#include "native/llni.h"
+#include "threads/atomic.hpp"
#include "threads/lock.hpp"
#include "threads/mutex.hpp"
#include "threads/threadlist.hpp"
#include <vmlog_cacao.h>
#endif
-/* arch.h must be here because it defines USE_FAKE_ATOMIC_INSTRUCTIONS */
-
-#include "arch.h"
-
-/* includes for atomic instructions: */
-
-#if defined(USE_FAKE_ATOMIC_INSTRUCTIONS)
-#include "threads/posix/generic-primitives.h"
-#else
-#include "threads/atomic.hpp"
-#endif
-
#if defined(ENABLE_JVMTI)
#include "native/jvmti/cacaodbg.h"
#endif
* 1..............the shape bit is 1 in fat lock mode
*/
-#if SIZEOF_VOID_P == 8
-#define THIN_LOCK_WORD_SIZE 64
-#else
-#define THIN_LOCK_WORD_SIZE 32
-#endif
-
-#define THIN_LOCK_SHAPE_BIT 0x01
-
-#define THIN_UNLOCKED 0
-
-#define THIN_LOCK_COUNT_SHIFT 1
-#define THIN_LOCK_COUNT_SIZE 8
-#define THIN_LOCK_COUNT_INCR (1 << THIN_LOCK_COUNT_SHIFT)
-#define THIN_LOCK_COUNT_MAX ((1 << THIN_LOCK_COUNT_SIZE) - 1)
-#define THIN_LOCK_COUNT_MASK (THIN_LOCK_COUNT_MAX << THIN_LOCK_COUNT_SHIFT)
-
-#define THIN_LOCK_TID_SHIFT (THIN_LOCK_COUNT_SIZE + THIN_LOCK_COUNT_SHIFT)
-#define THIN_LOCK_TID_SIZE (THIN_LOCK_WORD_SIZE - THIN_LOCK_TID_SHIFT)
-
-#define IS_THIN_LOCK(lockword) (!((lockword) & THIN_LOCK_SHAPE_BIT))
-#define IS_FAT_LOCK(lockword) ((lockword) & THIN_LOCK_SHAPE_BIT)
-
-#define GET_FAT_LOCK(lockword) ((lock_record_t *) ((lockword) & ~THIN_LOCK_SHAPE_BIT))
-#define MAKE_FAT_LOCK(ptr) ((uintptr_t) (ptr) | THIN_LOCK_SHAPE_BIT)
-
-#define LOCK_WORD_WITHOUT_COUNT(lockword) ((lockword) & ~THIN_LOCK_COUNT_MASK)
-#define GET_THREAD_INDEX(lockword) ((unsigned) lockword >> THIN_LOCK_TID_SHIFT)
-
-
/* global variables ***********************************************************/
/* hashtable mapping objects to lock records */
static void lock_hashtable_init(void);
-static inline uintptr_t lock_lockword_get(threadobject *t, java_handle_t *o);
-static inline void lock_lockword_set(threadobject *t, java_handle_t *o, uintptr_t lockword);
+static inline Lockword* 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);
}
-/* lock_pre_compute_thinlock ***************************************************
-
- Pre-compute the thin lock value for a thread index.
-
- IN:
- index........the thead index (>= 1)
-
- RETURN VALUE:
- the thin lock value for this thread index
-
-*******************************************************************************/
-
-ptrint lock_pre_compute_thinlock(s4 index)
-{
- return (index << THIN_LOCK_TID_SHIFT) | THIN_UNLOCKED;
-}
-
-
/* lock_record_new *************************************************************
Allocate a lock record.
yet, create it and enter it in the hashtable.
IN:
- t....the current thread
o....the object to look up
RETURN VALUE:
static void lock_record_finalizer(void *object, void *p);
#endif
-static lock_record_t *lock_hashtable_get(threadobject *t, java_handle_t *o)
+static lock_record_t *lock_hashtable_get(java_handle_t* o)
{
- uintptr_t lockword;
+ // This function is inside a critical section.
