Techniques for resolving read-after-write (RAW) conflicts using backup area

A method for a client device to create a new data image from a base data image based on instructions included in an update package, the method comprising:

• receiving, by the client device, the update package, the update package including COPYBACK instructions and other instructions;
• performing, by the client device, a first operation using the update package, the first operation comprising:
• detecting COPYBACK instructions in the update package;
• and
• for each COPYBACK instruction detected, copying data corresponding to the COPYBACK instructions to a backup area;
• and
• performing, by the client device, a second operation using the update package after performing the first operation, the second operation comprising:
• performing by the client device, operations on the base data image corresponding to the COPYBACK instructions and the other instructions included in the update package to create the new data image,
• wherein, when a COPYBACK instruction is encountered in the second operation, data is copied from the corresponding backup area to the new data image.

A client device apparatus for creating a new data image from a base data image based on instructions included in an update package, the apparatus comprising:

• at least one controller for executing a download agent and an update decoder,
• wherein the download agent receives the update package, the update package including COPYBACK instructions and other instructions,
• wherein the update decoder performs a first operation using the update package, the first operation including detecting COPYBACK instructions in the update package, and copying data corresponding to the COPYBACK instructions to a backup area for each COPYBACK instruction detected,
• wherein the update decoder performs a second operation using the update package after performing the first operation, the second operation including performing operations on the base data image corresponding to the COPYBACK instructions and the other instructions included in the update package to create the new data image, and
• wherein, when a COPYBACK instruction is encountered in the second operation, data is copied from the corresponding backup area to the new data image.

A computer program product comprising a non-transitory computer usable medium having control logic stored therein for causing a computer to generate an update package based on a comparison between a base data image and a new data image, wherein the update package includes a set of instructions used for, in a remote client device, creating the new data image from the base data image, the control logic comprising:

• a first computer readable program code means for causing the computer to determine differences between the base data image and the new data image;
• a second computer readable program code means for causing the computer to generate COPY instructions corresponding to respective sections of code in the base data image that can be used in creating the new data image by copying the respective sections of code into new data locations in the new data image;
• a third computer readable program code means for causing the computer to organize the COPY instructions into a directed acyclic graph;
• a fourth computer readable program code means for causing the computer to perform cycle detection on the COPY instructions in the directed acyclic graph to detect any cycles;
• a fifth computer readable program code means for causing the computer to, when a cycle is detected, identify a COPY instruction in the detected cycle with a smallest overlapping part, remove the overlapping part from the identified COPY instruction, and generate a COPYBACK instruction including the overlapping part removed from the identified COPY instruction;
• and
• a sixth computer readable program code means for causing the computer to, after all cycles have been detected, generate the update package based on the COPY and COPYBACK instructions.

A computer program product comprising a non-transitory computer usable medium having control logic stored therein for causing a computer to create a new data image from a base data image based on instructions included in an update package, the control logic comprising:

• a first computer readable program code means for causing the computer to receive the update package, the update package including COPYBACK instructions and other instructions;
• a second computer readable program code means for causing the computer to performing a first operation using the update package, the first operation comprising:
• detecting COPYBACK instructions in the update package;
• and for each COPYBACK instruction detected, copying data corresponding to the COPYBACK instructions to a backup area;
• and
• a third computer readable program code means for causing the computer to perform a second operation using the update package after performing the first operation, the second operation comprising:
• performing operations on the base data image corresponding to the COPYBACK instructions and the other instructions included in the update package to create the new data image,
• wherein, when a COPYBACK instruction is encountered in the second operation, data is copied from the corresponding backup area to the new data image.