xref: /aosp_15_r20/external/ComputeLibrary/arm_compute/runtime/OMP/OMPScheduler.h (revision c217d954acce2dbc11938adb493fc0abd69584f3)
1 /*
2  * Copyright (c) 2017-2021 Arm Limited.
3  *
4  * SPDX-License-Identifier: MIT
5  *
6  * Permission is hereby granted, free of charge, to any person obtaining a copy
7  * of this software and associated documentation files (the "Software"), to
8  * deal in the Software without restriction, including without limitation the
9  * rights to use, copy, modify, merge, publish, distribute, sublicense, and/or
10  * sell copies of the Software, and to permit persons to whom the Software is
11  * furnished to do so, subject to the following conditions:
12  *
13  * The above copyright notice and this permission notice shall be included in all
14  * copies or substantial portions of the Software.
15  *
16  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
17  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
18  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
19  * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
20  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
21  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
22  * SOFTWARE.
23  */
24 #ifndef ARM_COMPUTE_OMPSCHEDULER_H
25 #define ARM_COMPUTE_OMPSCHEDULER_H
26 
27 #include "arm_compute/runtime/IScheduler.h"
28 
29 namespace arm_compute
30 {
31 /** Pool of threads to automatically split a kernel's execution among several threads. */
32 class OMPScheduler final : public IScheduler
33 {
34 public:
35     /** Constructor. */
36     OMPScheduler();
37     /** Sets the number of threads the scheduler will use to run the kernels.
38      *
39      * @param[in] num_threads If set to 0, then the number returned by omp_get_max_threads() will be used, otherwise the number of threads specified.
40      */
41     void set_num_threads(unsigned int num_threads) override;
42     /** Returns the number of threads that the OMPScheduler has in its pool.
43      *
44      * @return Number of threads available in OMPScheduler.
45      */
46     unsigned int num_threads() const override;
47     /** Multithread the execution of the passed kernel if possible.
48      *
49      * The kernel will run on a single thread if any of these conditions is true:
50      * - ICPPKernel::is_parallelisable() returns false
51      * - The scheduler has been initialized with only one thread.
52      *
53      * @param[in] kernel Kernel to execute.
54      * @param[in] hints  Hints for the scheduler.
55      */
56     void schedule(ICPPKernel *kernel, const Hints &hints) override;
57 
58     /** Multithread the execution of the passed kernel if possible.
59      *
60      * The kernel will run on a single thread if any of these conditions is true:
61      * - ICPPKernel::is_parallelisable() returns false
62      * - The scheduler has been initialized with only one thread.
63      *
64      * @param[in] kernel  Kernel to execute.
65      * @param[in] hints   Hints for the scheduler.
66      * @param[in] window  Window to use for kernel execution.
67      * @param[in] tensors Vector containing the tensors to operate on.
68      */
69     void schedule_op(ICPPKernel *kernel, const Hints &hints, const Window &window, ITensorPack &tensors) override;
70 
71 protected:
72     /** Execute all the passed workloads
73      *
74      * @note there is no guarantee regarding the order in which the workloads will be executed or whether or not they will be executed in parallel.
75      *
76      * @param[in] workloads Array of workloads to run
77      */
78     void run_workloads(std::vector<Workload> &workloads) override;
79 
80 private:
81     unsigned int _num_threads;
82 };
83 } // namespace arm_compute
84 #endif /* ARM_COMPUTE_OMPSCHEDULER_H */
85