Message passing with queues and channels

A non-transitory computer-readable storage medium encoded with instructions, wherein the instructions when executed comprise:

• receiving, by a send thread, an identifier that identifies a destination node and a data pointer;
• creating, by a send thread, a first send request in response to the receiving;
• selecting, by the send thread, a selected channel from among a plurality of channels, wherein the selected channel comprises a selected hand-off queue and a selected identification of a selected message unit, wherein the each of the plurality of channels comprise a respective hand-off queue and a respective identification of a respective message unit, wherein the selecting further comprises selecting the selected channel via a hash function on the identifier of the destination node and an identifier of a set of nodes to which a source node and the destination node belong, wherein the selected hand-off queue is randomly accessible;
• if the selected hand-off queue contains an available entry, adding, by the send thread, the first send request to the selected hand-off queue;
• and
• if the selected hand-off queue does not contain an available entry, removing, by the send thread, a second send request from the selected hand-off queue and sending the second send request to the selected message unit identified by the selected identification in the selected channel, wherein the selected message unit sends the data pointed to by the data pointer to the destination node asynchronously from execution of the send thread.

A node comprising:

• a processor;
• a plurality of message units communicatively connected to the processor;
• and
• memory communicatively connected to the processor and the message unit, wherein the memory is encoded with instructions, and wherein the instructions when executed on the processor comprise:
• receiving, by a send thread, an identifier that identifies a destination node and a data pointer,
• creating, by a send thread, a first send request in response to the receiving,
• selecting, by the send thread, a selected channel from among a plurality of channels, wherein the selected channel comprises a selected hand-off queue and a selected identification of a selected message unit, wherein the each of the plurality of channels comprise a respective hand-off queue and a respective identification of a respective different one of the plurality of message units, wherein the selecting further comprises selecting the selected channel via a hash function on the identifier of the destination node and an identifier of a set of nodes to which the node and the destination node belong, wherein the selected hand-off queue is randomly accessible,
• if the selected hand-off queue contains an available entry, adding, by the send thread, the first send request to the selected hand-off queue, and
• if the selected hand-off queue does not contain an available entry, removing, by the send thread, a second send request from the selected hand-off queue and sending the second send request to the selected message unit identified by the selected identification in the selected channel, wherein the selected message unit sends the data pointed to by the data pointer to the destination node asynchronously from execution of the send thread.