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_STREAM_EXECUTOR_RNG_H_ 17 #define TENSORFLOW_STREAM_EXECUTOR_RNG_H_ 18 19 #include <limits.h> 20 #include <complex> 21 22 #include "tensorflow/stream_executor/platform/logging.h" 23 #include "tensorflow/stream_executor/platform/port.h" 24 25 namespace stream_executor { 26 27 class Stream; 28 template <typename ElemT> 29 class DeviceMemory; 30 31 namespace rng { 32 33 // Random-number-generation support interface -- this can be derived from a GPU 34 // executor when the underlying platform has an RNG library implementation 35 // available. See StreamExecutor::AsRng(). 36 // When a seed is not specified, the backing RNG will be initialized with the 37 // default seed for that implementation. 38 // 39 // Thread-hostile: see StreamExecutor class comment for details on 40 // thread-hostility. 41 class RngSupport { 42 public: 43 static constexpr int kMinSeedBytes = 16; 44 static constexpr int kMaxSeedBytes = INT_MAX; 45 46 // Releases any random-number-generation resources associated with this 47 // support object in the underlying platform implementation. ~RngSupport()48 virtual ~RngSupport() {} 49 50 // Populates a GPU memory allocation with random values appropriate for the 51 // DeviceMemory element type; i.e. populates DeviceMemory<float> with random 52 // float values. 53 virtual bool DoPopulateRandUniform(Stream *stream, 54 DeviceMemory<float> *v) = 0; 55 virtual bool DoPopulateRandUniform(Stream *stream, 56 DeviceMemory<double> *v) = 0; 57 virtual bool DoPopulateRandUniform(Stream *stream, 58 DeviceMemory<std::complex<float>> *v) = 0; 59 virtual bool DoPopulateRandUniform(Stream *stream, 60 DeviceMemory<std::complex<double>> *v) = 0; 61 62 // Populates a GPU memory allocation with random values sampled from a 63 // Gaussian distribution with the given mean and standard deviation. DoPopulateRandGaussian(Stream * stream,float mean,float stddev,DeviceMemory<float> * v)64 virtual bool DoPopulateRandGaussian(Stream *stream, float mean, float stddev, 65 DeviceMemory<float> *v) { 66 LOG(ERROR) 67 << "platform's random number generator does not support gaussian"; 68 return false; 69 } DoPopulateRandGaussian(Stream * stream,double mean,double stddev,DeviceMemory<double> * v)70 virtual bool DoPopulateRandGaussian(Stream *stream, double mean, 71 double stddev, DeviceMemory<double> *v) { 72 LOG(ERROR) 73 << "platform's random number generator does not support gaussian"; 74 return false; 75 } 76 77 // Specifies the seed used to initialize the RNG. 78 // This call does not transfer ownership of the buffer seed; its data should 79 // not be altered for the lifetime of this call. At least 16 bytes of seed 80 // data must be provided, but not all seed data will necessarily be used. 81 // seed: Pointer to seed data. Must not be null. 82 // seed_bytes: Size of seed buffer in bytes. Must be >= 16. 83 virtual bool SetSeed(Stream *stream, const uint8 *seed, 84 uint64 seed_bytes) = 0; 85 86 protected: 87 static bool CheckSeed(const uint8 *seed, uint64 seed_bytes); 88 }; 89 90 } // namespace rng 91 } // namespace stream_executor 92 93 #endif // TENSORFLOW_STREAM_EXECUTOR_RNG_H_ 94