HardenedBSD/lib
John Birrell 02292f131a In the words of the author:
o The polling mechanism for I/O readiness was changed from
    select() to poll().  In additon, a wrapped version of poll()
    is now provided.

  o The wrapped select routine now converts each fd_set to a
    poll array so that the thread scheduler doesn't have to
    perform a bitwise search for selected fds each time file
    descriptors are polled for I/O readiness.

  o The thread scheduler was modified to use a new queue (_workq)
    for threads that need work.  Threads waiting for I/O readiness
    and spinblocks are added to the work queue in addition to the
    waiting queue.  This reduces the time spent forming/searching
    the array of file descriptors being polled.

  o The waiting queue (_waitingq) is now maintained in order of
    thread wakeup time.  This allows the thread scheduler to
    find the nearest wakeup time by looking at the first thread
    in the queue instead of searching the entire queue.

  o Removed file descriptor locking for select/poll routines.  An
    application should not rely on the threads library for providing
    this locking; if necessary, the application should use mutexes
    to protect selecting/polling of file descriptors.

  o Retrieve and use the kernel clock rate/resolution at startup
    instead of hardcoding the clock resolution to 10 msec (tested
    with kernel running at 1000 HZ).

  o All queues have been changed to use queue.h macros.  These
    include the queues of all threads, dead threads, and threads
    waiting for file descriptor locks.

  o Added reinitialization of the GC mutex and condition variable
    after a fork.  Also prevented reallocation of the ready queue
    after a fork.

  o Prevented the wrapped close routine from closing the thread
    kernel pipes.

  o Initialized file descriptor table for stdio entries at thread
    init.

  o Provided additional flags to indicate to what queues threads
    belong.

  o Moved TAILQ initialization for statically allocated mutex and
    condition variables to after the spinlock.

  o Added dispatching of signals to pthread_kill.  Removing the
    dispatching of signals from thread activation broke sigsuspend
    when pthread_kill was used to send a signal to a thread.

  o Temporarily set the state of a thread to PS_SUSPENDED when it
    is first created and placed in the list of threads so that it
    will not be accidentally scheduled before becoming a member
    of one of the scheduling queues.

  o Change the signal handler to queue signals to the thread kernel
    pipe if the scheduling queues are protected.  When scheduling
    queues are unprotected, signals are then dequeued and handled.

  o Ensured that all installed signal handlers block the scheduling
    signal and that the scheduling signal handler blocks all
    other signals.  This ensures that the signal handler is only
    interruptible for and by non-scheduling signals.  An atomic
    lock is used to decide which instance of the signal handler
    will handle pending signals.

  o Removed _lock_thread_list and _unlock_thread_list as they are
    no longer used to protect the thread list.

  o Added missing RCS IDs to modified files.

  o Added checks for appropriate queue membership and activity when
    adding, removing, and searching the scheduling queues.  These
    checks add very little overhead and are enabled when compiled
    with _PTHREADS_INVARIANTS defined.  Suggested and implemented
    by Tor Egge with some modification by me.

  o Close a race condition in uthread_close.  (Tor Egge)

  o Protect the scheduling queues while modifying them in
    pthread_cond_signal and _thread_fd_unlock.  (Tor Egge)

  o Ensure that when a thread gets a mutex, the mutex is on that
    threads list of owned mutexes.  (Tor Egge)

  o Set the kernel-in-scheduler flag in _thread_kern_sched_state
    and _thread_kern_sched_state_unlock to prevent a scheduling
    signal from calling the scheduler again.  (Tor Egge)

  o Don't use TAILQ_FOREACH macro while searching the waiting
    queue for threads in a sigwait state, because a change of
    state destroys the TAILQ link.  It is actually safe to do
    so, though, because once a sigwaiting thread is found, the
    loop ends and the function returns.  (Tor Egge)

  o When dispatching signals to threads, make the thread inherit
    the signal deferral flag of the currently running thread.
    (Tor Egge)

Submitted by: Daniel Eischen <eischen@vigrid.com> and
              Tor Egge <Tor.Egge@fast.no>
1999-06-20 08:28:48 +00:00
..
compat I seem to be having some CVS problems... I don't know why this wasn't 1999-05-22 16:21:47 +00:00
csu Call do_ctors() and do_dtors() using indirect calls through function 1999-06-06 15:59:08 +00:00
libalias brucify 1999-05-23 13:52:05 +00:00
libatm Print SPANS addresses in the correct byte order. 1999-05-20 23:52:15 +00:00
libbind
libc Typo in previous commit. 1999-06-18 10:41:13 +00:00
libc_r In the words of the author: 1999-06-20 08:28:48 +00:00
libcalendar
libcam Add a MAINTAINER line to modules that I maintain. 1999-06-18 00:41:47 +00:00
libcom_err
libcompat Correct typo. 1999-01-27 04:35:02 +00:00
libcrypt Simplified using new SYMLINKS macro, mainly to test this macro. The 1999-03-23 03:41:09 +00:00
libcurses
libdevstat Add a MAINTAINER line to modules that I maintain. 1999-06-18 00:41:47 +00:00
libdisk Fix my own Pie Floater. 1999-05-12 23:50:50 +00:00
libedit Switch to using ".So" as the extension for PIC object files rather 1999-01-09 21:51:00 +00:00
libfetch Fixed prototype for fetchParseURL(). 1999-03-05 18:45:32 +00:00
libftpio Cause PORT commands to use the high IP port range. This makes fetch 1999-03-30 22:06:08 +00:00
libgnumalloc
libio Cope with non page-aligned arguments to ioperm. 1999-05-22 17:35:04 +00:00
libipx
libkse In the words of the author: 1999-06-20 08:28:48 +00:00
libkvm Tidy up references to <sys/rlist.h> and support for the old swap management 1999-05-11 14:32:18 +00:00
libm
libmd add more MLINKS 1999-03-02 22:53:24 +00:00
libmytinfo Fixed CLEANFILES. 1998-12-27 15:04:33 +00:00
libncurses Correct prototype for tigetstr(). 1999-05-05 02:51:45 +00:00
libopie
libpam Revive the pam_deny and pam_permit modules from Linux-PAM. They are 1999-05-08 01:59:27 +00:00
libpcap Fixed CLEANFILES. 1998-12-27 15:04:33 +00:00
libpthread In the words of the author: 1999-06-20 08:28:48 +00:00
libradius Allow an alternate to rad_send_request() for programs that 1999-02-05 11:23:44 +00:00
libresolv
librpcsvc
libskey Fixed bitrot in synopsis (some const poisoning hadn't reached here). 1999-03-05 15:50:07 +00:00
libss
libstand More egcs warning fixes: 1999-04-25 22:29:30 +00:00
libtacplus
libtelnet Old stuff laying around: Don't use a function called getstr(), that has 1998-12-16 06:04:29 +00:00
libtermcap
libutil Remove the static declaration from the line[] variable to allow 1999-05-24 01:15:28 +00:00
libvgl
libwrap Add data storage for two application-provided variables. 1999-04-03 03:29:14 +00:00
libxpg4
liby
libz Merge changes from vendor branch (1.1.1 -> 1.1.3) into mainline. 1999-01-10 09:53:51 +00:00
msun Disable building with alpha software completion options until we upgrade 1998-12-24 13:17:58 +00:00
ncurses/ncurses
Makefile Turn off libf2c. Superseeded by EGCS's libg2c. 1999-04-18 09:50:58 +00:00
Makefile.inc