Atomic lock source.

2 files changed, 110 insertions, 0 deletions

diff --git a/lib/libc_r/arch/amd64/_atomic_lock.S b/lib/libc_r/arch/amd64/_atomic_lock.S
new file mode 100644
index 000000000000..d124fc37868c
--- /dev/null
+++ b/lib/libc_r/arch/amd64/_atomic_lock.S
@@ -0,0 +1,55 @@
+/*
+ * Copyright (c) 1995-1998 John Birrell <jb@cimlogic.com.au>.
+ * All rights reserved.
+ * copyright Douglas Santry 1996
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the above copyright is retained
+ * in the source form.
+ *
+ * THIS SOFTWARE IS PROVIDED BY Douglas Santry AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE  
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE   
+ * ARE DISCLAIMED.  IN NO EVENT SHALL Douglas Santry OR CONTRIBUTORS BE LIABLE 
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL   
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS      
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF  
+ * SUCH DAMAGE.    
+ *
+ * $Id$
+ *
+ */
+
+#if defined(LIBC_RCS) && !defined(lint)
+	.text
+	.asciz "$Id$"
+#endif /* LIBC_RCS and not lint */
+
+#include "DEFS.h"
+
+/*
+ * Atomicly lock a location with an identifier provided the location
+ * is not currently locked.
+ *
+ * long _atomic_lock(long *, long);
+ * eax will contain the return value.
+ */
+ENTRY(_atomic_lock)
+	movl	4(%esp), %ecx
+	movl	8(%esp), %eax
+	xchg	%eax, (%ecx)
+	ret
+
+/*
+ * Unlock a location.
+ *
+ * long _atomic_unlock(long *);
+ */
+ENTRY(_atomic_unlock)
+	movl	4(%esp), %ecx
+	movl	$0, %eax
+	xchg	%eax, (%ecx)
+	ret
diff --git a/lib/libc_r/arch/i386/_atomic_lock.S b/lib/libc_r/arch/i386/_atomic_lock.S
new file mode 100644
index 000000000000..d124fc37868c
--- /dev/null
+++ b/lib/libc_r/arch/i386/_atomic_lock.S
@@ -0,0 +1,55 @@
+/*
+ * Copyright (c) 1995-1998 John Birrell <jb@cimlogic.com.au>.
+ * All rights reserved.
+ * copyright Douglas Santry 1996
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the above copyright is retained
+ * in the source form.
+ *
+ * THIS SOFTWARE IS PROVIDED BY Douglas Santry AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE  
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE   
+ * ARE DISCLAIMED.  IN NO EVENT SHALL Douglas Santry OR CONTRIBUTORS BE LIABLE 
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL   
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS      
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF  
+ * SUCH DAMAGE.    
+ *
+ * $Id$
+ *
+ */
+
+#if defined(LIBC_RCS) && !defined(lint)
+	.text
+	.asciz "$Id$"
+#endif /* LIBC_RCS and not lint */
+
+#include "DEFS.h"
+
+/*
+ * Atomicly lock a location with an identifier provided the location
+ * is not currently locked.
+ *
+ * long _atomic_lock(long *, long);
+ * eax will contain the return value.
+ */
+ENTRY(_atomic_lock)
+	movl	4(%esp), %ecx
+	movl	8(%esp), %eax
+	xchg	%eax, (%ecx)
+	ret
+
+/*
+ * Unlock a location.
+ *
+ * long _atomic_unlock(long *);
+ */
+ENTRY(_atomic_unlock)
+	movl	4(%esp), %ecx
+	movl	$0, %eax
+	xchg	%eax, (%ecx)
+	ret