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High-res timers for Windows with IOCP support #1685

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11 changes: 11 additions & 0 deletions include/asio/detail/config.hpp
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Original file line number Diff line number Diff line change
Expand Up @@ -809,6 +809,17 @@
# endif // defined(ASIO_WINDOWS) || defined(__CYGWIN__)
#endif // !defined(ASIO_HAS_IOCP)

#if !defined(ASIO_HAS_IOCP_HIRES_TIMERS)
# if defined(ASIO_HAS_IOCP)
# include <sdkddkver.h>
# if defined(NTDDI_VERSION) && (NTDDI_VERSION >= NTDDI_WIN10_RS4)
# if defined(ASIO_ENABLE_IOCP_HIRES_TIMERS)
# define ASIO_HAS_IOCP_HIRES_TIMERS 1
# endif // defined(ASIO_ENABLE_IOCP_HIRES_TIMERS)
# endif // defined(NTDDI_VERSION) && (NTDDI_VERSION >= NTDDI_WIN10_RS4)
# endif // defined(ASIO_HAS_IOCP)
#endif // !defined(ASIO_HAS_IOCP_HIRES_TIMERS)

// On POSIX (and POSIX-like) platforms we need to include unistd.h in order to
// get access to the various platform feature macros, e.g. to be able to test
// for threads support.
Expand Down
98 changes: 98 additions & 0 deletions include/asio/detail/impl/win_iocp_io_context.ipp
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Original file line number Diff line number Diff line change
Expand Up @@ -30,6 +30,10 @@

#include "asio/detail/push_options.hpp"

#if defined(ASIO_HAS_IOCP_HIRES_TIMERS)
#include <winternl.h>
#endif // defined(ASIO_HAS_IOCP_HIRES_TIMERS)

namespace asio {
namespace detail {

Expand Down Expand Up @@ -59,6 +63,7 @@ struct win_iocp_io_context::work_finished_on_block_exit
win_iocp_io_context* io_context_;
};

#if !defined(ASIO_HAS_IOCP_HIRES_TIMERS)
struct win_iocp_io_context::timer_thread_function
{
void operator()()
Expand All @@ -77,6 +82,7 @@ struct win_iocp_io_context::timer_thread_function

win_iocp_io_context* io_context_;
};
#endif // !defined(ASIO_HAS_IOCP_HIRES_TIMERS)

win_iocp_io_context::win_iocp_io_context(
asio::execution_context& ctx, bool own_thread)
Expand All @@ -103,6 +109,51 @@ win_iocp_io_context::win_iocp_io_context(
asio::detail::throw_error(ec, "iocp");
}

#if defined(ASIO_HAS_IOCP_HIRES_TIMERS)
if (FARPROC nt_create_wait_completion_packet_ptr = ::GetProcAddress(
::GetModuleHandleA("NTDLL"), "NtCreateWaitCompletionPacket"))
{
NtCreateWaitCompletionPacket_ =
reinterpret_cast<NtCreateWaitCompletionPacket_fn>(
reinterpret_cast<void*>(nt_create_wait_completion_packet_ptr));
}
else
{
DWORD last_error = ::GetLastError();
asio::error_code ec(last_error,
asio::error::get_system_category());
asio::detail::throw_error(ec, "timer");
}

if (FARPROC nt_associate_wait_completion_packet_ptr = ::GetProcAddress(
::GetModuleHandleA("NTDLL"), "NtAssociateWaitCompletionPacket")) {
NtAssociateWaitCompletionPacket_ =
reinterpret_cast<NtAssociateWaitCompletionPacket_fn>(
reinterpret_cast<void*>(nt_associate_wait_completion_packet_ptr));
}
else
{
DWORD last_error = ::GetLastError();
asio::error_code ec(last_error,
asio::error::get_system_category());
asio::detail::throw_error(ec, "timer");
}

if (FARPROC rtl_nt_status_to_dos_error_ptr = ::GetProcAddress(
::GetModuleHandleA("NTDLL"), "RtlNtStatusToDosError")) {
RtlNtStatusToDosError_ =
reinterpret_cast<RtlNtStatusToDosError_fn>(
reinterpret_cast<void*>(rtl_nt_status_to_dos_error_ptr));
}
else
{
DWORD last_error = ::GetLastError();
asio::error_code ec(last_error,
asio::error::get_system_category());
asio::detail::throw_error(ec, "timer");
}
#endif // defined(ASIO_HAS_IOCP_HIRES_TIMERS)

if (own_thread)
{
::InterlockedIncrement(&outstanding_work_);
Expand Down Expand Up @@ -149,12 +200,14 @@ void win_iocp_io_context::shutdown()
{
::InterlockedExchange(&shutdown_, 1);