+ GCCriticalSection cs;
+
u4 slot;
lock_record_t *lr;
- lockword = lock_lockword_get(t, o);
+ Lockword* lockword = lock_lockword_get(o);
- if (IS_FAT_LOCK(lockword))
- return GET_FAT_LOCK(lockword);
+ if (lockword->is_fat_lock())
+ return lockword->get_fat_lock();
// Lock the hashtable.
lock_hashtable.mutex->lock();
/* lookup the lock record in the hashtable */
- LLNI_CRITICAL_START_THREAD(t);
slot = heap_hashcode(LLNI_DIRECT(o)) % lock_hashtable.size;
lr = lock_hashtable.ptr[slot];
if (lr->object == LLNI_DIRECT(o))
break;
}
- LLNI_CRITICAL_END_THREAD(t);
if (lr == NULL) {
/* not found, we must create a new one */
lr = lock_record_new();
- LLNI_CRITICAL_START_THREAD(t);
lr->object = LLNI_DIRECT(o);
- LLNI_CRITICAL_END_THREAD(t);
#if defined(ENABLE_GC_BOEHM)
/* register new finalizer to clean up the lock record */
static void lock_hashtable_remove(threadobject *t, java_handle_t *o)
{
- uintptr_t lockword;
lock_record_t *lr;
u4 slot;
lock_record_t *tmplr;
/* get lock record */
- lockword = lock_lockword_get(t, o);
+ Lockword* lockword = lock_lockword_get(o);
- assert(IS_FAT_LOCK(lockword));
+ // Sanity check.
+ assert(lockword->is_fat_lock());
- lr = GET_FAT_LOCK(lockword);
+ lr = lockword->get_fat_lock();
/* remove the lock-record from the hashtable */
- LLNI_CRITICAL_START_THREAD(t);
slot = heap_hashcode(LLNI_DIRECT(o)) % lock_hashtable.size;
tmplr = lock_hashtable.ptr[slot];
- LLNI_CRITICAL_END_THREAD(t);
if (tmplr == lr) {
/* special handling if it's the first in the chain */
}
-/*============================================================================*/
-/* OBJECT LOCK INITIALIZATION */
-/*============================================================================*/
-
-
-/* lock_init_object_lock *******************************************************
-
- Initialize the monitor pointer of the given object. The monitor gets
- initialized to an unlocked state.
-
-*******************************************************************************/
-
-void lock_init_object_lock(java_object_t *o)
-{
- assert(o);
-
- o->lockword = THIN_UNLOCKED;
-}
-
-
/*============================================================================*/
/* LOCKING ALGORITHM */
/*============================================================================*/
Get the lockword for the given object.
IN:
- t............the current thread
o............the object
*******************************************************************************/
-static inline uintptr_t lock_lockword_get(threadobject *t, java_handle_t *o)
+static inline Lockword* lock_lockword_get(java_handle_t* o)
{
- uintptr_t lockword;
-
- LLNI_CRITICAL_START_THREAD(t);
- lockword = LLNI_DIRECT(o)->lockword;
- LLNI_CRITICAL_END_THREAD(t);
-
- return lockword;
-}
-
-
-/* lock_lockword_set ***********************************************************
-
- Set the lockword for the given object.
-
- IN:
- t............the current thread
- o............the object
- lockword.....the new lockword value
-
-*******************************************************************************/
+#if defined(ENABLE_GC_CACAO)
+ // Sanity check.
+ assert(GCCriticalSection::inside() == true);
+#endif
-static inline void lock_lockword_set(threadobject *t, java_handle_t *o, uintptr_t lockword)
-{
- LLNI_CRITICAL_START_THREAD(t);
- LLNI_DIRECT(o)->lockword = lockword;
- LLNI_CRITICAL_END_THREAD(t);
+ return &(LLNI_DIRECT(o)->lockword);
}
owner of the monitor of the object.
IN:
- t............the current thread
o............the object of which to inflate the lock
lr...........the lock record to install. The current thread must
own the lock of this lock record!
*******************************************************************************/
-static void lock_inflate(threadobject *t, java_handle_t *o, lock_record_t *lr)
+static void lock_inflate(java_handle_t *o, lock_record_t *lr)
{
- uintptr_t lockword;
-
- /* get the current lock count */
-
- lockword = lock_lockword_get(t, o);
-
- if (IS_FAT_LOCK(lockword)) {
- assert(GET_FAT_LOCK(lockword) == lr);
- return;
- }
- else {
- assert(LOCK_WORD_WITHOUT_COUNT(lockword) == t->thinlock);
-
- /* copy the count from the thin lock */
-
- lr->count = (lockword & THIN_LOCK_COUNT_MASK) >> THIN_LOCK_COUNT_SHIFT;
- }
-
- DEBUGLOCKS(("[lock_inflate : lr=%p, t=%p, o=%p, o->lockword=%lx, count=%d]",
- lr, t, o, lockword, lr->count));
-
- /* install it */
-
- lock_lockword_set(t, o, MAKE_FAT_LOCK(lr));
+ Lockword* lockword = lock_lockword_get(o);
+ lockword->inflate(lr);
}
-static void sable_flc_waiting(ptrint lockword, threadobject *t, java_handle_t *o)
+static void sable_flc_waiting(Lockword *lockword, threadobject *t, java_handle_t *o)
{
- int index;
+ int32_t index;
threadobject *t_other;
int old_flc;
- index = GET_THREAD_INDEX(lockword);
+ index = lockword->get_thin_lock_thread_index();
t_other = ThreadList::get_thread_by_index(index);
- if (!t_other)
+ // The lockword could have changed during our way here. If the
+ // thread index is zero, the lock got unlocked and we simply
+ // return.
