/* thread.h
*
* This include file contains all constants and structures associated
* with the thread control block.
*
* COPYRIGHT (c) 1989, 1990, 1991, 1992, 1993, 1994.
* On-Line Applications Research Corporation (OAR).
* All rights assigned to U.S. Government, 1994.
*
* This material may be reproduced by or for the U.S. Government pursuant
* to the copyright license under the clause at DFARS 252.227-7013. This
* notice must appear in all copies of this file and its derivatives.
*
* $Id$
*/
#ifndef __RTEMS_THREAD_h
#define __RTEMS_THREAD_h
#ifdef __cplusplus
extern "C" {
#endif
#include <rtems/asr.h>
#include <rtems/attr.h>
#include <rtems/context.h>
#include <rtems/cpu.h>
#include <rtems/eventset.h>
#include <rtems/modes.h>
#include <rtems/mppkt.h>
#include <rtems/object.h>
#include <rtems/options.h>
#include <rtems/priority.h>
#include <rtems/stack.h>
#include <rtems/states.h>
#include <rtems/tod.h>
#include <rtems/tqdata.h>
#include <rtems/watchdog.h>
/*
* Notepads constants (indices into notepad array)
*/
#define RTEMS_NOTEPAD_FIRST 0 /* lowest numbered notepad */
#define RTEMS_NOTEPAD_0 0 /* notepad location 0 */
#define RTEMS_NOTEPAD_1 1 /* notepad location 1 */
#define RTEMS_NOTEPAD_2 2 /* notepad location 2 */
#define RTEMS_NOTEPAD_3 3 /* notepad location 3 */
#define RTEMS_NOTEPAD_4 4 /* notepad location 4 */
#define RTEMS_NOTEPAD_5 5 /* notepad location 5 */
#define RTEMS_NOTEPAD_6 6 /* notepad location 6 */
#define RTEMS_NOTEPAD_7 7 /* notepad location 7 */
#define RTEMS_NOTEPAD_8 8 /* notepad location 8 */
#define RTEMS_NOTEPAD_9 9 /* notepad location 9 */
#define RTEMS_NOTEPAD_10 10 /* notepad location 10 */
#define RTEMS_NOTEPAD_11 11 /* notepad location 11 */
#define RTEMS_NOTEPAD_12 12 /* notepad location 12 */
#define RTEMS_NOTEPAD_13 13 /* notepad location 13 */
#define RTEMS_NOTEPAD_14 14 /* notepad location 14 */
#define RTEMS_NOTEPAD_15 15 /* notepad location 15 */
#define RTEMS_NOTEPAD_LAST RTEMS_NOTEPAD_15 /* highest numbered notepad */
#define RTEMS_NUMBER_NOTEPADS (RTEMS_NOTEPAD_LAST+1)
/*
* The following defines the "return type" of an RTEMS thread.
*
* NOTE: Keep both types for internal threads.
*/
typedef void rtems_task;
typedef void Thread;
/*
* The following defines the argument to an RTEMS thread.
*/
typedef unsigned32 rtems_task_argument;
typedef unsigned32 Thread_Argument;
/*
* The following defines the type for the entry point of an RTEMS thread.
*/
typedef rtems_task ( *rtems_task_entry )(
rtems_task_argument
);
typedef Thread ( *Thread_Entry )(
Thread_Argument
);
/*
* The following structure contains the information which defines
* the starting state of a thread.
*/
typedef struct {
Thread_Entry entry_point; /* starting thread address */
unsigned32 initial_argument; /* initial argument */
rtems_mode initial_modes; /* initial mode */
rtems_task_priority initial_priority; /* initial priority */
void *fp_context; /* initial FP context area address */
Stack_Control Initial_stack; /* stack information */
} Thread_Start_information;
/*
* The following structure contains the information necessary to manage
* a thread which it is waiting for a resource.
*/
typedef struct {
Objects_Id id; /* waiting on this object */
rtems_option option_set; /* wait mode */
union {
unsigned32 segment_size; /* size of segment requested */
rtems_event_set event_condition;
unsigned32 *message_size_p; /* ptr for return size of message */
} Extra;
void *return_argument; /* address of user return param */
rtems_status_code return_code; /* status for thread awakened */
Chain_Control Block2n; /* 2 - n priority blocked chain */
Thread_queue_Control *queue; /* pointer to thread queue */
} Thread_Wait_information;
/*
* The following defines the control block used to manage
* each thread proxy.
