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-rw-r--r--linuxthreads/ChangeLog8
-rw-r--r--linuxthreads/internals.h1
-rw-r--r--linuxthreads/pthread.c2
-rw-r--r--linuxthreads/spinlock.c16
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);
}