+ if (t_other == NULL)
/* failure, TODO: add statistics */
return;
old_flc = t_other->flc_bit;
t_other->flc_bit = true;
- DEBUGLOCKS(("thread %d set flc bit for lock-holding thread %d",
- t->index, t_other->index));
+ DEBUGLOCKS(("thread %d set flc bit for lock-holding thread %d", t->index, t_other->index));
// Set FLC bit first, then read the lockword again.
Atomic::memory_barrier();
- lockword = lock_lockword_get(t, o);
+ lockword = lock_lockword_get(o);
/* Lockword is still the way it was seen before */
- if (IS_THIN_LOCK(lockword) && (GET_THREAD_INDEX(lockword) == 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 */
t->flc_object = o;
t->flc_next = t_other->flc_list;
t_other->flc_list = t;
+ if (t->flc_next == 0)
+ t_other->flc_tail = t;
+ f = t_other->flc_tail;
for (;;)
{
// us of unlocking.
t->flc_cond->wait(t_other->flc_lock);
+ if (t_other->flc_tail != f)
+ break;
/* Traverse FLC list looking if we're still there */
current = t_other->flc_list;
while (current && current != t)
/* The object has to be inflated so the other threads can properly
block on it. */
- /* Only if not already inflated */
- ptrint lockword = lock_lockword_get(t, current->flc_object);
- if (IS_THIN_LOCK(lockword)) {
- lock_record_t *lr = lock_hashtable_get(t, current->flc_object);
+ // Only if not already inflated.
+ 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);
DEBUGLOCKS(("thread %d inflating lock of %p to lr %p",
t->index, (void*) current->flc_object, (void*) lr));
- lock_inflate(t, current->flc_object, lr);
+ lock_inflate(current->flc_object, lr);
}
}
bool lock_monitor_enter(java_handle_t *o)
{
- threadobject *t;
- /* CAUTION: This code assumes that ptrint is unsigned! */
- ptrint lockword;
- ptrint thinlock;
- lock_record_t *lr;
+ // This function is inside a critical section.
+ GCCriticalSection cs;
if (o == NULL) {
exceptions_throw_nullpointerexception();
return false;
}
- t = THREADOBJECT;
+ threadobject* t = thread_get_current();
- thinlock = t->thinlock;
+ uintptr_t thinlock = t->thinlock;
retry:
- /* most common case: try to thin-lock an unlocked object */
-
- LLNI_CRITICAL_START_THREAD(t);
- lockword = Atomic::compare_and_swap(&(LLNI_DIRECT(o)->lockword), THIN_UNLOCKED, thinlock);
- LLNI_CRITICAL_END_THREAD(t);
-
- if (lockword == THIN_UNLOCKED) {
- /* success. we locked it */
- // The Java Memory Model requires an instruction barrier here
- // (because of the CAS above).
+ // Most common case: try to thin-lock an unlocked object.
+ Lockword* lockword = lock_lockword_get(o);
+ bool result = lockword->lock(thinlock);
+
+ if (result == true) {
+ // Success, we locked it.
+ // NOTE: The Java Memory Model requires an instruction barrier
+ // here (because of the CAS above).
Atomic::instruction_barrier();
return true;
}
- /* next common case: recursive lock with small recursion count */
- /* 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 (LOCK_WORD_WITHOUT_COUNT(lockword) == thinlock) {
- /* we own this monitor */
- /* check the current recursion count */
-
- if ((lockword ^ thinlock) < (THIN_LOCK_COUNT_MAX << THIN_LOCK_COUNT_SHIFT))
- {
- /* the recursion count is low enough */
-
- lock_lockword_set(t, o, lockword + THIN_LOCK_COUNT_INCR);
-
- /* success. we locked it */
+ // Next common case: recursive lock with small recursion count.
