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authorRickard Green <[email protected]>2010-06-17 10:23:50 +0200
committerRickard Green <[email protected]>2010-08-10 11:41:14 +0200
commit300b419486c1ca88e33938f182d5d5a8b90fb73f (patch)
tree55c37d5fb042bf6b3b5f56d89c9238a7e22f8b29 /erts/lib_src/common/ethr_cbf.c
parentc1e94fa9a6fe4ae717d35dfbd1b628dc2e06d26a (diff)
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Rewrite ethread library
Large parts of the ethread library have been rewritten. The ethread library is an Erlang runtime system internal, portable thread library used by the runtime system itself. Most notable improvement is a reader optimized rwlock implementation which dramatically improve the performance of read-lock/read-unlock operations on multi processor systems by avoiding ping-ponging of the rwlock cache lines. The reader optimized rwlock implementation is used by miscellaneous rwlocks in the runtime system that are known to be read-locked frequently, and can be enabled on ETS tables by passing the `{read_concurrency, true}' option upon table creation. See the documentation of `ets:new/2' for more information. The ethread library can now also use the libatomic_ops library for atomic memory accesses. This makes it possible for the Erlang runtime system to utilize optimized atomic operations on more platforms than before. Use the `--with-libatomic_ops=PATH' configure command line argument when specifying where the libatomic_ops installation is located. The libatomic_ops library can be downloaded from: http://www.hpl.hp.com/research/linux/atomic_ops/ The changed API of the ethread library has also caused modifications in the Erlang runtime system. Preparations for the to come "delayed deallocation" feature has also been done since it depends on the ethread library. Note: When building for x86, the ethread library will now use instructions that first appeared on the pentium 4 processor. If you want the runtime system to be compatible with older processors (back to 486) you need to pass the `--enable-ethread-pre-pentium4-compatibility' configure command line argument when configuring the system.
Diffstat (limited to 'erts/lib_src/common/ethr_cbf.c')
-rw-r--r--erts/lib_src/common/ethr_cbf.c36
1 files changed, 36 insertions, 0 deletions
diff --git a/erts/lib_src/common/ethr_cbf.c b/erts/lib_src/common/ethr_cbf.c
new file mode 100644
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+++ b/erts/lib_src/common/ethr_cbf.c
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+/*
+ * %CopyrightBegin%
+ *
+ * Copyright Ericsson AB 2010. All Rights Reserved.
+ *
+ * The contents of this file are subject to the Erlang Public License,
+ * Version 1.1, (the "License"); you may not use this file except in
+ * compliance with the License. You should have received a copy of the
+ * Erlang Public License along with this software. If not, it can be
+ * retrieved online at http://www.erlang.org/.
+ *
+ * Software distributed under the License is distributed on an "AS IS"
+ * basis, WITHOUT WARRANTY OF ANY KIND, either express or implied. See
+ * the License for the specific language governing rights and limitations
+ * under the License.
+ *
+ * %CopyrightEnd%
+ */
+
+
+/*
+ * We keep this function alone in a separate file so the
+ * compiler wont optimize it away.
+ */
+
+#ifdef HAVE_CONFIG_H
+#include "config.h"
+#endif
+
+#include "ethread.h"
+
+void
+ethr_compiler_barrier_fallback(void)
+{
+
+}