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      1 // Copyright 2010 the V8 project authors. All rights reserved.
      2 // Redistribution and use in source and binary forms, with or without
      3 // modification, are permitted provided that the following conditions are
      4 // met:
      5 //
      6 //     * Redistributions of source code must retain the above copyright
      7 //       notice, this list of conditions and the following disclaimer.
      8 //     * Redistributions in binary form must reproduce the above
      9 //       copyright notice, this list of conditions and the following
     10 //       disclaimer in the documentation and/or other materials provided
     11 //       with the distribution.
     12 //     * Neither the name of Google Inc. nor the names of its
     13 //       contributors may be used to endorse or promote products derived
     14 //       from this software without specific prior written permission.
     15 //
     16 // THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
     17 // "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
     18 // LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
     19 // A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
     20 // OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
     21 // SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
     22 // LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
     23 // DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
     24 // THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
     25 // (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
     26 // OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
     27 
     28 #ifndef V8_VM_STATE_INL_H_
     29 #define V8_VM_STATE_INL_H_
     30 
     31 #include "vm-state.h"
     32 #include "runtime-profiler.h"
     33 
     34 namespace v8 {
     35 namespace internal {
     36 
     37 //
     38 // VMState class implementation.  A simple stack of VM states held by the
     39 // logger and partially threaded through the call stack.  States are pushed by
     40 // VMState construction and popped by destruction.
     41 //
     42 #ifdef ENABLE_VMSTATE_TRACKING
     43 inline const char* StateToString(StateTag state) {
     44   switch (state) {
     45     case JS:
     46       return "JS";
     47     case GC:
     48       return "GC";
     49     case COMPILER:
     50       return "COMPILER";
     51     case OTHER:
     52       return "OTHER";
     53     case EXTERNAL:
     54       return "EXTERNAL";
     55     default:
     56       UNREACHABLE();
     57       return NULL;
     58   }
     59 }
     60 
     61 
     62 VMState::VMState(Isolate* isolate, StateTag tag)
     63     : isolate_(isolate), previous_tag_(isolate->current_vm_state()) {
     64 #ifdef ENABLE_LOGGING_AND_PROFILING
     65   if (FLAG_log_state_changes) {
     66     LOG(isolate, UncheckedStringEvent("Entering", StateToString(tag)));
     67     LOG(isolate, UncheckedStringEvent("From", StateToString(previous_tag_)));
     68   }
     69 #endif
     70 
     71   isolate_->SetCurrentVMState(tag);
     72 
     73 #ifdef ENABLE_HEAP_PROTECTION
     74   if (FLAG_protect_heap) {
     75     if (tag == EXTERNAL) {
     76       // We are leaving V8.
     77       ASSERT(previous_tag_ != EXTERNAL);
     78       isolate_->heap()->Protect();
     79     } else if (previous_tag_ = EXTERNAL) {
     80       // We are entering V8.
     81       isolate_->heap()->Unprotect();
     82     }
     83   }
     84 #endif
     85 }
     86 
     87 
     88 VMState::~VMState() {
     89 #ifdef ENABLE_LOGGING_AND_PROFILING
     90   if (FLAG_log_state_changes) {
     91     LOG(isolate_,
     92         UncheckedStringEvent("Leaving",
     93                               StateToString(isolate_->current_vm_state())));
     94     LOG(isolate_,
     95         UncheckedStringEvent("To", StateToString(previous_tag_)));
     96   }
     97 #endif  // ENABLE_LOGGING_AND_PROFILING
     98 
     99 #ifdef ENABLE_HEAP_PROTECTION
    100   StateTag tag = isolate_->current_vm_state();
    101 #endif
    102 
    103   isolate_->SetCurrentVMState(previous_tag_);
    104 
    105 #ifdef ENABLE_HEAP_PROTECTION
    106   if (FLAG_protect_heap) {
    107     if (tag == EXTERNAL) {
    108       // We are reentering V8.
    109       ASSERT(previous_tag_ != EXTERNAL);
    110       isolate_->heap()->Unprotect();
    111     } else if (previous_tag_ == EXTERNAL) {
    112       // We are leaving V8.
    113       isolate_->heap()->Protect();
    114     }
    115   }
    116 #endif  // ENABLE_HEAP_PROTECTION
    117 }
    118 
    119 #endif  // ENABLE_VMSTATE_TRACKING
    120 
    121 
    122 #ifdef ENABLE_LOGGING_AND_PROFILING
    123 
    124 ExternalCallbackScope::ExternalCallbackScope(Isolate* isolate, Address callback)
    125     : isolate_(isolate), previous_callback_(isolate->external_callback()) {
    126   isolate_->set_external_callback(callback);
    127 }
    128 
    129 ExternalCallbackScope::~ExternalCallbackScope() {
    130   isolate_->set_external_callback(previous_callback_);
    131 }
    132 
    133 #endif  // ENABLE_LOGGING_AND_PROFILING
    134 
    135 
    136 } }  // namespace v8::internal
    137 
    138 #endif  // V8_VM_STATE_INL_H_
    139