+ // 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) {
+ // We own this monitor. Check the current recursion count.
+ if (lockword->is_max_thin_lock_count() == false) {
+ // The recursion count is low enough.
+ lockword->increase_thin_lock_count();
+
+ // Success, we locked it.
return true;
}
else {
- /* recursion count overflow */
-
- lr = lock_hashtable_get(t, o);
+ // Recursion count overflow.
+ lock_record_t* lr = lock_hashtable_get(o);
lock_record_enter(t, lr);
- lock_inflate(t, o, lr);
+ lock_inflate(o, lr);
lr->count++;
notify_flc_waiters(t, o);
}
}
- /* the lock is either contented or fat */
-
- if (IS_FAT_LOCK(lockword)) {
-
- lr = GET_FAT_LOCK(lockword);
+ // The lock is either contented or fat.
+ if (lockword->is_fat_lock()) {
+ lock_record_t* lr = lockword->get_fat_lock();
- /* check for recursive entering */
+ // Check for recursive entering.
if (lr->owner == t) {
lr->count++;
return true;
}
- /* acquire the mutex of the lock record */
-
+ // Acquire the mutex of the lock record.
lock_record_enter(t, lr);
+ // Sanity check.
assert(lr->count == 0);
-
return true;
}
*******************************************************************************/
-bool lock_monitor_exit(java_handle_t *o)
+bool lock_monitor_exit(java_handle_t* o)
{
- threadobject *t;
- uintptr_t lockword;
- ptrint thinlock;
+ // This function is inside a critical section.
+ GCCriticalSection cs;
if (o == NULL) {
exceptions_throw_nullpointerexception();
return false;
}
- t = THREADOBJECT;
-
- thinlock = t->thinlock;
+ threadobject* t = thread_get_current();
- /* We don't have to worry about stale values here, as any stale value */
- /* will indicate that we don't own the lock. */
+ uintptr_t thinlock = t->thinlock;
- lockword = lock_lockword_get(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);
- /* most common case: we release a thin lock that we hold once */
-
- if (lockword == thinlock) {
+ // Most common case: we release a thin lock that we hold once.
+ if (lockword->get_thin_lock() == thinlock) {
// Memory barrier for Java Memory Model.
Atomic::write_memory_barrier();
- lock_lockword_set(t, o, THIN_UNLOCKED);
+ lockword->unlock();
// Memory barrier for thin locking.
Atomic::memory_barrier();
return true;
}
- /* next common case: we release a recursive lock, count > 0 */
-
- if (LOCK_WORD_WITHOUT_COUNT(lockword) == thinlock) {
- lock_lockword_set(t, o, lockword - THIN_LOCK_COUNT_INCR);
+ // Next common case: we release a recursive lock, count > 0.
+ if (lockword->get_thin_lock_without_count() == thinlock) {
+ lockword->decrease_thin_lock_count();
return true;
}
- /* either the lock is fat, or we don't hold it at all */
-
- if (IS_FAT_LOCK(lockword)) {
-
- lock_record_t *lr;
-
- lr = GET_FAT_LOCK(lockword);
-
- /* check if we own this monitor */
- /* We don't have to worry about stale values here, as any stale value */
- /* will be != t and thus fail this check. */
+ // 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();
+ // Check if we own this monitor.
+ // NOTE: We don't have to worry about stale values here, as
+ // any stale value will be != t and thus fail this check.
if (lr->owner != t) {
exceptions_throw_illegalmonitorstateexception();
return false;
/* { the current thread `t` owns the lock record `lr` on object `o` } */
if (lr->count != 0) {
- /* we had locked this one recursively. just decrement, it will */
- /* still be locked. */
+ // We had locked this one recursively. Just decrement, it
+ // will still be locked.
lr->count--;
return true;
}
- /* unlock this lock record */
-
- lr->owner = NULL;
- lr->mutex->unlock();
-
+ // Unlock this lock record.
