[heap] Rename Safepoint to GlobalSafepoint

Avoid name clash with Safepoint in src/codgen and use renaming to
emphasize that class reaches a safepoint in each background thread.

Bug: v8:10315
Change-Id: I391cdcfaf533a0fe0d5923207234eb2a8411eb93
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2139576Reviewed-by: Ulan Degenbaev <ulan@chromium.org>
Commit-Queue: Dominik Inführ <dinfuehr@chromium.org>
Cr-Commit-Position: refs/heads/master@{#67037}

src/heap/heap.cc

@@ -202,7 +202,7 @@ Heap::Heap()
     : isolate_(isolate()),
       memory_pressure_level_(MemoryPressureLevel::kNone),
       global_pretenuring_feedback_(kInitialFeedbackCapacity),
-      safepoint_(new Safepoint(this)),
+      safepoint_(new GlobalSafepoint(this)),
       external_string_table_(this) {
   // Ensure old_generation_size_ is a multiple of kPageSize.
   DCHECK_EQ(0, max_old_generation_size_ & (Page::kPageSize - 1));

src/heap/heap.h

@@ -66,6 +66,7 @@ class ConcurrentMarking;
 class GCIdleTimeHandler;
 class GCIdleTimeHeapState;
 class GCTracer;
+class GlobalSafepoint;
 class HeapObjectAllocationTracker;
 class HeapObjectsFilter;
 class HeapStats;
@@ -83,7 +84,6 @@ class Page;
 class PagedSpace;
 class ReadOnlyHeap;
 class RootVisitor;
-class Safepoint;
 class ScavengeJob;
 class Scavenger;
 class ScavengerCollector;
@@ -620,7 +620,7 @@ class Heap {
   void AppendArrayBufferExtension(JSArrayBuffer object,
                                   ArrayBufferExtension* extension);
 
-  Safepoint* safepoint() { return safepoint_.get(); }
+  GlobalSafepoint* safepoint() { return safepoint_.get(); }
 
   V8_EXPORT_PRIVATE double MonotonicallyIncreasingTimeInMs();
 
@@ -2166,7 +2166,7 @@ class Heap {
   GCCallbackFlags current_gc_callback_flags_ =
       GCCallbackFlags::kNoGCCallbackFlags;
 
-  std::unique_ptr<Safepoint> safepoint_;
+  std::unique_ptr<GlobalSafepoint> safepoint_;
 
   bool is_current_gc_forced_ = false;
 

src/heap/local-heap.h

@@ -11,6 +11,7 @@
 #include "src/base/platform/condition-variable.h"
 #include "src/base/platform/mutex.h"
 #include "src/execution/isolate.h"
+#include "src/heap/safepoint.h"
 
 namespace v8 {
 namespace internal {
@@ -78,7 +79,7 @@ class LocalHeap {
   std::unique_ptr<PersistentHandles> persistent_handles_;
 
   friend class Heap;
-  friend class Safepoint;
+  friend class GlobalSafepoint;
   friend class ParkedScope;
 };
 

src/heap/safepoint.cc

@@ -12,14 +12,14 @@
 namespace v8 {
 namespace internal {
 
-Safepoint::Safepoint(Heap* heap)
+GlobalSafepoint::GlobalSafepoint(Heap* heap)
     : heap_(heap), local_heaps_head_(nullptr), is_active_(false) {}
 
-void Safepoint::Start() { StopThreads(); }
+void GlobalSafepoint::Start() { StopThreads(); }
 
-void Safepoint::End() { ResumeThreads(); }
+void GlobalSafepoint::End() { ResumeThreads(); }
 
-void Safepoint::StopThreads() {
+void GlobalSafepoint::StopThreads() {
   local_heaps_mutex_.Lock();
 
   barrier_.Arm();
@@ -41,7 +41,7 @@ void Safepoint::StopThreads() {
   is_active_ = true;
 }
 
-void Safepoint::ResumeThreads() {
+void GlobalSafepoint::ResumeThreads() {
   is_active_ = false;
 
   for (LocalHeap* current = local_heaps_head_; current;
@@ -54,7 +54,7 @@ void Safepoint::ResumeThreads() {
   local_heaps_mutex_.Unlock();
 }
 
