Abstract: Techniques for providing a signal processing feature in an inventory management system are described herein. For example, instructions may be received by a computer system of an autonomous vehicle that identify a path to move inventory within a materials handling facility. Further, the computer system of the autonomous vehicle may reduce a current traveling speed of the autonomous vehicle in response to receiving a first signal that is provided by a transmitter coupled with an entity moving within the materials handling facility. The first signal may be span a first distance. In embodiments, the computer system of the autonomous vehicle may stop movement of the autonomous vehicle in response to receiving a second signal provided by the transmitter coupled with the entity. The second signal may span a second distance from the entity that is less than the first distance.

Abstract: Techniques for managing device interaction between components of an inventory management system are described herein. User input associated with an operational state of the user device may be received at the user device and the user device may begin operating in a particular operational state. While operating in this state, the user device may transmit a wireless signal having a predetermined frequency. A mobile drive unit of the system, upon receipt of the wireless signal, may slow or stop. Operational state information may be transmitted to other components of the inventory management system indicating that the wireless signal is being transmitted and/or that the user device is operating in a particular operational state and a fault detection process may commence. The user device may provide an indication (e.g., via visual, audible, and/or haptic feedback devices) that the user device is operating in the particular operational state.

Abstract: Techniques for providing a signal processing feature in an inventory management system are described herein. For example, instructions may be received by a computer system of an autonomous vehicle that identify a path to move inventory within a materials handling facility. Further, the computer system of the autonomous vehicle may reduce a current traveling speed of the autonomous vehicle in response to receiving a first signal that is provided by a transmitter coupled with an entity moving within the materials handling facility. The first signal may be span a first distance. In embodiments, the computer system of the autonomous vehicle may stop movement of the autonomous vehicle in response to receiving a second signal provided by the transmitter coupled with the entity. The second signal may span a second distance from the entity that is less than the first distance.

Abstract: Techniques for providing an entity monitoring safety feature in an inventory management system are described herein. For example, instructions may be received by a computer system of an autonomous vehicle that identify a path to move inventory within a materials handling facility. Further, the computer system of the autonomous vehicle may reduce a current traveling speed of the autonomous vehicle in response to receiving a first signal that is provided by a transmitter coupled with an entity moving with the materials handling facility. The first signal may be provided up to a first distance from the entity. In embodiments, the computer system of the autonomous vehicle may stop movement of the autonomous vehicle in response to receiving a second signal provided by the transmitter coupled with the entity. The second signal may be provided up to a second distance from the entity that is less than the first distance.

Abstract: The invention provides a system and method for resolving ambiguous invalidate messages received by an entity of a computer system. An invalidate message is considered ambiguous when the receiving entity cannot tell whether it applies to a previously victimized memory block or to a memory block that the entity is waiting to receive. When an entity receives such an invalidate message, it stores the message in its miss address file (MAF). When the entity subsequently receives the memory block, the entity “replays” the Invalidate message from its MAF by invalidating the block from its cache and issuing an Acknowledgement (Ack) to the entity that triggered issuance of the Invalidate message command.

Abstract: A multi-processor system includes a requesting node that provides a first request for data to a home node. The requesting node being operative to provide a second request for the data to at least one predicted node in parallel with first request. The requesting node receives at least one coherent copy of the data from at least one of the home node and the at least one predicted node.

Abstract: A system comprises a first node that provides a broadcast request for data. The first node receives a read conflict response to the broadcast request from the first node. The read conflict response indicates that a second node has a pending broadcast read request for the data. A third node provides the requested data to the first node in response to the broadcast request from the first node. The first node fills the data provided by the third node in a cache associated with the first node.

Abstract: A system includes a first node that broadcasts a request for data. A second node having a first state associated with the data defines the second node as an ordering point for the data. The second node provides a response to the first node that transfers the ordering point to the first node in response to the request for the data.

