Monitor.TryEnter waittime?

[Rainer Queck]

Hello NG,

is there a possibillity to determine how long a thread had to wait on
Monitor.TryEnter(lockObj,timeout) ?

Thanks for hints.
Rainer Queck

 

[Jon Skeet [C# MVP]]

is there a possibillity to determine how long a thread had to wait on
Monitor.TryEnter(lockObj,timeout) ?

Only by timing it - e.g. using the Stopwatch class.

Jon

 

[Chris Shepherd]

Hello NG,

is there a possibillity to determine how long a thread had to wait on
Monitor.TryEnter(lockObj,timeout) ?

You could take a snapshot of DateTime.Now both before and after it
acquires the lock, subtract them and interrogate the resulting TimeSpan:

DateTime startAcquire = DateTime.Now;
Monitor.TryEnter(lockObj,timeout);
DateTime endAcquire = DateTime.Now;

TimeSpan waitTime = endAcquire - startAcquire;


Chris.

 

[Rainer Queck]

Hi Jon, Hi Chris,

but would it be impossible to determine who does the StopWatch.Reset/Start
(or DateTime.Now) and who reads it?

Excample

StopWatch.Reset();
StopWatch.Start();
if(Monitor.TryEnter(lockObj,timeout) )
{
long ticks = StopWatch.ElapsedTicks();
DoTimeConsumingAccessToResource();
}

lets assume
thread1 comes. No Problem
while thread 1 is still working inside thread two come and has to wait.
Still no problem
BUT now it thread3 comes allong thread 1 is STILL working, it will do a
reset of the StopWatch before it starts waiting, won't it?
Now if thread2 can enter, ticks will have a wrong value true?

Regards
Rainer

 

[Jon Skeet [C# MVP]]

but would it be impossible to determine who does the StopWatch.Reset/Start
(or DateTime.Now) and who reads it?

You'd create a separate Stopwatch for that particular call - only that
thread would even know about it.

Jon

 

[Rainer Queck]

Thanks for that hint.
I wasn't sure that local vars are "on the stack".

Regards
Rainer