[QGIS-trac] [Quantum GIS] #2485: CPU load too high when waiting for WMS server response.

[Quantum GIS]

#2485: CPU load too high when waiting for WMS server response.
--------------------------------+-------------------------------------------
   Reporter:  jekhor            |              Owner:  mhugent      
       Type:  bug               |             Status:  new          
   Priority:  minor: annoyance  |          Milestone:  Version 1.5.0
  Component:  WMS+WFS           |            Version:  HEAD         
   Keywords:                    |   Platform_version:               
   Platform:  Debian            |           Must_fix:  No           
Status_info:  0                 |  
--------------------------------+-------------------------------------------
 When QGIS is waithing for WMS server response, CPU is fully loaded. Strace
 shows that many poll()/read() syscalls are calling:

 {{{
 poll([{fd=3, events=POLLIN}, {fd=7, events=POLLIN}, {fd=14,
 events=POLLIN}, {fd=10, events=POLLIN}], 4, 0) = 0 (Timeout)
 clock_gettime(CLOCK_MONOTONIC, {116821, 811510129}) = 0
 read(7, 0x94e5208, 4096)                = -1 EAGAIN (Resource temporarily
 unavailable)
 clock_gettime(CLOCK_MONOTONIC, {116821, 811564048}) = 0
 read(7, 0x94e5208, 4096)                = -1 EAGAIN (Resource temporarily
 unavailable)
 poll([{fd=3, events=POLLIN}, {fd=7, events=POLLIN}, {fd=14,
 events=POLLIN}, {fd=10, events=POLLIN}], 4, 0) = 0 (Timeout)
 clock_gettime(CLOCK_MONOTONIC, {116821, 811649676}) = 0
 read(7, 0x94e5208, 4096)                = -1 EAGAIN (Resource temporarily
 unavailable)
 clock_gettime(CLOCK_MONOTONIC, {116821, 820256260}) = 0
 read(7, 0x94e5208, 4096)                = -1 EAGAIN (Resource temporarily
 unavailable)
 poll([{fd=3, events=POLLIN}, {fd=7, events=POLLIN}, {fd=14,
 events=POLLIN}, {fd=10, events=POLLIN}], 4, 0) = 0 (Timeout)
 clock_gettime(CLOCK_MONOTONIC, {116821, 820352853}) = 0
 read(7, 0x94e5208, 4096)                = -1 EAGAIN (Resource temporarily
 unavailable)
 clock_gettime(CLOCK_MONOTONIC, {116821, 820408658}) = 0
 read(7, 0x94e5208, 4096)                = -1 EAGAIN (Resource temporarily
 unavailable)
 poll([{fd=3, events=POLLIN}, {fd=7, events=POLLIN}, {fd=14,
 events=POLLIN}, {fd=10, events=POLLIN}], 4, 0) = 0 (Timeout)
 clock_gettime(CLOCK_MONOTONIC, {116821, 820495543}) = 0
 read(7, 0x94e5208, 4096)                = -1 EAGAIN (Resource temporarily
 unavailable)
 clock_gettime(CLOCK_MONOTONIC, {116821, 820550370}) = 0
 read(7, 0x94e5208, 4096)                = -1 EAGAIN (Resource temporarily
 unavailable)
 poll([{fd=3, events=POLLIN}, {fd=7, events=POLLIN}, {fd=14,
 events=POLLIN}, {fd=10, events=POLLIN}], 4, 0) = 0 (Timeout)
 clock_gettime(CLOCK_MONOTONIC, {116821, 820636557}) = 0
 read(7, 0x94e5208, 4096)                = -1 EAGAIN (Resource temporarily
 unavailable)
 clock_gettime(CLOCK_MONOTONIC, {116821, 820690895}) = 0
 read(7, 0x94e5208, 4096)                = -1 EAGAIN (Resource temporarily
 unavailable)
 poll([{fd=3, events=POLLIN}, {fd=7, events=POLLIN}, {fd=14,
 events=POLLIN}, {fd=10, events=POLLIN}], 4, 0) = 0 (Timeout)
 clock_gettime(CLOCK_MONOTONIC, {116821, 820776383}) = 0
 read(7, 0x94e5208, 4096)                = -1 EAGAIN (Resource temporarily
 unavailable)
 clock_gettime(CLOCK_MONOTONIC, {116821, 820830861}) = 0
 read(7, 0x94e5208, 4096)                = -1 EAGAIN (Resource temporarily
 unavailable)
 }}}

-- 
Ticket URL: <https://trac.osgeo.org/qgis/ticket/2485>
Quantum GIS <http://qgis.org>
Quantum GIS is an Open Source GIS viewer/editor supporting OGR, PostGIS, and GRASS formats