[TS-4260] Change event loop to always stall on waiting for I/O.

• Type: Improvement
• Status: Open
• Priority: Major
• Resolution: Unresolved
• Fix Version/s: 7.1.0
• Component/s: Core
• Assignee: Alan M. Carroll
• Reporter: Alan M. Carroll
• Created: 06/Mar/16 18:21
• Updated: 17/Aug/16 17:52

Description

Currently the event loop has two wait conditions, one a condition variable and the other I/O (epoll or equivalent). As far as I can tell the conditiona variable is useful only during start up when the I/O wait data is not yet available. The event loop should be changed to wait on one or the other but not both as this can create artificial latency when an event breaks one wait condition but not both.

Issue Links

• depends upon: TS-4265 Provide per EThread and per event type thread initialization.
• depends upon: TS-1775 Cleanup of ink_hrtime.{cc,h}
• depends upon: TS-4261 Split statistic update logic from process handling.
• is blocked by: TS-4309 Reduced SSL upload/download speed after event loop change (TS-4260)
• is depended upon by: TS-2992 EThread schedule fast_signal default
• relates to: TS-4173 High latency with --enable-linux-native-aio