aboutsummaryrefslogtreecommitdiff
path: root/lib/libc_r/uthread/uthread_join.c
Commit message (Collapse)AuthorAgeFilesLines
* Implement continuations to correctly handle [sig|_]longjmp() inside of aJason Evans2000-01-191-5/+3
| | | | | | | | | | | | | | | | | | | | | | | | | 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 Notes: svn path=/head/; revision=56277
* Fix problems with cancellation while in critical regions.Daniel Eischen1999-12-171-0/+1
| | | | | | | | | | | | | | 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 Notes: svn path=/head/; revision=54708
* add pthread_cancel, obtained from OpenBSD.Alfred Perlstein1999-11-281-2/+29
| | | | | | | | | | | | | | | | | 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 Notes: svn path=/head/; revision=53812
* $Id$ -> $FreeBSD$Peter Wemm1999-08-281-1/+1
| | | | Notes: svn path=/head/; revision=50476
* Add RCS IDs to those files without them.Daniel Eischen1999-08-051-2/+2
| | | | | | | | | | Fix copyrights (s/REGENTS/AUTHOR). Suggested by: tg Approved by: jb Notes: svn path=/head/; revision=49439
* In the words of the author:John Birrell1999-06-201-1/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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> Notes: svn path=/head/; revision=48046
* Add the missing {} that caused the function to return ESRCH if itJohn Birrell1998-06-251-1/+2
| | | | | | | | had to wait for the thread to exit and if the caller didn't want the thread exit status. Notes: svn path=/head/; revision=37146
* Change signal model to match POSIX (i.e. one set of signal handlersJohn Birrell1998-04-291-49/+23
| | | | | | | | | | | | | | | | | | | | | | | for the process, not a separate set for each thread). By default, the process now only has signal handlers installed for SIGVTALRM, SIGINFO and SIGCHLD. The thread kernel signal handler is installed for other signals on demand. This means that SIG_IGN and SIG_DFL processing is now left to the kernel, not the thread kernel. Change the signal dispatch to no longer use a signal thread, and call the signal handler using the stack of the thread that has the signal pending. Change the atomic lock method to use test-and-set asm code with a yield if blocked. This introduces separate locks for each type of object instead of blocking signals to prevent a context switch. It was this blocking of signals that caused the performance degradation the people have noted. This is a *big* change! Notes: svn path=/head/; revision=35509
* Add a magic field to the pthread structure to help recognize validJohn Birrell1998-04-031-0/+10
| | | | | | | | | | | | | | | | | threads from invalid ones. The pthread structure is opaque to the user so this change does not cause any incompatibilities. Hopefully this change will help code that was written for draft 4 fail gracefully if the programmer ignores the compiler warning about the change in the level of indirection for the argument passed to pthread_detach(). I got burnt, so I fixed then (expletive deleted) thing. These functions comply with the revised standard. That should shut Terry up! Notes: svn path=/head/; revision=35008
* Modify the return values to comply with POSIX. Previously theseAlexander Langer1997-11-251-6/+3
| | | | | | | | | functions would return -1 and set errno to indicate the specific error. POSIX requires that the functions return the error code as the return value of the function instead. Notes: svn path=/head/; revision=31402
* Submitted by: John BirrellJulian Elischer1997-02-051-3/+29
| | | | | | | uthreads update from the author. Notes: svn path=/head/; revision=22315
* Reviewed by: julianJulian Elischer1996-01-221-0/+90
Submitted by: john birrel One version of the pthreads library another will follow with differnt actions under some cases.. not QUITE complete Notes: svn path=/head/; revision=13546