Installation guide

quadword in memory. If you do and if your project allows, Compaq
recommends that you force alignment of each such member variable to a
quadword boundary by redefining the variable to be at least eight bytes, or by
defining sufficient padding storage after the variable to total eight bytes.
Alternatively, you can create one mutex for each composite data object in
which adjacent members can share the same quadword in memory. Then use
this single mutex to protect all write accesses by all threads to the composite
data object. This technique might be less desirable because of performance
considerations.
5.3.9 DECthreads pthread_debug() and pthread_debug_cmd()
Routines
In order to allow for the possibility of a more comprehensive and robust
threads debugging environment, it has become necessary to remove the
pthread_debug() and pthread_debug_cmd() routines. To prevent
existing binaries from failing, the routines will continue to be recognized.
However, a call to either routine now results in an immediate return to the
calling program. The pthread_debug_cmd() routine returns a zero (0)
indicating success. Debuggers such as Ladebug and TotalView provide
functionality formerly provided by these routines.
5.3.10 DECthreads SIGEV_THREAD Notification Mechanism
The SIGEV_THREAD notification mechanism works correctly, starting in
Version 4.0D. Using this notification mechanism, a user-defined function is
called to perform notification of an asynchronous event. The function is run
as though it were the start routine of a thread and can make full use of the
DECthreads synchronization objects.
The SIGEV_THREAD notification mechanism and the function to be called
are specified in the sigevent structure. This mechanism is useful for
programming with the POSIX 1.b realtime signal interfaces such as timers
and asynchronous I/O. For information and cautions concerning the use of
signals in a multithreaded environment, see the Guide to DECthreads. For
more information about using SIGEV_THREAD, see the IEEE POSIX
1003.1c-1996 standard and The Open Group Single UNIX Specification,
Version 2.
5.4 Profiling
The following notes apply to the profiler tools.
Development Environment Notes 5–7