US 5,345,588 AGranted

Thread private memory storage of multi-thread digital data processors using access descriptors for uniquely identifying copies of data created on an as-needed basis

AssigneeDigital Equipment Corporation

InventorsStephen R. Greenwood, R. Kim Peterson, Benn L. Schreiber

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Abstract

A method and arrangement for providing each thread of execution (28, 30, 32 and 34) of a multi-threading digital data processing environment with private copies of each set of initialization data (regions 60-1 through 60-4 and 62-1 through 62-4) that is required by procedures (44, 46) which are executed in the context of more than one of the threads. The regions (duplicate data copies) are generated from templates (56, 58) that include a base or original copy of the required set of initialization data. The templates are formulated during operation of the digital data processing system to compile, link and load the procedures and are each identified by a region descriptor (72) which includes a region index (a non-negative integer) and the memory address of the template. Regions are created when the initialization data of the region is required by a procedure that is executing within the context of a thread (i.e., regions are created on an as needed basis) and the memory address of each region is stored in a thread address array (70) so that subsequent access by procedures executing in the context of the same thread can be made using the region descriptor. To conserve system memory, the thread address array is not established in memory until the corresponding thread is being executed and a procedure of the thread requires initialization data (i.e., a region for that thread is to be created).

Claims42

Dependent claims

A thread private storage method performed in a digital data processing system of the type wherein one or more processing units and an addressable system memory are interconnected and are controlled by one or more sets of program instructions for compiling, linking, loading and executing a multi-threading process having multiple threads of execution which invoke and execute procedures that require one or more sets of initialization data, said thread private storage method comprising:

controlling the processing units and addressable system memory with the one or more sets of program instructions during the operation of said system for compiling, linking and loading said multi-threading process to perform the following steps for each thread of said multiple threads of execution:
(a) establishing and storing in system memory a template for each said set of initialization data, each said template being associated with a different set of initialization data, each said template including data identical to its associated set of initialization data;
(b) establishing for each said template an associated descriptor for use in subsequent creation of a copy of said initialization data that is private to each said thread that executes one or more procedures that require the initialization data associated with said template, said descriptor uniquely identifying the template with which it is associated and including information that allows the processing units to locate said template uniquely identified by said descriptor in said system memory at the time of said subsequent creation of said copy of said initialization data;
(c) establishing a sequence of coded instructions for locating said template uniquely identified by said descriptor;
(d) including said sequence of coded instructions in said one or more set of program instructions for controlling said processing units and said addressable system memory;
and,
controlling the processing units and system memory with the one or more sets of program instructions during execution of said procedure executed by each said thread to perform the steps of:
(a) creating said copy of said initialization data that is private to each said thread by copying into system memory a copy of the set of initialization data required by the procedure, said step of creating said copy being performed at the first point of execution at which said initialization data is required for further execution of said procedure, said copying into system memory being effected by accessing system memory by means of said descriptor that uniquely identifies the template associated with said required set of initialization data to locate the template associated with said required set of initialization data and by copying said initialization data of said template to an available previously unspecified system memory address.

5 more elements

A thread private storage method performed by a digital data processing system of the type wherein one or more processing units and an addressable system memory are interconnected and are programmed by one or more sets of program instructions for compiling, linking, loading and executing a multi-threading process having multiple threads of execution which invoke and execute procedures that require one or more sets of initialization data, said thread private storage method comprising:

during the programmed operation of said system for compiling, linking and loading of said procedures and for each said thread of execution, controlling said one or more processing units and the addressable system memory to perform the steps of:
establishing and storing in system memory a template for each said set of initialization data that is required by the procedures executed by a thread, each said template including the initialization data for a particular set of initialization data required by one of said multiple threads of execution;
selecting and storing a region descriptor in system memory for subsequent use in creating regions in system memory that store a duplicate copy of said initialization data for each procedure that requires a set of initialization data, each said region descriptor including the memory address of a template that includes a particular set of initialization data and including a region index that uniquely identifies a region to be established in system memory when that particular set of initialization data is first needed for use in one of said procedures of one of said multiple threads of execution, said region being stored in system memory at an address that is determined at said time at which said initialization is first needed;
establishing a sequence of program instructions that are executable to locate the memory storage address of the template that includes said particular set of initialization data;
including said sequence of program instructions in at least one of said one or more sets of program instructions so that said particular template will be located in execution of said multi-threading process when said particular set of initialization data is first needed for use in one of said procedures of said multiple threads of execution;
and
during the programmed operation of said system for execution of each procedure executed within the context of a thread;
establishing from said templates said regions in memory that store said duplicate copy of said initialization data, said step of establishing each of said regions being performed by said digital data processing system in response to said sequence of program instructions, said step of establishing each said region being performed at the first point of execution at which a procedure within the context of a thread that requires the initialization data associated with a particular template, said step of establishing each of said regions including the steps of accessing the region descriptor that is stored in system memory and is associated with the template that includes said particular initialization data, locating said template that includes said particular initialization data in system memory based upon the memory address included in said accessed region descriptor, and copying the set of initialization data included in said accessed template;
each of said regions being private to a thread to provide each said thread a copy of each set of initialization data required by the procedures that are executed within the context of that thread.

6 more elements

Dependencies are inferred from the claim text.