| // Copyright 2008 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. |
| |
| #include "v8.h" |
| |
| #include "api.h" |
| #include "debug.h" |
| #include "execution.h" |
| #include "v8threads.h" |
| |
| namespace v8 { |
| |
| static internal::Thread::LocalStorageKey thread_state_key = |
| internal::Thread::CreateThreadLocalKey(); |
| |
| // Constructor for the Locker object. Once the Locker is constructed the |
| // current thread will be guaranteed to have the big V8 lock. |
| Locker::Locker() : has_lock_(false), top_level_(true) { |
| // Get the big lock if necessary. |
| if (!internal::ThreadManager::IsLockedByCurrentThread()) { |
| internal::ThreadManager::Lock(); |
| has_lock_ = true; |
| // This may be a locker within an unlocker in which case we have to |
| // get the saved state for this thread and restore it. |
| if (internal::ThreadManager::RestoreThread()) { |
| top_level_ = false; |
| } |
| } |
| ASSERT(internal::ThreadManager::IsLockedByCurrentThread()); |
| } |
| |
| |
| bool Locker::IsLocked() { |
| return internal::ThreadManager::IsLockedByCurrentThread(); |
| } |
| |
| |
| Locker::~Locker() { |
| ASSERT(internal::ThreadManager::IsLockedByCurrentThread()); |
| if (has_lock_) { |
| if (!top_level_) { |
| internal::ThreadManager::ArchiveThread(); |
| } |
| internal::ThreadManager::Unlock(); |
| } |
| } |
| |
| |
| Unlocker::Unlocker() { |
| ASSERT(internal::ThreadManager::IsLockedByCurrentThread()); |
| internal::ThreadManager::ArchiveThread(); |
| internal::ThreadManager::Unlock(); |
| } |
| |
| |
| Unlocker::~Unlocker() { |
| ASSERT(!internal::ThreadManager::IsLockedByCurrentThread()); |
| internal::ThreadManager::Lock(); |
| internal::ThreadManager::RestoreThread(); |
| } |
| |
| |
| void Locker::StartPreemption(int every_n_ms) { |
| v8::internal::ContextSwitcher::StartPreemption(every_n_ms); |
| } |
| |
| |
| void Locker::StopPreemption() { |
| v8::internal::ContextSwitcher::StopPreemption(); |
| } |
| |
| |
| namespace internal { |
| |
| |
| bool ThreadManager::RestoreThread() { |
| // First check whether the current thread has been 'lazily archived', ie |
| // not archived at all. If that is the case we put the state storage we |
| // had prepared back in the free list, since we didn't need it after all. |
| if (lazily_archived_thread_.IsSelf()) { |
| lazily_archived_thread_.Initialize(ThreadHandle::INVALID); |
| ASSERT(Thread::GetThreadLocal(thread_state_key) == |
| lazily_archived_thread_state_); |
| lazily_archived_thread_state_->LinkInto(ThreadState::FREE_LIST); |
| lazily_archived_thread_state_ = NULL; |
| Thread::SetThreadLocal(thread_state_key, NULL); |
| return true; |
| } |
| // If there is another thread that was lazily archived then we have to really |
| // archive it now. |
| if (lazily_archived_thread_.IsValid()) { |
| EagerlyArchiveThread(); |
| } |
| ThreadState* state = |
| reinterpret_cast<ThreadState*>(Thread::GetThreadLocal(thread_state_key)); |
| if (state == NULL) { |
| return false; |
| } |
| char* from = state->data(); |
| from = HandleScopeImplementer::RestoreThread(from); |
| from = Top::RestoreThread(from); |
| from = Debug::RestoreDebug(from); |
| from = StackGuard::RestoreStackGuard(from); |
| Thread::SetThreadLocal(thread_state_key, NULL); |
| state->Unlink(); |
| state->LinkInto(ThreadState::FREE_LIST); |
| return true; |
| } |
| |
| |
| void ThreadManager::Lock() { |
| mutex_->Lock(); |
| mutex_owner_.Initialize(ThreadHandle::SELF); |
| ASSERT(IsLockedByCurrentThread()); |
| } |
| |
| |
| void ThreadManager::Unlock() { |
| mutex_owner_.Initialize(ThreadHandle::INVALID); |
| mutex_->Unlock(); |
| } |
| |
| |
| static int ArchiveSpacePerThread() { |
| return HandleScopeImplementer::ArchiveSpacePerThread() + |
| Top::ArchiveSpacePerThread() + |
| Debug::ArchiveSpacePerThread() + |
| StackGuard::ArchiveSpacePerThread(); |
| } |
| |
| |
| ThreadState* ThreadState::free_anchor_ = new ThreadState(); |
| ThreadState* ThreadState::in_use_anchor_ = new ThreadState(); |
| |
| |
| ThreadState::ThreadState() : next_(this), previous_(this) { |
| } |
| |
| |
| void ThreadState::AllocateSpace() { |
| data_ = NewArray<char>(ArchiveSpacePerThread()); |
| } |
| |
| |
| void ThreadState::Unlink() { |
| next_->previous_ = previous_; |
