479 // lockObject must be held.
480 // Complicated dance due to lock ordering:
481 // Must first release the classloader object lock to
482 // allow initial definer to complete the class definition
483 // and to avoid deadlock
484 // Reclaim classloader lock object with same original recursion count
485 // Must release SystemDictionary_lock after notify, since
486 // class loader lock must be claimed before SystemDictionary_lock
487 // to prevent deadlocks
488 //
489 // The notify allows applications that did an untimed wait() on
490 // the classloader object lock to not hang.
491 void SystemDictionary::double_lock_wait(Handle lockObject, TRAPS) {
492 assert_lock_strong(SystemDictionary_lock);
493
494 bool calledholdinglock
495 = ObjectSynchronizer::current_thread_holds_lock((JavaThread*)THREAD, lockObject);
496 assert(calledholdinglock,"must hold lock for notify");
497 assert((!(lockObject() == _system_loader_lock_obj) && !is_parallelCapable(lockObject)), "unexpected double_lock_wait");
498 ObjectSynchronizer::notifyall(lockObject, THREAD);
499 intptr_t recursions = ObjectSynchronizer::complete_exit(lockObject, THREAD);
500 SystemDictionary_lock->wait();
501 SystemDictionary_lock->unlock();
502 ObjectSynchronizer::reenter(lockObject, recursions, THREAD);
503 SystemDictionary_lock->lock();
504 }
505
506 // If the class in is in the placeholder table, class loading is in progress
507 // For cases where the application changes threads to load classes, it
508 // is critical to ClassCircularity detection that we try loading
509 // the superclass on the same thread internally, so we do parallel
510 // super class loading here.
511 // This also is critical in cases where the original thread gets stalled
512 // even in non-circularity situations.
513 // Note: must call resolve_super_or_fail even if null super -
514 // to force placeholder entry creation for this class for circularity detection
515 // Caller must check for pending exception
516 // Returns non-null Klass* if other thread has completed load
517 // and we are done,
518 // If return null Klass* and no pending exception, the caller must load the class
519 instanceKlassHandle SystemDictionary::handle_parallel_super_load(
520 Symbol* name, Symbol* superclassname, Handle class_loader,
521 Handle protection_domain, Handle lockObject, TRAPS) {
522
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479 // lockObject must be held.
480 // Complicated dance due to lock ordering:
481 // Must first release the classloader object lock to
482 // allow initial definer to complete the class definition
483 // and to avoid deadlock
484 // Reclaim classloader lock object with same original recursion count
485 // Must release SystemDictionary_lock after notify, since
486 // class loader lock must be claimed before SystemDictionary_lock
487 // to prevent deadlocks
488 //
489 // The notify allows applications that did an untimed wait() on
490 // the classloader object lock to not hang.
491 void SystemDictionary::double_lock_wait(Handle lockObject, TRAPS) {
492 assert_lock_strong(SystemDictionary_lock);
493
494 bool calledholdinglock
495 = ObjectSynchronizer::current_thread_holds_lock((JavaThread*)THREAD, lockObject);
496 assert(calledholdinglock,"must hold lock for notify");
497 assert((!(lockObject() == _system_loader_lock_obj) && !is_parallelCapable(lockObject)), "unexpected double_lock_wait");
498 ObjectSynchronizer::notifyall(lockObject, THREAD);
499 intptr_t saved_recursions, saved_trace_exit_stack;
500 ObjectSynchronizer::complete_exit(lockObject, &saved_recursions, &saved_trace_exit_stack, THREAD);
501 SystemDictionary_lock->wait();
502 SystemDictionary_lock->unlock();
503 ObjectSynchronizer::reenter(lockObject, saved_recursions, saved_trace_exit_stack, THREAD);
504 SystemDictionary_lock->lock();
505 }
506
507 // If the class in is in the placeholder table, class loading is in progress
508 // For cases where the application changes threads to load classes, it
509 // is critical to ClassCircularity detection that we try loading
510 // the superclass on the same thread internally, so we do parallel
511 // super class loading here.
512 // This also is critical in cases where the original thread gets stalled
513 // even in non-circularity situations.
514 // Note: must call resolve_super_or_fail even if null super -
515 // to force placeholder entry creation for this class for circularity detection
516 // Caller must check for pending exception
517 // Returns non-null Klass* if other thread has completed load
518 // and we are done,
519 // If return null Klass* and no pending exception, the caller must load the class
520 instanceKlassHandle SystemDictionary::handle_parallel_super_load(
521 Symbol* name, Symbol* superclassname, Handle class_loader,
522 Handle protection_domain, Handle lockObject, TRAPS) {
523
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