1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
|
// Copyright 2014 The Chromium Authors
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
#ifndef COMPONENTS_KEYED_SERVICE_CORE_DEPENDENCY_MANAGER_H_
#define COMPONENTS_KEYED_SERVICE_CORE_DEPENDENCY_MANAGER_H_
#include <set>
#include <string>
#include "base/dcheck_is_on.h"
#include "base/memory/raw_ptr.h"
#include "components/keyed_service/core/dependency_graph.h"
#include "components/keyed_service/core/features_buildflags.h"
#include "components/keyed_service/core/keyed_service_export.h"
class KeyedServiceBaseFactory;
namespace base {
class FilePath;
}
namespace user_prefs {
class PrefRegistrySyncable;
}
// DependencyManager manages dependency between KeyedServiceBaseFactory
// broadcasting the context creation and destruction to each factory in
// a safe order based on the stated dependencies.
class KEYED_SERVICE_EXPORT DependencyManager {
public:
DependencyManager(const DependencyManager&) = delete;
DependencyManager& operator=(const DependencyManager&) = delete;
// Shuts down all keyed services managed by two
// DependencyManagers (DMs), then destroys them. The order of execution is:
// - Shutdown services in DM1
// - Shutdown services in DM2
// - Destroy services in DM1
// - Destroy services in DM2
static void PerformInterlockedTwoPhaseShutdown(
DependencyManager* dependency_manager1,
void* context1,
DependencyManager* dependency_manager2,
void* context2);
// Returns the dependency graph for Keyed Services Factory testing purposes.
DependencyGraph& GetDependencyGraphForTesting();
// After this function is called, any KeyedServiceFactory trying to register
// itself will cause a DCHECK. It should have been registered in the
// appropriate `EnsureBrowserContextKeyedServiceFactoriesBuilt()` function.
// `registration_function_name` param is used to display the right
// registration method in the error message.
void DisallowKeyedServiceFactoryRegistration(
const std::string& registration_function_name_error_message);
protected:
DependencyManager();
virtual ~DependencyManager();
// Adds/Removes a component from our list of live components. Removing will
// also remove live dependency links.
void AddComponent(KeyedServiceBaseFactory* component);
void RemoveComponent(KeyedServiceBaseFactory* component);
// Adds a dependency between two factories.
void AddEdge(KeyedServiceBaseFactory* depended,
KeyedServiceBaseFactory* dependee);
// Registers preferences for all services via |registry|.
void RegisterPrefsForServices(user_prefs::PrefRegistrySyncable* registry);
// Called upon creation of |context| to create services that want to be
// started at the creation of a context and register service-related
// preferences.
//
// To have a KeyedService started when a context is created the method
// KeyedServiceBaseFactory::ServiceIsCreatedWithContext() must be overridden
// to return true.
//
// If |is_testing_context| then the service will not be started unless the
// method KeyedServiceBaseFactory::ServiceIsNULLWhileTesting() return false.
void CreateContextServices(void* context, bool is_testing_context);
// Called upon destruction of |context| to destroy all services associated
// with it.
void DestroyContextServices(void* context);
// Runtime assertion called as a part of GetServiceForContext() to check if
// |context| is considered stale. This will NOTREACHED() to avoid a potential
// use-after-free from services created after context destruction.
void AssertContextWasntDestroyed(void* context) const;
// Marks |context| as live (i.e., not stale). This method can be called as a
// safeguard against |AssertContextWasntDestroyed()| checks going off due to
// |context| aliasing an instance from a prior construction (i.e., 0xWhatever
// might be created, be destroyed, and then a new object might be created at
// 0xWhatever).
void MarkContextLive(void* context);
// Marks |context| as dead (i.e., stale). Calls passing |context| to
//|AssertContextWasntDestroyed()| will flag an error until that context is
// marked as live again with MarkContextLive().
void MarkContextDead(void* context);
#ifndef NDEBUG
// Dumps service dependency graph as a Graphviz dot file |dot_file| with a
// title |top_level_name|. Helper for |DumpContextDependencies|.
void DumpDependenciesAsGraphviz(const std::string& top_level_name,
const base::FilePath& dot_file) const;
#endif // NDEBUG
private:
friend class KeyedServiceBaseFactory;
// An ordered container of pointers to KeyedServiceBaseFactory. The order
// depends on the operation to perform (initialisation, destruction, ...).
using OrderedFactories =
std::vector<raw_ptr<KeyedServiceBaseFactory, VectorExperimental>>;
#ifndef NDEBUG
// Hook for subclass to dump the dependency graph of service for |context|.
virtual void DumpContextDependencies(void* context) const = 0;
#endif // NDEBUG
// Returns the list of factories in the order they should be initialised.
OrderedFactories GetConstructionOrder();
// Returns the list of factories in the order they should be destroyed.
OrderedFactories GetDestructionOrder();
// Invokes `ContextShutdown(context)` for all factories in the order
// specified by `factories`.
static void ShutdownFactoriesInOrder(void* context,
const OrderedFactories& factories);
// Invokes `ContextDestroyed(context)` for all factories in the order
// specified by `factories`.
static void DestroyFactoriesInOrder(void* context,
const OrderedFactories& factories);
DependencyGraph dependency_graph_;
// A list of context objects that have gone through the Shutdown() phase.
// These pointers are most likely invalid, but we keep track of their
// locations in memory so we can nicely assert if we're asked to do anything
// with them.
std::set<raw_ptr<void, SetExperimental>> dead_context_pointers_;
#if DCHECK_IS_ON()
#if BUILDFLAG(KEYED_SERVICE_HAS_TIGHT_REGISTRATION)
// Used to count the number of `context` that have been created. This is used
// to prevent registering KeyedServiceFactories while any context exist, while
// still allowing to register/unregister factories during unit tests.
size_t context_created_count_ = 0;
#else
// Used to record whether any `context` has been created. This is used
// to prevent registering KeyedServiceFactories after the creation of
// a context.
bool any_context_created_ = false;
#endif
#endif
bool disallow_factory_registration_ = false;
std::string registration_function_name_error_message_;
};
#endif // COMPONENTS_KEYED_SERVICE_CORE_DEPENDENCY_MANAGER_H_
|