| previous_->next_ = next_; |
| } |
| |
| |
| void ThreadState::LinkInto(List list) { |
| ThreadState* flying_anchor = |
| list == FREE_LIST ? free_anchor_ : in_use_anchor_; |
| next_ = flying_anchor->next_; |
| previous_ = flying_anchor; |
| flying_anchor->next_ = this; |
| next_->previous_ = this; |
| } |
| |
| |
| ThreadState* ThreadState::GetFree() { |
| ThreadState* gotten = free_anchor_->next_; |
| if (gotten == free_anchor_) { |
| ThreadState* new_thread_state = new ThreadState(); |
| new_thread_state->AllocateSpace(); |
| return new_thread_state; |
| } |
| return gotten; |
| } |
| |
| |
| // Gets the first in the list of archived threads. |
| ThreadState* ThreadState::FirstInUse() { |
| return in_use_anchor_->Next(); |
| } |
| |
| |
| ThreadState* ThreadState::Next() { |
| if (next_ == in_use_anchor_) return NULL; |
| return next_; |
| } |
| |
| |
| Mutex* ThreadManager::mutex_ = OS::CreateMutex(); |
| ThreadHandle ThreadManager::mutex_owner_(ThreadHandle::INVALID); |
| ThreadHandle ThreadManager::lazily_archived_thread_(ThreadHandle::INVALID); |
| ThreadState* ThreadManager::lazily_archived_thread_state_ = NULL; |
| |
| |
| void ThreadManager::ArchiveThread() { |
| ASSERT(!lazily_archived_thread_.IsValid()); |
| ASSERT(Thread::GetThreadLocal(thread_state_key) == NULL); |
| ThreadState* state = ThreadState::GetFree(); |
| state->Unlink(); |
| Thread::SetThreadLocal(thread_state_key, reinterpret_cast<void*>(state)); |
| lazily_archived_thread_.Initialize(ThreadHandle::SELF); |
| lazily_archived_thread_state_ = state; |
| } |
| |
| |
| void ThreadManager::EagerlyArchiveThread() { |
| ThreadState* state = lazily_archived_thread_state_; |
| state->LinkInto(ThreadState::IN_USE_LIST); |
| char* to = state->data(); |
| to = HandleScopeImplementer::ArchiveThread(to); |
| to = Top::ArchiveThread(to); |
| to = Debug::ArchiveDebug(to); |
| to = StackGuard::ArchiveStackGuard(to); |
| lazily_archived_thread_.Initialize(ThreadHandle::INVALID); |
| lazily_archived_thread_state_ = NULL; |
| } |
| |
| |
| void ThreadManager::Iterate(ObjectVisitor* v) { |
| // Expecting no threads during serialization/deserialization |
| for (ThreadState* state = ThreadState::FirstInUse(); |
| state != NULL; |
| state = state->Next()) { |
| char* data = state->data(); |
| data = HandleScopeImplementer::Iterate(v, data); |
| data = Top::Iterate(v, data); |
| } |
| } |
| |
| |
| void ThreadManager::MarkCompactPrologue() { |
| for (ThreadState* state = ThreadState::FirstInUse(); |
| state != NULL; |
| state = state->Next()) { |
| char* data = state->data(); |
| data += HandleScopeImplementer::ArchiveSpacePerThread(); |
| Top::MarkCompactPrologue(data); |
| } |
| } |
| |
| |
| void ThreadManager::MarkCompactEpilogue() { |
| for (ThreadState* state = ThreadState::FirstInUse(); |
| state != NULL; |
| state = state->Next()) { |
| char* data = state->data(); |
| data += HandleScopeImplementer::ArchiveSpacePerThread(); |
| Top::MarkCompactEpilogue(data); |
| } |
| } |
| |
| |
| ContextSwitcher::ContextSwitcher(int every_n_ms) |
| : preemption_semaphore_(OS::CreateSemaphore(0)), |
| keep_going_(true), |
| sleep_ms_(every_n_ms) { |
| } |
| |
| |
| static v8::internal::ContextSwitcher* switcher; |
| |
| |
| void ContextSwitcher::StartPreemption(int every_n_ms) { |
| ASSERT(Locker::IsLocked()); |
| if (switcher == NULL) { |
| switcher = new ContextSwitcher(every_n_ms); |
| switcher->Start(); |
| } else { |
| switcher->sleep_ms_ = every_n_ms; |
| } |
| } |
| |
| |
| void ContextSwitcher::StopPreemption() { |
| ASSERT(Locker::IsLocked()); |
| if (switcher != NULL) { |
| switcher->Stop(); |
| delete(switcher); |
| switcher = NULL; |
| } |
| } |
| |
| |
| void ContextSwitcher::Run() { |
| while (keep_going_) { |
| OS::Sleep(sleep_ms_); |
| StackGuard::Preempt(); |
| WaitForPreemption(); |
| } |
| } |
| |
| |
| void ContextSwitcher::Stop() { |
| ASSERT(Locker::IsLocked()); |
| keep_going_ = false; |
| preemption_semaphore_->Signal(); |
| Join(); |
| } |
| |
| |
| void ContextSwitcher::WaitForPreemption() { |
| preemption_semaphore_->Wait(); |
| } |
| |
| |
| void ContextSwitcher::PreemptionReceived() { |
| ASSERT(Locker::IsLocked()); |
| switcher->preemption_semaphore_->Signal(); |
| } |
| |
| |
| } // namespace internal |
| } // namespace v8 |