Attempt at fixing https://bugs.mysql.com/bug.php?id=72439 with insert instead and sqlalchemy

mysql_unique_index_lock_attempt.py

from sqlalchemy import create_engine
from sqlalchemy.orm import sessionmaker
from multiprocessing import Process
from sqlalchemy.ext.declarative import declarative_base
from sqlalchemy import Column, Integer, String, Integer
from sqlalchemy import func, UniqueConstraint

Base = declarative_base()

class Models(Base):
    __tablename__ = 'model_test'
    __table_args__ = (UniqueConstraint('tenant_id', 'short_id', name='tenant_id_short_id_constraint'),)
    id = Column(Integer, primary_key=True)
    tenant_id = Column(Integer, nullable=False)
    short_id = Column(Integer, nullable=False)


def setup(create = False):
    # engine = create_engine('mysql://username:pass@something.com/db_here',
    #                       echo=False)
    engine = create_engine('mysql://username:pass@something.com/db_here')
    if create:
        Base.metadata.create_all(engine)
    return sessionmaker(bind=engine, autocommit = False)

def insert_orm(ses, tenant_id):
    # .with_hint(Models, "IGNORE INDEX (tenant_id_short_id_constraint)").with_for_update().scalar()
    short_id =  ses.query(func.max(Models.short_id)).filter_by(tenant_id=tenant_id)\
                                                    .with_for_update()
    if short_id is None:
        short_id = 0

    # model = Models(tenant_id=tenant_id, short_id=short_id + 1)
    # ses.add(model)
    # ses.execute("INSERT INTO model_test (short_id, tenant_id) values ((SELECT ifnull(max(model_alias.short_id), 0) + 1 AS max_1 FROM (SELECT * FROM model_test) as model_alias WHERE model_alias.tenant_id = {} FOR UPDATE), {})".format(tenant_id, tenant_id))
    ses.execute("SELECT @max_1 := ifnull(max(model_test.short_id), 0) + 1 FROM model_test WHERE model_test.tenant_id = {} FOR UPDATE; INSERT INTO model_test (short_id, tenant_id) values (max_1, {})".format(tenant_id, tenant_id))
    
def transact(ses, func, tenant_id):
    func(ses, tenant_id)
    ses.commit()

def task(tenant_id):
    Session = setup();
    ses = Session()
    for i in range(100):
        transact(ses, insert_orm, tenant_id)

setup(True)

processes = []

for m in range(15):
    p = Process(target=task, args=(m % 5,))
    p.start()
    processes.append(p)

for p in processes:
    p.join()

# NOTE: THIS DOES NOT WORK DUE TO DEADLOCK ISSUE IN TITLE