1 files changed, 77 insertions, 0 deletions
diff --git a/libjava/sysdep/s390/locks.h b/libjava/sysdep/s390/locks.h
new file mode 100644
index 000000000..b0f318525
--- /dev/null
+++ b/libjava/sysdep/s390/locks.h
@@ -0,0 +1,77 @@
+// locks.h - Thread synchronization primitives. S/390 implementation.
+
+/* Copyright (C) 2002  Free Software Foundation
+
+   This file is part of libgcj.
+
+This software is copyrighted work licensed under the terms of the
+Libgcj License.  Please consult the file "LIBGCJ_LICENSE" for
+details.  */
+
+#ifndef __SYSDEP_LOCKS_H__
+#define __SYSDEP_LOCKS_H__
+
+typedef size_t obj_addr_t;	/* Integer type big enough for object	*/
+				/* address.				*/
+
+// Atomically replace *addr by new_val if it was initially equal to old.
+// Return true if the comparison succeeded.
+// Assumed to have acquire semantics, i.e. later memory operations
+// cannot execute before the compare_and_swap finishes.
+inline static bool
+compare_and_swap(volatile obj_addr_t *addr,
+		 obj_addr_t old, obj_addr_t new_val) 
+{
+  int result;
+
+  __asm__ __volatile__ (
+#ifndef __s390x__
+    "       cs  %1,%2,0(%3)\n"
+#else
+    "       csg %1,%2,0(%3)\n"
+#endif
+    "       ipm %0\n"
+    "       srl %0,28\n"
+    : "=&d" (result), "+d" (old)
+    : "d" (new_val), "a" (addr)
+    : "cc", "memory");
+
+  return result == 0;
+}
+
+// Set *addr to new_val with release semantics, i.e. making sure
+// that prior loads and stores complete before this
+// assignment.
+inline static void
+release_set(volatile obj_addr_t *addr, obj_addr_t new_val)
+{
+  __asm__ __volatile__("bcr 15,0" : : : "memory");
+  *(addr) = new_val;
+}
+
+// Compare_and_swap with release semantics instead of acquire semantics.
+// On many architecture, the operation makes both guarantees, so the
+// implementation can be the same.
+inline static bool
+compare_and_swap_release(volatile obj_addr_t *addr,
+		  	 obj_addr_t old, obj_addr_t new_val)
+{
+  return compare_and_swap(addr, old, new_val);
+}
+
+// Ensure that subsequent instructions do not execute on stale
+// data that was loaded from memory before the barrier.
+inline static void
+read_barrier()
+{
+  __asm__ __volatile__("bcr 15,0" : : : "memory");
+}
+
+// Ensure that prior stores to memory are completed with respect to other
+// processors.
+inline static void
+write_barrier()
+{
+  __asm__ __volatile__("bcr 15,0" : : : "memory");
+}
+#endif