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Added coalesced timer support to Windows where that API is available. Tolerable delay is set to the maximum of 5% of interval or 32 ms.

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This commit is contained in:
Niall Douglas (s [underscore] sourceforge {at} nedprod [dot] com)
2015-02-04 13:58:11 +00:00
parent 095b53b2a2
commit 401f69f108
4 changed files with 64 additions and 43 deletions
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95
src/win32/thread.cpp
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@@ -634,7 +634,36 @@ namespace boost
}
}
#ifndef UNDER_CE
#if !BOOST_PLAT_WINDOWS_RUNTIME
namespace detail_
{
typedef BOOL (WINAPI *setwaitabletimerex_t)(HANDLE, const LARGE_INTEGER *, LONG, PTIMERAPCROUTINE, LPVOID, PREASON_CONTEXT, ULONG);
static inline BOOL WINAPI SetWaitableTimerEx_emulation(HANDLE hTimer, const LARGE_INTEGER *lpDueTime, LONG lPeriod, PTIMERAPCROUTINE pfnCompletionRoutine, LPVOID lpArgToCompletionRoutine, PREASON_CONTEXT WakeContext, ULONG TolerableDelay)
{
return SetWaitableTimer(hTimer, lpDueTime, lPeriod, pfnCompletionRoutine, lpArgToCompletionRoutine, FALSE);
}
static inline setwaitabletimerex_t SetWaitableTimerEx()
{
static setwaitabletimerex_t setwaitabletimerex_impl;
if(setwaitabletimerex_impl)
return setwaitabletimerex_impl;
void *addr=(void *) GetProcAddress(
#if !defined(BOOST_NO_ANSI_APIS)
GetModuleHandleA("KERNEL32.DLL"),
#else
GetModuleHandleW(L"KERNEL32.DLL"),
#endif
"SetWaitableTimerEx");
if(addr)
setwaitabletimerex_impl=(setwaitabletimerex_t) addr;
else
setwaitabletimerex_impl=&SetWaitableTimerEx_emulation;
return setwaitabletimerex_impl;
}
}
#endif
#endif
bool interruptible_wait(detail::win32::handle handle_to_wait_for,detail::timeout target_time)
{
detail::win32::handle handles[4]={0};
@@ -660,32 +689,26 @@ namespace boost
#ifndef UNDER_CE
#if !BOOST_PLAT_WINDOWS_RUNTIME
unsigned const min_timer_wait_period=20;
// Preferentially use coalescing timers for better power consumption and timer accuracy
if(!target_time.is_sentinel())
{
detail::timeout::remaining_time const time_left=target_time.remaining_milliseconds();
if(time_left.milliseconds > min_timer_wait_period)
timer_handle=CreateWaitableTimer(NULL,false,NULL);
if(timer_handle!=0)
{
// for a long-enough timeout, use a waitable timer (which tracks clock changes)
timer_handle=CreateWaitableTimer(NULL,false,NULL);
if(timer_handle!=0)
REASON_CONTEXT rc={POWER_REQUEST_CONTEXT_VERSION, POWER_REQUEST_CONTEXT_SIMPLE_STRING};
rc.Reason.SimpleReasonString=(LPWSTR)L"generic";
ULONG tolerable=32; // Empirical testing shows Windows ignores this when <= 26
if(time_left.milliseconds/20>tolerable) // 5%
tolerable=time_left.milliseconds/20;
LARGE_INTEGER due_time=get_due_time(target_time);
bool const set_time_succeeded=detail_::SetWaitableTimerEx()(timer_handle,&due_time,0,0,0,&rc,tolerable)!=0;
if(set_time_succeeded)
{
LARGE_INTEGER due_time=get_due_time(target_time);
bool const set_time_succeeded=SetWaitableTimer(timer_handle,&due_time,0,0,0,false)!=0;
if(set_time_succeeded)
{
timeout_index=handle_count;
handles[handle_count++]=timer_handle;
}
timeout_index=handle_count;
handles[handle_count++]=timer_handle;
}
}
else if(!target_time.relative)
{
// convert short absolute-time timeouts into relative ones, so we don't race against clock changes
target_time=detail::timeout(time_left.milliseconds);
}
}
#endif
#endif
@@ -752,32 +775,26 @@ namespace boost
#ifndef UNDER_CE
#if !BOOST_PLAT_WINDOWS_RUNTIME
unsigned const min_timer_wait_period=20;
// Preferentially use coalescing timers for better power consumption and timer accuracy
if(!target_time.is_sentinel())
{
detail::timeout::remaining_time const time_left=target_time.remaining_milliseconds();
if(time_left.milliseconds > min_timer_wait_period)
timer_handle=CreateWaitableTimer(NULL,false,NULL);
if(timer_handle!=0)
{
// for a long-enough timeout, use a waitable timer (which tracks clock changes)
timer_handle=CreateWaitableTimer(NULL,false,NULL);
if(timer_handle!=0)
REASON_CONTEXT rc={POWER_REQUEST_CONTEXT_VERSION, POWER_REQUEST_CONTEXT_SIMPLE_STRING};
rc.Reason.SimpleReasonString=(LPWSTR)L"generic";
ULONG tolerable=32; // Empirical testing shows Windows ignores this when <= 26
if(time_left.milliseconds/20>tolerable) // 5%
tolerable=time_left.milliseconds/20;
LARGE_INTEGER due_time=get_due_time(target_time);
bool const set_time_succeeded=detail_::SetWaitableTimerEx()(timer_handle,&due_time,0,0,0,&rc,tolerable)!=0;
if(set_time_succeeded)
{
LARGE_INTEGER due_time=get_due_time(target_time);
bool const set_time_succeeded=SetWaitableTimer(timer_handle,&due_time,0,0,0,false)!=0;
if(set_time_succeeded)
{
timeout_index=handle_count;
handles[handle_count++]=timer_handle;
}
timeout_index=handle_count;
handles[handle_count++]=timer_handle;
}
}
else if(!target_time.relative)
{
// convert short absolute-time timeouts into relative ones, so we don't race against clock changes
target_time=detail::timeout(time_left.milliseconds);
}
}
#endif
#endif