On Fri, 18 Aug 2023 00:24:07 GMT, David Holmes <[email protected]> wrote:
>> If they stay jlong returns (note that these fields are in fact int), then we
>> need to add casting to all the callers. Casting is worse than returning the
>> correct types. If someone wants to make these fields jlong someday then
>> they can propagate the change to the callers. This change corrects the
>> types.
>
> I don't follow. The fields are int so cast them to jlong before returning
> them. All the callers of these methods expect jlong so there can't be any
> issue there.
You don't need to cast from int to jlong. The callers of these methods expect
int:
src/hotspot/share/services/threadService.cpp:1103:55: warning: conversion from
'jlong' {aka 'long int'} to 'int' may change value [-Wconversion]
1103 | int init_size = ThreadService::get_live_thread_count();
| ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~^~
Changing int to jlong here, gets a new warning:
src/hotspot/share/services/threadService.cpp:1104:54: warning: conversion from
'jlong' {aka 'long int'} to 'int' may change value [-Wconversion]
1104 | _threads_array = new GrowableArray<instanceHandle>(init_size);
| ^~~~~~~~~
If you look up in the header file, the field is an int. It makes sense to
return an int:
static volatile int _atomic_threads_count;
static volatile int _atomic_daemon_threads_count;
Correcting the types means returning a type that matches the declaration so
that its consistent.
-------------
PR Review Comment: https://git.openjdk.org/jdk/pull/15233#discussion_r1297894123
