| // Copyright 2023 The Dawn & Tint Authors |
| // |
| // Redistribution and use in source and binary forms, with or without |
| // modification, are permitted provided that the following conditions are met: |
| // |
| // 1. Redistributions of source code must retain the above copyright notice, this |
| // list of conditions and the following disclaimer. |
| // |
| // 2. Redistributions in binary form must reproduce the above copyright notice, |
| // this list of conditions and the following disclaimer in the documentation |
| // and/or other materials provided with the distribution. |
| // |
| // 3. Neither the name of the copyright holder nor the names of its |
| // contributors may be used to endorse or promote products derived from |
| // this software without specific prior written permission. |
| // |
| // THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" |
| // AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE |
| // IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE |
| // DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE |
| // FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL |
| // DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR |
| // SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER |
| // CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, |
| // OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE |
| // OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. |
| |
| #include "dawn/native/SystemEvent.h" |
| #include <limits> |
| #include "dawn/common/Assert.h" |
| |
| #if DAWN_PLATFORM_IS(WINDOWS) |
| #include <windows.h> |
| #elif DAWN_PLATFORM_IS(POSIX) |
| #include <sys/poll.h> |
| #include <unistd.h> |
| #endif |
| |
| #include <tuple> |
| #include <utility> |
| #include <vector> |
| |
| #include "dawn/native/EventManager.h" |
| |
| namespace dawn::native { |
| |
| // SystemEventReceiver |
| |
| SystemEventReceiver::SystemEventReceiver(SystemHandle primitive) |
| : mPrimitive(std::move(primitive)) {} |
| |
| SystemEventReceiver SystemEventReceiver::CreateAlreadySignaled() { |
| SystemEventPipeSender sender; |
| SystemEventReceiver receiver; |
| std::tie(sender, receiver) = CreateSystemEventPipe(); |
| std::move(sender).Signal(); |
| return receiver; |
| } |
| |
| // SystemEventPipeSender |
| |
| SystemEventPipeSender::~SystemEventPipeSender() { |
| // Make sure it's been Signaled (or is empty) before being dropped. |
| // Dropping this would "leak" the receiver (it'll never get signalled). |
| DAWN_ASSERT(!mPrimitive.IsValid()); |
| } |
| |
| bool SystemEventPipeSender::IsValid() const { |
| return mPrimitive.IsValid(); |
| } |
| |
| void SystemEventPipeSender::Signal() && { |
| DAWN_ASSERT(mPrimitive.IsValid()); |
| #if DAWN_PLATFORM_IS(WINDOWS) |
| DAWN_CHECK(SetEvent(mPrimitive.Get())); |
| #elif DAWN_PLATFORM_IS(POSIX) |
| // Send one byte to signal the receiver |
| char zero[1] = {0}; |
| int status = write(mPrimitive.Get(), zero, 1); |
| DAWN_CHECK(status >= 0); |
| #else |
| // Not implemented for this platform. |
| DAWN_CHECK(false); |
| #endif |
| |
| mPrimitive.Close(); |
| } |
| |
| std::pair<SystemEventPipeSender, SystemEventReceiver> CreateSystemEventPipe() { |
| #if DAWN_PLATFORM_IS(WINDOWS) |
| HANDLE eventDup; |
| HANDLE event = CreateEvent(nullptr, /*bManualReset=*/true, /*bInitialState=*/false, nullptr); |
| |
| DAWN_CHECK(event != nullptr); |
| DAWN_CHECK(DuplicateHandle(GetCurrentProcess(), event, GetCurrentProcess(), &eventDup, 0, FALSE, |
| DUPLICATE_SAME_ACCESS)); |
| DAWN_CHECK(eventDup != nullptr); |
| |
| SystemEventReceiver receiver; |
| receiver.mPrimitive = SystemHandle::Acquire(event); |
| |
| SystemEventPipeSender sender; |
| sender.mPrimitive = SystemHandle::Acquire(eventDup); |
| |
| return std::make_pair(std::move(sender), std::move(receiver)); |
| #elif DAWN_PLATFORM_IS(POSIX) |
| int pipeFds[2]; |
| int status = pipe(pipeFds); |
| DAWN_CHECK(status >= 0); |
| |
| SystemEventReceiver receiver; |
| receiver.mPrimitive = SystemHandle::Acquire(pipeFds[0]); |
| |
| SystemEventPipeSender sender; |
| sender.mPrimitive = SystemHandle::Acquire(pipeFds[1]); |
| |
| return std::make_pair(std::move(sender), std::move(receiver)); |
| #else |
| // Not implemented for this platform. |
| DAWN_CHECK(false); |
| #endif |
| } |
| |
| // SystemEvent |
| |
| // static |
| Ref<SystemEvent> SystemEvent::CreateSignaled() { |
| auto ev = AcquireRef(new SystemEvent()); |
| ev->Signal(); |
| return ev; |
| } |
| |
| bool SystemEvent::IsSignaled() const { |
| return mSignaled.load(std::memory_order_acquire); |
| } |
| |
| void SystemEvent::Signal() { |
| if (!mSignaled.exchange(true, std::memory_order_acq_rel)) { |
| mPipe.Use([](auto pipe) { |
| // Check if there is a pipe and the sender is valid. |
| // This function may race with GetOrCreateSystemEventReceiver such that the pipe is |
| // already signaled and the sender is invalid. |
| if (*pipe && pipe->value().first.IsValid()) { |
| std::move(pipe->value().first).Signal(); |
| } |
| }); |
| } |
| } |
| |
| const SystemEventReceiver& SystemEvent::GetOrCreateSystemEventReceiver() { |
| return mPipe.Use([this](auto pipe) { |
| if (!*pipe) { |
| // Check whether the event was marked as completed. This may have happened if |
| // this function races with another thread performing Signal. If we won |
| // the race, then the pipe we just created will get signaled inside Signal. |
| // If we lost the race, then it will not be signaled and we must do it now. |
| if (IsSignaled()) { |
| *pipe = {SystemEventPipeSender{}, SystemEventReceiver::CreateAlreadySignaled()}; |
| } else { |
| *pipe = CreateSystemEventPipe(); |
| } |
| } |
| return std::cref(pipe->value().second); |
| }); |
| } |
| |
| } // namespace dawn::native |