Do not rely on uniquiness of pthread_t

src/isolate.cc

 // Copyright 2006-2010 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
@@ skipping 36 matching lines @@
 #include "serialize.h"
 #include "simulator.h"
 #include "spaces.h"
 #include "stub-cache.h"
 #include "version.h"
 
 
 namespace v8 {
 namespace internal {
 
+Atomic32 ThreadId::highest_thread_id_ = 0;
+
+int ThreadId::AllocateThreadId() {
+  int new_id = NoBarrier_AtomicIncrement(&highest_thread_id_, 1);
+  return new_id;
+}
+
+int ThreadId::GetCurrentThreadId() {
+  int thread_id = Thread::GetThreadLocalInt(Isolate::thread_id_key_);
+  if (thread_id == 0) {
+    thread_id = AllocateThreadId();
+    Thread::SetThreadLocalInt(Isolate::thread_id_key_, thread_id);
+  }
+  return thread_id;
+}
 
 // Create a dummy thread that will wait forever on a semaphore. The only
 // purpose for this thread is to have some stack area to save essential data
 // into for use by a stacks only core dump (aka minidump).
 class PreallocatedMemoryThread: public Thread {
  public:
   char* data() {
     if (data_ready_semaphore_ != NULL) {
       // Initial access is guarded until the data has been published.
       data_ready_semaphore_->Wait();
@@ skipping 171 matching lines @@
   storage->LinkTo(&free_list_);
 }
 
 
 Isolate* Isolate::default_isolate_ = NULL;
 Thread::LocalStorageKey Isolate::isolate_key_;
 Thread::LocalStorageKey Isolate::thread_id_key_;
 Thread::LocalStorageKey Isolate::per_isolate_thread_data_key_;
 Mutex* Isolate::process_wide_mutex_ = OS::CreateMutex();
 Isolate::ThreadDataTable* Isolate::thread_data_table_ = NULL;
-Isolate::ThreadId Isolate::highest_thread_id_ = 0;
 
 
 class IsolateInitializer {
  public:
   IsolateInitializer() {
     Isolate::EnsureDefaultIsolate();
   }
 };
 
 static IsolateInitializer* EnsureDefaultIsolateAllocated() {
   // TODO(isolates): Use the system threading API to do this once?
   static IsolateInitializer static_initializer;
   return &static_initializer;
 }
 
 // This variable only needed to trigger static intialization.
 static IsolateInitializer* static_initializer = EnsureDefaultIsolateAllocated();
 
 
-Isolate::ThreadId Isolate::AllocateThreadId() {
-  ThreadId new_id;
-  {
-    ScopedLock lock(process_wide_mutex_);
-    new_id = ++highest_thread_id_;
-  }
-  return new_id;
-}
+
 
 
 Isolate::PerIsolateThreadData* Isolate::AllocatePerIsolateThreadData(
     ThreadId thread_id) {
-  ASSERT(thread_id != 0);
-  ASSERT(Thread::GetThreadLocalInt(thread_id_key_) == thread_id);
+  ASSERT(!thread_id.Equals(ThreadId::Invalid()));
   PerIsolateThreadData* per_thread = new PerIsolateThreadData(this, thread_id);
   {
     ScopedLock lock(process_wide_mutex_);
     ASSERT(thread_data_table_->Lookup(this, thread_id) == NULL);
     thread_data_table_->Insert(per_thread);
     ASSERT(thread_data_table_->Lookup(this, thread_id) == per_thread);
   }
   return per_thread;
 }
 
 
 Isolate::PerIsolateThreadData*
     Isolate::FindOrAllocatePerThreadDataForThisThread() {
-  ThreadId thread_id = Thread::GetThreadLocalInt(thread_id_key_);
-  if (thread_id == 0) {
-    thread_id = AllocateThreadId();
-    Thread::SetThreadLocalInt(thread_id_key_, thread_id);
-  }
+  ThreadId thread_id = ThreadId::Current();
   PerIsolateThreadData* per_thread = NULL;
   {
     ScopedLock lock(process_wide_mutex_);
     per_thread = thread_data_table_->Lookup(this, thread_id);
     if (per_thread == NULL) {
       per_thread = AllocatePerIsolateThreadData(thread_id);
     }
   }
   return per_thread;
 }
@@ skipping 44 matching lines @@
   return default_isolate_;
 }
 
