Improve `__repr__` string of synchronize tools in the `multiprocessing` module.

Feature or enhancement

Proposal:

To be consistant with representation string of threading sychronize tools and in accordance with the discussion from the #149447 PR , the missing id information must be added in the __repr__ of the following synchronization classes:

• Lock, Rlock,
• Semaphore, BoundedSemaphore,
• Condition.

and refactoring must be performed to these 2 classes:

• Event,
• Barrier.

See some examples below:

import threading
import multiprocessing

print(threading.Semaphore(3))
print(multiprocessing.Semaphore(3))

print(threading.Lock())
print(multiprocessing.Lock())

print(threading.Event())
print(multiprocessing.Event())

print(threading.Barrier(2))
print(multiprocessing.Barrier(2))

The ouput is:

<threading.Semaphore at 0x10378c8a0: value=3>
<Semaphore(value=3)>
<unlocked _thread.lock object at 0x103612040>
<Lock(owner=None)>
<threading.Event at 0x10378ccc0: unset>
<Event at 0x10378ccc0 unset>
<threading.Barrier at 0x10378ccc0: waiters=0/2>
<multiprocessing.synchronize.Barrier at 0x10378ccc0: waiters=0/2>

A PR will be published soon.

cc @gpshead

Has this already been discussed elsewhere?

This is a minor feature, which does not need previous discussion elsewhere

Links to previous discussion of this feature:

#149447

Linked PRs

• gh-155593

Start in the multiprocessing module with the Lock, Rlock, Semaphore, BoundedSemaphore, Condition, Event, and Barrier classes, comparing their representations with threading and the discussion in #149447. Done means the requested id information is included for the listed synchronization tools and Event and Barrier receive the proposed refactoring; note that PR #155593 is already linked in the issue.