1/*
2 * Copyright (c) 2014-2017 Advanced Micro Devices, Inc.
3 * All rights reserved.
4 *
5 * For use for simulation and test purposes only
6 *
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions are met:
9 *
10 * 1. Redistributions of source code must retain the above copyright notice,
11 * this list of conditions and the following disclaimer.
12 *
13 * 2. Redistributions in binary form must reproduce the above copyright notice,
14 * this list of conditions and the following disclaimer in the documentation
15 * and/or other materials provided with the distribution.
16 *
17 * 3. Neither the name of the copyright holder nor the names of its
18 * contributors may be used to endorse or promote products derived from this
19 * software without specific prior written permission.
20 *
21 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
22 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
23 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
24 * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
25 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
26 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
27 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
28 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
29 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
30 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
31 * POSSIBILITY OF SUCH DAMAGE.
32 *
33 * Authors: Sooraj Puthoor,
34 *          Anthony Gutierrez
35 */
36
37#ifndef __GPU_COMPUTE_RR_SCHEDULING_POLICY_HH__
38#define __GPU_COMPUTE_RR_SCHEDULING_POLICY_HH__
39
40#include <vector>
41
42#include "gpu-compute/scheduling_policy.hh"
43#include "gpu-compute/wavefront.hh"
44
45// round-robin pick among the list of ready waves
46class RRSchedulingPolicy final : public __SchedulingPolicy<RRSchedulingPolicy>
47{
48  public:
49    RRSchedulingPolicy()
50    {
51    }
52
53    static Wavefront*
54    __chooseWave(std::vector<Wavefront*> *sched_list)
55    {
56        panic_if(!sched_list->size(), "RR scheduling policy sched list is "
57            "empty.\n");
58        Wavefront *selected_wave(nullptr);
59
60        /**
61         * For RR policy, select the wave that is at the front of
62         * the list. The selected wave is popped out from the schedule
63         * list immediately after selection to avoid starvation. It
64         * is the responsibility of the module invoking the RR scheduler
65         * to make sure it is scheduling eligible waves are added to the
66         * back of the schedule list.
67         */
68        selected_wave = sched_list->front();
69        panic_if(!selected_wave, "No wave found by RR scheduling policy.\n");
70        sched_list->erase(sched_list->begin());
71
72        return selected_wave;
73    }
74};
75
76#endif // __GPU_COMPUTE_RR_SCHEDULING_POLICY_HH__
77