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.

1 files changed, 67 insertions, 0 deletions

diff --git a/erts/include/internal/ethr_internal.h b/erts/include/internal/ethr_internal.h
new file mode 100644
index 0000000000..e9c3daf783
--- /dev/null
+++ b/erts/include/internal/ethr_internal.h
@@ -0,0 +1,67 @@
+/*
+ * %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%
+ */
+
+/*
+ * Description: Internal ethread exports
+ * Author: Rickard Green
+ */
+
+#ifndef ETHR_INTERNAL_H__
+#define ETHR_INTERNAL_H__
+
+#include "erl_misc_utils.h"
+
+extern ethr_memory_allocators ethr_mem__;
+extern erts_cpu_info_t *ethr_cpu_info__;
+extern size_t ethr_pagesize__;
+extern size_t ethr_min_stack_size__; /* kilo words */
+extern size_t ethr_max_stack_size__; /* kilo words */
+extern int ethr_not_completely_inited__;
+extern int ethr_not_inited__;
+
+extern void *(*ethr_thr_prepare_func__)(void);
+extern void (*ethr_thr_parent_func__)(void *);
+extern void (*ethr_thr_child_func__)(void *);
+
+#define ETHR_PAGE_ALIGN(SZ) \
+  (((((size_t) (SZ)) - 1)/ethr_pagesize__ + 1)*ethr_pagesize__)
+#define ETHR_B2KW(B) ((((size_t) (B)) - 1)/(sizeof(void *)*1024) + 1)
+#define ETHR_KW2B(KW) (((size_t) (KW))*sizeof(void *)*1024)
+
+#undef ETHR_STACK_GUARD_SIZE 
+#ifdef ETHR_HAVE_PTHREAD_ATTR_SETGUARDSIZE
+#  define ETHR_STACK_GUARD_SIZE (ethr_pagesize__)
+#endif
+
+/* implemented in lib_src/<thr-lib>/ethread.c */
+int ethr_set_tse__(ethr_ts_event *tsep);
+ethr_ts_event *ethr_get_tse__(void);
+ETHR_PROTO_NORETURN__ ethr_abort__(void);
+#ifdef ETHR_WIN32_THREADS
+int ethr_win_get_errno__(void);
+#endif
+
+/* implemented in lib_src/common/ethread_aux.c */
+int ethr_init_common__(ethr_init_data *id);
+int ethr_late_init_common__(ethr_late_init_data *lid);
+void ethr_run_exit_handlers__(void);
+void ethr_ts_event_destructor__(void *vtsep);
+
+
+#endif