1 // 2 // Copyright (c) 2017 The Khronos Group Inc. 3 // 4 // Licensed under the Apache License, Version 2.0 (the "License"); 5 // you may not use this file except in compliance with the License. 6 // You may obtain a copy of the License at 7 // 8 // http://www.apache.org/licenses/LICENSE-2.0 9 // 10 // Unless required by applicable law or agreed to in writing, software 11 // distributed under the License is distributed on an "AS IS" BASIS, 12 // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 13 // See the License for the specific language governing permissions and 14 // limitations under the License. 15 // 16 #ifndef THREAD_POOL_H 17 #define THREAD_POOL_H 18 19 #if defined(__APPLE__) 20 #include <OpenCL/opencl.h> 21 #else 22 #include <CL/cl.h> 23 #endif 24 25 // 26 // An atomic add operator 27 cl_int ThreadPool_AtomicAdd(volatile cl_int *a, cl_int b); // returns old value 28 29 // Your function prototype 30 // 31 // A function pointer to the function you want to execute in a multithreaded 32 // context. No synchronization primitives are provided, other than the atomic 33 // add above. You may not call ThreadPool_Do from your function. 34 // ThreadPool_AtomicAdd() and GetThreadCount() should work, however. 35 // 36 // job ids and thread ids are 0 based. If number of jobs or threads was 8, they 37 // will numbered be 0 through 7. Note that while every job will be run, it is 38 // not guaranteed that every thread will wake up before the work is done. 39 typedef cl_int (*TPFuncPtr)(cl_uint /*job_id*/, cl_uint /* thread_id */, 40 void *userInfo); 41 42 // returns first non-zero result from func_ptr, or CL_SUCCESS if all are zero. 43 // Some workitems may not run if a non-zero result is returned from func_ptr(). 44 // This function may not be called from a TPFuncPtr. 45 cl_int ThreadPool_Do(TPFuncPtr func_ptr, cl_uint count, void *userInfo); 46 47 // Returns the number of worker threads that underlie the threadpool. The value 48 // passed as the TPFuncPtrs thread_id will be between 0 and this value less one, 49 // inclusive. This is safe to call from a TPFuncPtr. 50 cl_uint GetThreadCount(void); 51 52 // SetThreadCount() may be used to artifically set the number of worker threads 53 // If the value is 0 (the default) the number of threads will be determined 54 // based on the number of CPU cores. If it is a unicore machine, then 2 will be 55 // used, so that we still get some testing for thread safety. 56 // 57 // If count < 2 or the CL_TEST_SINGLE_THREADED environment variable is set then 58 // the code will run single threaded, but will report an error to indicate that 59 // the test is invalid. This option is intended for debugging purposes only. It 60 // is suggested as a convention that test apps set the thread count to 1 in 61 // response to the -m flag. 62 // 63 // SetThreadCount() must be called before the first call to GetThreadCount() or 64 // ThreadPool_Do(), otherwise the behavior is indefined. It may not be called 65 // from a TPFuncPtr. 66 void SetThreadCount(int count); 67 68 69 #endif /* THREAD_POOL_H */ 70