* src/vm/global.h: Made 'lockword' member of java_object_t a plain

integer type because offsetof works only on POD structs (and gcc
complains about that).
* src/threads/lockword.hpp: Lockword references its data member now
instead of containing it.
* src/threads/lock.cpp: Adapted to new Lockword signature.
* src/vm/array.hpp: Likewise.
* src/vm/class.cpp: Likewise.
* src/vm/jit/builtin.cpp: Likewise.
* src/vm/string.cpp: Likewise.

diff --git a/src/threads/lock.cpp b/src/threads/lock.cpp
index 140905e2b6625ae6b6bf497ff41947e8bbf494e0..87851a731f1af33fb61a249c8510ac7a60caee70 100644 (file)
--- a/src/threads/lock.cpp
+++ b/src/threads/lock.cpp
@@ -1,6 +1,6 @@
 /* src/threads/lock.cpp - lock implementation
 
-   Copyright (C) 1996-2005, 2006, 2007, 2008
+   Copyright (C) 1996-2005, 2006, 2007, 2008, 2010
    CACAOVM - Verein zur Foerderung der freien virtuellen Maschine CACAO
 
    This file is part of CACAO.
@@ -143,7 +143,7 @@ static lock_hashtable_t lock_hashtable;
 
 static void lock_hashtable_init(void);
 
-static inline Lockword* lock_lockword_get(java_handle_t* o);
+static inline uintptr_t* lock_lockword_get(java_handle_t* o);
 static void lock_record_enter(threadobject *t, lock_record_t *lr);
 static void lock_record_exit(threadobject *t, lock_record_t *lr);
 static bool lock_record_wait(threadobject *t, lock_record_t *lr, s8 millis, s4 nanos);
@@ -431,10 +431,16 @@ static lock_record_t *lock_hashtable_get(java_handle_t* o)
        u4             slot;
        lock_record_t *lr;
 
-       Lockword* lockword = lock_lockword_get(o);
+       // lw_cache is used throughout this file because the lockword can change at
+       // any time, unless it is absolutely certain that we are holding the lock.
+       // We don't do deflation, so we would also not expect a fat lockword to
+       // change, but for the sake of uniformity, lw_cache is used even in this
+       // case.
+       uintptr_t lw_cache = *lock_lockword_get(o);
+       Lockword lockword(lw_cache);
 
-       if (lockword->is_fat_lock())
-               return lockword->get_fat_lock();
+       if (lockword.is_fat_lock())
+               return lockword.get_fat_lock();
 
        // Lock the hashtable.
        lock_hashtable.mutex->lock();
@@ -503,8 +509,8 @@ static lock_record_t *lock_hashtable_get(java_handle_t* o)
 #if defined(ENABLE_GC_BOEHM)
 void lock_schedule_lockrecord_removal(java_handle_t *o)
 {
-       Lockword* lockword = lock_lockword_get(o);
-       if (!lockword->is_fat_lock())
+       Lockword lockword(*lock_lockword_get(o));
+       if (!lockword.is_fat_lock())
                /* there is no lock record */
                return;
 
@@ -536,12 +542,13 @@ static void lock_hashtable_remove(threadobject *t, java_handle_t *o)
 
        /* get lock record */
 
-       Lockword* lockword = lock_lockword_get(o);
+       uintptr_t lw_cache = *lock_lockword_get(o);
+       Lockword lockword(lw_cache);
 
        // Sanity check.
-       assert(lockword->is_fat_lock());
+       assert(lockword.is_fat_lock());
 
-       lr = lockword->get_fat_lock();
+       lr = lockword.get_fat_lock();
 
        /* remove the lock-record from the hashtable */
 
@@ -628,7 +635,7 @@ static void lock_record_finalizer(void *object, void *p)
 
 *******************************************************************************/
 
-static inline Lockword* lock_lockword_get(java_handle_t* o)
+static inline uintptr_t* lock_lockword_get(java_handle_t* o)
 {
 #if defined(ENABLE_GC_CACAO)
        // Sanity check.
@@ -695,8 +702,8 @@ static inline void lock_record_exit(threadobject *t, lock_record_t *lr)
 
 static void lock_inflate(java_handle_t *o, lock_record_t *lr)
 {
-       Lockword* lockword = lock_lockword_get(o);
-       lockword->inflate(lr);
+       Lockword lockword(*lock_lockword_get(o));
+       lockword.inflate(lr);
 }
 
