stan::math::ad_tape_observer Class Reference

Detailed Description

TBB observer object which is a callback hook called whenever the TBB scheduler adds a new thread to the TBB managed threadpool.

This hook ensures that each worker thread has an initialized AD tape ready for use.

On Apple Silicon, this also sets the thread QoS class to USER_INITIATED so that macOS prefers scheduling compute threads on performance cores rather than efficiency cores.

Refer to https://software.intel.com/content/www/us/en/develop/documentation/tbb-documentation/top/intel-threading-building-blocks-developer-reference/task-scheduler/taskschedulerobserver.html for details on the observer concept.

Definition at line 36 of file init_chainablestack.hpp.

#include <init_chainablestack.hpp>

Inheritance diagram for stan::math::ad_tape_observer:

Public Member Functions
	ad_tape_observer ()
	~ad_tape_observer ()
void	on_scheduler_entry (bool worker)
void	on_scheduler_exit (bool worker)

Private Types
using	stack_ptr = std::unique_ptr< ChainableStack >
using	ad_map = std::unordered_map< std::thread::id, stack_ptr >

Private Attributes
ad_map	thread_tape_map_
std::mutex	thread_tape_map_mutex_

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The documentation for this class was generated from the following file:

• stan/math/rev/core/init_chainablestack.hpp