Abstract: A computer system supports a first set of processors configured to operate in a dirty-shared mode and a second set of processors configured to operate in a non dirty-shared mode. The computer system may include a portion of shared memory that stores data in terms of memory blocks. Upon receiving a snoop read requesting shared access to a memory block held in a dirty state, a dirty-shared processor sends a copy of the memory block to the originator of the snoop read and retains a valid a copy of the block in its cache. Non dirty-shared processors additionally write the block back to main memory in response to snoop reads and may also send a copy to the originator. Until the write back is completed at main memory or another processor is granted write access to the block, the dirty-shared and non dirty-shared processors preferably continue to satisfy subsequent snoop reads targeting the memory block.

Abstract: Systems and methods are disclosed for blocking data responses. One system includes a target node that, in response to a source broadcast request for requested data, provides a response that includes a copy of the requested data. The target node also provides a blocking message to a home node associated with the requested data. The blocking message being operative cause the home node to provide a non-data response to the source broadcast request if the blocking message is matched with the source broadcast request at the home node.

Abstract: Systems and methods are disclosed for interaction between different cache coherency protocols. One system may comprise a home node that receives a request for data from a first node in a first cache coherency protocol. A second node provides a conflict response to a request for the data from the home node. The conflict response indicates that an ordering point for the data is migrating according to a second cache coherency protocol, which is different from the first cache coherency protocol.

Abstract: A system comprises a first node including data having an associated D-state and a second node operative to provide a source broadcast requesting the data. The first node is operative in response to the source broadcast to provide the data to the second node and transition the state associated with the data at the first node from the D-state to an O-state without concurrently updating memory. An S-state is associated with the data at the second node.

Abstract: A system comprises a first node that employs a source broadcast protocol to initiate a transaction. The first node employs a forward progress protocol to resolve the transaction if the source broadcast protocol cannot provide a deterministic resolution of the transaction.

Abstract: A system comprises a first node that provides a source broadcast request for data. The first node is operable to respond in a first manner to other source broadcast requests for the data while the source broadcast for the data is pending at the first node. The first node is operable to respond in a second manner to the other source broadcast requests for the data in response to receiving an ownership data response at the first node.

Abstract: A system comprises a first node having an associated cache including data having an associated first cache state. The first cache state is capable of identifying the first node as being an ordering point for serializing requests from other nodes for the data.

Abstract: A system may comprise a first node that includes an ordering point for data, the first node being operative to employ a write-back transaction associated with writing the data back to memory. The first node broadcasts a write-back message to at least one other node in the system in response to an acknowledgement provided by the memory indicating that the ordering point for the data has migrated from the first node to the memory.

Abstract: One disclosed embodiment may comprise a system that includes a home node that provides a transaction reference to a requester in response to a request from the requester. The requester provides an acknowledgement message to the home node in response to the transaction reference, the transaction reference enabling the requester to determine an order of requests at the home node relative to the request from the requester.

Abstract: A system comprises a first node including data having an associated state. The associated state of the data at the first node is a modified state. The system also comprises a second node operative to provide a non-migratory source broadcast request for the data. The first node is operative in response to the non-migratory source broadcast request to provide the data to the second node and to transition the associated state of the data at the first node from the modified state to an owner state without updating memory. The second node is operative to receive the data from the first node and assign a shared state to an associated state of the data at the second node.

Abstract: Systems and methods are disclosed for updating owner predictor structures. In one embodiment, a multi-processor system includes an owner predictor control that provides an ownership update message corresponding to a block of data to at least one of a plurality of owner predictors in response to a change in an ownership state of the block of data. The update message comprises an address tag associated with the block of data and an identification associated with an owner node of the block of data.

Abstract: A system comprises a first node operative to provide a source broadcast requesting data. The first node associates an F-state with a copy of the data in response to receiving the copy of the data from memory and receiving non-data responses from other nodes in the system. The non-data responses include an indication that at least a second node includes a shared copy of the data. The F-state enabling the first node to serve as an ordering point in the system capable of responding to requests from other nodes in the system with a shared copy of the data.