Wiring OS API
Wiring OS API
Description
A wrapper to CMSIS (Cortex Microcontroller Software Interface Standard) OS API which serves as an RTOS to create the multi-threaded application with real-time behavior.
Syntax
NA
Members
| Public Methods | |
| os_thread_create_arduino | Create a thread and add it to Active Threads and set it to state READY. |
| os_thread_get_id_arduino | Return the thread ID of the current running thread. |
| os_thread_terminate_arduino | Terminate execution of a thread and remove it from Active Threads. |
| os_thread_yield_arduino | Pass control to next thread that is in READY state. |
| os_thread_set_priority_arduino | Change priority of an active thread. |
| os_thread_get_priority_arduino | Get current priority of an active thread. |
| os_signal_set_arduino | Set the specified Signal Flags of an active thread. |
| os_signal_clear_arduino | Clear the specified Signal Flags of an active thread. |
| os_signal_wait_arduino | Wait for one or more Signal Flags to become signalled for the current RUNNING thread. |
| os_timer_create_arduino | Create a timer. |
| os_timer_start_arduino | Start or restart a timer. |
| os_timer_stop_arduino | Stop the timer. |
| os_timer_delete_arduino | Delete a timer that was created by os_timer_create_arduino. |
| os_semaphore_create_arduino | Create and initialize a Semaphore object used for managing resources. |
| os_semaphore_wait_arduino | Wait until a Semaphore token becomes available. |
| os_semaphore_release_arduino | Release a Semaphore token. |
| os_semaphore_delete_arduino | Delete a Semaphore that was created by os_timer_create_arduino. |
| os_get_free_heap_size_arduino | Return the available heap memory space when called. |
os_thread_create_arduino
Description
Create a thread and add it to Active Threads and set it to state READY.
Syntax
uint32_t os_thread_create_arduino (void (*task)(const void *argument), void *argument, int priority, uint32_t stack_size);
Parameters
task: task Function pointer which is the thread body. It should not run into the end of function unless os_thread_terminate_arduino is invoked.
argument: The pointer that is passed to the thread function as start argument.
priority: The underlying os is FreeRTOS. It executes tasks with highest priority which are not in idle state.
stack_size: The stack_size is used as memory heap only for this task.
Returns
This function returns the thread ID in 32-bit which is used in thread operation for reference by other functions or NULL in case of error.
Example Code
NA
Notes and Warnings
“wiring_os.h” must be included to use the class function.
os_thread_get_id_arduino
Description
Get the thread ID of the current running thread.
Syntax
uint32_t os_thread_get_id_arduino(void);
Parameters
NA
Returns
This function returns current thread id in 32-bit which calls os_thread_get_id_arduino.
Example Code
NA
Notes and Warnings
“wiring_os.h” must be included to use the class function.
os_thread_terminate_arduino
Description
Terminate execution of a thread and remove it from Active Threads.
Syntax
uint32_t os_thread_terminate_arduino(uint32_t thread_id);
Parameters
thread_id: Terminate the thread with specific thread_id.
Returns
This function returns the os_status code.
Example Code
NA
Notes and Warnings
Thread should not end without terminate first. “wiring_os.h” must be included to use the class function.
os_thread_yield_arduino
Description
Pass control to next thread that is in READY state.
Syntax
uint32_t os_thread_yield_arduino(void);
Parameters
NA
Returns
This function returns the os_status code.
Example Code
NA
Notes and Warnings
The smallest execution unit by default is one millisecond. When a thread with a lower priority wants to instantly give execution rights to a thread with a higher priority rather than waiting for the current 1 millisecond to expire, calling os_thread yield can transfer execution rights to the OS’s idle task and determine which thread will execute next.
“wiring_os.h” must be included to use the class function.
os_thread_set_priority_arduino
Description
Change priority of an active thread.
Syntax
uint32_t os_thread_set_priority_arduino(uint32_t thread_id, int priority);
Parameters
thread_id: Thread ID identifies the thread (pointer to a thread control block).
priority: The updated priority.
Returns
This function returns os_status code.
Example Code
NA
Notes and Warnings
“wiring_os.h” must be included to use the class function.
os_thread_get_priority_arduino
Description
Get current priority of an active thread.
Syntax
uint32_t os_thread_get_priority_arduino(uint32_t thread_id);
Parameters
thread_id: The target thread with the thread id to be searched.
Returns
This function returns os_priority.
Example Code
NA
Notes and Warnings
“wiring_os.h” must be included to use the class function.
os_signal_set_arduino
Description
Set the specified Signal Flags of an active thread.
Syntax
int32_t os_signal_set_arduino(uint32_t thread_id, int32_t signals);
Parameters
thread_id: Thread ID obtained by os_thread_create_arduino or os_thread_get_id_arduino.signals: The signal flags of the thread that should be set.
Returns
This function returns previous signal flags of the specified thread or 0x80000000 in case of incorrect parameters.
Example Code
NA
Notes and Warnings
“wiring_os.h” must be included to use the class function.
os_signal_clear_arduino
Description
Clear the specified Signal Flags of an active thread.
