3 files changed, 121 insertions, 1 deletions
diff --git a/erts/emulator/Makefile.in b/erts/emulator/Makefile.in
index ecbf76595b..8b2dd5dbb9 100644
--- a/erts/emulator/Makefile.in
+++ b/erts/emulator/Makefile.in
@@ -813,7 +813,7 @@ RUN_OBJS = \
 	$(OBJDIR)/erl_bif_binary.o      $(OBJDIR)/erl_ao_firstfit_alloc.o \
 	$(OBJDIR)/erl_thr_queue.o	$(OBJDIR)/erl_sched_spec_pre_alloc.o \
 	$(OBJDIR)/erl_ptab.o		$(OBJDIR)/erl_map.o \
-	$(OBJDIR)/erl_msacc.o
+	$(OBJDIR)/erl_msacc.o		$(OBJDIR)/erl_lock_flags.o
 
 LTTNG_OBJS = $(OBJDIR)/erlang_lttng.o
 NIF_OBJS = $(OBJDIR)/erl_tracer_nif.o
diff --git a/erts/emulator/beam/erl_lock_flags.c b/erts/emulator/beam/erl_lock_flags.c
new file mode 100644
index 0000000000..ba6a7217f2
--- /dev/null
+++ b/erts/emulator/beam/erl_lock_flags.c
@@ -0,0 +1,46 @@
+/*
+ * %CopyrightBegin%
+ *
+ * Copyright Ericsson AB 2017. All Rights Reserved.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ * %CopyrightEnd%
+ */
+
+#ifdef HAVE_CONFIG_H
+#  include "config.h"
+#endif
+
+#include "erl_lock_flags.h"
+
+const char *erts_lock_flags_get_type_name(erts_lock_flags_t flags) {
+    switch(flags & ERTS_LOCK_FLAGS_MASK_TYPE) {
+        case ERTS_LOCK_FLAGS_TYPE_PROCLOCK:
+            return "proclock";
+        case ERTS_LOCK_FLAGS_TYPE_MUTEX:
+            if(flags & ERTS_LOCK_FLAGS_PROPERTY_READ_WRITE) {
+                return "rw_mutex";
+            }
+
+            return "mutex";
+        case ERTS_LOCK_FLAGS_TYPE_SPINLOCK:
+            if(flags & ERTS_LOCK_FLAGS_PROPERTY_READ_WRITE) {
+                return "rw_spinlock";
+            }
+
+            return "spinlock";
+        default:
+            return "garbage";
+    }
+}
diff --git a/erts/emulator/beam/erl_lock_flags.h b/erts/emulator/beam/erl_lock_flags.h
new file mode 100644
index 0000000000..b66c160af5
--- /dev/null
+++ b/erts/emulator/beam/erl_lock_flags.h
@@ -0,0 +1,74 @@
+/*
+ * %CopyrightBegin%
+ *
+ * Copyright Ericsson AB 2017. All Rights Reserved.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ * %CopyrightEnd%
+ */
+
+#ifndef ERTS_LOCK_FLAGS_H__
+#define ERTS_LOCK_FLAGS_H__
+
+#define ERTS_LOCK_OPTION_READ  (1 << 1)
+#define ERTS_LOCK_OPTION_WRITE (1 << 2)
+
+#define ERTS_LOCK_OPTION_RDWR (ERTS_LOCK_OPTION_READ | ERTS_LOCK_OPTION_WRITE)
+
+/* Property/category are bitfields to simplify their use in masks. */
+#define ERTS_LOCK_FLAGS_MASK_CATEGORY (0xFFC0)
+#define ERTS_LOCK_FLAGS_MASK_PROPERTY (0x0030)
+
+/* Type is a plain number. */
+#define ERTS_LOCK_FLAGS_MASK_TYPE     (0x000F)
+
+#define ERTS_LOCK_FLAGS_TYPE_SPINLOCK (1)
+#define ERTS_LOCK_FLAGS_TYPE_MUTEX    (2)
+#define ERTS_LOCK_FLAGS_TYPE_PROCLOCK (3)
+
+/* "Static" guarantees that the lock will never be destroyed once created. */
+#define ERTS_LOCK_FLAGS_PROPERTY_STATIC     (1 << 4)
+#define ERTS_LOCK_FLAGS_PROPERTY_READ_WRITE (1 << 5)
+
+#define ERTS_LOCK_FLAGS_CATEGORY_ALLOCATOR    (1 << 6)
+#define ERTS_LOCK_FLAGS_CATEGORY_PROCESS      (1 << 7)
+#define ERTS_LOCK_FLAGS_CATEGORY_IO           (1 << 8)
+#define ERTS_LOCK_FLAGS_CATEGORY_DB           (1 << 9)
+#define ERTS_LOCK_FLAGS_CATEGORY_DEBUG        (1 << 10)
+#define ERTS_LOCK_FLAGS_CATEGORY_SCHEDULER    (1 << 11)
+#define ERTS_LOCK_FLAGS_CATEGORY_GENERIC      (1 << 12)
+#define ERTS_LOCK_FLAGS_CATEGORY_DISTRIBUTION (1 << 13)
+
+#define ERTS_LOCK_TYPE_SPINLOCK \
+    (ERTS_LOCK_FLAGS_TYPE_SPINLOCK)
+#define ERTS_LOCK_TYPE_RWSPINLOCK \
+    (ERTS_LOCK_TYPE_SPINLOCK | \
+     ERTS_LOCK_FLAGS_PROPERTY_READ_WRITE)
+#define ERTS_LOCK_TYPE_MUTEX \
+    (ERTS_LOCK_FLAGS_TYPE_MUTEX)
+#define ERTS_LOCK_TYPE_RWMUTEX \
+    (ERTS_LOCK_TYPE_MUTEX | \
+     ERTS_LOCK_FLAGS_PROPERTY_READ_WRITE)
+#define ERTS_LOCK_TYPE_PROCLOCK \
+    (ERTS_LOCK_FLAGS_CATEGORY_PROCESS | \
+     ERTS_LOCK_FLAGS_TYPE_PROCLOCK)
+
+/* -- -- */
+
+typedef unsigned short erts_lock_flags_t;
+
+/* @brief Gets the type name of the lock, honoring the RW flag if supplied. */
+const char *erts_lock_flags_get_type_name(erts_lock_flags_t flags);
+
+#endif /* ERTS_LOCK_FLAGS_H__ */