src-test2/lib/libpthread/thread/thr_cond.c, branch release/5.1.0_cvs

This commit was manufactured by cvs2svn to create tag

2003-06-04T16:00:27Z

'RELENG_5_1_0_RELEASE'. This commit was manufactured to restore the state of the 5.1-RELEASE image. Releases prior to 5.3-RELEASE are omitting the secure/ and crypto/ subdirs.

MFC: Free internal low level lock's memory.

2003-06-04T01:01:18Z

Approved by: re (scottl)

Attempt to eliminate PLT relocations from rwlock aquire/release

2003-05-30T00:21:52Z

path, making them suitable for direct use by the dynamic loader. Register libpthread-specific locking API with rtld on startup. This still has some rough edges with signals which should be addresses later. Approved by: re (scottl)

Change low-level locking a bit so that we can tell if

2003-05-24T02:29:25Z

a lock is being waitied on. Fix a races in join and cancellation. When trying to wait on a CV and the library is not yet threaded, make it threaded so that waiting actually works. When trying to nanosleep() and we're not threaded, just call the system call nanosleep instead of adding the thread to the wait queue. Clean up adding/removing new threads to the "all threads queue", assigning them unique ids, and tracking how many active threads there are. Do it all when the thread is added to the scheduling queue instead of making pthread_create() know how to do it. Fix a race where a thread could be marked for signal delivery but it could be exited before we actually add the signal to it. Other minor cleanups and bug fixes. Submitted by: davidxu Approved by: re@ (blanket for libpthread)

Eek, staticize a couple of functions that shouldn't

2003-05-19T23:04:50Z

be external (initialize()!). Remove cancellation points from _pthread_cond_wait and _pthread_cond_timedwait (single underscore versions are libc private functions). Point the weak reference(!) for these functions to the versions with cancellation points. Approved by: re@(blanket till 5/19) Pointed out by: kan (cancellation point bug)

Add a method of yielding the current thread with the scheduler

2003-05-16T19:58:30Z

lock held (_thr_sched_switch_unlocked()) and use this to avoid dropping the scheduler lock and having the scheduler retake the same lock again. Add a better way of detecting if a low-level lock is in use. When switching out a thread due to blocking in the UTS, don't switch to the KSE's scheduler stack only to switch back to another thread. If possible switch to the new thread directly from the old thread and avoid the overhead of the extra context switch. Check for pending signals on a thread when entering the scheduler and add them to the threads signal frame. This includes some other minor signal fixes. Most of this was a joint effor between davidxu and myself. Reviewed by: davidxu Approved by: re@ (blanket for libpthread)

Handle thread canceled case, it is same as signal caused backout,

2003-05-02T11:39:00Z

but will break out of loop.

o Don't add a scope system thread's KSE to the list of available

2003-04-28T23:56:12Z

KSEs when it's thread exits; allow the GC handler to do that. o Make spinlock/spinlock critical regions. The following were submitted by davidxu o Alow thr_switch() to take a null mailbox argument. o Better protect cancellation checks. o Don't set KSE specific data when creating new KSEs; rely on the first upcall of the KSE to set it. o Add the ability to set the maximum concurrency level and do this automatically. We should have a way to enable/disable this with some sort of tunable because some applications may not want this to be the default. o Hold the scheduling lock across thread switch calls. o If scheduling of a thread fails, make sure to remove it from the list of active threads. o Better protect accesses to a joining threads when the target thread is exited and detached. o Remove some macro definitions that are now provided by . o Don't leave the library in threaded mode if creation of the initial KSE fails. o Wakeup idle KSEs when there are threads ready to run. o Maintain the number of threads active in the priority queue.

Add a couple asserts to pthread_cond_foo to ensure the (low-level)

2003-04-22T20:28:33Z

lock level is 0. Thus far, the threads implementation doesn't use mutexes or condition variables so the lock level should be 0. Save the return value when trying to schedule a new thread and use this to return an error from pthread_create(). Change the max sleep time for an idle KSE to 1 minute from 2 minutes. Maintain a count of the number of KSEs within a KSEG. With these changes scope system threads seem to work, but heavy use of them crash the kernel (supposedly VM bugs).

Add an i386-specifc hack to always set %gs. There still seems

2003-04-21T04:02:56Z

to be instances where the kernel doesn't properly save and/or restore it. Use noupcall and nocompleted flags in the KSE mailbox. These require kernel changes to work which will be committed sometime later. Things still work without the changes. Remove the general kse entry function and use two different functions -- one for scope system threads and one for scope process threads. The scope system function is not yet enabled and we use the same function for all threads at the moment. Keep a copy of the KSE stack for the case that a KSE runs a scope system thread and uses the same stack as the thread (no upcalls are generated, so a separate stack isn't needed). This isn't enabled yet. Use a separate field for the KSE waiting flag. It isn't correct to use the mailbox flags field. The following fixes were provided by David Xu: o Initialize condition variable locks with thread versions of the low-level locking functions instead of the kse versions. o Enable threading before creating the first thread instead of after. o Don't enter critical regions when trying to malloc/free or call functions that malloc/free. o Take the scheduling lock when inheriting thread attributes. o Check the attribute's stack pointer instead of the attributes stack size for null when allocating a thread's stack. o Add a kseg reinit function so we don't have to destroy and then recreate the same lock. o Check the return value of kse_create() and return an appropriate error if it fails. o Don't forget to destroy a thread's locks when freeing it. o Examine the correct flags word for checking to see if a thread is in a synchronization queue. Things should now work on an SMP kernel.