1// Copyright (c) 2012, the Dart project authors. Please see the AUTHORS file
2// for details. All rights reserved. Use of this source code is governed by a
3// BSD-style license that can be found in the LICENSE file.
4
5#include "vm/handles.h"
6
7#include "platform/assert.h"
8#include "platform/utils.h"
9#include "vm/dart_api_state.h"
10#include "vm/flags.h"
11#include "vm/os.h"
12#include "vm/raw_object.h"
13#include "vm/visitor.h"
14#include "vm/zone.h"
15
16#include "vm/handles_impl.h"
17
18namespace dart {
19
20void VMHandles::VisitObjectPointers(ObjectPointerVisitor* visitor) {
21 return Handles<kVMHandleSizeInWords, kVMHandlesPerChunk,
22 kOffsetOfRawPtr>::VisitObjectPointers(visitor);
23}
24
25#if defined(DEBUG)
26static bool IsCurrentApiNativeScope(Zone* zone) {
27 ApiNativeScope* scope = ApiNativeScope::Current();
28 return (scope != nullptr) && (scope->zone() == zone);
29}
30#endif // DEBUG
31
32uword VMHandles::AllocateHandle(Zone* zone) {
33 DEBUG_ASSERT(!IsCurrentApiNativeScope(zone));
34 uword handle = Handles<kVMHandleSizeInWords, kVMHandlesPerChunk,
35 kOffsetOfRawPtr>::AllocateHandle(zone);
36#if defined(DEBUG)
37 *reinterpret_cast<uword*>(handle + kOffsetOfIsZoneHandle * kWordSize) = 0;
38#endif
39 return handle;
40}
41
42uword VMHandles::AllocateZoneHandle(Zone* zone) {
43 DEBUG_ASSERT(!IsCurrentApiNativeScope(zone));
44 uword handle = Handles<kVMHandleSizeInWords, kVMHandlesPerChunk,
45 kOffsetOfRawPtr>::AllocateZoneHandle(zone);
46#if defined(DEBUG)
47 *reinterpret_cast<uword*>(handle + kOffsetOfIsZoneHandle * kWordSize) = 1;
48#endif
49 return handle;
50}
51
52#if defined(DEBUG)
53bool VMHandles::IsZoneHandle(uword handle) {
54 return *reinterpret_cast<uword*>(handle +
55 kOffsetOfIsZoneHandle * kWordSize) != 0;
56}
57#endif
58
59int VMHandles::ScopedHandleCount() {
60 Thread* thread = Thread::Current();
61 ASSERT(thread->zone() != nullptr);
62 VMHandles* handles = thread->zone()->handles();
63 return handles->CountScopedHandles();
64}
65
66int VMHandles::ZoneHandleCount() {
67 Thread* thread = Thread::Current();
68 ASSERT(thread->zone() != nullptr);
69 VMHandles* handles = thread->zone()->handles();
70 return handles->CountZoneHandles();
71}
72
73void HandleScope::Initialize() {
74 ASSERT(thread()->MayAllocateHandles());
75 VMHandles* handles = thread()->zone()->handles();
76 ASSERT(handles != nullptr);
77 saved_handle_block_ = handles->scoped_blocks_;
78 saved_handle_slot_ = handles->scoped_blocks_->next_handle_slot();
79#if defined(DEBUG)
80 link_ = thread()->top_handle_scope();
81 thread()->set_top_handle_scope(this);
82#endif
83}
84
85HandleScope::HandleScope(ThreadState* thread) : StackResource(thread) {
86 Initialize();
87}
88
89HandleScope::~HandleScope() {
90 ASSERT(thread()->zone() != nullptr);
91 VMHandles* handles = thread()->zone()->handles();
92 ASSERT(handles != nullptr);
93#if defined(DEBUG)
94 VMHandles::HandlesBlock* last = handles->scoped_blocks_;
95#endif
96 handles->scoped_blocks_ = saved_handle_block_;
97 handles->scoped_blocks_->set_next_handle_slot(saved_handle_slot_);
98#if defined(DEBUG)
99 VMHandles::HandlesBlock* block = handles->scoped_blocks_;
100 for (;;) {
101 block->ZapFreeHandles();
102 if (block == last) break;
103 block = block->next_block();
104 }
105 ASSERT(thread()->top_handle_scope() == this);
106 thread()->set_top_handle_scope(link_);
107#endif
108}
109
110} // namespace dart
111

source code of flutter_engine/third_party/dart/runtime/vm/handles.cc