-void Safepoint::EnterFromThread(LocalHeap* local_heap) {
+void GlobalSafepoint::EnterFromThread(LocalHeap* local_heap) {
   {
     base::MutexGuard guard(&local_heap->state_mutex_);
     local_heap->state_ = LocalHeap::ThreadState::Safepoint;
@@ -69,20 +69,20 @@ void Safepoint::EnterFromThread(LocalHeap* local_heap) {
   }
 }
 
-void Safepoint::Barrier::Arm() {
+void GlobalSafepoint::Barrier::Arm() {
   base::MutexGuard guard(&mutex_);
   CHECK(!armed_);
   armed_ = true;
 }
 
-void Safepoint::Barrier::Disarm() {
+void GlobalSafepoint::Barrier::Disarm() {
   base::MutexGuard guard(&mutex_);
   CHECK(armed_);
   armed_ = false;
   cond_.NotifyAll();
 }
 
-void Safepoint::Barrier::Wait() {
+void GlobalSafepoint::Barrier::Wait() {
   base::MutexGuard guard(&mutex_);
   while (armed_) {
     cond_.Wait(&mutex_);
@@ -95,7 +95,7 @@ SafepointScope::SafepointScope(Heap* heap) : safepoint_(heap->safepoint()) {
 
 SafepointScope::~SafepointScope() { safepoint_->ResumeThreads(); }
 
-void Safepoint::AddLocalHeap(LocalHeap* local_heap) {
+void GlobalSafepoint::AddLocalHeap(LocalHeap* local_heap) {
   base::MutexGuard guard(&local_heaps_mutex_);
   if (local_heaps_head_) local_heaps_head_->prev_ = local_heap;
   local_heap->prev_ = nullptr;
@@ -103,7 +103,7 @@ void Safepoint::AddLocalHeap(LocalHeap* local_heap) {
   local_heaps_head_ = local_heap;
 }
 
-void Safepoint::RemoveLocalHeap(LocalHeap* local_heap) {
+void GlobalSafepoint::RemoveLocalHeap(LocalHeap* local_heap) {
   base::MutexGuard guard(&local_heaps_mutex_);
   if (local_heap->next_) local_heap->next_->prev_ = local_heap->prev_;
   if (local_heap->prev_)
@@ -112,7 +112,7 @@ void Safepoint::RemoveLocalHeap(LocalHeap* local_heap) {
     local_heaps_head_ = local_heap->next_;
 }
 
-bool Safepoint::ContainsLocalHeap(LocalHeap* local_heap) {
+bool GlobalSafepoint::ContainsLocalHeap(LocalHeap* local_heap) {
   base::MutexGuard guard(&local_heaps_mutex_);
   LocalHeap* current = local_heaps_head_;
 
@@ -124,12 +124,12 @@ bool Safepoint::ContainsLocalHeap(LocalHeap* local_heap) {
   return false;
 }
 
-bool Safepoint::ContainsAnyLocalHeap() {
+bool GlobalSafepoint::ContainsAnyLocalHeap() {
   base::MutexGuard guard(&local_heaps_mutex_);
   return local_heaps_head_ != nullptr;
 }
 
-void Safepoint::Iterate(RootVisitor* visitor) {
+void GlobalSafepoint::Iterate(RootVisitor* visitor) {
   DCHECK(IsActive());
   for (LocalHeap* current = local_heaps_head_; current;
        current = current->next_) {

src/heap/safepoint.h

@@ -17,9 +17,11 @@ class Heap;
 class LocalHeap;
 class RootVisitor;
 
-class Safepoint {
+// Used to bring all background threads with heap access to a safepoint such
+// that e.g. a garabge collection can be performed.
+class GlobalSafepoint {
  public:
-  explicit Safepoint(Heap* heap);
+  explicit GlobalSafepoint(Heap* heap);
 
   // Enter the safepoint from a thread
   void EnterFromThread(LocalHeap* local_heap);
@@ -75,7 +77,7 @@ class SafepointScope {
   V8_EXPORT_PRIVATE ~SafepointScope();
 
  private:
-  Safepoint* safepoint_;
+  GlobalSafepoint* safepoint_;
 };
 
 }  // namespace internal