Date: Mon, 31 Mar 2003 17:10:42 -0800 (PST) From: Jeff Roberson <jeff@FreeBSD.org> To: src-committers@FreeBSD.org, cvs-src@FreeBSD.org, cvs-all@FreeBSD.org Subject: cvs commit: src/sys/kern kern_umtx.c src/sys/sys umtx.h Message-ID: <200304010110.h311AgXB049113@repoman.freebsd.org>
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jeff 2003/03/31 17:10:42 PST
FreeBSD src repository
Added files:
sys/kern kern_umtx.c
sys/sys umtx.h
Log:
- Add an api for doing smp safe locks in userland.
- umtx_lock() is defined as an inline in umtx.h. It tries to do an
uncontested acquire of a lock which falls back to the _umtx_lock()
system-call if that fails.
- umtx_unlock() is also an inline which falls back to _umtx_unlock() if the
uncontested unlock fails.
- Locks are keyed off of the thr_id_t of the currently running thread which
is currently just the pointer to the 'struct thread' in kernel.
- _umtx_lock() uses the proc pointer to synchronize access to blocked thread
queues which are stored in the first blocked thread.
Revision Changes Path
1.1 +303 -0 src/sys/kern/kern_umtx.c (new)
1.1 +87 -0 src/sys/sys/umtx.h (new)
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