xref: /aosp_15_r20/external/tensorflow/tensorflow/core/framework/device_factory.h (revision b6fb3261f9314811a0f4371741dbb8839866f948)
1 /* Copyright 2015 The TensorFlow Authors. All Rights Reserved.
2 
3 Licensed under the Apache License, Version 2.0 (the "License");
4 you may not use this file except in compliance with the License.
5 You may obtain a copy of the License at
6 
7     http://www.apache.org/licenses/LICENSE-2.0
8 
9 Unless required by applicable law or agreed to in writing, software
10 distributed under the License is distributed on an "AS IS" BASIS,
11 WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
12 See the License for the specific language governing permissions and
13 limitations under the License.
14 ==============================================================================*/
15 
16 #ifndef TENSORFLOW_CORE_FRAMEWORK_DEVICE_FACTORY_H_
17 #define TENSORFLOW_CORE_FRAMEWORK_DEVICE_FACTORY_H_
18 
19 #include <string>
20 #include <vector>
21 
22 #include "absl/base/attributes.h"
23 #include "tensorflow/core/platform/status.h"
24 #include "tensorflow/core/platform/types.h"
25 
26 namespace tensorflow {
27 
28 class Device;
29 struct SessionOptions;
30 
31 class DeviceFactory {
32  public:
~DeviceFactory()33   virtual ~DeviceFactory() {}
34   static void Register(const std::string& device_type,
35                        std::unique_ptr<DeviceFactory> factory, int priority,
36                        bool is_pluggable_device);
37   ABSL_DEPRECATED("Use the `Register` function above instead")
Register(const std::string & device_type,DeviceFactory * factory,int priority,bool is_pluggable_device)38   static void Register(const std::string& device_type, DeviceFactory* factory,
39                        int priority, bool is_pluggable_device) {
40     Register(device_type, std::unique_ptr<DeviceFactory>(factory), priority,
41              is_pluggable_device);
42   }
43   static DeviceFactory* GetFactory(const std::string& device_type);
44 
45   // Append to "*devices" CPU devices.
46   static Status AddCpuDevices(const SessionOptions& options,
47                               const std::string& name_prefix,
48                               std::vector<std::unique_ptr<Device>>* devices);
49 
50   // Append to "*devices" all suitable devices, respecting
51   // any device type specific properties/counts listed in "options".
52   //
53   // CPU devices are added first.
54   static Status AddDevices(const SessionOptions& options,
55                            const std::string& name_prefix,
56                            std::vector<std::unique_ptr<Device>>* devices);
57 
58   // Helper for tests.  Create a single device of type "type".  The
59   // returned device is always numbered zero, so if creating multiple
60   // devices of the same type, supply distinct name_prefix arguments.
61   static std::unique_ptr<Device> NewDevice(const string& type,
62                                            const SessionOptions& options,
63                                            const string& name_prefix);
64 
65   // Iterate through all device factories and build a list of all of the
66   // possible physical devices.
67   //
68   // CPU is are added first.
69   static Status ListAllPhysicalDevices(std::vector<string>* devices);
70 
71   // Iterate through all device factories and build a list of all of the
72   // possible pluggable physical devices.
73   static Status ListPluggablePhysicalDevices(std::vector<string>* devices);
74 
75   // Get details for a specific device among all device factories.
76   // 'device_index' indexes into devices from ListAllPhysicalDevices.
77   static Status GetAnyDeviceDetails(
78       int device_index, std::unordered_map<string, string>* details);
79 
80   // For a specific device factory list all possible physical devices.
81   virtual Status ListPhysicalDevices(std::vector<string>* devices) = 0;
82 
83   // Get details for a specific device for a specific factory. Subclasses
84   // can store arbitrary device information in the map. 'device_index' indexes
85   // into devices from ListPhysicalDevices.
GetDeviceDetails(int device_index,std::unordered_map<string,string> * details)86   virtual Status GetDeviceDetails(int device_index,
87                                   std::unordered_map<string, string>* details) {
88     return OkStatus();
89   }
90 
91   // Most clients should call AddDevices() instead.
92   virtual Status CreateDevices(
93       const SessionOptions& options, const std::string& name_prefix,
94       std::vector<std::unique_ptr<Device>>* devices) = 0;
95 
96   // Return the device priority number for a "device_type" string.
97   //
98   // Higher number implies higher priority.
99   //
100   // In standard TensorFlow distributions, GPU device types are
101   // preferred over CPU, and by default, custom devices that don't set
102   // a custom priority during registration will be prioritized lower
103   // than CPU.  Custom devices that want a higher priority can set the
104   // 'priority' field when registering their device to something
105   // higher than the packaged devices.  See calls to
106   // REGISTER_LOCAL_DEVICE_FACTORY to see the existing priorities used
107   // for built-in devices.
108   static int32 DevicePriority(const std::string& device_type);
109 
110   // Returns true if 'device_type' is registered from plugin. Returns false if
111   // 'device_type' is a first-party device.
112   static bool IsPluggableDevice(const std::string& device_type);
113 };
114 
115 namespace dfactory {
116 
117 template <class Factory>
118 class Registrar {
119  public:
120   // Multiple registrations for the same device type with different priorities
121   // are allowed.  Priorities are used in two different ways:
122   //
123   // 1) When choosing which factory (that is, which device
124   //    implementation) to use for a specific 'device_type', the
125   //    factory registered with the highest priority will be chosen.
126   //    For example, if there are two registrations:
127   //
128   //      Registrar<CPUFactory1>("CPU", 125);
129   //      Registrar<CPUFactory2>("CPU", 150);
130   //
131   //    then CPUFactory2 will be chosen when
132   //    DeviceFactory::GetFactory("CPU") is called.
133   //
134   // 2) When choosing which 'device_type' is preferred over other
135   //    DeviceTypes in a DeviceSet, the ordering is determined
136   //    by the 'priority' set during registration.  For example, if there
137   //    are two registrations:
138   //
139   //      Registrar<CPUFactory>("CPU", 100);
140   //      Registrar<GPUFactory>("GPU", 200);
141   //
142   //    then DeviceType("GPU") will be prioritized higher than
143   //    DeviceType("CPU").
144   //
145   // The default priority values for built-in devices is:
146   // GPU: 210
147   // GPUCompatibleCPU: 70
148   // ThreadPoolDevice: 60
149   // Default: 50
150   explicit Registrar(const std::string& device_type, int priority = 50) {
151     DeviceFactory::Register(device_type, std::make_unique<Factory>(), priority,
152                             /*is_pluggable_device*/ false);
153   }
154 };
155 
156 }  // namespace dfactory
157 
158 #define REGISTER_LOCAL_DEVICE_FACTORY(device_type, device_factory, ...) \
159   INTERNAL_REGISTER_LOCAL_DEVICE_FACTORY(device_type, device_factory,   \
160                                          __COUNTER__, ##__VA_ARGS__)
161 
162 #define INTERNAL_REGISTER_LOCAL_DEVICE_FACTORY(device_type, device_factory, \
163                                                ctr, ...)                    \
164   static ::tensorflow::dfactory::Registrar<device_factory>                  \
165   INTERNAL_REGISTER_LOCAL_DEVICE_FACTORY_NAME(ctr)(device_type, ##__VA_ARGS__)
166 
167 // __COUNTER__ must go through another macro to be properly expanded
168 #define INTERNAL_REGISTER_LOCAL_DEVICE_FACTORY_NAME(ctr) ___##ctr##__object_
169 
170 }  // namespace tensorflow
171 
172 #endif  // TENSORFLOW_CORE_FRAMEWORK_DEVICE_FACTORY_H_
173