From 39cfa9724c71796f2c16aa1ed90fbd4425540eef Mon Sep 17 00:00:00 2001 From: Fabian Mastenbroek Date: Wed, 20 Sep 2017 00:59:54 +0200 Subject: Add support for timeouts on receive calls This change allows processes to set a timeout when waiting for a message to arrive. --- .../atlarge/opendc/kernel/omega/OmegaSimulation.kt | 33 +++++++++++++++++++++- .../nl/atlarge/opendc/kernel/omega/Timeout.kt | 33 ++++++++++++++++++++++ 2 files changed, 65 insertions(+), 1 deletion(-) create mode 100644 opendc-omega/src/main/kotlin/nl/atlarge/opendc/kernel/omega/Timeout.kt (limited to 'opendc-omega') diff --git a/opendc-omega/src/main/kotlin/nl/atlarge/opendc/kernel/omega/OmegaSimulation.kt b/opendc-omega/src/main/kotlin/nl/atlarge/opendc/kernel/omega/OmegaSimulation.kt index ec7701e7..65d9dd60 100644 --- a/opendc-omega/src/main/kotlin/nl/atlarge/opendc/kernel/omega/OmegaSimulation.kt +++ b/opendc-omega/src/main/kotlin/nl/atlarge/opendc/kernel/omega/OmegaSimulation.kt @@ -101,8 +101,14 @@ internal class OmegaSimulation(override val kernel: OmegaKernel, override val to // Tick has already occurred logger.warn { "message processed out of order" } } + // Remove the message from the queue queue.poll() + // If the sender has canceled the message, we move on to the next message + if (envelope.canceled) { + continue + } + val context = registry[envelope.destination] ?: continue if (envelope.message !is Interrupt) { @@ -244,7 +250,9 @@ internal class OmegaSimulation(override val kernel: OmegaKernel, override val to } /** - * Retrieves and removes a single message from this channel suspending the caller while the channel is empty. + * Retrieve and removes a single message from the entity's mailbox, suspending the function if the mailbox is empty. + * The execution is resumed after the message has landed in the entity's mailbox after which the message [Envelope] + * is mapped through `block` to generate a processed message. * * @param block The block to process the message with. * @return The processed message. @@ -254,6 +262,29 @@ internal class OmegaSimulation(override val kernel: OmegaKernel, override val to return block(envelope, envelope.message) } + /** + * Retrieve and removes a single message from the entity's mailbox, suspending the function if the mailbox is empty. + * The execution is resumed after the message has landed in the entity's mailbox or the timeout was reached, + * + * If the message has been received, the message [Envelope] is mapped through `block` to generate a processed + * message. If the timeout was reached, `block` is not called and `null` is returned. + * + * @param timeout The duration to wait before resuming execution. + * @param block The block to process the message with. + * @return The processed message or `null` if the timeout was reached. + */ + suspend override fun receive(timeout: Duration, block: Envelope<*>.(Any) -> T): T? { + val receipt = schedule(Timeout, entity, entity, timeout) + val envelope = receiveEnvelope() + + if (envelope.message !is Timeout) { + receipt.cancel() + return block(envelope, envelope.message) + } + + return null + } + /** * Send the given message to the specified entity. * diff --git a/opendc-omega/src/main/kotlin/nl/atlarge/opendc/kernel/omega/Timeout.kt b/opendc-omega/src/main/kotlin/nl/atlarge/opendc/kernel/omega/Timeout.kt new file mode 100644 index 00000000..41dcce71 --- /dev/null +++ b/opendc-omega/src/main/kotlin/nl/atlarge/opendc/kernel/omega/Timeout.kt @@ -0,0 +1,33 @@ +/* + * MIT License + * + * Copyright (c) 2017 atlarge-research + * + * Permission is hereby granted, free of charge, to any person obtaining a copy + * of this software and associated documentation files (the "Software"), to deal + * in the Software without restriction, including without limitation the rights + * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell + * copies of the Software, and to permit persons to whom the Software is + * furnished to do so, subject to the following conditions: + * + * The above copyright notice and this permission notice shall be included in all + * copies or substantial portions of the Software. + * + * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR + * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, + * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE + * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER + * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, + * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE + * SOFTWARE. + */ + +package nl.atlarge.opendc.kernel.omega + +/** + * An internal message used by the Omega simulation kernel to indicate to a suspended [Process], that a timeout has been + * reached and that it should wake up and resume execution. + * + * @author Fabian Mastenbroek (f.s.mastenbroek@student.tudelft.nl) + */ +object Timeout -- cgit v1.2.3