| 1 | /*++ |
| 2 | |
| 3 | Copyright (c) Microsoft. All rights reserved. |
| 4 | |
| 5 | Module Name: |
| 6 | |
| 7 | IORelay.cpp |
| 8 | |
| 9 | Abstract: |
| 10 | |
| 11 | Contains the implementation of the IORelay class. |
| 12 | |
| 13 | --*/ |
| 14 | |
| 15 | #include "IORelay.h" |
| 16 | |
| 17 | using wsl::windows::common::io::DockerIORelayHandle; |
| 18 | using wsl::windows::common::io::MultiHandleWait; |
| 19 | using wsl::windows::common::io::OverlappedIOHandle; |
| 20 | using wsl::windows::service::wslc::IORelay; |
| 21 | |
| 22 | IORelay::IORelay() |
| 23 | { |
| 24 | m_thread = std::thread([this]() { Run(); }); |
| 25 | } |
| 26 | |
| 27 | IORelay::~IORelay() |
| 28 | { |
| 29 | Stop(); |
| 30 | } |
| 31 | |
| 32 | void IORelay::AddHandle(std::unique_ptr<common::io::OverlappedIOHandle>&& Handle) |
| 33 | { |
| 34 | std::vector<std::unique_ptr<common::io::OverlappedIOHandle>> handles; |
| 35 | handles.emplace_back(std::move(Handle)); |
| 36 | |
| 37 | AddHandles(std::move(handles)); |
| 38 | } |
| 39 | |
| 40 | void IORelay::AddHandles(std::vector<std::unique_ptr<common::io::OverlappedIOHandle>>&& Handles) |
| 41 | { |
| 42 | WI_ASSERT(!m_exit); |
| 43 | |
| 44 | std::lock_guard lock(m_pendingHandlesLock); |
| 45 | |
| 46 | // Append the new handles |
| 47 | // N.B. IgnoreErrors is set so the IO doesn't stop on individual handle errors. |
| 48 | |
| 49 | for (auto& e : Handles) |
| 50 | { |
| 51 | WI_ASSERT(!!e); |
| 52 | m_pendingHandles.emplace_back(std::move(e)); |
| 53 | } |
| 54 | |
| 55 | // Restart the relay thread. |
| 56 | m_refreshEvent.SetEvent(); |
| 57 | } |
| 58 | |
| 59 | void IORelay::Stop() |
| 60 | { |
| 61 | m_exit = true; |
| 62 | m_refreshEvent.SetEvent(); |
| 63 | |
| 64 | // Skip join if called from the IORelay thread itself (e.g., from a handle callback). |
| 65 | if (m_thread.joinable() && m_thread.get_id() != std::this_thread::get_id()) |
| 66 | { |
| 67 | m_thread.join(); |
| 68 | } |
| 69 | } |
| 70 | |
| 71 | bool IORelay::IsRelayThread() const noexcept |
| 72 | { |
| 73 | return m_thread.get_id() == std::this_thread::get_id(); |
| 74 | } |
| 75 | |
| 76 | void IORelay::Run() |
| 77 | try |
| 78 | { |
| 79 | common::wslutil::SetThreadDescription(L"IORelay"); |
| 80 | |
| 81 | // Handle callbacks dispatched from this thread (e.g. unexpected VM exit) can tear the VM down, |
| 82 | // releasing cross-process COM proxies, so join the process MTA to avoid RPC_E_WRONG_THREAD. |
| 83 | const auto coInit = wil::CoInitializeEx(COINIT_MULTITHREADED); |
| 84 | |
| 85 | windows::common::io::MultiHandleWait io; |
| 86 | |
| 87 | // N.B. All the IO must happen on the thread. |
| 88 | // If the thread that scheduled the IO exits, the IO is cancelled. |
| 89 | while (!m_exit) |
| 90 | { |
| 91 | { |
| 92 | // Add any pending handles. |
| 93 | std::lock_guard lock(m_pendingHandlesLock); |
| 94 | for (auto& e : m_pendingHandles) |
| 95 | { |
| 96 | io.AddHandle(std::move(e), MultiHandleWait::IgnoreErrors); |
| 97 | } |
| 98 | |
| 99 | m_pendingHandles.clear(); |
| 100 | } |
| 101 | |
| 102 | io.AddHandle(std::make_unique<common::io::EventHandle>(m_refreshEvent.get()), MultiHandleWait::CancelOnCompleted); |
| 103 | io.Run({}); |
| 104 | } |
| 105 | } |
| 106 | CATCH_LOG(); |