src/hotspot/share/gc/x/xBarrierSetNMethod.cpp

/*
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 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
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 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
 * version 2 for more details (a copy is included in the LICENSE file that
 * accompanied this code).
 *
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 * 2 along with this work; if not, write to the Free Software Foundation,
 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
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#include "precompiled.hpp"
#include "code/nmethod.hpp"
#include "gc/x/xBarrierSetNMethod.hpp"
#include "gc/x/xGlobals.hpp"
#include "gc/x/xLock.inline.hpp"
#include "gc/x/xNMethod.hpp"
#include "gc/x/xThreadLocalData.hpp"
#include "logging/log.hpp"
#include "runtime/threadWXSetters.inline.hpp"

bool XBarrierSetNMethod::nmethod_entry_barrier(nmethod* nm) {
  XLocker<XReentrantLock> locker(XNMethod::lock_for_nmethod(nm));
  log_trace(nmethod, barrier)("Entered critical zone for %p", nm);

  if (!is_armed(nm)) {
    // Some other thread got here first and healed the oops
    // and disarmed the nmethod.
    return true;
  }

  MACOS_AARCH64_ONLY(ThreadWXEnable wx(WXWrite, Thread::current()));

  if (nm->is_unloading()) {
    // We don't need to take the lock when unlinking nmethods from
    // the Method, because it is only concurrently unlinked by
    // the entry barrier, which acquires the per nmethod lock.
    nm->unlink_from_method();

    // We can end up calling nmethods that are unloading
    // since we clear compiled ICs lazily. Returning false
    // will re-resovle the call and update the compiled IC.
    return false;
  }

  // Heal oops
  XNMethod::nmethod_oops_barrier(nm);


  // CodeCache unloading support
  nm->mark_as_maybe_on_stack();

  // Disarm
  disarm(nm);

  return true;
}

int* XBarrierSetNMethod::disarmed_guard_value_address() const {
  return (int*)XAddressBadMaskHighOrderBitsAddr;
}

ByteSize XBarrierSetNMethod::thread_disarmed_guard_value_offset() const {
  return XThreadLocalData::nmethod_disarmed_offset();
}