Syntax
int32_t os_signal_clear_arduino(uint32_t thread_id, int32_t signals);
Parameters
thread_id: Clear signal to a thread with the thread_id
signals: The signal flags of the thread that shall be cleared.
Returns
This function returns previous signal flags of the specified thread or 0x80000000 in case of incorrect parameters.
Example Code
NA
Notes and Warnings
“wiring_os.h” must be included to use the class function.
os_signal_wait_arduino
Description
Wait for one or more Signal Flags to become signalled for the current RUNNING thread.
Syntax
os_event_t os_signal_wait_arduino(int32_t signals, uint32_t millisec);
Parameters
signals: the signals to be wait.
millisec: the timeout value if no signal comes in (in ms). (Acceptable range: 0 – 0xFFFFFFFF, 0 indicates no timeout, 0xFFFFFFFF indicates infinite timeout)
Returns
This function returns event flag information or error code.
Example Code
NA
Notes and Warnings
“wiring_os.h” must be included to use the class function.
os_timer_create_arduino
Description
Create a timer.
Syntax
uint32_t os_timer_create_arduino(void (*callback)(void const *argument), uint8_t isPeriodic, void *argument);
Parameters
callback: The function to be invoke when timer timeout.
isPeriodic: OS_TIMER_ONCE or OS_TIMER_PERIODIC.
argument: The argument that is brought into callback function.
Returns
This function returns the timer id.
Example Code
NA
Notes and Warnings
“wiring_os.h” must be included to use the class function.
os_timer_start_arduino
Description
Start or restart a timer.
Syntax
uint32_t os_timer_start_arduino(uint32_t timer_id, uint32_t millisec);
Parameters
timer_id: The timer id obtained from os_timer_create_arduino.
millisec: The delay after timer starts (in ms). (Acceptable range: 0 – 0xFFFFFFFF, 0 indicates no timeout, 0xFFFFFFFF indicates infinite timeout)
Returns
This function returns os_status code.
Example Code
NA
Notes and Warnings
“wiring_os.h” must be included to use the class function.
os_timer_stop_arduino
Description
Stop the timer.
Syntax
uint32_t os_timer_stop_arduino(uint32_t timer_id);
Parameters
timer_id: The timer id obtained from os_timer_create_arduino.
Returns
This function returns os_status code.
Example Code
NA
Notes and Warnings
“wiring_os.h” must be included to use the class function.
os_timer_delete_arduino
Description
Delete a timer that was created by “os_timer_create_arduino”.
Syntax
uint32_t os_timer_delete_arduino(uint32_t timer_id);
Parameters
timer_id: The timer id obtained from os_timer_create_arduino.
Returns
This function returns os_status code.
Example Code
NA
Notes and Warnings
“wiring_os.h” must be included to use the class function.
os_semaphore_create_arduino
Description
Create and initialize a Semaphore object used for managing resources.
Syntax
uint32_t os_semaphore_create_arduino(int32_t count);
Parameters
count: The number of available resources.
Returns
This function returns semaphore ID.
Example Code
NA
Notes and Warnings
“wiring_os.h” must be included to use the class function.
os_semaphore_wait_arduino
Description
Wait until a Semaphore token becomes available.
Syntax
int32_t os_semaphore_wait_arduino(uint32_t semaphore_id, uint32_t millisec);
Parameters
semaphore_id: semaphore id obtained from os_semaphore_create_arduino.
millisec: timeout value (in ms). (Acceptable range: 0 – 0xFFFFFFFF, 0 indicates no timeout, 0xFFFFFFFF indicates infinite timeout)
Returns
This function returns “1” if “os_semaphoe_wait_arduino” gets the available semaphore token, otherwise returns “0”.
Example Code
NA
Notes and Warnings
“wiring_os.h” must be included to use the class function.
os_semaphore_release_arduino
Description
Release a Semaphore token.
Syntax
uint32_t os_semaphore_release_arduino(uint32_t semaphore_id);
Parameters
semaphore_id: semaphore id obtained from os_semaphore_create_arduino
Returns
This function returns os_status code that indicates the execution status of the function.
Example Code
NA
Notes and Warnings
“wiring_os.h” must be included to use the class function.
os_semaphore_delete_arduino
Description
Delete a Semaphore that was created by os_semaphore_create_arduino.
Syntax
uint32_t os_semaphore_delete_arduino(uint32_t semaphore_id);
Parameters
semaphore_id: semaphore id obtained from os_semaphore_create_arduino.
Returns
This function returns os_status code that indicates the execution status of the function.
Example Code
NA
Notes and Warnings
“wiring_os.h” must be included to use the class function.
“os_semaphore_delete_arduino” shall be consistent in every CMSIS_RTOS.
os_get_free_heap_size_arduino
Description
Get the available heap memory space when called.
Syntax
size_t os_get_free_heap_size_arduino(void);
Parameters
NA
Returns
This function returns the current free heap size as unsigned integer.
Example Code
Example: MemInfo
(https://github.com/ambiot/ambd_arduino/blob/dev/Arduino_package/hardware/libraries/Sys/examples/MemInfo/MemInfo.ino)
Notes and Warnings
“wiring_os.h” must be included to use the class function.