*
* NOTE: It is critical that proxies and threads have identical
* memory images for the shared part.
*/
typedef struct {
Objects_Control Object;
States_Control current_state;
rtems_task_priority current_priority;
rtems_task_priority real_priority;
unsigned32 resource_count;
Thread_Wait_information Wait;
Watchdog_Control Timer;
rtems_packet_prefix *receive_packet;
/****************** end of common block ********************/
Chain_Node Active;
} Thread_Proxy_control;
/*
* The following record defines the control block used
* to manage each thread.
*
* NOTE: It is critical that proxies and threads have identical
* memory images for the shared part.
*/
typedef struct {
Objects_Control Object;
States_Control current_state;
rtems_task_priority current_priority;
rtems_task_priority real_priority;
unsigned32 resource_count;
Thread_Wait_information Wait;
Watchdog_Control Timer;
rtems_packet_prefix *receive_packet;
/****************** end of common block ********************/
Chain_Control *ready;
Priority_Information Priority_map;
rtems_event_set pending_events;
rtems_event_set events_out;
Thread_Start_information Start;
ASR_Information Signal;
rtems_mode current_modes;
rtems_attribute attribute_set;
Context_Control Registers;
void *fp_context;
unsigned32 Notepads[ RTEMS_NUMBER_NOTEPADS ];
void *extension;
} Thread_Control;
/*
* External API name for Thread_Control
*/
typedef Thread_Control rtems_tcb;
/*
* The following declares the dispatch critical section nesting
* counter which is used to prevent context switches at inopportune
* moments.
*/
EXTERN unsigned32 _Thread_Dispatch_disable_level;
/*
* The following data items are used to manage timeslicing.
*/
EXTERN unsigned32 _Thread_Ticks_remaining_in_timeslice;
EXTERN unsigned32 _Thread_Ticks_per_timeslice;
/*
* The following points to the array of FIFOs used to manage the
* set of ready threads.
*/
EXTERN Chain_Control *_Thread_Ready_chain;
/*
* The following points to the thread which is currently executing.
* This thread is implicitly manipulated by numerous directives.
*/
EXTERN Thread_Control *_Thread_Executing;
/*
* The following points to the highest priority ready thread
* in the system. Unless the current thread is RTEMS_NO_PREEMPT,
* then this thread will be context switched to when the next
* dispatch occurs.
*/
EXTERN Thread_Control *_Thread_Heir;
/*
* The following points to the thread whose floating point
* context is currently loaded.
*/
EXTERN Thread_Control *_Thread_Allocated_fp;
/*
* The following context area contains the context of the "thread"
* which invoked rtems_initialize_executive. This context is restored
* as the last action of the rtems_shutdown_executive directive. Thus
* control of the processor can be returned to the environment
* which initiated RTEMS.
*/
EXTERN Context_Control _Thread_BSP_context;
/*
* _Thread_Handler_initialization
*
* DESCRIPTION:
*
* This routine performs the initialization necessary for this handler.
*/
void _Thread_Handler_initialization (
unsigned32 ticks_per_timeslice,
unsigned32 maximum_proxies
);
/*
* _Thread_Start_multitasking
*
* DESCRIPTION:
*
* This routine initiates multitasking. It is invoked only as
* part of initialization and its invocation is the last act of
* the rtems_initialize_executive directive.
*/
void _Thread_Start_multitasking (
Thread_Control *system_thread,
Thread_Control *idle_thread
);
/*
* _Thread_Stop_multitasking
*
* DESCRIPTION:
*
* This routine halts multitasking and returns control to
* the "thread" which initially invoked the rtems_initialize_executive
* directive.
*/
STATIC INLINE void _Thread_Stop_multitasking( void );
/*
* _Thread_Dispatch_initialization
*
* DESCRIPTION:
*
* This routine initializes the thread dispatching subsystem.
*/
STATIC INLINE void _Thread_Dispatch_initialization( void );
/*
* _Thread_Dispatch
*
* DESCRIPTION:
*
* This routine is responsible for transferring control of the
* processor from the executing thread to the heir thread. As part
* of this process, it is responsible for the following actions:
*
* + saving the context of the executing thread
* + restoring the context of the heir thread
* + dispatching any signals for the resulting executing thread
*/
void _Thread_Dispatch( void );
/*
* _Thread_Ready
*
* DESCRIPTION:
*
* This routine removes any set states for the_thread. It performs
* any necessary scheduling operations including the selection of
* a new heir thread.
