[src/nathanw_sa]: src/lib/libpthread/arch/i386 Make pthread__switch() actuall...

[nathanw <nathanw%NetBSD.org@localhost>]

details:   https://anonhg.NetBSD.org/src/rev/fc85e0e8c7f3
branches:  nathanw_sa
changeset: 504860:fc85e0e8c7f3
user:      nathanw <nathanw%NetBSD.org@localhost>
date:      Mon Jul 16 20:21:10 2001 +0000

description:
Make pthread__switch() actually decrement fake spinlock counts when
told to do so by pthread__upcall_switch() or pthread__lock_switch().

diffstat:

 lib/libpthread/arch/i386/pthread_switch.S |  17 ++++++++++++++++-
 1 files changed, 16 insertions(+), 1 deletions(-)

diffs (38 lines):

diff -r 4f889db474d3 -r fc85e0e8c7f3 lib/libpthread/arch/i386/pthread_switch.S
--- a/lib/libpthread/arch/i386/pthread_switch.S Mon Jul 16 05:45:53 2001 +0000
+++ b/lib/libpthread/arch/i386/pthread_switch.S Mon Jul 16 20:21:10 2001 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: pthread_switch.S,v 1.1.2.3 2001/07/13 02:42:40 nathanw Exp $   */
+/*     $NetBSD: pthread_switch.S,v 1.1.2.4 2001/07/16 20:21:10 nathanw Exp $   */
 
 /*-
  * Copyright (c) 2001 The NetBSD Foundation, Inc.
@@ -57,6 +57,10 @@
        PIC_PROLOGUE
        movl    8(%ebp), %eax  /* eax holds the current thread */
        movl    12(%ebp), %ecx /* ecx holds the thread to switch to  */
+       movl    $0, %edx       /* edx indicates whether eax's lockcount
+                               * should be decremented once its stack
+                               * isn't current.
+                               */
 pthread__switch_no_save:
        subl    $CONTEXTSIZE, %esp
        movl    %esp, PT_UC(%eax)
@@ -64,6 +68,17 @@
 
        STACK_SWITCH
 
+       /* If we're invoked from the switch-to-next provisions of
+        * pthread__locked_switch or pthread__upcall_switch, there
+        * may be a fake spinlock present. If so, they will set %edx
+        * to let us know, and we decrement it once we're no longer using
+        * the old stack.
+        */ 
+       cmpl    $0, %edx
+       je pthread__switch_no_decrement
+       decl    PT_SPINLOCKS(%eax)
+
+pthread__switch_no_decrement:  
        pushl   %esi
        pushl   %edi
        call    PIC_PLT(_C_LABEL(_swapcontext_u))