Commit Graph

14 Commits

Author SHA1 Message Date
Daniel Eischen
24f33bca1c Add a simple work-around for deadlocking on recursive read locks
on a rwlock while there are writers waiting.  We normally favor
writers but when a reader already has at least one other read lock,
we favor the reader.  We don't track all the rwlocks owned by a
thread, nor all the threads that own a rwlock -- we just keep
a count of all the read locks owned by a thread.

PR:	24641
2004-01-08 15:37:09 +00:00
David Xu
407c3de522 Add small piece of code to support pthread_rwlock_timedrdlock and
pthread_rwlock_timedrwlock.
2003-09-06 00:07:52 +00:00
Alexander Kabaev
84d55c7fad Attempt to eliminate PLT relocations from rwlock aquire/release
path, making them suitable for direct use by the dynamic loader.

Register libpthread-specific locking API with rtld on startup.

This still has some rough edges with signals which should be
addresses later.

Approved by:	re (scottl)
2003-05-30 00:21:52 +00:00
Daniel Eischen
a0240e2cb0 Revamp libpthread so that it has a chance of working in an SMP
environment.  This includes support for multiple KSEs and KSEGs.

The ability to create more than 1 KSE via pthread_setconcurrency()
is in the works as well as support for PTHREAD_SCOPE_SYSTEM threads.
Those should come shortly.

There are still some known issues which davidxu and I are working
on, but it'll make it easier for us by committing what we have.

This library now passes all of the ACE tests that libc_r passes
with the exception of one.  It also seems to work OK with KDE
including konqueror, kwrite, etc.  I haven't been able to get
mozilla to run due to lack of java plugin, so I'd be interested
to see how it works with that.

Reviewed by:	davidxu
2003-04-18 05:04:16 +00:00
David Xu
5b54b0891a Backout last commit.
Requested by: jhb
2003-03-15 04:45:42 +00:00
David Xu
047a20e644 Fix a bug in rwlock. When a rwlock was locked by reader threads, a
writter thread can block reader threads to get read lock.
2003-03-14 01:02:47 +00:00
Jonathan Mini
cc118d869b Make the changes needed for libpthread to compile in its new home.
The new libpthread will provide POSIX threading support using KSE.
These files were previously repo-copied from src/lib/libc_r.

Reviewed by:	deischen
Approved by:	-arch
2002-09-16 08:45:36 +00:00
Brian S. Dean
b18ae9245d Fix the return code from pthread_rwlock_try[rw|rd]lock() functions;
these should return EBUSY when the calling thread would block.

MFC after: 2 weeks
2002-03-15 18:27:58 +00:00
Daniel Eischen
437df4859a To be consistent, use the __weak_reference macro from <sys/cdefs.h>
instead of #pragma weak to create weak definitions.

Suggested by:	bde
2001-04-10 04:19:21 +00:00
Daniel Eischen
e5106342c6 Add weak definitions for wrapped system calls. In general:
_foo - wrapped system call
	foo - weak definition to _foo

and for cancellation points:

	_foo - wrapped system call
	__foo - enter cancellation point, call _foo(), leave
	        cancellation point
	foo - weak definition to __foo

Change use of global _thread_run to call a function to get the
currently running thread.

Make all pthread_foo functions weak definitions to _pthread_foo,
where _pthread_foo is the implementation.  This allows an application
to provide its own pthread functions.

Provide slightly different versions of pthread_mutex_lock and
pthread_mutex_init so that we can tell the difference between
a libc mutex and an application mutex.  Threads holding mutexes
internal to libc should never be allowed to exit, call signal
handlers, or cancel.

Approved by:	-arch
2001-01-24 13:03:38 +00:00
Peter Wemm
7f3dea244c $Id$ -> $FreeBSD$ 1999-08-28 00:22:10 +00:00
Alexander Langer
e66632a35c Removed some variable initializations which were unnecessary and divergent
from style(9).
1998-09-07 21:07:59 +00:00
Alexander Langer
23424a1f9a -Wall clean. 1998-09-07 19:23:55 +00:00
Alexander Langer
c0e366326f Implement pthread read/write locks as defined by Version 2 of the Single
UNIX Specification.

As with our standard mutexes, process shared locks are not supported at
this time.
1998-09-07 19:01:43 +00:00