process-pool-work-item

This struct, instances of which are created by process-pool-run or by make-process-pool-work-item, holds information about what a process-pool process is supposed to do and the state of the work. It has the following slots:

• function: The function to be run when the work-item is active. There is no reader for this slot.
• arguments: The list of arguments which will be passed to the work-item's function. There is no reader for this slot.
• queued-time: The time when the entry was queued, in internal time units. The associated reader function is process-pool-work-item-queued-time.
• start-time: The time when the entry started running in internal time units. The associated reader function is process-pool-work-item-start-time.
• end-time: The time when the entry stopped running in internal time units. The associated reader function is process-pool-work-item-end-time.
• report-start: A function of one argument (the work-item) called before the work-item function. If this slot is nil, use the report-start function in the process-pool instance. To have nothing done, define a function that does nothing and make it the value of this slot.
• report-end: A function of three arguments (work-item values error) called after the work item function exits. If this slot is nil, use the report-start function in the process-pool instance. To have nothing done, define a function that does nothing and make it the value of this slot.
• values: The values returned by the work-item function. If the work-item was terminated because of a call to cancel-process-pool-work, a list of the values of the values arguments (which are the &rest arguments to cancel-process-pool-work after the first) is saved in this slot. The associated reader function is process-pool-work-item-values.
• error: If the work-item function signals an error when run, the value of this slot is the condition instance. If the function exited because of a call to throw, the value of this slot will be the keyword :throw. If the work-item was terminated because of a call to cancel-process-pool-work or cancel-process-pool-worker, the value of this slot will be the value of the reason argument (which is the first of the &rest arguments to cancel-process-pool-work and the optional argument to cancel-process-pool-worker). If two things would supply a value for this slot (an error signaled in the work-function and a call to cancel-process-pool-worker in the report-end function), the last to occur will provide the value of the slot. Otherwise, the value of this slot is nil. The associated reader function is process-pool-work-item-error.
• data: Application data accessible to the work function. The associated reader function is process-pool-work-item-data. The variable *process-pool-work-item* is bound to the running work-item when a work-item is being run by a process. Applying the data reader function to that variable will return the value of the data slot, which can then be used by the work-item function or report-start or report-end functions.
• property-list: The value of this slot is stored in the process-property-list slot of the worker process while the work-item is running. The associated reader function is process-pool-work-item-property-list.

See Process pools in multiprocessing.htm for more information on process pools.

Copyright (c) 1998-2022, Franz Inc. Lafayette, CA., USA. All rights reserved.
This page is new in the 10.1 release.
Created 2019.8.20.