 4; ++i) {
-    CHECK(!cq.IsEmpty());
-    cq.Dequeue(&rec);
-    CHECK_EQ(i, rec);
-  }
-  for (int i = 6; i <= 12; ++i) {
-    cq.Enqueue(i);
-    CHECK(!cq.IsEmpty());
-  }
-  for (int i = 5; i <= 12; ++i) {
-    CHECK(!cq.IsEmpty());
-    cq.Dequeue(&rec);
-    CHECK_EQ(i, rec);
-  }
-  CHECK(cq.IsEmpty());
-}
-
-
 TEST(SamplingCircularQueue) {
   typedef SamplingCircularQueue::Cell Record;
   const int kRecordsPerChunk = 4;

test/cctest/test-unbound-queue.cc

@@ -0,0 +1,54 @@
+// Copyright 2010 the V8 project authors. All rights reserved.
+//
+// Tests of the unbound queue.
+
+#include "v8.h"
+#include "unbound-queue-inl.h"
+#include "cctest.h"
+
+namespace i = v8::internal;
+
+using i::UnboundQueue;
+
+
+TEST(SingleRecord) {
+  typedef int Record;
+  UnboundQueue<Record> cq;
+  CHECK(cq.IsEmpty());
+  cq.Enqueue(1);
+  CHECK(!cq.IsEmpty());
+  Record rec = 0;
+  cq.Dequeue(&rec);
+  CHECK_EQ(1, rec);
+  CHECK(cq.IsEmpty());
+}
+
+
+TEST(MultipleRecords) {
+  typedef int Record;
+  UnboundQueue<Record> cq;
+  CHECK(cq.IsEmpty());
+  cq.Enqueue(1);
+  CHECK(!cq.IsEmpty());
+  for (int i = 2; i <= 5; ++i) {
+    cq.Enqueue(i);
+    CHECK(!cq.IsEmpty());
+  }
+  Record rec = 0;
+  for (int i = 1; i <= 4; ++i) {
+    CHECK(!cq.IsEmpty());
+    cq.Dequeue(&rec);
+    CHECK_EQ(i, rec);
+  }
+  for (int i = 6; i <= 12; ++i) {
+    cq.Enqueue(i);
+    CHECK(!cq.IsEmpty());
+  }
+  for (int i = 5; i <= 12; ++i) {
+    CHECK(!cq.IsEmpty());
+    cq.Dequeue(&rec);
+    CHECK_EQ(i, rec);
+  }
+  CHECK(cq.IsEmpty());
+}
+

tools/gyp/v8.gyp

@@ -412,6 +412,8 @@
         '../../src/top.h',
         '../../src/type-info.cc',
         '../../src/type-info.h',
+        '../../src/unbound-queue-inl.h',
+        '../../src/unbound-queue.h',
         '../../src/unicode-inl.h',
         '../../src/unicode.cc',
         '../../src/unicode.h',

tools/v8.xcodeproj/project.pbxproj

@@ -627,6 +627,8 @@
 		9FBE03E410BD412600F8BFBA /* fast-codegen-arm.cc */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.cpp.cpp; name = "fast-codegen-arm.cc"; path = "arm/fast-codegen-arm.cc"; sourceTree = "<group>"; };
 		9FC86ABB0F5FEDAC00F22668 /* oprofile-agent.cc */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.cpp.cpp; path = "oprofile-agent.cc"; sourceTree = "<group>"; };
 		9FC86ABC0F5FEDAC00F22668 /* oprofile-agent.h */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.h; path = "oprofile-agent.h"; sourceTree = "<group>"; };
+		9FF7A28211A642EA0051B8F2 /* unbound-queue-inl.h */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.h; path = "unbound-queue-inl.h"; sourceTree = "<group>"; };
+		9FF7A28311A642EA0051B8F2 /* unbound-queue.h */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.h; path = "unbound-queue.h"; sourceTree = "<group>"; };
 /* End PBXFileReference section */
 
 /* Begin PBXFrameworksBuildPhase section */
@@ -970,6 +972,8 @@
 				897FF1910E719B8F00D62E90 /* top.h */,
 				9FA38BAE1175B2D200C4CD55 /* type-info.cc */,
 				9FA38BAF1175B2D200C4CD55 /* type-info.h */,
+				9FF7A28211A642EA0051B8F2 /* unbound-queue-inl.h */,
+				9FF7A28311A642EA0051B8F2 /* unbound-queue.h */,
 				897FF1920E719B8F00D62E90 /* unicode-inl.h */,
 				897FF1930E719B8F00D62E90 /* unicode.cc */,
 				897FF1940E719B8F00D62E90 /* unicode.h */,

tools/visual_studio/v8_base.vcproj

@@ -960,6 +960,14 @@
 				RelativePath="..\..\src\type-info.h"
 				>
 			</File>
+			<File
+				RelativePath="..\..\src\unbound-queue-inl.h"
+				>
+			</File>
+			<File
+				RelativePath="..\..\src\unbound-queue.h"
+				>
+			</File>
 			<File
 				RelativePath="..\..\src\unicode-inl.h"
 				>

tools/visual_studio/v8_base_arm.vcproj

@@ -952,6 +952,14 @@
 				RelativePath="..\..\src\type-info.h"
 				>
 			</File>
+			<File
+				RelativePath="..\..\src\unbound-queue-inl.h"
+				>
+			</File>
+			<File
+				RelativePath="..\..\src\unbound-queue.h"
+				>
+			</File>
 			<File
 				RelativePath="..\..\src\unicode-inl.h"
 				>

tools/visual_studio/v8_base_x64.vcproj

@@ -937,6 +937,14 @@
 				RelativePath="..\..\src\type-info.h"
 				>
 			</File>
+			<File
+				RelativePath="..\..\src\unbound-queue-inl.h"
+				>
+			</File>
+			<File
+				RelativePath="..\..\src\unbound-queue.h"
+				>
+			</File>
 			<File
 				RelativePath="..\..\src\unicode-inl.h"
 				>

tools/visual_studio/v8_cctest.vcproj

@@ -247,6 +247,10 @@
 			RelativePath="..\..\test\cctest\test-strings.cc"
 			>
 		</File>
+		<File
+			RelativePath="..\..\test\cctest\test-unbound-queue.cc"
+			>
+		</File>
 		<File
 			RelativePath="..\..\test\cctest\test-utils.cc"
 			>