#if !defined(ASIO_HAS_IOCP_HIRES_TIMERS)
if (timer_thread_.joinable())
{
LARGE_INTEGER timeout;
timeout.QuadPart = 1;
::SetWaitableTimer(waitable_timer_.handle, &timeout, 1, 0, 0, FALSE);
}
#endif // !defined(ASIO_HAS_IOCP_HIRES_TIMERS)

if (thread_.joinable())
{
Expand Down Expand Up @@ -192,7 +245,9 @@ void win_iocp_io_context::shutdown()
}
}

#if !defined(ASIO_HAS_IOCP_HIRES_TIMERS)
timer_thread_.join();
#endif // !defined(ASIO_HAS_IOCP_HIRES_TIMERS)
}

asio::error_code win_iocp_io_context::register_handle(
Expand Down Expand Up @@ -520,6 +575,10 @@ size_t win_iocp_io_context::do_one(DWORD msec,
{
// We have been woken up to try to acquire responsibility for dispatching
// timers and completed operations.
#if defined(ASIO_HAS_IOCP_HIRES_TIMERS)
mutex::scoped_lock lock(dispatch_mutex_);
::InterlockedExchange(&dispatch_required_, 1);
#endif // defined(ASIO_HAS_IOCP_HIRES_TIMERS)
}
else
{
Expand Down Expand Up @@ -575,9 +634,26 @@ void win_iocp_io_context::do_add_timer_queue(timer_queue_base& queue)

timer_queues_.insert(&queue);

#if defined(ASIO_HAS_IOCP_HIRES_TIMERS)
if (!iocp_wait_handle_.handle)
{
NTSTATUS status = NtCreateWaitCompletionPacket_(&iocp_wait_handle_.handle, GENERIC_ALL, 0);
if (!NT_SUCCESS(status) || (iocp_wait_handle_.handle == 0)) {
DWORD win32_error = RtlNtStatusToDosError_(status);
asio::error_code ec(win32_error, asio::error::get_system_category());
asio::detail::throw_error(ec, "timer");
}
}
#endif // defined(ASIO_HAS_IOCP_HIRES_TIMERS)

if (!waitable_timer_.handle)
{
#if defined(ASIO_HAS_IOCP_HIRES_TIMERS)
waitable_timer_.handle = ::CreateWaitableTimerExW(
0, 0, CREATE_WAITABLE_TIMER_HIGH_RESOLUTION, SYNCHRONIZE | TIMER_MODIFY_STATE);
#else
waitable_timer_.handle = ::CreateWaitableTimer(0, FALSE, 0);
#endif // defined(ASIO_HAS_IOCP_HIRES_TIMERS)
if (waitable_timer_.handle == 0)
{
DWORD last_error = ::GetLastError();
Expand All @@ -591,13 +667,25 @@ void win_iocp_io_context::do_add_timer_queue(timer_queue_base& queue)
timeout.QuadPart *= 10;
::SetWaitableTimer(waitable_timer_.handle,
&timeout, max_timeout_msec, 0, 0, FALSE);
#if defined(ASIO_HAS_IOCP_HIRES_TIMERS)
NTSTATUS status = NtAssociateWaitCompletionPacket_(iocp_wait_handle_.handle, iocp_.handle,
waitable_timer_.handle, (PVOID)wake_for_dispatch,
0, 0, 0, 0);
if (!NT_SUCCESS(status)) {
DWORD win32_error = RtlNtStatusToDosError_(status);
asio::error_code ec(win32_error, asio::error::get_system_category());
asio::detail::throw_error(ec, "timer");
}
#endif // defined(ASIO_HAS_IOCP_HIRES_TIMERS)
}

