race between rpl_parallel_change_thread_count and slave start upon server start without --skip-slave-start

Description

Reported on maria-developers@ by nanyi607rao:

Second is in rpl_parallel_change_thread_count()

I think it need add mysql_cond_broadcast(&pool->COND_rpl_thread_pool) after all new threads are ok, this is for
the case that skip_slave_start=OFF,then SQL thread would start automaticlly, it could wait forever in rpl_parallel_thread_pool::get_thread(), because SQL thread may reach this function before another thread reach the rpl_parallel_change_thread_count().

Environment

None

Status

Assignee

Kristian Nielsen

Reporter

Kristian Nielsen

Labels

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External issue ID

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External issue ID

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Fix versions

Affects versions

10.0.8

Priority

Major