 
@@ -716,13 +723,14 @@ static void lock_inflate(java_handle_t *o, lock_record_t *lr)
 
 *******************************************************************************/
 
-static void sable_flc_waiting(Lockword *lockword, threadobject *t, java_handle_t *o)
+static void sable_flc_waiting(uintptr_t lw_cache, threadobject *t, java_handle_t *o)
 {
        int32_t index;
        threadobject *t_other;
        int old_flc;
 
-       index = lockword->get_thin_lock_thread_index();
+       Lockword lockword(lw_cache);
+       index = lockword.get_thin_lock_thread_index();
        t_other = ThreadList::get_thread_by_index(index);
 
        // The lockword could have changed during our way here.  If the
@@ -741,10 +749,10 @@ static void sable_flc_waiting(Lockword *lockword, threadobject *t, java_handle_t
        // Set FLC bit first, then read the lockword again.
        Atomic::memory_barrier();
 
-       lockword = lock_lockword_get(o);
+       lw_cache = *lock_lockword_get(o);
 
        /* Lockword is still the way it was seen before */
-       if (lockword->is_thin_lock() && (lockword->get_thin_lock_thread_index() == index))
+       if (lockword.is_thin_lock() && (lockword.get_thin_lock_thread_index() == index))
        {
                threadobject *f;
                /* Add tuple (t, o) to the other thread's FLC list */
@@ -801,8 +809,8 @@ static void notify_flc_waiters(threadobject *t, java_handle_t *o)
                           block on it. */
 
                        // Only if not already inflated.
-                       Lockword* lockword = lock_lockword_get(current->flc_object);
-                       if (lockword->is_thin_lock()) {
+                       Lockword lockword(*lock_lockword_get(current->flc_object));
+                       if (lockword.is_thin_lock()) {
                                lock_record_t *lr = lock_hashtable_get(current->flc_object);
                                lock_record_enter(t, lr);
 
@@ -859,15 +867,17 @@ bool lock_monitor_enter(java_handle_t *o)
 
 retry:
        // Most common case: try to thin-lock an unlocked object.
-       Lockword* lockword = lock_lockword_get(o);
-       bool result = lockword->lock(thinlock);
+       uintptr_t *lw_ptr = lock_lockword_get(o);
+       uintptr_t lw_cache = *lw_ptr;
+       Lockword lockword(lw_cache);
+       bool result = Lockword(*lw_ptr).lock(thinlock);
 
        if (result == true) {
                // Success, we locked it.
                // NOTE: The Java Memory Model requires a memory barrier here.
 #if defined(CAS_PROVIDES_FULL_BARRIER) && CAS_PROVIDES_FULL_BARRIER
                // On some architectures, the CAS (hidden in the
-               // lockword->lock call above), already provides this barrier,
+               // lockword.lock call above), already provides this barrier,
                // so we only need to inform the compiler.
                Atomic::instruction_barrier();
 #else
@@ -880,11 +890,11 @@ retry:
        // NOTE: We don't have to worry about stale values here, as any
        // stale value will indicate another thread holding the lock (or
        // an inflated lock).
-       if (lockword->get_thin_lock_without_count() == thinlock) {
+       if (lockword.get_thin_lock_without_count() == thinlock) {
                // We own this monitor.  Check the current recursion count.
-               if (lockword->is_max_thin_lock_count() == false) {
+               if (lockword.is_max_thin_lock_count() == false) {
                        // The recursion count is low enough.
-                       lockword->increase_thin_lock_count();
+                       Lockword(*lw_ptr).increase_thin_lock_count();
 
                        // Success, we locked it.
                        return true;
@@ -903,8 +913,8 @@ retry:
        }
 
        // The lock is either contented or fat.
-       if (lockword->is_fat_lock()) {
-               lock_record_t* lr = lockword->get_fat_lock();
+       if (lockword.is_fat_lock()) {
+               lock_record_t* lr = lockword.get_fat_lock();
 
                // Check for recursive entering.
                if (lr->owner == t) {
@@ -927,7 +937,7 @@ retry:
        jvmti_MonitorContendedEntering(false, o);
 #endif
 
-       sable_flc_waiting(lockword, t, o);
+       sable_flc_waiting(lw_cache, t, o);
 
 #if defined(ENABLE_JVMTI)
        /* Monitor Contended Entered */
@@ -971,13 +981,15 @@ bool lock_monitor_exit(java_handle_t* o)
 
