ESC San Jose, Ca. – Express Logic, Inc., the worldwide leader in royalty-free real-time operating systems (RTOS), here unveiled a new development tool that helps developers avoid stack overflow problems that traditionally have plagued embedded systems.
The new tool, StackX, performs a comprehensive analysis of a complete application at the executable code level, computing the worst-case stack usage the application can experience.
William E. Lamie, president of Express Logic, claims that his RTOS company is the only one to help developers identify how large a stack is needed for each application thread and automatically alerts them if they fail to allocate sufficient memory!
“In the C programming language, the stack—a region of memory on which local variables are created and function arguments are passed—is allocated memory by the programmer,” he said, “with the amount based on factors such as machine architecture, OS, application design, and amount of memory available.”
When the program requires more memory for its stack than has been allocated, the stack overflows—without warning in most cases—which can corrupt other memory areas and typically results in a program crash.
Such crashes are very difficult to trace back to the stack overflow, causing programmers to expend considerable time and energy to find the overflow. As a result, they tend to overallocate stack memory as a precaution.
Deciding how much memory to allocate for the stack has been a trial and error process, said Lamie, pointing out that StackX solves this problem for embedded developers by computing the required stack size automatically for developers, enabling them to allocate just the amount of memory needed to be safe, and avoid wasting any additional, unnecessary memory.
“StackX analyzes a program's executable (.elf) file, mapping all function calls, interrupt service routines, local variables, and any other factors related to stack usage,” he said.
“This enables StackX to calculate each thread's maximum stack memory requirements. StackX produces a “call-tree” that shows the maximum stack usage for each thread. Developers can see their program flow and are better able to optimize their code.”
StackX employs a proprietary, patent-pending algorithm that is accurate, efficient, and only requires an “.elf” file. While it may be used with any .elf file, StackX has particular visibility into ThreadX RTOS-based applications, with its thread-aware stack size calculation.
It recognizes recursion conditions, where infinite memory would be required to avoid potential overflow, so programmers can correct the code, rather than attempt to allocate more memory.
StackX is available from Express Logic at a price of $1,000 per developer for a perpetual license. To learn more, go to www.rtos.com>.