From owner-cvs-all  Thu Feb 22 20:59:18 2001
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From: Brian Feldman <green@FreeBSD.org>
Date: Thu, 22 Feb 2001 20:59:13 -0800 (PST)
To: cvs-committers@FreeBSD.org, cvs-all@FreeBSD.org
Subject: cvs commit: src/lib/libc/stdio _flock_stub.c
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green       2001/02/22 20:59:13 PST

  Modified files:
    lib/libc/stdio       _flock_stub.c 
  Log:
  Fix the problems I (and others, undoubtedly) have been having for a
  while with threaded software in -CURRENT acting very "weird".  It has
  seemed, for example, in Mozilla that threads attempting to do host
  lookups have been locking up.  That's exactly the case.
  
  There was a race condition in the implementation of the initialization
  of the mutex used to protect FILE operations, first of all: multiple
  instances of FLOCKFILE() in libc could occur on the same FILE at
  the same time and cause strange behavior by overwriting eachothers'
  creation of the mutex and the rest of the file lock.
  
  Secondly, it's not appropriate to test the "validity" of the file
  descriptor referenced by the FILE; if the code is calling FLOCKFILE()
  or FUNLOCKFILE(), it wants the FILE to be locked or unlocked, not
  to be locked or unlocked on the condition that _file is >= 0.  This
  also could quite easily cause leaks by failing to perform the lock or
  unlock operation when it actually is needed.
  
  Mozilla now works again on -CURRENT when linked to libc_r.so.5 and
  libc.so.5.
  
  Revision  Changes    Path
  1.7       +13 -4     src/lib/libc/stdio/_flock_stub.c


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