PROBLEM:  (QAR 58658)    (Patch ID: OSF425-343)
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Thread-aware debuggers (particularly TotalView) that make extensive use of 
the libpthreaddebug.so HOLD/UNHOLD mechanisms for breakpoints may expose a 
race condition that can lead to a SIGSEGV within the user-mode thread 
scheduling code. This can lead to a "quiet" process exit: a core file is 
generated, but no message appears, and the proc filesystem reports a normal 
termination to the debugger.

Other HOLD-related races can result in the process being debugged ignoring the 
debugger's HOLD request, or in corrupting the saved state of a thread.

PROBLEM:  (QAR 58658)    (Patch ID: OSF425-343)
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DECthreads can optimize the performance of some common thread operations for 
programs compiled using DEC C, by utilizing the DEC C asm() syntax to include 
machine instructions.  DECthreads does not use asm() syntax under other 
compilers, but nevertheless included the DEC C header file <c_asm.h>. This 
header is incompatible with the gcc compiler asm() syntax.

PROBLEM:  (MCPM31P0Q/QAR 60741)    (Patch ID: OSF425-407)
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This patch is a fix to libtli/libxti to correctly handle a continuation data 
message still on the stream head.

PROBLEM:  (SSRT0546U, SSRT0542U)    (Patch ID: OSF425-405403)
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A potential security vulnerability has been discovered, where under certain 
circumstances, system integrity may be compromised. This may be in the form of 
improper file or privilege management. Digital has corrected this potential 
vulnerability.

In addressing this issue, a warning message not previously seen may be
placed in the daemon.log by named.  An example of the message follows:

  Jan  7 14:03:25 hostname named[316]: owner name "xx_yy.zz.com"
  IN (secondary) is invalid - proceeding anyway

This message has no impact on system operation and will only be seen
once for any given node name on a BIND server at startup.  It is
informing the user that this node name contains non-standard
characters.  Standard characters are defined as A-Z, a-z, 0-9 and
hyphen.  Non-standard characters are characters that fall out of the
standard set such as underscores.

PROBLEM:  (QAR 66683)    (Patch ID: OSF425-539)
********

	DECthreads was not properly changing the priority of a suspended 
	thread, adversely effecting Java programs.  The routine 
	pthread_setschedparam() was not properly handling threads that 
	are suspended.  

PROBLEM:  (QAR 66254)    (Patch ID: OSF425-539)
********

	The routines, pthread_mutex_trylock() and tis_mutex_trylock(), as 
	coded in the libpthread and libc, respectively, can cause uncontested 
	lock operations to take the "slow path" when they would not have to 
	otherwise.  This shows a significant performance problem for the malloc 
	mutex under heavy load.

PROBLEM:  (QAR 60355)    (Patch ID: OSF425-539)
********

	A bug in DECthreads affected the preemption of realtime SCS
	threads.  In once instance a low priority SCS thread would run
	before a higher priority SCS threads.  Another problem occurred when 
	one SCS thread joined with another SCS thread, by calling the 
	pthread_join() function before the "target" SCS thread had terminated. 
	In that situation, the joiner thread may never be unblocked from the
	wait.

PROBLEM:  (CLD HPAQ81B6C)    (Patch ID: OSF425-539)
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	Multithreaded applications can experience performance problems
	if they are run on multi-cpu systems and make heavy use of any of
	the functions on the malloc(3) manpage.  This includes C++ applications
	making heavy use of "new" and "delete".  The primary fix for this
	problem exists within libc, however DECthreads contained inefficiencies
	in the mutex logic code which made the problem worse.
	
PROBLEM:        ( QAR 69251)    (Patch ID: OSF425-582)
********

		With version 52, Ladebug has begun to employ a
		"user thread hold" mechanism.  This patch fixes problems
	       in DECthreads, when using this mechanism, which 
		might result in missed breakpoints and watchpoints,
		as well as causing application hangs.

PROBLEM:        ( CLD HPAQ21HQ9)    (Patch ID: OSF425-582)
********

		This patch fixes a DECthreads problem in which an
invalid
		scheduling priority bugcheck in encountered.  This
		is caused by incorrect referencing of scheduling data
		structures inside DECthreads.


PROBLEM:        ( QAR 69364)    (Patch ID: OSF425-582)
********
This patch fixes a problem in DECthreads manager thread logic.  The
manager thread is being scheduled to run in response to a system event
(nxm action, timer queue expiration, etc.) but is not recognizing the
event as the reason it was scheduled to run.  The manager thread then
goes back to sleep, only to wake up again in response to the still
unserviced system event.  An infinite loop results.

PROBLEM: (72100, 74961, 75971, 77080,
          77288, n/a) (PATCH ID: OSF425-1018)
********
Threaded applications which make extensive use of synchronization objects
(mutexes, condition variables) may encounter performance and scaling
regressions when run on some EV6 SMP machines.  Customers encountering
these regressions may observe negative scaling, decreased application 
throughput and increased CPU utilitzation, as the number of EV6 CPUs 
is increased.  This version of DECthreads contains changes to the 
implementation of synchronization objects and thread scheduling around
those objects to improve performance on all SMP systems.  No functional
or interface changes were made.