Bug 26405 - Performance improvements in read_block()
Summary: Performance improvements in read_block()
Status: RESOLVED NOTABUG
Alias: None
Product: XCB
Classification: Unclassified
Component: Library (show other bugs)
Version: 1.1
Hardware: All All
: medium enhancement
Assignee: xcb mailing list dummy
QA Contact: xcb mailing list dummy
URL:
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Keywords:
Depends on:
Blocks:
 
Reported: 2010-02-03 01:46 UTC by Markus Fleschutz
Modified: 2010-02-03 16:57 UTC (History)
0 users

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Attachments

Description Markus Fleschutz 2010-02-03 01:46:14 UTC 
in libxcb-1.5/src/xcb_in.c: read_block() should read: (replace the new ELSE by else)

...
        if(ret > 0)
            done += ret;
        ELSE if(ret < 0 && errno == EAGAIN)
        {
...
        }
        ELSE if(ret <= 0)
             return ret;
...

This saves 2 if() on partial read.
Comment 1 Julien Danjou 2010-02-03 01:55:52 UTC 
I agree for the first else, but the second seems like a bad idea:
poll or select might return 0.
Comment 2 Bart Massey 2010-02-03 16:57:51 UTC 
Inspection of the assembly code convinces me that the compiler does the right thing here, as I expected.  So there's no performance issue.  The style of the existing code isn't so bad, I think.  I tried some restructurings, and couldn't find one so much better that it was worth a patch.  So for now I think we'll leave the elses off.

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