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// 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_VM_STATE_INL_H_
#define V8_VM_STATE_INL_H_
#include "vm-state.h"
namespace v8 {
namespace internal {
//
// VMState class implementation. A simple stack of VM states held by the
// logger and partially threaded through the call stack. States are pushed by
// VMState construction and popped by destruction.
//
#ifdef ENABLE_VMSTATE_TRACKING
inline const char* StateToString(StateTag state) {
switch (state) {
case JS:
return "JS";
case GC:
return "GC";
case COMPILER:
return "COMPILER";
case OTHER:
return "OTHER";
default:
UNREACHABLE();
return NULL;
}
}
VMState::VMState(StateTag state)
: disabled_(true),
state_(OTHER),
external_callback_(NULL) {
#ifdef ENABLE_LOGGING_AND_PROFILING
if (!Logger::is_logging() && !CpuProfiler::is_profiling()) {
return;
}
#endif
disabled_ = false;
#if !defined(ENABLE_HEAP_PROTECTION)
// When not protecting the heap, there is no difference between
// EXTERNAL and OTHER. As an optimization in that case, we will not
// perform EXTERNAL->OTHER transitions through the API. We thus
// compress the two states into one.
if (state == EXTERNAL) state = OTHER;
#endif
state_ = state;
// Save the previous state.
previous_ = reinterpret_cast<VMState*>(current_state_);
// Install the new state.
OS::ReleaseStore(&current_state_, reinterpret_cast<AtomicWord>(this));
#ifdef ENABLE_LOGGING_AND_PROFILING
if (FLAG_log_state_changes) {
LOG(UncheckedStringEvent("Entering", StateToString(state_)));
if (previous_ != NULL) {
LOG(UncheckedStringEvent("From", StateToString(previous_->state_)));
}
}
#endif
#ifdef ENABLE_HEAP_PROTECTION
if (FLAG_protect_heap) {
if (state_ == EXTERNAL) {
// We are leaving V8.
ASSERT((previous_ != NULL) && (previous_->state_ != EXTERNAL));
Heap::Protect();
} else if ((previous_ == NULL) || (previous_->state_ == EXTERNAL)) {
// We are entering V8.
Heap::Unprotect();
}
}
#endif
}
VMState::~VMState() {
if (disabled_) return;
// Return to the previous state.
OS::ReleaseStore(&current_state_, reinterpret_cast<AtomicWord>(previous_));
#ifdef ENABLE_LOGGING_AND_PROFILING
if (FLAG_log_state_changes) {
LOG(UncheckedStringEvent("Leaving", StateToString(state_)));
if (previous_ != NULL) {
LOG(UncheckedStringEvent("To", StateToString(previous_->state_)));
}
}
#endif // ENABLE_LOGGING_AND_PROFILING
#ifdef ENABLE_HEAP_PROTECTION
if (FLAG_protect_heap) {
if (state_ == EXTERNAL) {
// We are reentering V8.
ASSERT((previous_ != NULL) && (previous_->state_ != EXTERNAL));
Heap::Unprotect();
} else if ((previous_ == NULL) || (previous_->state_ == EXTERNAL)) {
// We are leaving V8.
Heap::Protect();
}
}
#endif // ENABLE_HEAP_PROTECTION
}
#endif // ENABLE_VMSTATE_TRACKING
} } // namespace v8::internal
#endif // V8_VM_STATE_INL_H_