Commit Graph

5 Commits

Author SHA1 Message Date
Jason Evans
314be1347b pthread_mutex_lock(), pthread_cond_trywait(), and pthread_cond_wait() are
not allowed to return EINTR, but use of pthread_suspend_np() could cause
EINTR to be returned.  To fix this, restructure pthread_suspend_np() so that
it does not interrupt a thread that is waiting on a mutex or condition, and
keep enough state around that pthread_resume_np() can fix things up
afterwards.

Reviewed by:	deischen
2000-06-14 17:17:41 +00:00
Daniel Eischen
1d013a86ed Fix pthread_suspend_np/pthread_resume_np. For the record, suspending a
thread waiting on an event (I/O, condvar, etc) will, when resumed using
pthread_resume_np, return with EINTR.  For example, suspending and resuming
a thread blocked on read() will not requeue the thread for the read, but
will return -1 with errno = EINTR.  If the suspended thread is in a critical
region, the thread is suspended as soon as it leaves the critical region.

Fix a bogon in pthread_kill() where a signal was being delivered twice
to threads waiting in sigwait().

Reported by (suspend/resume bug):	jdp
Reviewed by:	jasone
2000-03-15 13:59:27 +00:00
Jason Evans
0a3fa43c7e Implement continuations to correctly handle [sig|_]longjmp() inside of a
signal handler.  Explicitly check for jumps to anywhere other than the
current stack, since such jumps are undefined according to POSIX.

While we're at it, convert thread cancellation to use continuations, since
it's cleaner than the original cancellation code.

Avoid delivering a signal to a thread twice.  This was a pre-existing bug,
but was likely unexposed until these other changes were made.

Defer signals generated by pthread_kill() so that they can be delivered on
the appropriate stack.  deischen claims that this is unnecessary, which is
likely true, but without this change, pthread_kill() can cause undefined
priority queue states and/or PANICs in [sig|_]longjmp(), so I'm leaving
this in for now.  To compile this code out and exercise the bug, define
the _NO_UNDISPATCH cpp macro.  Defining _PTHREADS_INVARIANTS as well will
cause earlier crashes.

PR:			kern/14685
Collaboration with:	deischen
2000-01-19 07:04:50 +00:00
Daniel Eischen
fc8f3f5bfe Fix problems with cancellation while in critical regions.
o Cancellation flags were not getting properly set/cleared.
  o Loops waiting for internal locks were not being exited
    correctly by a cancelled thread.
  o Minor spelling (cancelation -> cancellation) and formatting
    corrections (missing tab).

Found by:	tg
Reviewed by:	jasone
1999-12-17 00:57:54 +00:00
Alfred Perlstein
7285bccf1a add pthread_cancel, obtained from OpenBSD.
eischen (Daniel Eischen) added wrappers to protect against cancled
threads orphaning internal resources.

the cancelability code is still a bit fuzzy but works for test
programs of my own, OpenBSD's and some examples from ORA's books.

add readdir_r to both libc and libc_r

add some 'const' attributes to function parameters

Reviewed by: eischen, jasone
1999-11-28 05:38:13 +00:00