Bug 119762 – app-admin/showconsole failes to compile against uclibc, missing pthread_yield()

• Status: RESOLVED FIXED
• Product: Gentoo Linux

[Description Dan Callaghan 2006-01-20 20:32:18 UTC]

showconsole-1.07 and -1.08 fail to compile on systems running uclibc, as it does not seem to provide pthread_yield().

armeb-softfloat-linux-uclibc-gcc  -Os -march=armv5te -mtune=xscale  -D_GNU_SOURCE -DLOG_BUFFER_SIZE=65536 -DTRANS_BUFFER_SIZE=4096 -DBOOT_LOGFILE=\"/var/log/boot.msg\" -D_PATH_BLOG_FIFO=\"/dev/blog\" -Wall -pipe -funroll-loops -c libconsole.c -pthread
libconsole.c: In function `poll':
libconsole.c:442: warning: implicit declaration of function `pthread_yield'
armeb-softfloat-linux-uclibc-gcc  -Os -march=armv5te -mtune=xscale  -D_GNU_SOURCE -DLOG_BUFFER_SIZE=65536 -DTRANS_BUFFER_SIZE=4096 -DBOOT_LOGFILE=\"/var/log/boot.msg\" -D_PATH_BLOG_FIFO=\"/dev/blog\" -Wall -pipe -funroll-loops -o showconsole showconsole.c libconsole.o -pthread
libconsole.o: In function `action':
libconsole.c:(.text+0x498): undefined reference to `pthread_yield'
collect2: ld returned 1 exit status
make: *** [showconsole] Error 1

sched_yield() is the suggested alternative. Here is a patch that changes the only instance of pthread_yield() to sched_yield():

--- showconsole-1.08-orig/libconsole.c  2006-01-21 13:35:43 +1000
+++ showconsole-1.08/libconsole.c       2006-01-21 13:39:47 +1000
@@ -439,7 +439,7 @@
                ret = 0;
        }
     } else
-       pthread_yield();
+       sched_yield();

     return ret;
 }

This fixes the problem on my uclibc-0.9.27-r1 system (host type armeb-softfloat-linux-uclibc). Also tested against glibc-2.3.5-r2 (on i686-pc-linux-gnu).

[Comment 1 Jan Girlich 2006-03-04 07:34:55 UTC]

I modified the showconsole-1.08.ebuild and it work's for me too.

But I don't know if the above patch works only for uclibc or also for glibc and if we need to check what is used within the ebuild.

[Comment 2 Jan Girlich 2006-03-04 07:36:07 UTC]

Created attachment 81294 [details]
modified ebuild

[Comment 3 Jan Girlich 2006-03-04 07:38:23 UTC]

Created attachment 81295 [details, diff]
changes pthread_yield() to sched_yield()

[Comment 4 solar (RETIRED) 2006-03-04 08:02:50 UTC]

The safe bet is.

#include <features.h>

#ifndef __UCLIBC__
  
#else

#endif

[Comment 5 SpanKY 2006-03-04 20:27:41 UTC]

pthread_yield should just be changed to sched_yield:
http://sourceware.org/cgi-bin/cvsweb.cgi/~checkout~/linuxthreads/linuxthreads/FAQ.html?rev=1.2.2.1&content-type=text/html&cvsroot=glibc#E

[Comment 6 SpanKY 2006-03-04 20:32:00 UTC]

fixed in cvs, thanks for the report