Unfortunately lots of packages do set the systems timer resolution very high, e.g. A must read for those interested in timer coalescing: MSDN: Windows Timer Coalescing.įor performance reasons every effort should be made to reduce the amout of interrupts as The granularity of this scheme is determined by the interrupt frequency. Consequently, the events are coalesced with the interrupt. Anything set up to occurr at a specific time relies on a due time to expire with an interrut. Windows, as well as other interrupt based operating systems, has always "batched" timed events. the scheduler may have to schedule a large number of processes at this time (-).a bulk of of operations may have to be done at those batched interrupts (-).the number of context switches may be lower.the number of interrupts may be reduced.This allows the operating system to "batch" interrupts with a couple of consequences: Applications are allowed to specify a tolerance for their timing demands. Timer coalescing provides a way to reduce the number of interrupts. Does this parameter just change the global timer resolution like timeBeginPeriod does, for the duration of the timer event wait, or does it affect only this particular timer, providing also timer coalescing?įinally, are there any additional or alternative functions that provide timer coalescing under Windows XP or Vista? I can see that timeSetEvent available since XP has parameter called uResolution. Is that sentence correct for all Windows versions that support SetThreadpoolTimer function? It’s based on a technique called timer coalescing." "This is actually a feature that affects energy efficiency and helps reduce overall power consumption. Or does it only offer the interface and actually implements coalescing only since Windows 7?įrom "Thread Pool Timers and I/O" I can read that Is it so?įirst, is it correct that SetThreadpoolTimer available since Vista provides timer coalescing under Vista. But then it seems like it may have been implemented already earlier. So lots of talk about timer coalescing in Windows 7 and Windows 8. Windows 8 has additionally a function SetCoalescableTimer which supports coalescing according to MSDN. Windows 7 has a function SetWaitableTimerEx about which it is claimed that it supports coalescing here and here. There is timer coalescing support in Windows 7 and Windows 8, see for example this: Timer coalescing in.
0 Comments
Leave a Reply. |