From 2c0b891afe29dd28d0e6d75e0da8681db7fd100d Mon Sep 17 00:00:00 2001
From: Ulrich Drepper <drepper@redhat.com>
Date: Wed, 24 Mar 2004 06:36:06 +0000
Subject: Update.

	* sysdeps/unix/sysv/linux/smp.h: New file.
	* sysdeps/unix/sysv/linux/sh/smp.h: New file.
	* init.c: Define __is_smp.
	(__pthread_initialize_minimal_internal): Call is_smp_system to
	initialize __is_smp.
	* pthreadP.h: Declare __is_smp.
	Define MAX_ADAPTIVE_COUNT is necessary.
	* pthread_mutex_init.c: Add comment regarding __spins field.
	* pthread_mutex_lock.c: Implement adaptive mutex type.
	* pthread_mutex_timedlock.c: Likewise.
	* sysdeps/unix/sysv/linux/pthread_mutex_cond_lock.c: Likewise.
	* sysdeps/unix/sysv/linux/alpha/bits/pthreadtypes.h (pthread_mutex_t):
	Add __spins field.
	* sysdeps/unix/sysv/linux/i386/bits/pthreadtypes.h: Likewise.
	* sysdeps/unix/sysv/linux/ia64/bits/pthreadtypes.h: Likewise.
	* sysdeps/unix/sysv/linux/powerpc/bits/pthreadtypes.h: Likewise.
	* sysdeps/unix/sysv/linux/sh/bits/pthreadtypes.h: Likewise.
	* sysdeps/unix/sysv/linux/s390/bits/pthreadtypes.h: Likewise.
	* sysdeps/unix/sysv/linux/sparc/bits/pthreadtypes.h: Likewise.
	* sysdeps/unix/sysv/linux/x86_64/bits/pthreadtypes.h: Likewise.
	* sysdeps/unix/sysv/linux/alpha/bits/pthreadtypes.h: Define
	lll_mutex_cond_trylock.
	* sysdeps/unix/sysv/linux/powerpc/bits/pthreadtypes.h: Likewise.
	* sysdeps/unix/sysv/linux/sh/bits/pthreadtypes.h: Likewise.
	* sysdeps/unix/sysv/linux/s390/bits/pthreadtypes.h: Likewise.
	* sysdeps/unix/sysv/linux/sparc/bits/pthreadtypes.h: Likewise.
	* sysdeps/unix/sysv/linux/i386/bits/pthreadtypes.h: Likewise.
	Define BUSY_WAIT_NOP.
	* sysdeps/unix/sysv/linux/ia64/bits/pthreadtypes.h: Likewise.
	* sysdeps/unix/sysv/linux/x86_64/bits/pthreadtypes.h: Likewise.

	* tst-mutex5.c: Add support for testing adaptive mutexes.
	* tst-mutex7.c: Likewise.
	* tst-mutex5a.c: New file.
	* tst-mutex7a.c: New file.
	* Makefile (tests): Add tst-mutex5a and tst-mutex7a.
---
 nptl/pthread_mutex_lock.c | 34 ++++++++++++++++++++++++++++++++--
 1 file changed, 32 insertions(+), 2 deletions(-)

(limited to 'nptl/pthread_mutex_lock.c')

diff --git a/nptl/pthread_mutex_lock.c b/nptl/pthread_mutex_lock.c
index ac770c5c00..ee39f20820 100644
--- a/nptl/pthread_mutex_lock.c
+++ b/nptl/pthread_mutex_lock.c
@@ -1,4 +1,4 @@
-/* Copyright (C) 2002, 2003 Free Software Foundation, Inc.
+/* Copyright (C) 2002, 2003, 2004 Free Software Foundation, Inc.
    This file is part of the GNU C Library.
    Contributed by Ulrich Drepper <drepper@redhat.com>, 2002.
 
@@ -25,6 +25,7 @@
 
 #ifndef LLL_MUTEX_LOCK
 # define LLL_MUTEX_LOCK(mutex) lll_mutex_lock (mutex)
+# define LLL_MUTEX_TRYLOCK(mutex) lll_mutex_trylock (mutex)
 #endif
 
 
@@ -32,6 +33,8 @@ int
 __pthread_mutex_lock (mutex)
      pthread_mutex_t *mutex;
 {
+  assert (sizeof (mutex->__size) >= sizeof (mutex->__data));
+
   pid_t id = THREAD_GETMEM (THREAD_SELF, tid);
 
   switch (__builtin_expect (mutex->__data.__kind, PTHREAD_MUTEX_TIMED_NP))
@@ -68,10 +71,37 @@ __pthread_mutex_lock (mutex)
     default:
       /* Correct code cannot set any other type.  */
     case PTHREAD_MUTEX_TIMED_NP:
-    case PTHREAD_MUTEX_ADAPTIVE_NP:
+    simple:
       /* Normal mutex.  */
       LLL_MUTEX_LOCK (mutex->__data.__lock);
       break;
+
+    case PTHREAD_MUTEX_ADAPTIVE_NP:
+      if (! __is_smp)
+	goto simple;
+
+      if (LLL_MUTEX_TRYLOCK (mutex->__data.__lock) != 0)
+	{
+	  int cnt = 0;
+	  int max_cnt = MIN (MAX_ADAPTIVE_COUNT,
+			     mutex->__data.__spins * 2 + 10);
+	  do
+	    {
+	      if (cnt++ >= max_cnt)
+		{
+		  LLL_MUTEX_LOCK (mutex->__data.__lock);
+		  break;
+		}
+
+#ifdef BUSY_WAIT_NOP
+	      BUSY_WAIT_NOP;
+#endif
+	    }
+	  while (LLL_MUTEX_TRYLOCK (mutex->__data.__lock) != 0);
+
+	  mutex->__data.__spins += (cnt - mutex->__data.__spins) / 8;
+	}
+      break;
     }
 
   /* Record the ownership.  */
-- 
cgit 1.4.1