revert of mass delete of the posix subsystem. perhaps there is hope for it yet.

[reactos.git] / posix / lib / psxdll / misc / interlock.c

diff --git a/posix/lib/psxdll/misc/interlock.c b/posix/lib/psxdll/misc/interlock.c
new file mode 100644 (file)
index 0000000..983dd71
--- /dev/null
+++ b/posix/lib/psxdll/misc/interlock.c
@@ -0,0 +1,83 @@
+/* $Id: interlock.c,v 1.4 2002/10/29 04:45:33 rex Exp $
+ */
+/*
+ * COPYRIGHT:   See COPYING in the top level directory
+ * PROJECT:     ReactOS POSIX+ Subsystem
+ * FILE:        subsys/psx/lib/psxdll/misc/interlock.c
+ * PURPOSE:     inter-locked increments/decrements
+ * PROGRAMMER:  KJK::Hyperion <noog@libero.it>
+ * UPDATE HISTORY:
+ *              20/01/2002: Adapted from lib/kernel32/synch/intrlck.c
+ */
+
+/*
+ * NOTE by KJK::Hyperion: I do not understand what's behind these functions.
+ *                        Don't ask me how they work, or to fix errors in them.
+ *                        Please refer to the authors referenced in the original
+ *                        file, lib/kernel32/synch/intrlck.c
+ */
+
+/* TODO? move these in some shared library */
+
+#include <psx/interlock.h>
+
+int __interlock_inc(int * addend)
+{
+ int ret = 0;
+
+ __asm__
+ (              
+  "    lock\n" /* for SMP systems */
+  "    incl    (%1)\n"
+  "    je      2f\n"
+  "    jl      1f\n"
+  "    incl    %0\n"
+  "    jmp     2f\n"
+  "1:  dec     %0\n"             
+  "2:\n"
+  :"=r" (ret):"r" (addend), "0" (0): "memory"
+ );
+
+ return (ret);
+}
+
+int __interlock_dec(int * addend)
+{
+ int ret = 0;
+
+ __asm__
+ (              
+  "    lock\n" /* for SMP systems */
+  "    decl    (%1)\n"
+  "    je      2f\n"
+  "    jl      1f\n"
+  "    incl    %0\n"
+  "    jmp     2f\n"
+  "1:  dec     %0\n"             
+  "2:\n"
+  :"=r" (ret):"r" (addend), "0" (0): "memory"          
+ );
+
+ return (ret);
+
+}
+
+int __interlock_add(int * addend, int increment)
+{
+ int ret = 0;
+
+ __asm__
+ (
+  "    lock\n" /* for SMP systems */
+  "    xaddl %0,(%1)"
+  :"=r" (ret)
+  :"r"  (addend), "0" (increment)
+  :"memory"
+ );
+
+ return (ret);
+
+}
+
+/* EOF */
+