Package io.temporal.worker.tuning

Class FixedSizeSlotSupplier<SI extends SlotInfo>

  • Type Parameters:
    SI - The slot info type for this supplier.
    All Implemented Interfaces:
    SlotSupplier<SI>
    public class FixedSizeSlotSupplier<SI extends SlotInfo>
extends java.lang.Object
implements SlotSupplier<SI>
    This implementation of SlotSupplier provides a fixed number of slots backed by a semaphore, and is the default behavior when a custom supplier is not explicitly specified.

    • Constructor Detail

      • FixedSizeSlotSupplier

        public FixedSizeSlotSupplier​(int numSlots)

    • Method Detail

      • reserveSlot

        public SlotPermit reserveSlot​(SlotReserveContext<SI> ctx)
                       throws java.lang.InterruptedException
        Description copied from interface: SlotSupplier
        This function is called before polling for new tasks. Your implementation should block until a slot is available, then return a permit to use that slot.
        Specified by:
        reserveSlot in interface SlotSupplier<SI extends SlotInfo>
        Parameters:
        ctx - The context for slot reservation.
        Returns:
        A permit to use the slot which may be populated with your own data.
        Throws:
        java.lang.InterruptedException - The worker may choose to interrupt the thread in order to cancel the reservation, or during shutdown. You may perform cleanup, and then should rethrow the exception.

      • tryReserveSlot

        public java.util.Optional<SlotPermit> tryReserveSlot​(SlotReserveContext<SI> ctx)
        Description copied from interface: SlotSupplier
        This function is called when trying to reserve slots for "eager" workflow and activity tasks. Eager tasks are those which are returned as a result of completing a workflow task, rather than from polling. Your implementation must not block, and If a slot is available, return a permit to use that slot.
        Specified by:
        tryReserveSlot in interface SlotSupplier<SI extends SlotInfo>
        Parameters:
        ctx - The context for slot reservation.
        Returns:
        Maybe a permit to use the slot which may be populated with your own data.

      • markSlotUsed

        public void markSlotUsed​(SlotMarkUsedContext<SI> ctx)
        Description copied from interface: SlotSupplier
        This function is called once a slot is actually being used to process some task, which may be some time after the slot was reserved originally. For example, if there is no work for a worker, a number of slots equal to the number of active pollers may already be reserved, but none of them are being used yet. This call should be non-blocking.
        Specified by:
        markSlotUsed in interface SlotSupplier<SI extends SlotInfo>
        Parameters:
        ctx - The context for marking a slot as used.

      • releaseSlot

        public void releaseSlot​(SlotReleaseContext<SI> ctx)
        Description copied from interface: SlotSupplier
        This function is called once a permit is no longer needed. This could be because the task has finished, whether successfully or not, or because the slot was no longer needed (ex: the number of active pollers decreased). This call should be non-blocking.
        Specified by:
        releaseSlot in interface SlotSupplier<SI extends SlotInfo>
        Parameters:
        ctx - The context for releasing a slot.

      • getMaximumSlots

        public int getMaximumSlots()
        Description copied from interface: SlotSupplier
        Because we currently use thread pools to execute tasks, there must be *some* defined upper-limit on the size of the thread pool for each kind of task. You must not hand out more permits than this number. If unspecified, the default is Integer.MAX_VALUE. Be aware that if your implementation hands out unreasonable numbers of permits, you could easily oversubscribe the worker, and cause it to run out of resources.

        This value should never change during the lifetime of the supplier.

        Specified by:
        getMaximumSlots in interface SlotSupplier<SI extends SlotInfo>
        Returns:
        the maximum number of slots that can ever be in use at one type for this slot type.

      • toString

        public java.lang.String toString()
        Overrides:
        toString in class java.lang.Object