drivers/gpu/msd-intel-gen/src/scheduler.cc

// Copyright 2017 The Fuchsia Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#include "scheduler.h"
#include "msd_intel_connection.h"
#include "msd_intel_context.h"
#include "platform_trace.h"

class FifoScheduler : public Scheduler {
public:
    FifoScheduler() : gpu_vthread_id_(TRACE_NONCE()) {}

    void CommandBufferQueued(std::weak_ptr<MsdIntelContext> context) override;
    void CommandBufferCompleted(std::shared_ptr<MsdIntelContext> context) override;

    std::shared_ptr<MsdIntelContext> ScheduleContext() override;

private:
    std::queue<std::weak_ptr<MsdIntelContext>> fifo_;
    std::shared_ptr<MsdIntelContext> current_context_;
    uint32_t current_count_{};
    const uint64_t gpu_vthread_id_;
};

void FifoScheduler::CommandBufferQueued(std::weak_ptr<MsdIntelContext> context)
{
    fifo_.push(context);
}

std::shared_ptr<MsdIntelContext> FifoScheduler::ScheduleContext()
{
    std::shared_ptr<MsdIntelContext> context;

    while (!context) {
        if (fifo_.empty())
            return nullptr;

        context = fifo_.front().lock();
        if (!context) {
            fifo_.pop();
            continue;
        }

        if (context->killed()) {
            DLOG("context killed");
            fifo_.pop();
            context = nullptr;
        }
    }

    if (current_context_ == nullptr || current_context_ == context) {
        if (current_context_ == nullptr) {
            auto connection = context->connection().lock();
            uint64_t current_id = connection ? connection->client_id() : 0;
            uint64_t current_ticks = magma::PlatformTrace::GetCurrentTicks();

            TRACE_VTHREAD_DURATION_BEGIN("magma", "Context Exec", "GPU", gpu_vthread_id_,
                                         current_ticks, "id", current_id);
        }

        fifo_.pop();
        current_context_ = context;
        current_count_++;
        return context;
    }

    return nullptr;
}

void FifoScheduler::CommandBufferCompleted(std::shared_ptr<MsdIntelContext> context)
{
    DASSERT(current_count_);
    if (--current_count_ == 0) {
        auto connection = context->connection().lock();
        uint64_t current_id = connection ? connection->client_id() : 0;
        uint64_t current_ticks = magma::PlatformTrace::GetCurrentTicks();

        TRACE_VTHREAD_DURATION_END("magma", "Context Exec", "GPU", gpu_vthread_id_, current_ticks,
                                   "id", current_id);
        current_context_.reset();
    }
}

//////////////////////////////////////////////////////////////////////////////////////////////////

std::unique_ptr<Scheduler> Scheduler::CreateFifoScheduler()
{
    return std::make_unique<FifoScheduler>();
}