zBarrierSetNMethod.cpp

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#include "precompiled.hpp"
#include "code/nmethod.hpp"
#include "gc/z/zBarrierSetNMethod.hpp"
#include "gc/z/zGlobals.hpp"
#include "gc/z/zLock.inline.hpp"
#include "gc/z/zNMethod.hpp"
#include "gc/z/zThreadLocalData.hpp"
#include "logging/log.hpp"
#include "runtime/threadWXSetters.inline.hpp"

bool ZBarrierSetNMethod::nmethod_entry_barrier(nmethod* nm) {
  ZLocker<ZReentrantLock> locker(ZNMethod::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
  ZNMethod::nmethod_oops_barrier(nm);

  // Disarm
  disarm(nm);

  return true;
}

int* ZBarrierSetNMethod::disarmed_value_address() const {
  return (int*)ZAddressBadMaskHighOrderBitsAddr;
}

ByteSize ZBarrierSetNMethod::thread_disarmed_offset() const {
  return ZThreadLocalData::nmethod_disarmed_offset();
}