*/
void _Thread_Ready(
Thread_Control *the_thread
);
/*
* _Thread_Clear_state
*
* DESCRIPTION:
*
* This routine clears the indicated STATES for the_thread. It performs
* any necessary scheduling operations including the selection of
* a new heir thread.
*/
void _Thread_Clear_state(
Thread_Control *the_thread,
States_Control state
);
/*
* _Thread_Set_state
*
* DESCRIPTION:
*
* This routine sets the indicated states for the_thread. It performs
* any necessary scheduling operations including the selection of
* a new heir thread.
*
*/
void _Thread_Set_state(
Thread_Control *the_thread,
States_Control state
);
/*
* _Thread_Set_transient
*
* DESCRIPTION:
*
* This routine sets the TRANSIENT state for the_thread. It performs
* any necessary scheduling operations including the selection of
* a new heir thread.
*/
void _Thread_Set_transient(
Thread_Control *the_thread
);
/*
* _Thread_Reset_timeslice
*
* DESCRIPTION:
*
* This routine is invoked upon expiration of the currently
* executing thread's timeslice. If no other thread's are ready
* at the priority of the currently executing thread, then the
* executing thread's timeslice is reset. Otherwise, the
* currently executing thread is placed at the rear of the
* RTEMS_FIFO for this priority and a new heir is selected.
*/
void _Thread_Reset_timeslice( void );
/*
* _Thread_Tickle_timeslice
*
* DESCRIPTION:
*
* This routine is invoked as part of processing each clock tick.
* It is responsible for determining if the current thread allows
* timeslicing and, if so, when its timeslice expires.
*/
void _Thread_Tickle_timeslice( void );
/*
* _Thread_Yield_processor
*
* DESCRIPTION:
*
* This routine is invoked when a thread wishes to voluntarily
* transfer control of the processor to another thread of equal
* or greater priority.
*/
void _Thread_Yield_processor( void );
/*
* _Thread_Is_executing
*
* DESCRIPTION:
*
* This function returns TRUE if the_thread is the currently executing
* thread, and FALSE otherwise.
*/
STATIC INLINE boolean _Thread_Is_executing (
Thread_Control *the_thread
);
/*
* _Thread_Is_heir
*
* DESCRIPTION:
*
* This function returns TRUE if the_thread is the heir
* thread, and FALSE otherwise.
*/
STATIC INLINE boolean _Thread_Is_executing (
Thread_Control *the_thread
);
/*
* _Thread_Is_executing_also_the_heir
*
* DESCRIPTION:
*
* This function returns TRUE if the currently executing thread
* is also the heir thread, and FALSE otherwise.
*/
STATIC INLINE boolean _Thread_Is_executing_also_the_heir( void );
/*
* _Thread_Load_environment
*
* DESCRIPTION:
*
* This routine initializes the context of the_thread to its
* appropriate starting state.
*/
void _Thread_Load_environment(
Thread_Control *the_thread
);
/*
* _Thread_Handler
*
* DESCRIPTION:
*
* This routine is the wrapper function for all threads. It is
* the starting point for all threads. The user provided thread
* entry point is invoked by this routine. Operations
* which must be performed immediately before and after the user's
* thread executes are found here.
*/
void _Thread_Handler( void );
/*
* _Thread_Delay_ended
*
* DESCRIPTION:
*
* This routine is invoked when a thread must be unblocked at the
* end of a delay such as the rtems_task_wake_after and rtems_task_wake_when
* directives.
*/
void _Thread_Delay_ended(
Objects_Id id,
void *ignored
);
/*
* _Thread_Change_priority
*
* DESCRIPTION:
*
* This routine changes the current priority of the_thread to
* new_priority. It performs any necessary scheduling operations
* including the selection of a new heir thread.
*/
void _Thread_Change_priority (
Thread_Control *the_thread,
rtems_task_priority new_priority
);
/*
* _Thread_Set_priority
*
* DESCRIPTION:
*
* This routine updates the priority related fields in the_thread
* control block to indicate the current priority is now new_priority.
*/
void _Thread_Set_priority(
Thread_Control *the_thread,
rtems_task_priority new_priority
);
/*
* _Thread_Change_mode
*
* DESCRIPTION:
*
* This routine changes the current values of the modes
* indicated by mask of the calling thread are changed to that
* indicated in mode_set. The former mode of the thread is
* returned in mode_set. If the changes in the current mode
* indicate that a thread dispatch operation may be necessary,
* then need_dispatch is TRUE, otherwise it is FALSE.
