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0582478c96
After removing the isc_task_onshutdown(), the isc_task_shutdown() and isc_task_destroy() became obsolete. Remove calls to isc_task_shutdown() and replace the calls to isc_task_destroy() with isc_task_detach(). Simplify the internal logic to destroy the task when the last reference is removed.
59 lines
1.6 KiB
Plaintext
59 lines
1.6 KiB
Plaintext
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Copyright (C) Internet Systems Consortium, Inc. ("ISC")
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Changes I made last week to the task code simplified the task shutdown
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and termination model. Here's how things now work:
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Task termination occurs when:
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The task has no references
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The task has an empty event queue
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Notes from the task/event discussion led by Bob Halley on 13 March 2000:
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A task is an event queue.
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(task) --V
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(event)-->(event)-->(event)
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(runnable queue)--V
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(task)-->(task)-->(task)
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Normally only one task manager in an application.
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Task becomes runnable if it has a non-empty event queue.
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One or more worker threads run tasks.
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Event routines should be relatively short.
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Only one runnable queue that all workers share.
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Events for a task are always posted serially. Multiple worker threads
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will not be working on multiple events for one task at the same time.
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isc_event_send, posting an event, can't fail. It just adds an event
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to the task queue.
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Event action (callback) rules:
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* no locks held on your behald when entering a callback.
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* not allowed to block, except when acquiring a lock.
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* not allowed to hold a lock when exiting the callback.
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TIMERS?
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OMAPI -- need taskmgr to omapi_lib_init
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-- one task per client connection
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