From 6deabb439b7870759f16db0c9a3968e3755bf61a Mon Sep 17 00:00:00 2001
From: deischen <deischen@FreeBSD.org>
Date: Mon, 28 Apr 2003 23:56:12 +0000
Subject: o Don't add a scope system thread's KSE to the list of available  
 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 <sys/kse.h>.

  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.
---
 lib/libpthread/thread/thr_spinlock.c | 31 ++++++++++++++++---------------
 1 file changed, 16 insertions(+), 15 deletions(-)

(limited to 'lib/libpthread/thread/thr_spinlock.c')

diff --git a/lib/libpthread/thread/thr_spinlock.c b/lib/libpthread/thread/thr_spinlock.c
index cb71a46..56691dd 100644
--- a/lib/libpthread/thread/thr_spinlock.c
+++ b/lib/libpthread/thread/thr_spinlock.c
@@ -33,12 +33,8 @@
  *
  */
 
-#include <stdlib.h>
-#include <stdio.h>
-#include <string.h>
-#include <sched.h>
-#include <pthread.h>
-#include <unistd.h>
+#include <sys/types.h>
+#include <machine/atomic.h>
 
 #include <libc_private.h>
 #include "spinlock.h"
@@ -52,7 +48,12 @@
 void
 _spinunlock(spinlock_t *lck)
 {
-	lck->access_lock = 0;
+	kse_critical_t crit;
+
+	crit = (kse_critical_t)lck->fname;
+	atomic_store_rel_long(&lck->access_lock, 0);
+	if (crit != NULL)
+		_kse_critical_leave(crit);
 }
 
 
@@ -65,14 +66,21 @@ _spinunlock(spinlock_t *lck)
 void
 _spinlock(spinlock_t *lck)
 {
+	kse_critical_t crit;
+
 	/*
 	 * Try to grab the lock and loop if another thread grabs
 	 * it before we do.
 	 */
+	if (_kse_isthreaded())
+		crit = _kse_critical_enter();
+	else
+		crit = NULL;
 	while(_atomic_lock(&lck->access_lock)) {
 		while (lck->access_lock)
 			;
 	}
+	lck->fname = (char *)crit;
 }
 
 /*
@@ -88,12 +96,5 @@ _spinlock(spinlock_t *lck)
 void
 _spinlock_debug(spinlock_t *lck, char *fname, int lineno)
 {
-	/*
-	 * Try to grab the lock and loop if another thread grabs
-	 * it before we do.
-	 */
-	while(_atomic_lock(&lck->access_lock)) {
-		while (lck->access_lock)
-			;
-	}
+	_spinlock(lck);
 }
-- 
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