Mercurial > hg > nginx
comparison auto/unix @ 7583:efd71d49bde0
Events: available bytes calculation via ioctl(FIONREAD).
This makes it possible to avoid looping for a long time while working
with a fast enough peer when data are added to the socket buffer faster
than we are able to read and process them (ticket #1431). This is
basically what we already do on FreeBSD with kqueue, where information
about the number of bytes in the socket buffer is returned by
the kevent() call.
With other event methods rev->available is now set to -1 when the socket
is ready for reading. Later in ngx_recv() and ngx_recv_chain(), if
full buffer is received, real number of bytes in the socket buffer is
retrieved using ioctl(FIONREAD). Reading more than this number of bytes
ensures that even with edge-triggered event methods the event will be
triggered again, so it is safe to stop processing of the socket and
switch to other connections.
Using ioctl(FIONREAD) only after reading a full buffer is an optimization.
With this approach we only call ioctl(FIONREAD) when there are at least
two recv()/readv() calls.
author | Maxim Dounin <mdounin@mdounin.ru> |
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date | Thu, 17 Oct 2019 16:02:19 +0300 |
parents | 04ebf29eaf5b |
children | 8cc5b0365ee5 |
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7582:70749256af79 | 7583:efd71d49bde0 |
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941 ngx_feature_libs= | 941 ngx_feature_libs= |
942 ngx_feature_test="int i = FIONBIO; printf(\"%d\", i)" | 942 ngx_feature_test="int i = FIONBIO; printf(\"%d\", i)" |
943 . auto/feature | 943 . auto/feature |
944 | 944 |
945 | 945 |
946 ngx_feature="ioctl(FIONREAD)" | |
947 ngx_feature_name="NGX_HAVE_FIONREAD" | |
948 ngx_feature_run=no | |
949 ngx_feature_incs="#include <sys/ioctl.h> | |
950 #include <stdio.h> | |
951 $NGX_INCLUDE_SYS_FILIO_H" | |
952 ngx_feature_path= | |
953 ngx_feature_libs= | |
954 ngx_feature_test="int i = FIONREAD; printf(\"%d\", i)" | |
955 . auto/feature | |
956 | |
957 | |
946 ngx_feature="struct tm.tm_gmtoff" | 958 ngx_feature="struct tm.tm_gmtoff" |
947 ngx_feature_name="NGX_HAVE_GMTOFF" | 959 ngx_feature_name="NGX_HAVE_GMTOFF" |
948 ngx_feature_run=no | 960 ngx_feature_run=no |
949 ngx_feature_incs="#include <time.h> | 961 ngx_feature_incs="#include <time.h> |
950 #include <stdio.h>" | 962 #include <stdio.h>" |