src/hotspot/cpu/x86/c1_MacroAssembler_x86.cpp

*** 36,46 ****
  #include "runtime/biasedLocking.hpp"
  #include "runtime/os.hpp"
  #include "runtime/sharedRuntime.hpp"
  #include "runtime/stubRoutines.hpp"
  
! int C1_MacroAssembler::lock_object(Register hdr, Register obj, Register disp_hdr, Register scratch, Label& slow_case) {
    const int aligned_mask = BytesPerWord -1;
    const int hdr_offset = oopDesc::mark_offset_in_bytes();
    assert(hdr == rax, "hdr must be rax, for the cmpxchg instruction");
    assert(hdr != obj && hdr != disp_hdr && obj != disp_hdr, "registers must be different");
    Label done;
--- 36,46 ----
  #include "runtime/biasedLocking.hpp"
  #include "runtime/os.hpp"
  #include "runtime/sharedRuntime.hpp"
  #include "runtime/stubRoutines.hpp"
  
! int C1_MacroAssembler::lock_object(Register hdr, Register obj, Register disp_hdr, Register scratch, Label& slow_case, bool check_always_locked) {
    const int aligned_mask = BytesPerWord -1;
    const int hdr_offset = oopDesc::mark_offset_in_bytes();
    assert(hdr == rax, "hdr must be rax, for the cmpxchg instruction");
    assert(hdr != obj && hdr != disp_hdr && obj != disp_hdr, "registers must be different");
    Label done;
*** 58,67 ****
--- 58,71 ----
      null_check_offset = offset();
    }
  
    // Load object header
    movptr(hdr, Address(obj, hdr_offset));
+   if (check_always_locked) {
+     testl(hdr, markOopDesc::always_locked_pattern);
+     jcc(Assembler::notZero, slow_case);
+   }
    // and mark it as unlocked
    orptr(hdr, markOopDesc::unlocked_value);
    // save unlocked object header into the displaced header location on the stack
    movptr(Address(disp_hdr, 0), hdr);
    // test if object header is still the same (i.e. unlocked), and if so, store the