diff options
author | Stanislaw Halik <sthalik@misaki.pl> | 2017-05-01 10:59:19 +0200 |
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committer | Stanislaw Halik <sthalik@misaki.pl> | 2017-05-02 23:19:38 +0200 |
commit | aaa3a04577a7d4633ef0eb9eb7dc2aa33db0d0eb (patch) | |
tree | d83709d246b390c7279720105f2269fb2b373259 | |
parent | 81d11949122c63feb14e6595fc59e49cd264c89e (diff) |
compat/timer-resolution: use undocumented windows API
Unlike timeBeginPeriod in winmm, this one sets the timer
resolution for the calling process, only.
-rw-r--r-- | compat/timer-resolution.cpp | 103 | ||||
-rw-r--r-- | compat/timer-resolution.hpp | 19 | ||||
-rw-r--r-- | logic/tracker.cpp | 3 |
3 files changed, 125 insertions, 0 deletions
diff --git a/compat/timer-resolution.cpp b/compat/timer-resolution.cpp new file mode 100644 index 00000000..597ee91e --- /dev/null +++ b/compat/timer-resolution.cpp @@ -0,0 +1,103 @@ +/* Copyright (c) 2017 Stanislaw Halik <sthalik@misaki.pl> + * + * Permission to use, copy, modify, and/or distribute this software for any + * purpose with or without fee is hereby granted, provided that the above + * copyright notice and this permission notice appear in all copies. + */ + +#include "timer-resolution.hpp" + +#if defined _WIN32 +# include <windows.h> + +# include <QLibrary> +# include <QDebug> + +typedef LONG (__stdcall *funptr_NtSetTimerResolution) (ULONG, BOOLEAN, PULONG); +static funptr_NtSetTimerResolution init_timer_resolution_funptr(); +static funptr_NtSetTimerResolution get_funptr(); + +static funptr_NtSetTimerResolution init_timer_resolution_funptr() +{ + static QLibrary ntdll; + ntdll.setLoadHints(QLibrary::PreventUnloadHint); + ntdll.setFileName("ntdll.dll"); + const bool load = ntdll.load(); + if (!load) + { + qDebug() << "can't load ntdll:" << ntdll.errorString(); + return nullptr; + } + + auto ret = reinterpret_cast<funptr_NtSetTimerResolution>(ntdll.resolve("NtSetTimerResolution")); + if (ret == nullptr) + { + qDebug() << "can't find NtSetTimerResolution in ntdll:" << ntdll.errorString(); + return nullptr; + } + + return ret; +} + +static funptr_NtSetTimerResolution get_funptr() +{ + static auto ret = init_timer_resolution_funptr(); + return ret; +} + +timer_resolution::timer_resolution(int msecs) : old_value(-1) +{ + if (msecs <= 0 || msecs > 30) + { + qDebug() << "can't set timer resolution to" << msecs << "ms"; + return; + } + + funptr_NtSetTimerResolution f = get_funptr(); + if (f == nullptr) + return; + + // hundredth of a nanosecond + const ULONG value = msecs * ULONG(10000); + NTSTATUS error = f(value, TRUE, &old_value); + ULONG old_value_ = -1; + + if (error != 0) + { + old_value = -1; + qDebug() << "NtSetTimerResolution erred with" << error; + return; + } + + // see if it stuck + + error = f(value, TRUE, &old_value_); + if (error != 0) + { + old_value = -1; + qDebug() << "NtSetTimerResolution check erred with" << error; + return; + } + + if (old_value_ != old_value) + { + qDebug() << "NtSetTimerResolution:" + << "old value didn't stick" + << "current resolution" << old_value_ + << "* 100 ns"; + old_value = -1; + return; + } +} + +timer_resolution::~timer_resolution() +{ + if (old_value != ULONG(-1)) + { + funptr_NtSetTimerResolution f = get_funptr(); + ULONG fuzz = -1; + (void) f(old_value, TRUE, &fuzz); + } +} + +#endif diff --git a/compat/timer-resolution.hpp b/compat/timer-resolution.hpp new file mode 100644 index 00000000..5db877c0 --- /dev/null +++ b/compat/timer-resolution.hpp @@ -0,0 +1,19 @@ +#pragma once + +#if defined _WIN32 +# include "export.hpp" + +class OTR_COMPAT_EXPORT timer_resolution final +{ + unsigned long old_value; + +public: + timer_resolution(int msecs); + ~timer_resolution(); +}; +#else +struct timer_resolution final +{ + inline timer_resolution(int) {} +}; +#endif diff --git a/logic/tracker.cpp b/logic/tracker.cpp index 3ba81af7..7411d3b4 100644 --- a/logic/tracker.cpp +++ b/logic/tracker.cpp @@ -14,6 +14,7 @@ #include "compat/sleep.hpp" #include "compat/util.hpp" +#include "compat/timer-resolution.hpp" #include "tracker.h" @@ -376,6 +377,8 @@ void Tracker::run() { setPriority(QThread::HighPriority); + timer_resolution res(1); + { static constexpr const char* posechannels[6] = { "TX", "TY", "TZ", "Yaw", "Pitch", "Roll" }; static constexpr const char* datachannels[5] = { "dt", "raw", "corrected", "filtered", "mapped" }; |