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/*
ChibiOS/RT - Copyright (C) 2006-2007 Giovanni Di Sirio.
This file is part of ChibiOS/RT.
ChibiOS/RT is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 3 of the License, or
(at your option) any later version.
ChibiOS/RT is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
/**
* @addtogroup Threads
* @{
*/
#ifndef _THREADS_H_
#define _THREADS_H_
/**
* Structure representing a thread.
* @note Not all the listed fields are always needed, by switching off some
* not needed ChibiOS/RT subsystems it is possible to save RAM space by
* shrinking the \p Thread structure.
*/
struct Thread {
/** Next \p Thread in the threads list.*/
Thread *p_next;
/* End of the fields shared with the ThreadsList structure. */
/** Previous \p Thread in the threads list.*/
Thread *p_prev;
/* End of the fields shared with the ThreadsQueue structure. */
/** The thread priority.*/
t_prio p_prio;
/* End of the fields shared with the ReadyList structure. */
/** Current thread state.*/
t_tstate p_state;
/** Mode flags.*/
t_tmode p_flags;
/*
* The following fields are merged in an union because they are all
* state-specific fields. This trick saves some extra space for each
* thread in the system.
*/
union {
/** Thread wakeup code, normally set to \p RDY_OK by the \p chSchReadyI()
* (only while in \p PRREADY state).*/
t_msg p_rdymsg;
/** The thread exit code (only while in \p PREXIT state).*/
t_msg p_exitcode;
#ifdef CH_USE_SEMAPHORES
/** Semaphore where the thread is waiting on (only in \p PRWTSEM state).*/
Semaphore *p_semp;
#endif
#ifdef CH_USE_EVENTS
/** Enabled events mask (only while in \p PRWTEVENT state).*/
t_eventmask p_ewmask;
#endif
#ifdef CH_USE_MESSAGES
/** Message (only while in \p PRSNDMSG state).*/
t_msg p_msg;
#endif
};
/** Machine dependent processor context.*/
Context p_ctx;
/*
* Start of the optional fields. Note, the null thread may also let its
* stack overwrite the following fields since it never uses semaphores,
* events, messages, exit etc, this can save some space on RAM starved
* systems, be caruful in doing so.
*/
#ifdef CH_USE_WAITEXIT
/** The list of the threads waiting for this thread termination.*/
ThreadsList p_waiting;
#endif
#ifdef CH_USE_EXIT_EVENT
/** The thread termination \p EventSource.*/
EventSource p_exitesource;
#endif
#ifdef CH_USE_MESSAGES
ThreadsQueue p_msgqueue;
#endif
#ifdef CH_USE_EVENTS
/** Pending events mask.*/
t_eventmask p_epending;
#endif
#ifdef CH_USE_RT_SEMAPHORES
/** RT semaphores depth counter.*/
t_cnt p_rtcnt;
#endif
};
/** Thread state: Reserved.*/
#define PRFREE 0
/** Thread state: Current.*/
#define PRCURR 1
/** Thread state: Thread in the ready list.*/
#define PRREADY 2
/** Thread state: Thread created in suspended state.*/
#define PRSUSPENDED 3
/** Thread state: Waiting on a semaphore.*/
#define PRWTSEM 4
/** Thread state: Waiting in \p chThdSleep() or \p chThdSleepUntil().*/
#define PRSLEEP 5
/** Thread state: Waiting in \p chThdWait().*/
#define PRWAIT 6
/** Thread state: Waiting in \p chEvtWait().*/
#define PRWTEVENT 7
/** Thread state: Waiting in \p chMsgSend().*/
#define PRSNDMSG 8
/** Thread state: Waiting in \p chMsgWait().*/
#define PRWTMSG 9
/** Thread state: After termination.*/
#define PREXIT 10
/** Thread option: Termination requested flag.*/
#define P_TERMINATE 1
/** Thread option: Create suspended thread.*/
#define P_SUSPENDED 2
/** Idle thread priority.*/
#define IDLEPRIO 0
/** Lowest user priority.*/
#define LOWPRIO 1
/** Normal user priority.*/
#define NORMALPRIO 64
/** Highest user priority.*/
#define HIGHPRIO 127
/** Boosted base priority.*/
#define MEPRIO 128
/** Greatest possible priority.*/
#define ABSPRIO 255
/* Not an API, don't use into the application code.*/
void _InitThread(t_prio prio, t_tmode mode, Thread *tp);
/** Thread function.*/
typedef t_msg (*t_tfunc)(void *);
/*
* Threads APIs.
*/
#ifdef __cplusplus
extern "C" {
#endif
Thread *chThdCreate(t_prio prio, t_tmode mode, void *workspace,
t_size wsize, t_tfunc pf, void *arg);
void chThdSetPriority(t_prio newprio);
void chThdExit(t_msg msg);
#ifdef CH_USE_RESUME
void chThdResume(Thread *tp);
#endif
#ifdef CH_USE_SUSPEND
void chThdSuspend(Thread **tpp);
#endif
#ifdef CH_USE_TERMINATE
void chThdTerminate(Thread *tp);
#endif
#ifdef CH_USE_WAITEXIT
t_msg chThdWait(Thread *tp);
#endif
#ifdef __cplusplus
}
#endif
/** Returns the pointer to the \p Thread currently in execution.*/
#define chThdSelf() currp
/** Returns the pointer to the \p Thread local storage area, if any.*/
#define chThdLS() (void *)(currp + 1)
/** Verifies if the specified thread is in the \p PREXIT state.*/
#define chThdTerminated(tp) ((tp)->p_state == PREXIT)
/**
* Verifies if the current thread has a termination request pending.
*/
#define chThdShouldTerminate() (currp->p_flags & P_TERMINATE)
/**
* Returns the exit event source for the specified thread. The source is
* signaled when the thread terminates.
* @param tp the pointer to the thread
* @note When registering on a thread termination make sure the thread
* is still alive, if you do that after the thread termination
* then you would miss the event. There are two ways to ensure
* this:<br>
* <ul>
* <li>Create the thread suspended, register on the event source
* and then resume the thread (recommended).</li>
* <li>Create the thread with a lower priority then register on it.
* This does not work if the hardware is capable of multiple
* physical threads.</li>
* </ul>
* @note You dont need to unregister from a terminated thread because
* the event source becomes inactive.
* @note The function is available only if the \p CH_USE_EXIT_EVENT
* option is enabled in \p chconf.h.
*/
#define chThdGetExitEventSource(tp) (&(tp)->p_exitesource)
/**
* Resumes a thread created with the \p P_SUSPENDED option or suspended with
* \p chThdSuspend().
* @param tp the pointer to the thread
*/
#define chThdResumeI(tp) chSchReadyI(tp)
#endif /* _THREADS_H_ */
/** @} */
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