Date: Tue, 29 Jan 2002 14:54:19 -0800 (PST) From: Alfred Perlstein <alfred@FreeBSD.org> To: cvs-committers@FreeBSD.org, cvs-all@FreeBSD.org Subject: cvs commit: src/sys/sys filedesc.h src/sys/kern kern_descrip.c sys_generic.c Message-ID: <200201292254.g0TMsJn05053@freefall.freebsd.org>
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alfred 2002/01/29 14:54:19 PST
Modified files:
sys/sys filedesc.h
sys/kern kern_descrip.c sys_generic.c
Log:
Attempt to fixup select(2) and poll(2), this should fix some races with
other threads as well as speed up the interfaces.
To fix the race and accomplish the speedup, remove selholddrop and
pollholddrop. The entire concept is somewhat bogus because holding
the individual struct file pointers offers us no guarantees that
another thread context won't close it on us thereby removing our
access to our own reference.
Selholddrop and pollholddrop also would do multiple locks and unlocks
of mutexes _per-file_ in the fd arrays to be scanned, this needed to
be sped up.
Instead of using selholddrop and pollholddrop, simply hold the
filedesc lock over the selscan and pollscan functions. This should
protect us against close(2)'s on the files as reduce the multiple
lock/unlock pairs per fd into a single lock over the filedesc.
Revision Changes Path
1.122 +1 -3 src/sys/kern/kern_descrip.c
1.90 +9 -122 src/sys/kern/sys_generic.c
1.34 +12 -0 src/sys/sys/filedesc.h
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