        // We don't have to worry about stale values here, as any stale
        // value will indicate that we don't own the lock.
-       Lockword* lockword = lock_lockword_get(o);
+       uintptr_t *lw_ptr = lock_lockword_get(o);
+       uintptr_t lw_cache = *lw_ptr;
+       Lockword lockword(lw_cache);
 
        // Most common case: we release a thin lock that we hold once.
-       if (lockword->get_thin_lock() == thinlock) {
+       if (lockword.get_thin_lock() == thinlock) {
                // Memory barrier for Java Memory Model.
                Atomic::write_memory_barrier();
-               lockword->unlock();
+               Lockword(*lw_ptr).unlock();
                // Memory barrier for FLC bit testing.
                Atomic::memory_barrier();
 
@@ -994,14 +1006,14 @@ bool lock_monitor_exit(java_handle_t* o)
        }
 
        // Next common case: we release a recursive lock, count > 0.
-       if (lockword->get_thin_lock_without_count() == thinlock) {
-               lockword->decrease_thin_lock_count();
+       if (lockword.get_thin_lock_without_count() == thinlock) {
+               Lockword(*lw_ptr).decrease_thin_lock_count();
                return true;
        }
 
        // Either the lock is fat, or we don't hold it at all.
-       if (lockword->is_fat_lock()) {
-               lock_record_t* lr = lockword->get_fat_lock();
+       if (lockword.is_fat_lock()) {
+               lock_record_t* lr = lockword.get_fat_lock();
 
                // Check if we own this monitor.
                // NOTE: We don't have to worry about stale values here, as
@@ -1175,13 +1187,15 @@ static void lock_monitor_wait(threadobject *t, java_handle_t *o, s8 millis, s4 n
 {
        lock_record_t *lr;
 
-       Lockword* lockword = lock_lockword_get(o);
+       uintptr_t *lw_ptr = lock_lockword_get(o);
+       uintptr_t lw_cache = *lw_ptr;
+       Lockword lockword(lw_cache);
 
        // Check if we own this monitor.
        // NOTE: We don't have to worry about stale values here, as any
        // stale value will fail this check.
-       if (lockword->is_fat_lock()) {
-               lr = lockword->get_fat_lock();
+       if (lockword.is_fat_lock()) {
+               lr = lockword.get_fat_lock();
 
                if (lr->owner != t) {
                        exceptions_throw_illegalmonitorstateexception();
@@ -1190,7 +1204,7 @@ static void lock_monitor_wait(threadobject *t, java_handle_t *o, s8 millis, s4 n
        }
        else {
                // It's a thin lock.
-               if (lockword->get_thin_lock_without_count() != t->thinlock) {
+               if (lockword.get_thin_lock_without_count() != t->thinlock) {
                        exceptions_throw_illegalmonitorstateexception();
                        return;
                }
@@ -1200,7 +1214,7 @@ static void lock_monitor_wait(threadobject *t, java_handle_t *o, s8 millis, s4 n
                lock_record_enter(t, lr);
 
                // Inflate this lock.
-               lockword->inflate(lr);
+               Lockword(*lw_ptr).inflate(lr);
 
                notify_flc_waiters(t, o);
        }
@@ -1287,14 +1301,15 @@ static void lock_monitor_notify(threadobject *t, java_handle_t *o, bool one)
                // This scope is inside a critical section.
                GCCriticalSection cs;
 
-               Lockword* lockword = lock_lockword_get(o);
+               uintptr_t lw_cache = *lock_lockword_get(o);
+               Lockword lockword(lw_cache);
 
                // Check if we own this monitor.
                // NOTE: We don't have to worry about stale values here, as any
                // stale value will fail this check.
 
-               if (lockword->is_fat_lock()) {
-                       lr = lockword->get_fat_lock();
+               if (lockword.is_fat_lock()) {
+                       lr = lockword.get_fat_lock();
 
                        if (lr->owner != t) {
                                exceptions_throw_illegalmonitorstateexception();
@@ -1303,7 +1318,7 @@ static void lock_monitor_notify(threadobject *t, java_handle_t *o, bool one)
                }
                else {
                        // It's a thin lock.
-                       if (lockword->get_thin_lock_without_count() != t->thinlock) {
+                       if (lockword.get_thin_lock_without_count() != t->thinlock) {
                                exceptions_throw_illegalmonitorstateexception();
                                return;
                        }
@@ -1345,16 +1360,17 @@ bool lock_is_held_by_current_thread(java_handle_t *o)
        // NOTE: We don't have to worry about stale values here, as any
        // stale value will fail this check.
        threadobject* t = thread_get_current();
-       Lockword* lockword = lock_lockword_get(o);
+       uintptr_t lw_cache = *lock_lockword_get(o);
+       Lockword lockword(lw_cache);
 
