µC/OS-III contains an internal task that provides such run-time statistics as overall CPU utilization (0.00 to 100.00%), per-task CPU utilization (0.00 to 100.00%), and per-task stack usage. As of V3.03.00, CPU utilization is represented as a integer from 0 to 10,000 (0.00% to 100.00%). Prior to V3.03.00, CPU utilization was represented an integer ranging from 0 to 100.
The statistic task is optional in a µC/OS-III application and its presence is controlled by a compile-time configuration constant OS_CFG_STAT_TASK_EN defined in os_cfg.h. Specifically, the code is included in the build when OS_CFG_STAT_TASK_EN is set to DEF_ENABLED.
Also, the priority of this task and the location and size of the statistic task’s stack is configurable via OS_CFG_STAT_TASK_PRIO declared in os_cfg_app.h ().
If the application uses the statistic task, it should call OSStatTaskCPUUsageInit() from the first, and only application task created in the main() function as shown in the listing below. The startup code should create only one task before calling OSStart(). The single task created is, of course, allowed to create other tasks, but only after calling OSStatTaskCPUUsageInit().