 
 Isolate::ThreadDataTable::ThreadDataTable()
     : list_(NULL) {
 }
 
 
 Isolate::PerIsolateThreadData*
-    Isolate::ThreadDataTable::Lookup(Isolate* isolate, ThreadId thread_id) {
+    Isolate::ThreadDataTable::Lookup(Isolate* isolate,
+                                     ThreadId thread_id) {
   for (PerIsolateThreadData* data = list_; data != NULL; data = data->next_) {
     if (data->Matches(isolate, thread_id)) return data;
   }
   return NULL;
 }
 
 
 void Isolate::ThreadDataTable::Insert(Isolate::PerIsolateThreadData* data) {
   if (list_ != NULL) list_->prev_ = data;
   data->next_ = list_;
   list_ = data;
 }
 
 
 void Isolate::ThreadDataTable::Remove(PerIsolateThreadData* data) {
   if (list_ == data) list_ = data->next_;
   if (data->next_ != NULL) data->next_->prev_ = data->prev_;
   if (data->prev_ != NULL) data->prev_->next_ = data->next_;
 }
 
 
-void Isolate::ThreadDataTable::Remove(Isolate* isolate, ThreadId thread_id) {
+void Isolate::ThreadDataTable::Remove(Isolate* isolate,
+                                      ThreadId thread_id) {
   PerIsolateThreadData* data = Lookup(isolate, thread_id);
   if (data != NULL) {
     Remove(data);
   }
 }
 
 
 #ifdef DEBUG
 #define TRACE_ISOLATE(tag)                                              \
   do {                                                                  \
@@ skipping 429 matching lines @@
 void Isolate::Enter() {
   Isolate* current_isolate = NULL;
   PerIsolateThreadData* current_data = CurrentPerIsolateThreadData();
   if (current_data != NULL) {
     current_isolate = current_data->isolate_;
     ASSERT(current_isolate != NULL);
     if (current_isolate == this) {
       ASSERT(Current() == this);
       ASSERT(entry_stack_ != NULL);
       ASSERT(entry_stack_->previous_thread_data == NULL ||
-             entry_stack_->previous_thread_data->thread_id() ==
-                 Thread::GetThreadLocalInt(thread_id_key_));
+             entry_stack_->previous_thread_data->thread_id().Equals(
+                 ThreadId::Current()));
       // Same thread re-enters the isolate, no need to re-init anything.
       entry_stack_->entry_count++;
       return;
     }
   }
 
   // Threads can have default isolate set into TLS as Current but not yet have
   // PerIsolateThreadData for it, as it requires more advanced phase of the
   // initialization. For example, a thread might be the one that system used for
   // static initializers - in this case the default isolate is set in TLS but
@@ skipping 17 matching lines @@
   CHECK(PreInit());
 
   // In case it's the first time some thread enters the isolate.
   set_thread_id(data->thread_id());
 }
 
 
 void Isolate::Exit() {
   ASSERT(entry_stack_ != NULL);
   ASSERT(entry_stack_->previous_thread_data == NULL ||
-         entry_stack_->previous_thread_data->thread_id() ==
-             Thread::GetThreadLocalInt(thread_id_key_));
+         entry_stack_->previous_thread_data->thread_id().Equals(
+             ThreadId::Current()));
 
   if (--entry_stack_->entry_count > 0) return;
 
   ASSERT(CurrentPerIsolateThreadData() != NULL);
   ASSERT(CurrentPerIsolateThreadData()->isolate_ == this);
 
   // Pop the stack.
   EntryStackItem* item = entry_stack_;
   entry_stack_ = item->previous_item;
 
@@ skipping 14 matching lines @@
 
 #ifdef DEBUG
 #define ISOLATE_FIELD_OFFSET(type, name, ignored)                       \
 const intptr_t Isolate::name##_debug_offset_ = OFFSET_OF(Isolate, name##_);
 ISOLATE_INIT_LIST(ISOLATE_FIELD_OFFSET)
 ISOLATE_INIT_ARRAY_LIST(ISOLATE_FIELD_OFFSET)
 #undef ISOLATE_FIELD_OFFSET
 #endif
 
 } }  // namespace v8::internal