/**
* \b atomThreadSwitch
*
* This is an internal function not for use by application code.
*
* The function is called by the scheduler to perform a context switch.
* Execution will switch to the new thread's context, therefore the
* function doesn't actually return until the old thread is scheduled
* back in.
*
* @param[in] old_tcb Pointer to TCB for thread being scheduled out
* @param[in] new_tcb Pointer to TCB for thread being scheduled in
*
* @return None
*/
static void atomThreadSwitch(ATOM_TCB *old_tcb, ATOM_TCB *new_tcb)
{
/**
* Check if the new thread is actually the current one, in which
* case we don't need to do any context switch. This can happen
* if a thread goes into suspend but is unsuspended again before
* it is fully scheduled out.
*/
if (old_tcb != new_tcb)
{
/* Set the new currently-running thread pointer */
curr_tcb = new_tcb;
/* Call the architecture-specific context switch */
archContextSwitch (old_tcb, new_tcb);
}
/**
* The context switch shifted execution to a different thread. By the time
* we get back here, we are running in old_tcb context again. Clear its
* suspend status now that we're back.
*/
old_tcb->suspended = FALSE;
}
/**
* \b atomThreadSwitch
*
* This is an internal function not for use by application code.
*
* The function is called by the scheduler to perform a context switch.
* Execution will switch to the new thread's context, therefore the
* function doesn't actually return until the old thread is scheduled
* back in.
*
* @param[in] old_tcb Pointer to TCB for thread being scheduled out
* @param[in] new_tcb Pointer to TCB for thread being scheduled in
*
* @return None
*/
static void atomThreadSwitch(ATOM_TCB *old_tcb, ATOM_TCB *new_tcb)
{
/**
* Check if the new thread is actually the current one, in which
* case we don't need to do any context switch. This can happen
* if a thread goes into suspend but is unsuspended again before
* it is fully scheduled out.
*/
if (old_tcb != new_tcb)
{
/* Set the new currently-running thread pointer */
curr_tcb = new_tcb;
/**
* The context switch will shift execution to a different thread. The
* new thread is now ready to run so clear its suspend status in
* preparation for it waking up.
*/
new_tcb->suspended = FALSE;
/* Call the architecture-specific context switch */
archContextSwitch (old_tcb, new_tcb);
}
}
