[Mono-list] NetworkStream.Read latency

[Jay L. T. Cornwall]

Hi,

I've run into an odd problem in a streaming TV application that I'm 
building. I have a client and server on the same machine with the server 
sending data as fast as Socket.Send() allows. The client uses 
NetworkStream.Read() to retrieve data on-demand.

Occasionally the client will underrun a quite sizable buffer set aside 
to smooth out gaps in network delivery. Here's a sample from when that 
occurs:

Read 2048 bytes took 00:00:00.0000810
Read 2048 bytes took 00:00:00.0000570
Read 2048 bytes took 00:00:00.0000650
Read 2048 bytes took 00:00:00.0000630
Read 2048 bytes took 00:00:00.0000550
Read 2048 bytes took 00:00:00.0000650
Read 2048 bytes took 00:00:00.0000620
Read 2048 bytes took 00:00:00.0990950
Read 2048 bytes took 00:00:00.0001190
Read 2048 bytes took 00:00:00.0000670
Read 2048 bytes took 00:00:00.0996880
Read 2048 bytes took 00:00:00.0001030
Read 2048 bytes took 00:00:00.0000700

There are small expected fluctuations in recv() latency across all of 
the reads, but notice the two at suspiciously close to 0.1s. I added 
timings probes to mono/metadata/socket-io.c to measure the 
Socket_Receive_internal call and it showed no significant correlating 
spike in latency, so I must assume this spike is being introduced 
elsewhere in the Mono runtime.

Might there be an obvious cause of this? The spikes are always so close 
to 0.1s that it cannot be coincidental.

-- 
Jay L. T. Cornwall
http://www.jcornwall.me.uk/