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* Fixes for signal handling:deischen1999-12-171-1/+3
| | | | | | | | | | | | | | o Don't call signal handlers with the signal handler access lock held. o Remove pending signals before calling signal handlers. If pending signals were not removed prior to handling them, invocation of the handler could cause the handler to be called more than once for the same signal. Found by: JB o When SIGCHLD arrives, wake up all threads in PS_WAIT_WAIT (wait4). PR: bin/15328 Reviewed by: jasone
* Change signal handling to conform to POSIX specified semantics.deischen1999-12-041-2/+6
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Before this change, a signal was delivered to each thread that didn't have the signal masked. Signals also improperly woke up threads waiting on I/O. With this change, signals are now handled in the following way: o If a thread is waiting in a sigwait for the signal, then the thread is woken up. o If no threads are sigwait'ing on the signal and a thread is in a sigsuspend waiting for the signal, then the thread is woken up. o In the case that no threads are waiting or suspended on the signal, then the signal is delivered to the first thread we find that has the signal unmasked. o If no threads are waiting or suspended on the signal, and no threads have the signal unmasked, then the signal is added to the process wide pending signal set. The signal will be delivered to the first thread that unmasks the signal. If there is an installed signal handler, it is only invoked if the chosen thread was not in a sigwait. In the case that multiple threads are waiting or suspended on a signal, or multiple threads have the signal unmasked, we wake up/deliver the signal to the first thread we find. The above rules still apply. Reported by: Scott Hess <scott@avantgo.com> Reviewed by: jb, jasone
* * Fix the stack allocation code so that it works for alpha. Change itdfr1999-11-281-1/+3
| | | | | | | | | to use mmap(..., MAP_STACK, ...) on alpha too since that should work now. * Add hooks to allow GDB to access the internals of pthreads without having to know the exact layout of struct pthread. Reviewed by: deischen
* add pthread_cancel, obtained from OpenBSD.alfred1999-11-281-6/+27
| | | | | | | | | | | | | | 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
* sigset_t change (part 5 of 5)marcel1999-09-291-5/+5
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | ----------------------------- Most of the userland changes are in libc. For both the alpha and the i386 setjmp has been changed to accomodate for the new sigset_t. Internally, libc is mostly rewritten to use the new syscalls. The exception is in compat-43/sigcompat.c The POSIX thread library has also been rewritten to use the new sigset_t. Except, that it currently only handles NSIG signals instead of the maximum _SIG_MAXSIG. This should not be a problem because current applications don't use any signals higher than NSIG. There are version bumps for the following libraries: libdialog libreadline libc libc_r libedit libftpio libss These libraries either a) have one of the modified structures visible in the interface, or b) use sigset_t internally and may cause breakage if new binaries are used against libraries that don't have the sigset_t change. This not an immediate issue, but will be as soon as applications start using the new range to its fullest. NOTE: libncurses already had an version bump and has not been given one now. NOTE: doscmd is a real casualty and has been disconnected for the moment. Reconnection will eventually happen after doscmd has been fixed. I'm aware that being the last one to touch it, I'm automaticly promoted to being maintainer. According to good taste this means that I will receive a badge which either will be glued or mechanically stapled, drilled or otherwise violently forced onto me :-) NOTE: pcvt/vttest cannot be compiled with -traditional. The change cause sys/types to be included along the way which contains the const and volatile modifiers. I don't consider this a solution, but more a workaround.
* $Id$ -> $FreeBSD$peter1999-08-281-1/+1
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* Fix thread initialization to allow for the case where stdio filedeischen1999-08-051-3/+3
| | | | | | | descriptors are not opened. PR: bin/12853 Reviewed by: jb
* Use USRSTACK (defined in <machine/vmparam.h>) to get top of the initial stack.dt1999-07-121-13/+2
| | | | PTHREAD_STACK_TOP was wrong for all supported architectures.
