WL#2595 kernel-independent atomic operations

Backport from 6.0.14 to 5.6.0

Original code from Sergei Golubchik

3 files changed, 142 insertions, 107 deletions

diff --git a/unittest/mysys/Makefile.am b/unittest/mysys/Makefile.am
index 56c65d71396..6e8058c4d9b 100644
--- a/unittest/mysys/Makefile.am
+++ b/unittest/mysys/Makefile.am
@@ -16,6 +16,8 @@
 AM_CPPFLAGS      = @ZLIB_INCLUDES@ -I$(top_builddir)/include 
 AM_CPPFLAGS     += -I$(top_srcdir)/include -I$(top_srcdir)/unittest/mytap
 
+noinst_HEADERS = thr_template.c
+
 LDADD 		= $(top_builddir)/unittest/mytap/libmytap.a \
 		  $(top_builddir)/mysys/libmysys.a \
 		  $(top_builddir)/dbug/libdbug.a \
diff --git a/unittest/mysys/my_atomic-t.c b/unittest/mysys/my_atomic-t.c
index f2bcd360508..1a558e8cb73 100644
--- a/unittest/mysys/my_atomic-t.c
+++ b/unittest/mysys/my_atomic-t.c
@@ -1,4 +1,4 @@
-/* Copyright (C) 2006 MySQL AB
+/* Copyright (C) 2006-2008 MySQL AB, 2008 Sun Microsystems, Inc.
 
    This program is free software; you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
@@ -13,10 +13,7 @@
    along with this program; if not, write to the Free Software
    Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA */
 
-#include <my_global.h>
-#include <my_sys.h>
-#include <my_atomic.h>
-#include <tap.h>
+#include "thr_template.c"
 
 /* at least gcc 3.4.5 and 3.4.6 (but not 3.2.3) on RHEL */
 #if __GNUC__ == 3 && __GNUC_MINOR__ == 4
@@ -25,181 +22,125 @@
 #define GCC_BUG_WORKAROUND
 #endif
 
-int32 a32,b32,c32;
+volatile uint32 b32;
+volatile int32  c32;
 my_atomic_rwlock_t rwl;
 
-pthread_attr_t thr_attr;
-pthread_mutex_t mutex;
-pthread_cond_t cond;
-int N;
-
 /* add and sub a random number in a loop. Must get 0 at the end */
-pthread_handler_t test_atomic_add_handler(void *arg)
+pthread_handler_t test_atomic_add(void *arg)
 {
-  int    m=*(int *)arg;
+  int    m= (*(int *)arg)/2;
   GCC_BUG_WORKAROUND int32 x;
-  for (x=((int)((long)(&m))); m ; m--)
+  for (x= ((int)(intptr)(&m)); m ; m--)
   {
-    x=x*m+0x87654321;
+    x= (x*m+0x87654321) & INT_MAX32;
     my_atomic_rwlock_wrlock(&rwl);
-    my_atomic_add32(&a32, x);
+    my_atomic_add32(&bad, x);
     my_atomic_rwlock_wrunlock(&rwl);
 
     my_atomic_rwlock_wrlock(&rwl);
-    my_atomic_add32(&a32, -x);
+    my_atomic_add32(&bad, -x);
     my_atomic_rwlock_wrunlock(&rwl);
   }
   pthread_mutex_lock(&mutex);
-  N--;
-  if (!N) pthread_cond_signal(&cond);
+  if (!--running_threads) pthread_cond_signal(&cond);
   pthread_mutex_unlock(&mutex);
   return 0;
 }
 
 /*
   1. generate thread number 0..N-1 from b32
-  2. add it to a32
+  2. add it to bad
   3. swap thread numbers in c32
   4. (optionally) one more swap to avoid 0 as a result
-  5. subtract result from a32
-  must get 0 in a32 at the end
+  5. subtract result from bad
+  must get 0 in bad at the end
 */
-pthread_handler_t test_atomic_swap_handler(void *arg)
+pthread_handler_t test_atomic_fas(void *arg)
 {
-  int    m=*(int *)arg;
-  int32 x;
+  int    m= *(int *)arg;
+  int32  x;
 
   my_atomic_rwlock_wrlock(&rwl);
-  x=my_atomic_add32(&b32, 1);
+  x= my_atomic_add32(&b32, 1);
   my_atomic_rwlock_wrunlock(&rwl);
 