#if !defined(ASIO_HAS_IOCP_HIRES_TIMERS)
if (!timer_thread_.joinable())
{
timer_thread_function thread_function = { this };
timer_thread_ = thread(thread_function, 65536);
}
#endif // !defined(ASIO_HAS_IOCP_HIRES_TIMERS)
}

void win_iocp_io_context::do_remove_timer_queue(timer_queue_base& queue)
Expand All @@ -609,8 +697,11 @@ void win_iocp_io_context::do_remove_timer_queue(timer_queue_base& queue)

void win_iocp_io_context::update_timeout()
{

#if !defined(ASIO_HAS_IOCP_HIRES_TIMERS)
if (timer_thread_.joinable())
{
#endif // !defined(ASIO_HAS_IOCP_HIRES_TIMERS)
// There's no point updating the waitable timer if the new timeout period
// exceeds the maximum timeout. In that case, we might as well wait for the
// existing period of the timer to expire.
Expand All @@ -622,8 +713,15 @@ void win_iocp_io_context::update_timeout()
timeout.QuadPart *= 10;
::SetWaitableTimer(waitable_timer_.handle,
&timeout, max_timeout_msec, 0, 0, FALSE);
#if defined(ASIO_HAS_IOCP_HIRES_TIMERS)
NtAssociateWaitCompletionPacket_(iocp_wait_handle_.handle, iocp_.handle,
waitable_timer_.handle,
(PVOID)wake_for_dispatch, 0, 0, 0, 0);
#endif // defined(ASIO_HAS_IOCP_HIRES_TIMERS)
}
#if !defined(ASIO_HAS_IOCP_HIRES_TIMERS)
}
#endif // !defined(ASIO_HAS_IOCP_HIRES_TIMERS)
}

} // namespace detail
Expand Down
22 changes: 22 additions & 0 deletions include/asio/detail/win_iocp_io_context.hpp
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Original file line number Diff line number Diff line change
Expand Up @@ -224,6 +224,18 @@ class win_iocp_io_context
typedef ULONG_PTR ulong_ptr_t;
#endif // defined(WINVER) && (WINVER < 0x0500)

#if defined(ASIO_HAS_IOCP_HIRES_TIMERS)
typedef LONG(NTAPI* NtCreateWaitCompletionPacket_fn)(PHANDLE, ACCESS_MASK, PVOID);

typedef LONG(NTAPI* NtAssociateWaitCompletionPacket_fn)(
HANDLE WaitCompletionPacketHandle, HANDLE IoCompletionHandle,
HANDLE TargetObjectHandle, PVOID KeyContext,
PVOID ApcContext, LONG IoStatus,
ULONG_PTR IoStatusInformation, PBOOLEAN AlreadySignaled);

typedef ULONG(NTAPI* RtlNtStatusToDosError_fn)(LONG Status);
#endif // defined(ASIO_HAS_IOCP_HIRES_TIMERS)

// Dequeues at most one operation from the I/O completion port, and then
// executes it. Returns the number of operations that were dequeued (i.e.
// either 0 or 1).
Expand Down Expand Up @@ -303,16 +315,26 @@ class win_iocp_io_context
struct thread_function;
friend struct thread_function;

#if !defined(ASIO_HAS_IOCP_HIRES_TIMERS)
// Function object for processing timeouts in a background thread.
struct timer_thread_function;
friend struct timer_thread_function;

// Background thread used for processing timeouts.
asio::detail::thread timer_thread_;
#endif // !defined(ASIO_HAS_IOCP_HIRES_TIMERS)

// A waitable timer object used for waiting for timeouts.
auto_handle waitable_timer_;

#if defined(ASIO_HAS_IOCP_HIRES_TIMERS)
auto_handle iocp_wait_handle_;

NtCreateWaitCompletionPacket_fn NtCreateWaitCompletionPacket_;
NtAssociateWaitCompletionPacket_fn NtAssociateWaitCompletionPacket_;
RtlNtStatusToDosError_fn RtlNtStatusToDosError_;
#endif // defined(ASIO_HAS_IOCP_HIRES_TIMERS)

// Non-zero if timers or completed operations need to be dispatched.
long dispatch_required_;

Expand Down