* Modify previous changes to conform better to libc_r's coding style.jasone1999-07-111-5/+9
| | | | | | | | Always use mmap() for default-size stack allocation. Use MAP_ANON instead of MAP_STACK on the alpha architecture. Reduce the amount of code executed while owning _gc_mutex during stack allocation.
* Always use growable thread stacks on the i386. The VM_STACK kernel optionjasone1999-07-061-14/+10
| | | | | must be made default for the alpha before growable thread stacks are enabled for the alpha.
* Use growable stacks for thread stacks that are the default stack size.jasone1999-07-051-2/+44
| | | | | | | | | | | | | Cache discarded default thread stacks for use in subsequent thread creations. Create a red zone at the end of each stack (including the initial thread stack), with the hope of causing a segfault if a stack overflows. To activate these modifications, add -D_PTHREAD_GSTACK to CFLAGS in src/lib/libc_r/Makefile. Since the modifications depend on the VM_STACK kernel option, I'm not sure how to safely use growable stacks by default. Testing, as well as algorithmic and stylistic comments are welcome.
* In the words of the author:jb1999-06-201-88/+169
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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>
* Added a missing comma to the static condition variable initialisationjb1999-05-241-1/+1
| | | | | | definition. Submitted by: David Leonard <David.Leonard@csee.uq.edu.au>, an OpenBSD guy.
* Fix a problem with static initialisation of mutexes and conditionjb1999-05-231-2/+3
| | | | | | variables. Submitted by: Dan Eischen <eischen@vigrid.com>
* [ The author's description... ]jb1999-03-231-21/+214
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | o Runnable threads are now maintained in priority queues. The implementation requires two things: 1.) The priority queues must be protected during insertion and removal of threads. Since the kernel scheduler must modify the priority queues, a spinlock for protection cannot be used. The functions _thread_kern_sched_defer() and _thread_kern_sched_undefer() were added to {un}defer kernel scheduler activation. 2.) A thread (active) priority change can be performed only when the thread is removed from the priority queue. The implementation uses a threads active priority when inserting it into the queue. A by-product is that thread switches are much faster. A separate queue is used for waiting and/or blocked threads, and it is searched at most 2 times in the kernel scheduler when there are active threads. It should be possible to reduce this to once by combining polling of threads waiting on I/O with the loop that looks for timed out threads and the minimum timeout value. o Functions to defer kernel scheduler activation were added. These are _thread_kern_sched_defer() and _thread_kern_sched_undefer() and may be called recursively. These routines do not block the scheduling signal, but latch its occurrence. The signal handler will not call the kernel scheduler when the running thread has deferred scheduling, but it will be called when running thread undefers scheduling. o Added support for _POSIX_THREAD_PRIORITY_SCHEDULING. All the POSIX routines required by this should now be implemented. One note, SCHED_OTHER, SCHED_FIFO, and SCHED_RR are required to be defined by including pthread.h. These defines are currently in sched.h. I modified pthread.h to include sched.h but don't know if this is the proper thing to do. o Added support for priority protection and inheritence mutexes. This allows definition of _POSIX_THREAD_PRIO_PROTECT and _POSIX_THREAD_PRIO_INHERIT. o Added additional error checks required by POSIX for mutexes and condition variables. o Provided a wrapper for sigpending which is marked as a hidden syscall. o Added a non-portable function as a debugging aid to allow an application to monitor thread context switches. An application can install a routine that gets called everytime a thread (explicitly created by the application) gets context switched. The routine gets passed the pthread IDs of the threads that are being switched in and out. Submitted by: Dan Eischen <eischen@vigrid.com> Changes by me: o Added a PS_SPINBLOCK state to deal with the priority inversion problem most often (I think) seen by threads calling malloc/free/realloc. o Dispatch signals to the running thread directly rather than at a context switch to avoid the situation where the switch never occurs.
