Locking and signaling for implementing messaging transports with shared memory

A method for transporting data using shared memory, where in the method comprises:

• identifying, by both a first sender application and a second sender application, a same first free page from among one or more pages partitioned in a shared memory by reading a first free pointer from a free list, wherein the first free pointer is a pointer to the first free page of the free list, and wherein the free list is a circular buffer data structure residing in the shared memory and accessible directly by the first and second sender applications;
• competing, by the first sender application and the second sender application, for the allocation of the first free page;
• allocating, by the first sender application, the first free page identified by the first sender application and the second sender application when the first sender application completes a compare and swap operation or similar atomic processor instruction before the second sender application, wherein the first sender application completes the compare and swap operation or similar atomic processor instruction before the second sender application when the first sender application sets the first free page to point to an allocated pages list of the first sender application, wherein the identified first free page is stored in a shared memory, wherein the shared memory is partitioned into one or more pages;
• writing data, by the first sender application, to the allocated page, wherein a page is either available for use or allocated to only one of the sender applications, wherein the allocated page becomes available for a receiver application to read data after the first sender application has completed writing the data;
• sending a signal, by the first sender application, to the receiver application, wherein the signal notifies the receiver application that writing the data to the allocated page is complete;
• reading, by the receiver application, the data from the allocated page;
• and
• de-allocating, by the receiver application, the allocated page, wherein each of the pages available for use can be allocated to any one of the plurality of sender applications.

Logic for transporting data using shared memory, the logic being embodied in a non-transitory computer-readable medium and when executed operable to:

• identify, by both a first sender application and a second sender application, a same first free page from among one or more pages partitioned in a shared memory by reading a first free pointer from a free list, wherein the first free pointer is a pointer to the first free page of the free list, and wherein the free list is a circular buffer data structure residing in the shared memory and accessible directly by the first and second sender applications;
• compete, by the first sender application and the second sender application, for the allocation of the first free page;
• allocate, by the first sender application, the first free page identified by the first sender application and the second sender application when the first sender application completes a compare and swap operation or similar atomic processor instruction before the second sender application, wherein the first sender application completes the compare and swap operation or similar atomic processor instruction before the second sender application when the first sender application sets the first free page to point to an allocated pages list of the first sender application, wherein the identified first free page is stored in a shared memory, wherein the shared memory is partitioned into one or more pages;
• write data, by the first sender application, to the allocated page, wherein a page is either available for use or allocated to only one of the sender applications, wherein the allocated page becomes available for a receiver application to read data after the first sender application has completed writing the data;
• send a signal, by the first sender application, to the receiver application, wherein the signal notifies the receiver application that writing the data to the allocated page is complete;
• read, by the receiver application, the data from the allocated page;
• and
• de-allocate, by the receiver application, the allocated page, wherein each of the pages available for use can be allocated to any one of the plurality of sender applications.

A server for transporting data comprising:

• a first sender application and a second sender application;
• one or more receiver applications;
• and
• shared memory partitioned into one or more pages and a free list, the free list comprising of one or more free pages having a first free pointer pointing to a first free page of the one or more free pages, wherein the free list is a circular buffer data structure and accessible by the first and second sender applications, wherein each free page is available to any one of the sender applications;
• wherein each sender application is operable to send data to one or more of the receiver applications by:
• identifying, by both the first sender application and the second sender application, a same first free page from among the one or more free pages by reading the first free pointer from the free list;
• performing, by the first sender application before the second sender application, a compare and swap operation or similar atomic processor instruction, wherein the first sender application completes the compare and swap operation or similar atomic processor instruction before the second sender application when the first sender application sets the first free page to point to an allocated pages list of the first sender application;
• writing data to the first free page;
• and
• notifying the one or more receiver applications when the writing is complete;
• and
• wherein each notified receiver application is operable to read the data of the one or more written pages and return the one or more read pages to the free list.

A server for transporting data comprising:

• a first sender application and a second sender application;
• one or more receiver applications;
• and
• shared memory partitioned into one or more pages and a free list, the free list comprising of one or more free pages having a first free pointer pointing to a first free page of the one or more free pages, wherein the free list is a circular buffer data structure and accessible by the first and second sender applications, wherein each free page is available to any one of the sender applications;
• wherein each sender application is operable to send data to one or more of the receiver applications by:
• identifying, by both the first sender application and the second sender application, a same first free page from among the one or more free pages by reading the first free pointer from the free list;
• performing, by the first sender application before the second sender application, a compare and swap operation or similar atomic processor instruction, wherein the first sender application complete the compare and swap operation or similar atomic processor instruction before the second sender application when the first sender application sets the first free page to point to an allocated pages list of the first sender application;
• writing data to first free page;
• and
• notifying the one or more receiver applications when the writing is complete;
• and
• wherein each notified receiver application is operable to return the one or more written pages to the free list when a data transport fault occurs.