src/share/vm/runtime/biasedLocking.cpp

rev 11465 : Revert obsolete shared-code changes in runtime synchronizer code

*** 541,551 ****
      // compare-and-exchange an unbiased header into the mark word of
      // the object, meaning that no other thread has raced to acquire
      // the bias of the object.
      markOop biased_value       = mark;
      markOop unbiased_prototype = markOopDesc::prototype()->set_age(mark->age());
!     markOop res_mark = obj->cas_set_mark(unbiased_prototype, mark);
      if (res_mark == biased_value) {
        return BIAS_REVOKED;
      }
    } else if (mark->has_bias_pattern()) {
      Klass* k = obj->klass();
--- 541,551 ----
      // compare-and-exchange an unbiased header into the mark word of
      // the object, meaning that no other thread has raced to acquire
      // the bias of the object.
      markOop biased_value       = mark;
      markOop unbiased_prototype = markOopDesc::prototype()->set_age(mark->age());
!     markOop res_mark = (markOop) Atomic::cmpxchg_ptr(unbiased_prototype, obj->mark_addr(), mark);
      if (res_mark == biased_value) {
        return BIAS_REVOKED;
      }
    } else if (mark->has_bias_pattern()) {
      Klass* k = obj->klass();
*** 556,567 ****
        // heuristics at this point so simply update the header with a
        // CAS. If we fail this race, the object's bias has been revoked
        // by another thread so we simply return and let the caller deal
        // with it.
        markOop biased_value       = mark;
!       markOop res_mark = obj->cas_set_mark(prototype_header, mark);
!       assert(! obj->mark()->has_bias_pattern(), "even if we raced, should still be revoked");
        return BIAS_REVOKED;
      } else if (prototype_header->bias_epoch() != mark->bias_epoch()) {
        // The epoch of this biasing has expired indicating that the
        // object is effectively unbiased. Depending on whether we need
        // to rebias or revoke the bias of this object we can do it
--- 556,567 ----
        // heuristics at this point so simply update the header with a
        // CAS. If we fail this race, the object's bias has been revoked
        // by another thread so we simply return and let the caller deal
        // with it.
        markOop biased_value       = mark;
!       markOop res_mark = (markOop) Atomic::cmpxchg_ptr(prototype_header, obj->mark_addr(), mark);
!       assert(!(*(obj->mark_addr()))->has_bias_pattern(), "even if we raced, should still be revoked");
        return BIAS_REVOKED;
      } else if (prototype_header->bias_epoch() != mark->bias_epoch()) {
        // The epoch of this biasing has expired indicating that the
        // object is effectively unbiased. Depending on whether we need
        // to rebias or revoke the bias of this object we can do it
*** 571,588 ****
        // needing to revoke biases.
        if (attempt_rebias) {
          assert(THREAD->is_Java_thread(), "");
          markOop biased_value       = mark;
          markOop rebiased_prototype = markOopDesc::encode((JavaThread*) THREAD, mark->age(), prototype_header->bias_epoch());
!         markOop res_mark = obj->cas_set_mark(rebiased_prototype, mark);
          if (res_mark == biased_value) {
            return BIAS_REVOKED_AND_REBIASED;
          }
        } else {
          markOop biased_value       = mark;
          markOop unbiased_prototype = markOopDesc::prototype()->set_age(mark->age());
!         markOop res_mark = obj->cas_set_mark(unbiased_prototype, mark);
          if (res_mark == biased_value) {
            return BIAS_REVOKED;
          }
        }
      }
--- 571,588 ----
        // needing to revoke biases.
        if (attempt_rebias) {
          assert(THREAD->is_Java_thread(), "");
          markOop biased_value       = mark;
          markOop rebiased_prototype = markOopDesc::encode((JavaThread*) THREAD, mark->age(), prototype_header->bias_epoch());
!         markOop res_mark = (markOop) Atomic::cmpxchg_ptr(rebiased_prototype, obj->mark_addr(), mark);
          if (res_mark == biased_value) {
            return BIAS_REVOKED_AND_REBIASED;
          }
        } else {
          markOop biased_value       = mark;
          markOop unbiased_prototype = markOopDesc::prototype()->set_age(mark->age());
!         markOop res_mark = (markOop) Atomic::cmpxchg_ptr(unbiased_prototype, obj->mark_addr(), mark);
          if (res_mark == biased_value) {
            return BIAS_REVOKED;
          }
        }
      }