3 Nov
2010
3 Nov
'10
12:38 p.m.
On 11/03/2010 07:23 AM, Daniel P. Berrange wrote:
I was wondering about reusing saferead/write but they have a different semantic on blocking,
Yep, saferead/write cannot be used on any FD with O_NONBLOCK set, because they'll just spin in a 100% CPU loop whenever EAGAIN occurs, until they get nbytes worth of data.
Is it worth teaching saferead/write to use fcntl() to determine if an fd is O_NONBLOCK? And if so, should it outright reject an O_NONBLOCK fd (to help us diagnose bugs) or be documented as allowing an EAGAIN failure on non-blocking fds? -- Eric Blake eblake@redhat.com +1-801-349-2682 Libvirt virtualization library http://libvirt.org