src/hotspot/share/oops/method.cpp

rev 56098 : imported patch 8226705-8221734-baseline

*** 101,111 ****
    set_vtable_index(Method::garbage_vtable_index);
  
    // Fix and bury in Method*
    set_interpreter_entry(NULL); // sets i2i entry and from_int
    set_adapter_entry(NULL);
!   clear_code(false /* don't need a lock */); // from_c/from_i get set to c2i/i2i
  
    if (access_flags.is_native()) {
      clear_native_function();
      set_signature_handler(NULL);
    }
--- 101,111 ----
    set_vtable_index(Method::garbage_vtable_index);
  
    // Fix and bury in Method*
    set_interpreter_entry(NULL); // sets i2i entry and from_int
    set_adapter_entry(NULL);
!   Method::clear_code(); // from_c/from_i get set to c2i/i2i
  
    if (access_flags.is_native()) {
      clear_native_function();
      set_signature_handler(NULL);
    }
*** 823,833 ****
  void Method::clear_native_function() {
    // Note: is_method_handle_intrinsic() is allowed here.
    set_native_function(
      SharedRuntime::native_method_throw_unsatisfied_link_error_entry(),
      !native_bind_event_is_interesting);
!   clear_code();
  }
  
  
  void Method::set_signature_handler(address handler) {
    address* signature_handler =  signature_handler_addr();
--- 823,833 ----
  void Method::clear_native_function() {
    // Note: is_method_handle_intrinsic() is allowed here.
    set_native_function(
      SharedRuntime::native_method_throw_unsatisfied_link_error_entry(),
      !native_bind_event_is_interesting);
!   this->unlink_code();
  }
  
  
  void Method::set_signature_handler(address handler) {
    address* signature_handler =  signature_handler_addr();
*** 939,950 ****
    CompilationPolicy::policy()->disable_compilation(this);
    assert(!CompilationPolicy::can_be_osr_compiled(this, comp_level), "sanity check");
  }
  
  // Revert to using the interpreter and clear out the nmethod
! void Method::clear_code(bool acquire_lock /* = true */) {
!   MutexLocker pl(acquire_lock ? Patching_lock : NULL, Mutex::_no_safepoint_check_flag);
    // this may be NULL if c2i adapters have not been made yet
    // Only should happen at allocate time.
    if (adapter() == NULL) {
      _from_compiled_entry    = NULL;
    } else {
--- 939,949 ----
    CompilationPolicy::policy()->disable_compilation(this);
    assert(!CompilationPolicy::can_be_osr_compiled(this, comp_level), "sanity check");
  }
  
  // Revert to using the interpreter and clear out the nmethod
! void Method::clear_code() {
    // this may be NULL if c2i adapters have not been made yet
    // Only should happen at allocate time.
    if (adapter() == NULL) {
      _from_compiled_entry    = NULL;
    } else {
*** 954,963 ****
--- 953,981 ----
    _from_interpreted_entry = _i2i_entry;
    OrderAccess::storestore();
    _code = NULL;
  }
  
+ void Method::unlink_code(CompiledMethod *compare) {
+   MutexLocker ml(CompiledMethod_lock->owned_by_self() ? NULL : CompiledMethod_lock, Mutex::_no_safepoint_check_flag);
+   // We need to check if either the _code or _from_compiled_code_entry_point
+   // refer to this nmethod because there is a race in setting these two fields
+   // in Method* as seen in bugid 4947125.
+   // If the vep() points to the zombie nmethod, the memory for the nmethod
+   // could be flushed and the compiler and vtable stubs could still call
+   // through it.
+   if (code() == compare ||
+       from_compiled_entry() == compare->verified_entry_point()) {
+     clear_code();
+   }
+ }
+ 
+ void Method::unlink_code() {
+   MutexLocker ml(CompiledMethod_lock->owned_by_self() ? NULL : CompiledMethod_lock, Mutex::_no_safepoint_check_flag);
+   clear_code();
+ }
+ 
  #if INCLUDE_CDS
  // Called by class data sharing to remove any entry points (which are not shared)
  void Method::unlink_method() {
    _code = NULL;
  
*** 1180,1190 ****
    return code == NULL || (code->method() == NULL) || (code->method() == (Method*)this && !code->is_osr_method());
  }
  
  // Install compiled code.  Instantly it can execute.
  void Method::set_code(const methodHandle& mh, CompiledMethod *code) {
!   MutexLocker pl(Patching_lock, Mutex::_no_safepoint_check_flag);
    assert( code, "use clear_code to remove code" );
    assert( mh->check_code(), "" );
  
    guarantee(mh->adapter() != NULL, "Adapter blob must already exist!");
  
--- 1198,1208 ----
    return code == NULL || (code->method() == NULL) || (code->method() == (Method*)this && !code->is_osr_method());
  }
  
  // Install compiled code.  Instantly it can execute.
  void Method::set_code(const methodHandle& mh, CompiledMethod *code) {
!   MutexLocker pl(CompiledMethod_lock, Mutex::_no_safepoint_check_flag);
    assert( code, "use clear_code to remove code" );
    assert( mh->check_code(), "" );
  
    guarantee(mh->adapter() != NULL, "Adapter blob must already exist!");