SYNOPSIS
#include <hal.h>
int hal_create_thread(const char *name, unsigned long period, int uses_fp);
int hal_thread_delete(const char *name);ARGUMENTS
- name
-
The name of the thread.
- period
-
The interval, in nanoseconds, between iterations of the thread.
- uses_fp
-
Deprecated and ignored. All threads now unconditionally save and restore floating point state. This parameter will be removed in a future version.
DESCRIPTION
hal_create_thread establishes a realtime thread that will execute one or more HAL functions periodically.
All thread periods are rounded to integer multiples of the hardware timer period, and the timer period is based on the first thread created. Threads must be created in order, from the fastest to the slowest. HAL assigns decreasing priorities to threads that are created later, so creating them from fastest to slowest results in rate monotonic priority scheduling.
hal_delete_thread deletes a previously created thread.
REALTIME CONSIDERATIONS
Call only from realtime init code, not from other realtime or non-realtime code.
RETURN VALUE
Returns a HAL status code.
| -EFAULT |
The shared memory was not mapped. |
| -EINVAL |
An invalid argument was passed. |
| -EPERM |
HAL is config locked. |
| -EEXIST |
The thread name already exists (hal_create_thread). |
| -ENOMEM |
Failed to allocate memory for thread registration. |
| -ENOENT |
The thread does not exist (hal_thread_delete). |