Bug 163228

Summary:	libc.info about threads are too misleading
Product:	Red Hat Enterprise Linux 4	Reporter:	Suzuki Takashi <suzuki-t>
Component:	glibc	Assignee:	Jakub Jelinek <jakub>
Status:	CLOSED NOTABUG	QA Contact:	Brian Brock <bbrock>
Severity:	medium	Docs Contact:
Priority:	medium
Version:	4.0	CC:	drepper
Target Milestone:	---
Target Release:	---
Hardware:	i386
OS:	Linux
Whiteboard:
Fixed In Version:		Doc Type:	Bug Fix
Doc Text:		Story Points:	---
Clone Of:		Environment:
Last Closed:	2005-07-25 20:04:02 UTC	Type:	---
Regression:	---	Mount Type:	---
Documentation:	---	CRM:
Verified Versions:		Category:	---
oVirt Team:	---	RHEL 7.3 requirements from Atomic Host:
Cloudforms Team:	---	Target Upstream Version:
Embargoed:

Description Suzuki Takashi 2005-07-14 09:19:33 UTC

From Bugzilla Helper:
User-Agent: Mozilla/5.0 (Windows; U; Windows NT 5.1; ja-JP; rv:1.7.8) Gecko/20050511 Firefox/1.0.4

Description of problem:
Info document in glibc (libc.info) describes LinuxThreads.
But when running or compiling a program, NPTL is used instead by default.
There are perhaps some inappropriate explanations against NPTL.
That's too misleading for general users.

A few things I noticed were:
. Cancellation points are too limited and eg. select is not a cancellation point.
  (on NPTL, cancellation points are conformed to POSIX standard and
  almost all syscalls are cancellation points).
. pthread_cond_timedwait may return EINTR
  (one in LinuxThread also didn't return EINTR since glibc-2.1.3 though).


Version-Release number of selected component (if applicable):
glibc-2.3.4-2.9

How reproducible:
Always

Steps to Reproduce:
1. Invoke info libc.
2. Search Cancellation or pthread_cond_timedwait.


Additional info:

Comment 1 Jakub Jelinek 2005-07-14 09:27:38 UTC

For NPTL, the documentation is at
http://www.opengroup.org/onlinepubs/009695399/nfindex.html
or in the 3p section of manual pages.
info libc thread section simply documents LinuxThreads, so you shouldn't
be using it when writing NPTL (or portable POSIX threads) programs.

Comment 2 Suzuki Takashi 2005-07-14 10:13:33 UTC

I understand what you are saying.
But is there any documentation a general user can see at a glance
that he or she should't consult info.libc about threads?

Comment 3 Ulrich Drepper 2005-07-25 20:04:02 UTC

Use the POSIX man pages we ship (as Jakub pointed out) or buy a book on POSIX
threads.  Nobody has volunteered to write decent documentation for the upstream
glibc so there is nothing for us to import.

If you have a RHEL license and insist of RH providing such documentation then
talk to your Red Hat representative.