*/
boolean _Thread_Change_mode(
rtems_mode new_mode_set,
rtems_mode mask,
rtems_mode *old_mode_set
);
/*
* _Thread_Resume
*
* DESCRIPTION:
*
* This routine clears the SUSPENDED state for the_thread. It performs
* any necessary scheduling operations including the selection of
* a new heir thread.
*/
STATIC INLINE void _Thread_Resume (
Thread_Control *the_thread
);
/*
* _Thread_Unblock
*
* DESCRIPTION:
*
* This routine clears any blocking state for the_thread. It performs
* any necessary scheduling operations including the selection of
* a new heir thread.
*/
STATIC INLINE void _Thread_Unblock (
Thread_Control *the_thread
);
/*
* _Thread_Restart_self
*
* DESCRIPTION:
*
* This routine resets the current context of the calling thread
* to that of its initial state.
*/
STATIC INLINE void _Thread_Restart_self( void );
/*
* _Thread_Calculate_heir
*
* DESCRIPTION:
*
* This function returns a pointer to the highest priority
* ready thread.
*/
STATIC INLINE void _Thread_Calculate_heir( void );
/*
* _Thread_Is_allocated_fp
*
* DESCRIPTION:
*
* This function returns TRUE if the floating point context of
* the_thread is currently loaded in the floating point unit, and
* FALSE otherwise.
*/
STATIC INLINE boolean _Thread_Is_allocated_fp (
Thread_Control *the_thread
);
/*
* _Thread_Deallocate_fp
*
* DESCRIPTION:
*
* This routine is invoked when the currently loaded floating
* point context is now longer associated with an active thread.
*/
STATIC INLINE void _Thread_Deallocate_fp( void );
/*
* _Thread_Disable_dispatch
*
* DESCRIPTION:
*
* This routine prevents dispatching.
*/
STATIC INLINE void _Thread_Disable_dispatch( void );
/*
* _Thread_Enable_dispatch
*
* DESCRIPTION:
*
* This routine allows dispatching to occur again. If this is
* the outer most dispatching critical section, then a dispatching
* operation will be performed and, if necessary, control of the
* processor will be transferred to the heir thread.
*/
#if ( CPU_INLINE_ENABLE_DISPATCH == TRUE )
STATIC INLINE void _Thread_Enable_dispatch();
#endif
#if ( CPU_INLINE_ENABLE_DISPATCH == FALSE )
void _Thread_Enable_dispatch( void );
#endif
/*
* _Thread_Unnest_dispatch
*
* DESCRIPTION:
*
* This routine allows dispatching to occur again. However,
* no dispatching operation is performed even if this is the outer
* most dispatching critical section.
*/
STATIC INLINE void _Thread_Unnest_dispatch( void );
/*
* _Thread_Is_dispatching_enabled
*
* DESCRIPTION:
*
* This function returns TRUE if dispatching is disabled, and FALSE
* otherwise.
*/
STATIC INLINE boolean _Thread_Is_dispatching_enabled( void );
/*
* _Thread_Is_context_switch_necessary
*
* DESCRIPTION:
*
* This function returns TRUE if dispatching is disabled, and FALSE
* otherwise.
*/
STATIC INLINE boolean _Thread_Is_context_switch_necessary( void );
/*
* _Thread_Is_null
*
* DESCRIPTION:
*
* This function returns TRUE if the_thread is NULL and FALSE otherwise.
*/
STATIC INLINE boolean _Thread_Is_null (
Thread_Control *the_thread
);
/*
* _Thread_Get
*
* DESCRIPTION:
*
* This function maps thread IDs to thread control
* blocks. If ID corresponds to a local thread, then it
* returns the_thread control pointer which maps to ID
* and location is set to OBJECTS_LOCAL. If the thread ID is
* global and resides on a remote node, then location is set
* to OBJECTS_REMOTE, and the_thread is undefined.
* Otherwise, location is set to OBJECTS_ERROR and
* the_thread is undefined.
*/
STATIC INLINE Thread_Control *_Thread_Get (
Objects_Id id,
Objects_Locations *location
);
#include <rtems/thread.inl>
#include <rtems/threadmp.h>
#ifdef __cplusplus
}
#endif
#endif
/* end of include file */
