Method and apparatus traversing stacks for just-in-time compilers for Java virtual machines

A method in a data processing system for traversing a plurality of frames stored sequentially in a memory, the method comprising:

• locating a current frame within the plurality of frames in the memory;
• obtaining an offset to frame offset information within the current frame;
• reading the frame offset information;
• determining an address for a previous frame using the frame offset information;
• finding a pointer to a method block associated with the previous frame using the address;
• determining whether a method block is present;
• and
• responsive to a method block being present, obtaining an offset to frame information in the previous frame.

A data processing system comprising:

• a bus system;
• a communications unit connected to the bus system;
• a memory connected to the bus system, wherein the memory includes a set of instructions;
• and
• a processing unit connected to the bus system, wherein the processing unit executes the set of instructions to find a method block associated with a current frame, read the method block to identify an offset to previous frame information in the current frame, and locate a previous frame within the plurality of frames using the previous frame information.

A data processing system for traversing a plurality of frames for a stack stored sequentially in a memory, the data processing system comprising:

• finding means for finding a method block associated with a current frame;
• reading means for reading the method block to identify an offset to previous frame information in the current frame;
• and
• locating means for locating a previous frame within the plurality of frames using the previous frame information.

A data processing system for traversing a plurality of frames stored sequentially in a memory comprising:

• locating means for locating a current frame within the plurality of frames in the memory;
• obtaining means for obtaining an offset to frame offset information within the current frame;
• reading means for reading the frame offset information;
• determining means for determining an address for a previous frame using the frame offset information;
• finding means for finding a pointer to a method block associated with the previous frame using the address;
• determining means for determining whether a method block is present;
• and
• obtaining means, responsive to a method block being present, for obtaining an offset to frame information in the previous frame.

A computer program product in a computer readable medium for use in a data processing system for traversing a plurality of frames for a stack stored sequentially in a memory, the computer program product comprising:

• first instructions for finding a method block associated with a current frame;
• second instructions for reading the method block to identify an offset to previous frame information in the current frame;
• and
• third instructions for locating a previous frame within the plurality of frames using the previous frame information.

A computer program product in a computer readable medium for use in a data processing system for traversing a plurality of frames stored sequentially in a memory, the computer program product comprising:

• first instructions for locating a current frame within the plurality of frames in the memory;
• second instructions for obtaining an offset to frame offset information within the current frame;
• third instructions for reading the frame offset information;
• fourth instructions for determining an address for a previous frame using the frame offset information;
• fifth instructions for finding a pointer to a method block associated with the previous frame using the address;
• sixth instructions for determining whether a method block is present;
• and
• seventh instructions for, responsive to a method block being present, obtaining an offset to frame information in the previous frame.