Memory management for closures

Abstract

Methods, software media, compilers and programming techniques are described for creating copyable stack-based closures, such as a block, for languages which allocate automatic or local variables on a stack memory structure. In one exemplary method, a data structure of the block is first written to the stack memory structure, and this may be the automatic default operation, at run-time, for the block; then, a block copy instruction, added explicitly (in one embodiment) by a programmer during creation of the block, is executed to copy the block to a heap memory structure. The block includes a function pointer that references a function which uses data in the block.

What is claimed is: 
     
         1 . A machine readable storage medium storing executable program instructions which when executed by a data processing system cause the data processing system to perform a method comprising:
 retrieving first data indicating an association between a pointer to a function and a block layout description table;   exposing data in the block in a debugging operation by using the block layout description table, wherein the block includes the pointer to the function which uses data in the block for computation by the function.   
     
     
         2 . The medium as in  claim 1 , wherein a debugger performs the debugging operations and wherein a lookup function of the debugger finds the block layout description table in the block. 
     
     
         3 . The medium as in  claim 2 , wherein the block is initially stored in a stack memory structure and is copied, by a block copy instruction explicitly added by a programmer, to a heap memory structure. 
     
     
         4 . The medium as in  claim 3 , wherein the block includes data in the block's syntax and the function is configured to recognize and use data in the block. 
     
     
         5 . The medium as in  claim 2 , wherein the block is initially stored in a stack memory and is copied to a heap memory structure. 
     
     
         6 . A data processing system, comprising:
 a memory to store a block, the block comprising a block layout description table, a function pointer to reference a function, the function pointer including a pointer to the block layout description table; and   a debugger coupled to the memory, to expose data in the block relevant to the function using the block layout description table.   
     
     
         7 . The data processing system of  claim 6 , wherein a lookup function of the debugger finds the block layout description table in the block using the pointer. 
     
     
         8 . The data processing system of  claim 6 , wherein the memory comprises:
 a stack memory structure; and   a heap memory structure, wherein the block is initially stored in the stack memory structure and is copied, by a block copy instruction explicitly added by a programmer, to the heap memory structure.   
     
     
         9 . The data processing system as in  claim 8 , wherein the block includes data in the block's syntax and the function is configured to recognize and use data in the block. 
     
     
         10 . The data processing system as in  claim 6 , wherein the block is initially stored in a stack memory and is copied to a heap memory structure. 
     
     
         11 . A computer-implemented method, comprising:
 retrieving first data indicating an association between a pointer to a function and a block layout description table;   exposing data in the block in a debugging operation by using the block layout description table, wherein the block includes the pointer to the function which uses data in the block for computation by the function.   
     
     
         12 . The method as in  claim 11 , wherein a debugger performs the debugging operations and wherein a lookup function of the debugger finds the block layout description table in the block. 
     
     
         13 . The method as in  claim 12 , wherein the block is initially stored in a stack memory structure and is copied, by a block copy instruction explicitly added by a programmer, to a heap memory structure. 
     
     
         14 . The method as in  claim 13 , wherein the block includes data in the block's syntax and the function is configured to recognize and use data in the block. 
     
     
         15 . The method as in  claim 11 , wherein the block is initially stored in a stack memory and is copied to a heap memory structure.