-       if (lockword->is_fat_lock()) {
+       if (lockword.is_fat_lock()) {
                // It's a fat lock.
-               lock_record_t* lr = lockword->get_fat_lock();
+               lock_record_t* lr = lockword.get_fat_lock();
                return (lr->owner == t);
        }
        else {
                // It's a thin lock.
-               return (lockword->get_thin_lock_without_count() == t->thinlock);
+               return (lockword.get_thin_lock_without_count() == t->thinlock);
        }
 }
 

diff --git a/src/threads/lockword.hpp b/src/threads/lockword.hpp
index 74ccb94fd9542edc1fd0b76bef443a6b14867a9e..99b2d82960261b2c57becf87228c8deabdfa2565 100644 (file)
--- a/src/threads/lockword.hpp
+++ b/src/threads/lockword.hpp
@@ -1,6 +1,6 @@
 /* src/threads/lockword.hpp - lockword implementation
 
-   Copyright (C) 2008
+   Copyright (C) 2008-2010
    CACAOVM - Verein zur Foerderung der freien virtuellen Maschine CACAO
 
    This file is part of CACAO.
@@ -53,13 +53,10 @@ private:
 
 private:
        // The actual lockword.
-       uintptr_t _lockword;
-
-private:
-       Lockword(uintptr_t lockword) : _lockword(lockword) {}
+       uintptr_t& _lockword;
 
 public:
-       Lockword() : _lockword(THIN_UNLOCKED) {}
+       Lockword(uintptr_t& lockword) : _lockword(lockword) {}
 
        void init() { _lockword = THIN_UNLOCKED; } // REMOVEME
 

diff --git a/src/vm/array.hpp b/src/vm/array.hpp
index 1097734dc7c6632096f9e6f3d70edd31477a4185..d6406eae4290c76a880ed890b4cbf8e632b7504c 100644 (file)
--- a/src/vm/array.hpp
+++ b/src/vm/array.hpp
@@ -1,6 +1,6 @@
 /* src/vm/array.hpp - Java array functions
 
-   Copyright (C) 2007, 2009
+   Copyright (C) 2007, 2009, 2010
    CACAOVM - Verein zur Foerderung der freien virtuellen Maschine CACAO
    Copyright (C) 2008 Theobroma Systems Ltd.
 
@@ -160,7 +160,7 @@ inline Array::Array(int32_t size, classinfo* arrayclass)
        LLNI_vftbl_direct(a) = arrayclass->vftbl;
 
 #if defined(ENABLE_THREADS)
-       a->objheader.lockword.init();
+       Lockword(a->objheader.lockword).init();
 #endif
 
        a->size = size;

diff --git a/src/vm/class.cpp b/src/vm/class.cpp
index ee17a20ca34b2cf212d14a819c07425fee45992c..601ac6cfd7a235c89d9d12d39f4baf38dc235391 100644 (file)
--- a/src/vm/class.cpp
+++ b/src/vm/class.cpp
@@ -1,6 +1,6 @@
 /* src/vm/class.cpp - class related functions
 
-   Copyright (C) 1996-2005, 2006, 2007, 2008
+   Copyright (C) 1996-2005, 2006, 2007, 2008, 2010
    CACAOVM - Verein zur Foerderung der freien virtuellen Maschine CACAO
 
    This file is part of CACAO.
@@ -177,7 +177,7 @@ classinfo *class_create_classinfo(utf *classname)
        if (classname != utf_not_named_yet)
                class_set_packagename(c);
 
-       c->object.header.lockword.init();
+       Lockword(c->object.header.lockword).init();
 
        return c;
 }

diff --git a/src/vm/global.h b/src/vm/global.h
index 45287193b1bcab37471c04ca56d04be3132fc8e4..e761d76eb3a0af8d705ee15dad35f10247856d93 100644 (file)
--- a/src/vm/global.h
+++ b/src/vm/global.h
@@ -1,6 +1,6 @@
 /* src/vm/global.h - global definitions
 