+ lock_record_exit(t, lr);
return true;
}
- /* legal thin lock cases have been handled above, so this is an error */
-
+ // Legal thin lock cases have been handled above, so this is an
+ // error.
exceptions_throw_illegalmonitorstateexception();
return false;
static void lock_monitor_wait(threadobject *t, java_handle_t *o, s8 millis, s4 nanos)
{
- uintptr_t lockword;
lock_record_t *lr;
- lockword = lock_lockword_get(t, o);
-
- /* check if we own this monitor */
- /* We don't have to worry about stale values here, as any stale value */
- /* will fail this check. */
+ Lockword* lockword = lock_lockword_get(o);
- if (IS_FAT_LOCK(lockword)) {
-
- lr = GET_FAT_LOCK(lockword);
+ // 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 (lr->owner != t) {
exceptions_throw_illegalmonitorstateexception();
}
}
else {
- /* it's a thin lock */
-
- if (LOCK_WORD_WITHOUT_COUNT(lockword) != t->thinlock) {
+ // It's a thin lock.
+ if (lockword->get_thin_lock_without_count() != t->thinlock) {
exceptions_throw_illegalmonitorstateexception();
return;
}
- /* inflate this lock */
-
- lr = lock_hashtable_get(t, o);
+ // Get the lock-record.
+ lr = lock_hashtable_get(o);
lock_record_enter(t, lr);
- lock_inflate(t, o, lr);
+
+ // Inflate this lock.
+ lockword->inflate(lr);
notify_flc_waiters(t, o);
}
static void lock_record_notify(threadobject *t, lock_record_t *lr, bool one)
{
- /* { the thread t owns the fat lock record lr on the object o } */
+#if defined(ENABLE_GC_CACAO)
+ // Sanity check.
+ assert(GCCriticalSection::inside() == false);
+#endif
+
+ // { The thread t owns the fat lock record lr on the object o }
for (List<threadobject*>::iterator it = lr->waiters->begin(); it != lr->waiters->end(); it++) {
threadobject* waiter = *it;
static void lock_monitor_notify(threadobject *t, java_handle_t *o, bool one)
{
- uintptr_t lockword;
- lock_record_t *lr;
+ lock_record_t* lr = NULL;
- lockword = lock_lockword_get(t, o);
+ {
+ // This scope is inside a critical section.
+ GCCriticalSection cs;
- /* check if we own this monitor */
- /* We don't have to worry about stale values here, as any stale value */
- /* will fail this check. */
+ Lockword* lockword = lock_lockword_get(o);
- if (IS_FAT_LOCK(lockword)) {
+ // 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.
- lr = GET_FAT_LOCK(lockword);
+ if (lockword->is_fat_lock()) {
+ lr = lockword->get_fat_lock();
- if (lr->owner != t) {
- exceptions_throw_illegalmonitorstateexception();
- return;
+ if (lr->owner != t) {
+ exceptions_throw_illegalmonitorstateexception();
+ return;
+ }
}
- }
- else {
- /* it's a thin lock */
+ else {
+ // It's a thin lock.
+ if (lockword->get_thin_lock_without_count() != t->thinlock) {
+ exceptions_throw_illegalmonitorstateexception();
+ return;
+ }
- if (LOCK_WORD_WITHOUT_COUNT(lockword) != t->thinlock) {
- exceptions_throw_illegalmonitorstateexception();
+ // No thread can wait on a thin lock, so there's nothing to do.
return;
}
-
- /* no thread can wait on a thin lock, so there's nothing to do. */
- return;
}
- /* { the thread t owns the fat lock record lr on the object o } */
-
+ // { The thread t owns the fat lock record lr on the object o }
lock_record_notify(t, lr, one);
}
bool lock_is_held_by_current_thread(java_handle_t *o)
{
- threadobject *t;
- uintptr_t lockword;
- lock_record_t *lr;
-
- t = THREADOBJECT;
-
- /* check if we own this monitor */
- /* We don't have to worry about stale values here, as any stale value */
- /* will fail this check. */
-
- lockword = lock_lockword_get(t, o);
-
- if (IS_FAT_LOCK(lockword)) {
- /* it's a fat lock */
-
- lr = GET_FAT_LOCK(lockword);
-
+ // This function is inside a critical section.
+ GCCriticalSection cs;
+
+ // 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.
+ threadobject* t = thread_get_current();
+ Lockword* lockword = lock_lockword_get(o);
+
+ if (lockword->is_fat_lock()) {
+ // It's a fat lock.
+ lock_record_t* lr = lockword->get_fat_lock();
return (lr->owner == t);
}
else {
- /* it's a thin lock */
-
- return (LOCK_WORD_WITHOUT_COUNT(lockword) == t->thinlock);
+ // It's a thin lock.
+ return (lockword->get_thin_lock_without_count() == t->thinlock);
}
}
projects / cacao.git / blobdiff