diff options
Diffstat (limited to 'linuxthreads')
| -rw-r--r-- | linuxthreads/ChangeLog | 8 | ||||
| -rw-r--r-- | linuxthreads/internals.h | 1 | ||||
| -rw-r--r-- | linuxthreads/pthread.c | 2 | ||||
| -rw-r--r-- | linuxthreads/spinlock.c | 16 |
4 files changed, 20 insertions, 7 deletions
diff --git a/linuxthreads/ChangeLog b/linuxthreads/ChangeLog index ab97529a83..dfb0e3d66a 100644 --- a/linuxthreads/ChangeLog +++ b/linuxthreads/ChangeLog @@ -1,3 +1,11 @@ +1999-06-23 Robey Pointer <robey@netscape.com> + + * internals.h: Added p_nextlock entry to separate queueing for a + lock from queueing for a CV (sometimes a thread queues on a lock + to serialize removing itself from a CV queue). + * pthread.c: Added p_nextlock to initializers. + * spinlock.c: Changed to use p_nextlock instead of p_nextwaiting. + 1999-07-09 Ulrich Drepper <drepper@cygnus.com> * manager.c (pthread_handle_create): Free mmap region after stack diff --git a/linuxthreads/internals.h b/linuxthreads/internals.h index db84707312..bcbfbcf5eb 100644 --- a/linuxthreads/internals.h +++ b/linuxthreads/internals.h @@ -74,6 +74,7 @@ struct _pthread_descr_struct { pthread_descr p_nextlive, p_prevlive; /* Double chaining of active threads */ pthread_descr p_nextwaiting; /* Next element in the queue holding the thr */ + pthread_descr p_nextlock; /* can be on a queue and waiting on a lock */ pthread_t p_tid; /* Thread identifier */ int p_pid; /* PID of Unix process */ int p_priority; /* Thread priority (== 0 if not realtime) */ diff --git a/linuxthreads/pthread.c b/linuxthreads/pthread.c index b7cf573fe9..c94e7e6f31 100644 --- a/linuxthreads/pthread.c +++ b/linuxthreads/pthread.c @@ -34,6 +34,7 @@ struct _pthread_descr_struct __pthread_initial_thread = { &__pthread_initial_thread, /* pthread_descr p_nextlive */ &__pthread_initial_thread, /* pthread_descr p_prevlive */ NULL, /* pthread_descr p_nextwaiting */ + NULL, /* pthread_descr p_nextlock */ PTHREAD_THREADS_MAX, /* pthread_t p_tid */ 0, /* int p_pid */ 0, /* int p_priority */ @@ -75,6 +76,7 @@ struct _pthread_descr_struct __pthread_manager_thread = { NULL, /* pthread_descr p_nextlive */ NULL, /* pthread_descr p_prevlive */ NULL, /* pthread_descr p_nextwaiting */ + NULL, /* pthread_descr p_nextlock */ 0, /* int p_tid */ 0, /* int p_pid */ 0, /* int p_priority */ diff --git a/linuxthreads/spinlock.c b/linuxthreads/spinlock.c index c8f8f71293..ce6ff9e310 100644 --- a/linuxthreads/spinlock.c +++ b/linuxthreads/spinlock.c @@ -27,7 +27,7 @@ 1: fastlock is taken, no thread is waiting on it ADDR: fastlock is taken, ADDR is address of thread descriptor for first waiting thread, other waiting threads are linked via - their p_nextwaiting field. + their p_nextlock field. The waiting list is not sorted by priority order. Actually, we always insert at top of list (sole insertion mode that can be performed without locking). @@ -50,8 +50,10 @@ void internal_function __pthread_lock(struct _pthread_fastlock * lock, self = thread_self(); newstatus = (long) self; } - if (self != NULL) - THREAD_SETMEM(self, p_nextwaiting, (pthread_descr) oldstatus); + if (self != NULL) { + ASSERT(self->p_nextlock == NULL); + THREAD_SETMEM(self, p_nextlock, (pthread_descr) oldstatus); + } } while(! compare_and_swap(&lock->__status, oldstatus, newstatus, &lock->__spinlock)); if (oldstatus != 0) suspend(self); @@ -83,7 +85,7 @@ again: maxptr = ptr; maxprio = thr->p_priority; } - ptr = &(thr->p_nextwaiting); + ptr = &(thr->p_nextlock); thr = *ptr; } /* Remove max prio thread from waiting list. */ @@ -92,16 +94,16 @@ again: to guard against concurrent lock operation */ thr = (pthread_descr) oldstatus; if (! compare_and_swap(&lock->__status, - oldstatus, (long)(thr->p_nextwaiting), + oldstatus, (long)(thr->p_nextlock), &lock->__spinlock)) goto again; } else { /* No risk of concurrent access, remove max prio thread normally */ thr = *maxptr; - *maxptr = thr->p_nextwaiting; + *maxptr = thr->p_nextlock; } /* Wake up the selected waiting thread */ - thr->p_nextwaiting = NULL; + thr->p_nextlock = NULL; restart(thr); } |