-   Copyright (C) 1996-2005, 2006, 2007, 2008
+   Copyright (C) 1996-2005, 2006, 2007, 2008, 2010
    CACAOVM - Verein zur Foerderung der freien virtuellen Maschine CACAO
 
    This file is part of CACAO.
@@ -247,7 +247,7 @@ typedef struct java_objectarray_t java_objectarray_t;
 struct java_object_t {                 /* header for all objects              */
        struct _vftbl *vftbl;              /* pointer to virtual function table   */
 #if defined(ENABLE_THREADS)
-       Lockword       lockword;
+       uintptr_t      lockword;
 #endif
 #if defined(ENABLE_GC_CACAO)
        uintptr_t      hdrflags;           /* word containing the GC bits         */

diff --git a/src/vm/jit/builtin.cpp b/src/vm/jit/builtin.cpp
index 46945ada4a0d21e6163602cf5cb7cacd1a598287..146e64dffdb87a8fbbc3820076088d0d08cb02ab 100644 (file)
--- a/src/vm/jit/builtin.cpp
+++ b/src/vm/jit/builtin.cpp
@@ -1,6 +1,6 @@
 /* src/vm/jit/builtin.cpp - functions for unsupported operations
 
-   Copyright (C) 1996-2005, 2006, 2007, 2008
+   Copyright (C) 1996-2005, 2006, 2007, 2008, 2010
    CACAOVM - Verein zur Foerderung der freien virtuellen Maschine CACAO
 
    This file is part of CACAO.
@@ -863,7 +863,7 @@ java_handle_t *builtin_new(classinfo *c)
        LLNI_vftbl_direct(o) = c->vftbl;
 
 #if defined(ENABLE_THREADS)
-       LLNI_DIRECT(o)->lockword.init();
+       Lockword(LLNI_DIRECT(o)->lockword).init();
 #endif
 
        CYCLES_STATS_GET(cycles_end);
@@ -945,7 +945,7 @@ java_handle_t *builtin_tlh_new(classinfo *c)
        LLNI_vftbl_direct(o) = c->vftbl;
 
 # if defined(ENABLE_THREADS)
-       LLNI_DIRECT(o)->lockword.init();
+       Lockword(LLNI_DIRECT(o)->lockword).init();
 # endif
 
        CYCLES_STATS_GET(cycles_end);
@@ -1024,7 +1024,7 @@ java_object_t *builtin_fast_new(classinfo *c)
        o->vftbl = c->vftbl;
 
 #if defined(ENABLE_THREADS)
-       LLNI_DIRECT(o)->lockword.init();
+       Lockword(LLNI_DIRECT(o)->lockword).init();
 #endif
 
        CYCLES_STATS_GET(cycles_end);
@@ -2163,7 +2163,7 @@ java_handle_t *builtin_clone(void *env, java_handle_t *o)
 #endif
 
 #if defined(ENABLE_THREADS)
-               LLNI_DIRECT(co)->lockword.init();
+               Lockword(LLNI_DIRECT(co)->lockword).init();
 #endif
 
                LLNI_CRITICAL_END;
@@ -2198,7 +2198,7 @@ java_handle_t *builtin_clone(void *env, java_handle_t *o)
 #endif
 
 #if defined(ENABLE_THREADS)
-       LLNI_DIRECT(co)->lockword.init();
+       Lockword(LLNI_DIRECT(co)->lockword).init();
 #endif
 
        LLNI_CRITICAL_END;

diff --git a/src/vm/string.cpp b/src/vm/string.cpp
index 45b4ad46ebffcf421c594820e695361ad2c16980..ab38e66984428263db3c39ad4836597fb266cb12 100644 (file)
--- a/src/vm/string.cpp
+++ b/src/vm/string.cpp
@@ -1,6 +1,6 @@
 /* src/vm/string.cpp - java.lang.String related functions
 
-   Copyright (C) 1996-2005, 2006, 2007, 2008
+   Copyright (C) 1996-2005, 2006, 2007, 2008, 2010
    CACAOVM - Verein zur Foerderung der freien virtuellen Maschine CACAO
 
    This file is part of CACAO.
@@ -547,7 +547,7 @@ static java_handle_t *literalstring_u2(java_handle_chararray_t *a, int32_t lengt
 #endif
 
 #if defined(ENABLE_THREADS)
-       o->lockword.init();
+       Lockword(o->lockword).init();
 #endif
 
        o->vftbl = class_java_lang_String->vftbl;