* Increase the size of private thread flags so that the test for ajb1999-01-151-1/+1
| | | | | | | thread trying to call pthread_exit() from a cleanup handler actually works. Submitted by: David Leonard <david.leonard@csee.uq.edu.au> OpenBSD
* Close a window between unlocking a spinlock and changing the thread state.jb1998-11-151-0/+2
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* - Fix the debug macros.jb1998-09-301-4/+21
| | | | | | | | | | | - Add support of a thread being listed in the dead thread list as well as the thread list. - Add a new thread state to make sigwait work properly. (Submitted by Daniel M. Eischen <eischen@vigrid.com>) - Add global variable for the garbage collector mutex and condition variable. - Delete a couple of prototypes that are no longer required. - Add a prototype for the garbage collector thread.
* Implement pthread read/write locks as defined by Version 2 of the Singlealex1998-09-071-0/+12
| | | | | | | UNIX Specification. As with our standard mutexes, process shared locks are not supported at this time.
* Add compile time thread lock debug support.jb1998-06-091-6/+21
| | | | | Add a thread specific flag to trap the case where pthread_exit() is called from a destructor in violation of the Posix standard.
* Re-design the thread specific key structure.jb1998-06-061-3/+2
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* Change signal model to match POSIX (i.e. one set of signal handlersjb1998-04-291-32/+51
| | | | | | | | | | | | | | | | | | | | 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!
* Change the FILE locking to be by FILE, not by the underlying fd asjb1998-04-111-2/+9
| | | | | | | | | | | | | it was. Add a FILE_WAIT state and queue threads waiting for a FILE lock. Start using the sys/queue.h macros instead of the way that MIT pthreads did it. Add a thread name to the private thread structure and a non-POSIX function to set this. This helps (me at least) when sending a SIGINFO to a threaded process to get a /tmp/uthread.dump to see what the <expletive deleted> threads are doing this time. It is nice to be able to recognise (yes, I spell that with an 's' too) which threads are which.
* Rename static initializer defines for opaque structures so that thejb1998-04-041-2/+2
| | | | POSIX specified names can be declared in pthread.h.
* Add a magic field to the pthread structure to help recognize validjb1998-04-031-1/+8
| | | | | | | | | | | | | | 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!
* Add sched_yield() witch is the draft 10 equivalent of pthread_yield()jb1998-03-081-22/+8
| | | | | from draft 4. Move some of the schedule definitions to sched.h which is a POSIX header.
* remove prototype for nanosleep(), it's visible in unistd.h now.peter1997-05-121-1/+0
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* Submitted by: John Birrelljulian1997-02-051-19/+40
| | | | uthreads update from the author.
* Moved enum pthread_mutextype to pthread.h.hsu1996-11-111-6/+8
| | | | Add pthread_mutexattr_default definition.
* Submitted by: John Birrell <cimaxp1!jb@werple.net.au>julian1996-08-201-8/+140
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Here are the diffs for libc_r to get it one step closer to P1003.1c These make most of the thread/mutex/condvar structures opaque to the user. There are three functions which have been renamed with _np suffixes because they are extensions to P1003.1c (I did them for JAVA, which needs to suspend/resume threads and also start threads suspended). I've created a new header (pthread_np.h) for the non-POSIX stuff. The egrep tags stuff in /usr/src/lib/libc_r/Makefile that I uncommented doesn't work. I think its best to delete it. I don't think libc_r needs tags anyway, 'cause most of the source is in libc which does have tags. also: Here's the first batch of man pages for the thread functions. The diff to /usr/src/lib/libc_r/Makefile removes some stuff that was inherited from /usr/src/lib/libc/Makefile that should only be done with libc. also: I should have sent this diff with the pthread(3) man page. It allows people to type make -DWANT_LIBC_R world to get libc_r built with the rest of the world. I put this in the pthread(3) man page. The default is still not to build libc_r. also: The diff attached adds a pthread(3) man page to /usr/src/share/man/man3. The idea is that without libc_r installed, this man page will give people enough info to know that they have to build libc_r.
* Reviewed by: julianjulian1996-01-221-0/+629
Submitted by: john birrel One version of the pthreads library another will follow with differnt actions under some cases.. not QUITE complete
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