zephyr/kernel/nanokernel/nano_context.c

250 lines
6.9 KiB
C

/* nanokernel thread support */
/*
* Copyright (c) 2010-2014 Wind River Systems, Inc.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are met:
*
* 1) Redistributions of source code must retain the above copyright notice,
* this list of conditions and the following disclaimer.
*
* 2) Redistributions in binary form must reproduce the above copyright notice,
* this list of conditions and the following disclaimer in the documentation
* and/or other materials provided with the distribution.
*
* 3) Neither the name of Wind River Systems nor the names of its contributors
* may be used to endorse or promote products derived from this software without
* specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
* AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
* LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
* POSSIBILITY OF SUCH DAMAGE.
*/
/*
DESCRIPTION
This module provides general purpose thread support, with applies to both
tasks or fibers.
*/
#include <toolchain.h>
#include <sections.h>
#include <nano_private.h>
#include <misc/printk.h>
nano_thread_id_t sys_thread_self_get(void)
{
return _nanokernel.current;
}
nano_context_type_t sys_execution_context_type_get(void)
{
if (_IS_IN_ISR())
return NANO_CTX_ISR;
if ((_nanokernel.current->flags & TASK) == TASK)
return NANO_CTX_TASK;
return NANO_CTX_FIBER;
}
/**
*
* @brief Mark thread as essential to system
*
* This function tags the running fiber or task as essential to system
* option; exceptions raised by this thread will be treated as a fatal
* system error.
*
* @return N/A
*/
void _thread_essential_set(void)
{
_nanokernel.current->flags |= ESSENTIAL;
}
/**
*
* @brief Mark thread as not essential to system
*
* This function tags the running fiber or task as not essential to system
* option; exceptions raised by this thread may be recoverable.
* (This is the default tag for a thread.)
*
* @return N/A
*/
void _thread_essential_clear(void)
{
_nanokernel.current->flags &= ~ESSENTIAL;
}
/**
*
* @brief Is the specified thread essential?
*
* This routine indicates if the specified thread is an essential system
* thread. A NULL thread pointer indicates that the current thread is
* to be queried.
*
* @return Non-zero if specified thread is essential, zero if it is not
*/
int _is_thread_essential(struct tcs *pCtx /* pointer to thread */
)
{
return ((pCtx == NULL) ? _nanokernel.current : pCtx)->flags & ESSENTIAL;
}
#ifdef CONFIG_THREAD_CUSTOM_DATA
/**
*
* @brief Set thread's custom data
*
* This routine sets the custom data value for the current task or fiber.
* Custom data is not used by the kernel itself, and is freely available
* for the thread to use as it sees fit.
*
* @param value New to set the thread's custom data to.
*
* @return N/A
*/
void sys_thread_custom_data_set(void *value)
{
_nanokernel.current->custom_data = value;
}
/**
*
* @brief Get thread's custom data
*
* This function returns the custom data value for the current task or fiber.
*
* @return current handle value
*/
void *sys_thread_custom_data_get(void)
{
return _nanokernel.current->custom_data;
}
#endif /* CONFIG_THREAD_CUSTOM_DATA */
#if defined(CONFIG_THREAD_MONITOR)
/**
*
* @brief Thread exit routine
*
* This function is invoked when the specified thread is aborted, either
* normally or abnormally. It is called for the termination of any thread,
* (fibers and tasks).
*
* This routine must be invoked either from a fiber or from a task with
* interrupts locked to guarantee that the list of threads does not change in
* mid-operation. It cannot be called from ISR context.
*
* @return N/A
*/
void _thread_exit(struct tcs *thread)
{
/*
* Remove thread from the list of threads. This singly linked list of
* threads maintains ALL the threads in the system: both tasks and
* fibers regardless of whether they are runnable.
*/
if (thread == _nanokernel.threads) {
_nanokernel.threads = _nanokernel.threads->next_thread;
} else {
struct tcs *prev_thread;
prev_thread = _nanokernel.threads;
while (thread != prev_thread->next_thread) {
prev_thread = prev_thread->next_thread;
}
prev_thread->next_thread = thread->next_thread;
}
}
#endif /* CONFIG_THREAD_MONITOR */
/**
*
* @brief Common thread entry point function
*
* This function serves as the entry point for _all_ threads, i.e. both
* task and fibers are instantiated such that initial execution starts
* here.
*
* This routine invokes the actual task or fiber entry point function and
* passes it three arguments. It also handles graceful termination of the
* task or fiber if the entry point function ever returns.
*
* @internal
* The 'noreturn' attribute is applied to this function so that the compiler
* can dispense with generating the usual preamble that is only required for
* functions that actually return.
*
* @return Does not return
*
*/
FUNC_NORETURN void _thread_entry(
_thread_entry_t pEntry, /* address of app entry point function */
_thread_arg_t parameter1, /* 1st arg to app entry point function */
_thread_arg_t parameter2, /* 2nd arg to app entry point function */
_thread_arg_t parameter3 /* 3rd arg to app entry point function */
)
{
/* Execute the "application" entry point function */
pEntry(parameter1, parameter2, parameter3);
/* Determine if thread can legally terminate itself via "return" */
if (_is_thread_essential(NULL)) {
#ifdef CONFIG_NANOKERNEL
/*
* Nanokernel's background task must always be present,
* so if it has nothing left to do just let it idle forever
*/
while (((_nanokernel.current)->flags & TASK) == TASK) {
nano_cpu_idle();
}
#endif /* CONFIG_NANOKERNEL */
/* Loss of essential thread is a system fatal error */
_NanoFatalErrorHandler(_NANO_ERR_INVALID_TASK_EXIT,
&_default_esf);
}
/* Gracefully terminate the currently executing thread */
#ifdef CONFIG_MICROKERNEL
if (((_nanokernel.current)->flags & TASK) == TASK) {
extern FUNC_NORETURN void _TaskAbort(void);
_TaskAbort();
} else
#endif /* CONFIG_MICROKERNEL */
{
fiber_abort();
}
/*
* Compiler can't tell that fiber_abort() won't return and issues
* a warning unless we explicitly tell it that control never gets this
* far.
*/
CODE_UNREACHABLE;
}