GPIB system and method which allows multiple thread access to global variables

A method of accessing global variables from multiple threads in a GPIB system, wherein the system comprises a GPIB application which interfaces through GPIB driver software to a GPIB device, wherein the GPIB application and the GPIB driver software execute on a computer system, wherein the GPIB application includes a plurality of threads, the method comprising:

• maintaining copies of one or more global variables for each of the plurality of threads, wherein copies of said one or more global variables for each of said plurality of threads are maintained on a per-thread basis;
• a first thread in said GPIB application calling a thread-local access function to access a first global variable of said one or more global variables;
• determining a value of the first global variable for said first thread in response to calling the thread-local access function, wherein said determining retrieves a value of the first global variable for said first thread being maintained in said step of maintaining;
• providing the value of the first global variable for said first thread in response to said determining the value of the first global variable for said first thread.

A GPIB system which enables multiple threads in a GPIB application to safely access global variables, the GPIB system comprising:

• a computer system comprising a CPU and memory, wherein the memory stores the GPIB application and GPIB driver software, wherein the GPIB application and the GPIB driver software execute on the computer system, wherein the GPIB application includes multiple threads;
• a GPIB device coupled to the computer system,
• wherein the GPIB application interfaces through the GPIB driver software to the GPIB device;
• wherein the computer system memory is operable to maintain a copy of a first global variable for a first thread and is operable to maintain a copy of the first global variable for a second thread;
• wherein said first thread in said GPIB application is operable to call a thread-local access function to access said first global variable;
• wherein the GPIB driver software is operable to determine a value of the first global variable for said first thread and provide the value of the first global variable for said first thread in response to the thread-local access function being called, wherein said determining retrieves a value of the first global variable for said first thread being maintained;
• wherein said second thread in said GPIB application is operable to call the thread-local access function to access said first global variable;
• wherein the GPIB driver software is operable to determine a value of the first global variable for said second thread and provide the value of the first global variable for said second thread in response to the thread-local access function being called, wherein said determining retrieves a value of the first global variable for said second thread being maintained.

A memory media which stores program instructions for accessing global variables from multiple threads in a GPIB system, wherein the system comprises a GPIB application which interfaces through GPIB driver software to a GPIB device, wherein the GPIB application and the GPIB driver software execute on a computer system, wherein the GPIB application includes a plurality of threads, wherein the program instructions are executable to implement the steps of:

• maintaining a copy of a first global variable for a first thread;
• maintaining a copy of the first global variable for a second thread;
• determining a value of the first global variable for said first thread in response to said first thread calling a thread-local access function, wherein said determining retrieves a value of the first global variable for said first thread being maintained in said step of maintaining a copy of the first global variable for said first thread;
• providing the value of the first global variable for said first thread in response to said determining the value of the first global variable for said first thread;
• determining a value of the first global variable for said second thread in response to said second thread calling the thread-local access function, wherein said determining retrieves a value of the first global variable for said second thread being maintained in said step of maintaining a copy of the first global variable for said second thread;
• providing the value of the first global variable for said second thread in response to said determining the value of the first global variable for said second thread.