   my_atomic_rwlock_wrlock(&rwl);
-  my_atomic_add32(&a32, x);
+  my_atomic_add32(&bad, x);
   my_atomic_rwlock_wrunlock(&rwl);
 
   for (; m ; m--)
   {
     my_atomic_rwlock_wrlock(&rwl);
-    x=my_atomic_swap32(&c32, x);
+    x= my_atomic_fas32(&c32, x);
     my_atomic_rwlock_wrunlock(&rwl);
   }
 
   if (!x)
   {
     my_atomic_rwlock_wrlock(&rwl);
-    x=my_atomic_swap32(&c32, x);
+    x= my_atomic_fas32(&c32, x);
     my_atomic_rwlock_wrunlock(&rwl);
   }
 
   my_atomic_rwlock_wrlock(&rwl);
-  my_atomic_add32(&a32, -x);
+  my_atomic_add32(&bad, -x);
   my_atomic_rwlock_wrunlock(&rwl);
 
   pthread_mutex_lock(&mutex);
-  N--;
-  if (!N) pthread_cond_signal(&cond);
+  if (!--running_threads) pthread_cond_signal(&cond);
   pthread_mutex_unlock(&mutex);
   return 0;
 }
 
 /*
-  same as test_atomic_add_handler, but my_atomic_add32 is emulated with
-  (slower) my_atomic_cas32
+  same as test_atomic_add, but my_atomic_add32 is emulated with
+  my_atomic_cas32 - notice that the slowdown is proportional to the
+  number of CPUs
 */
-pthread_handler_t test_atomic_cas_handler(void *arg)
+pthread_handler_t test_atomic_cas(void *arg)
 {
-  int    m=*(int *)arg, ok;
-  GCC_BUG_WORKAROUND int32 x,y;
-  for (x=((int)((long)(&m))); m ; m--)
+  int    m= (*(int *)arg)/2, ok= 0;
+  GCC_BUG_WORKAROUND int32 x, y;
+  for (x= ((int)(intptr)(&m)); m ; m--)
   {
     my_atomic_rwlock_wrlock(&rwl);
-    y=my_atomic_load32(&a32);
+    y= my_atomic_load32(&bad);
     my_atomic_rwlock_wrunlock(&rwl);
-
-    x=x*m+0x87654321;
+    x= (x*m+0x87654321) & INT_MAX32;
     do {
       my_atomic_rwlock_wrlock(&rwl);
-      ok=my_atomic_cas32(&a32, &y, y+x);
+      ok= my_atomic_cas32(&bad, &y, (uint32)y+x);
       my_atomic_rwlock_wrunlock(&rwl);
-    } while (!ok);
+    } while (!ok) ;
     do {
       my_atomic_rwlock_wrlock(&rwl);
-      ok=my_atomic_cas32(&a32, &y, y-x);
+      ok= my_atomic_cas32(&bad, &y, y-x);
       my_atomic_rwlock_wrunlock(&rwl);
-    } while (!ok);
+    } while (!ok) ;
   }
   pthread_mutex_lock(&mutex);
-  N--;
-  if (!N) pthread_cond_signal(&cond);
+  if (!--running_threads) pthread_cond_signal(&cond);
   pthread_mutex_unlock(&mutex);
   return 0;
 }
 
-void test_atomic(const char *test, pthread_handler handler, int n, int m)
-{
-  pthread_t t;
-  ulonglong now=my_getsystime();
-
-  a32= 0;
-  b32= 0;
-  c32= 0;
-
-  diag("Testing %s with %d threads, %d iterations... ", test, n, m);
-  for (N=n ; n ; n--)
-  {
-    if (pthread_create(&t, &thr_attr, handler, &m) != 0)
-    {
-      diag("Could not create thread");
-      a32= 1;
-      goto err;
-    }
-  }
-
-  pthread_mutex_lock(&mutex);
-  while (N)
-    pthread_cond_wait(&cond, &mutex);
-  pthread_mutex_unlock(&mutex);
-  now=my_getsystime()-now;
-err:
-  ok(a32 == 0, "tested %s in %g secs", test, ((double)now)/1e7);
-}
 
-int main()
+void do_tests()
 {
-  int err;
-  MY_INIT("my_atomic-t.c");
-
-  diag("N CPUs: %d", my_getncpus());
-  err= my_atomic_initialize();
-
   plan(4);
-  ok(err == 0, "my_atomic_initialize() returned %d", err);
 
-  pthread_attr_init(&thr_attr);
-  pthread_attr_setdetachstate(&thr_attr,PTHREAD_CREATE_DETACHED);
-  pthread_mutex_init(&mutex, 0);
-  pthread_cond_init(&cond, 0);
+  bad= my_atomic_initialize();
+  ok(!bad, "my_atomic_initialize() returned %d", bad);
+
   my_atomic_rwlock_init(&rwl);
 
-#ifdef HPUX11
-#define CYCLES 1000
-#else
-#define CYCLES 10000
-#endif
-#define THREADS 100
-  test_atomic("my_atomic_add32", test_atomic_add_handler, THREADS, CYCLES);
-  test_atomic("my_atomic_swap32", test_atomic_swap_handler, THREADS, CYCLES);
-  test_atomic("my_atomic_cas32", test_atomic_cas_handler, THREADS, CYCLES);
-  /*
-    workaround until we know why it crashes randomly on some machine
-    (BUG#22320).
-  */
-  sleep(2);
-
-  pthread_mutex_destroy(&mutex);
-  pthread_cond_destroy(&cond);
-  pthread_attr_destroy(&thr_attr);
+  b32= c32= 0;
+  test_concurrently("my_atomic_add32", test_atomic_add, THREADS, CYCLES);
+  b32= c32= 0;
+  test_concurrently("my_atomic_fas32", test_atomic_fas, THREADS, CYCLES);
+  b32= c32= 0;
+  test_concurrently("my_atomic_cas32", test_atomic_cas, THREADS, CYCLES);
+
   my_atomic_rwlock_destroy(&rwl);
-  return exit_status();
 }
-
diff --git a/unittest/mysys/thr_template.c b/unittest/mysys/thr_template.c
new file mode 100644
index 00000000000..1ac03e474fd
--- /dev/null
+++ b/unittest/mysys/thr_template.c
@@ -0,0 +1,92 @@
+/* Copyright (C) 2006-2008 MySQL AB, 2008 Sun Microsystems, Inc.
+
+   This program is free software; you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation; version 2 of the License.
+
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with this program; if not, write to the Free Software
+   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA */
+
+#include <my_global.h>
+#include <my_sys.h>
+#include <my_atomic.h>
+#include <tap.h>
+
+volatile uint32 bad;
+pthread_attr_t thr_attr;
+pthread_mutex_t mutex;
+pthread_cond_t cond;
+uint running_threads;
+
+void do_tests();
+
+void test_concurrently(const char *test, pthread_handler handler, int n, int m)
+{
+  pthread_t t;
+  ulonglong now= my_getsystime();
+
+  bad= 0;
+
+  diag("Testing %s with %d threads, %d iterations... ", test, n, m);
+  for (running_threads= n ; n ; n--)
+  {
+    if (pthread_create(&t, &thr_attr, handler, &m) != 0)
+    {
+      diag("Could not create thread");
+      abort();
+    }
+  }
+  pthread_mutex_lock(&mutex);
+  while (running_threads)
+    pthread_cond_wait(&cond, &mutex);
+  pthread_mutex_unlock(&mutex);
+
+  now= my_getsystime()-now;
+  ok(!bad, "tested %s in %g secs (%d)", test, ((double)now)/1e7, bad);
+}
+
+int main(int argc __attribute__((unused)), char **argv)
+{
+  MY_INIT("thd_template");
+
+  if (argv[1] && *argv[1])
+    DBUG_SET_INITIAL(argv[1]);
+
+  pthread_mutex_init(&mutex, 0);
+  pthread_cond_init(&cond, 0);
+  pthread_attr_init(&thr_attr);
+  pthread_attr_setdetachstate(&thr_attr,PTHREAD_CREATE_DETACHED);
+
+#ifdef MY_ATOMIC_MODE_RWLOCKS
+#if defined(HPUX11) || defined(__POWERPC__) /* showed to be very slow (scheduler-related) */
+#define CYCLES 300
+#else
+#define CYCLES 3000
+#endif
+#else
+#define CYCLES 3000
+#endif
+#define THREADS 30
+
+  diag("N CPUs: %d, atomic ops: %s", my_getncpus(), MY_ATOMIC_MODE);
+
+  do_tests();
+
+  /*
+    workaround until we know why it crashes randomly on some machine
+    (BUG#22320).
+  */
+  sleep(2);
+  pthread_mutex_destroy(&mutex);
+  pthread_cond_destroy(&cond);
+  pthread_attr_destroy(&thr_attr);
+  my_end(0);
+  return exit_status();
+}
+