/* 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 __THREAD_h
#define __THREAD_h
#ifdef __cplusplus
extern "C" {
#endif
#include <rtems/score/context.h>
#include <rtems/score/cpu.h>
#include <rtems/score/mppkt.h>
#include <rtems/score/object.h>
#include <rtems/score/priority.h>
#include <rtems/score/stack.h>
#include <rtems/score/states.h>
#include <rtems/score/tod.h>
#include <rtems/score/tqdata.h>
#include <rtems/score/watchdog.h>
/*
* The following defines the "return type" of a thread.
*/
typedef void Thread;
/*
* The following defines the ways in which the entry point for a
* thread can be invoked. Basically, it can be passed any
* combination/permutation of a pointer and an unsigned32 value.
*
* NOTE: For now, we are ignoring the return type.
*/
typedef enum {
THREAD_START_NUMERIC,
THREAD_START_POINTER,
THREAD_START_BOTH_POINTER_FIRST,
THREAD_START_BOTH_NUMERIC_FIRST
} Thread_Start_types;
typedef Thread ( *Thread_Entry )( );
/*
* The following structure contains the information which defines
* the starting state of a thread.
*/
typedef struct {
Thread_Entry entry_point; /* starting thread address */
Thread_Start_types prototype; /* how task is invoked */
void *pointer_argument; /* pointer argument */
unsigned32 numeric_argument; /* numeric argument */
/* initial execution modes */
boolean is_preemptible;
boolean is_timeslice;
unsigned32 isr_level;
Priority_Control initial_priority; /* initial priority */
Stack_Control Initial_stack; /* stack information */
void *fp_context; /* initial FP context area address */
void *stack; /* initial FP context area address */
} Thread_Start_information;
/*
* The following structure contains the information necessary to manage
* a thread which it is waiting for a resource.
*/
#define THREAD_STATUS_PROXY_BLOCKING 0x1111111
typedef struct {
Objects_Id id; /* waiting on this object */
unsigned32 count; /* "generic" fields to be used */
void *return_argument; /* when blocking */
void *return_argument_1;
unsigned32 option;
/*
* NOTE: The following assumes that all API return codes can be
* treated as an unsigned32.
*/
unsigned32 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;
Priority_Control current_priority;
Priority_Control real_priority;
unsigned32 resource_count;
Thread_Wait_information Wait;
Watchdog_Control Timer;
MP_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 enum {
THREAD_API_RTEMS,
THREAD_API_POSIX
} Thread_APIs;
#define THREAD_API_FIRST THREAD_API_RTEMS
#define THREAD_API_LAST THREAD_API_POSIX
typedef struct {
Objects_Control Object;
States_Control current_state;
Priority_Control current_priority;
Priority_Control real_priority;
unsigned32 resource_count;
Thread_Wait_information Wait;
Watchdog_Control Timer;
MP_packet_Prefix *receive_packet;
/****************** end of common block ********************/
boolean is_global;
boolean do_post_task_switch_extension;
Chain_Control *ready;
Priority_Information Priority_map;
Thread_Start_information Start;
boolean is_preemptible;
boolean is_timeslice;
Context_Control Registers;
void *fp_context;
void *API_Extensions[ THREAD_API_LAST + 1 ];
void **extensions;
} Thread_Control;
/*
* The following constants define the stack size requirements for
* the idle thread.
*/
#define THREAD_IDLE_STACK_SIZE STACK_MINIMUM_SIZE
/*
* The following defines the information control block used to
* manage this class of objects.
*/
EXTERN Objects_Information _Thread_Internal_information;
/*
* The following define the thread control pointers used to access
* and manipulate the idle thread.
*/
EXTERN Thread_Control *_Thread_Idle;
/*
* The following context area contains the context of the "thread"
* which invoked the start multitasking routine. This context is
* restored as the last action of the stop multitasking routine. Thus
* control of the processor can be returned to the environment
* which initiated the system.
*/
EXTERN Context_Control _Thread_BSP_context;
/*
* 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 holds how many user extensions are in the system. This
* is used to determine how many user extension data areas to allocate
* per thread.
*/
EXTERN unsigned32 _Thread_Maximum_extensions;
/*
* 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 not preemptibl,
* 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;
/*
* _Thread_Handler_initialization
*
* DESCRIPTION:
*
* This routine performs the initialization necessary for this handler.
*/
void _Thread_Handler_initialization (
unsigned32 ticks_per_timeslice,
unsigned32 maximum_extensions,
unsigned32 maximum_proxies
);
/*
* _Thread_Create_idle
*
* DESCRIPTION:
*
* This routine creates the idle thread.
*
* WARNING!! No thread should be created before this one.
*/
void _Thread_Create_idle( void );
/*
* _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 non-multitasking part of the system initialization.
*/
void _Thread_Start_multitasking( void );
/*
* _Thread_Stop_multitasking
*
* DESCRIPTION:
*
* This routine halts multitasking and returns control to
* the "thread" (i.e. the BSP) which initially invoked the
* routine which initialized the system.
*/
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_Initialize
*
* DESCRIPTION:
*
* XXX
*/
boolean _Thread_Initialize(
Objects_Information *information,
Thread_Control *the_thread,
void *stack_area, /* NULL if to be allocated */
unsigned32 stack_size, /* insure it is >= min */
boolean is_fp, /* TRUE if thread uses FP */
Priority_Control priority,
boolean is_preemptible,
boolean is_timeslice,
unsigned32 isr_level,
Objects_Name name
);
/*
* _Thread_Start
*
* DESCRIPTION:
*
* XXX
*/
boolean _Thread_Start(
Thread_Control *the_thread,
Thread_Start_types the_prototype,
void *entry_point,
void *pointer_argument,
unsigned32 numeric_argument
);
/*
* _Thread_Restart
*
* DESCRIPTION:
*
* XXX
*/
/* XXX multiple task arg profiles */
boolean _Thread_Restart(
Thread_Control *the_thread,
void *pointer_argument,
unsigned32 numeric_argument
);
/*
* _Thread_Close
*
* DESCRIPTION:
*
* XXX
*/
void _Thread_Close(
Objects_Information *information,
Thread_Control *the_thread
);
/*
* _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
* 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 time based delay (i.e. wake after or wake when).
*/
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,
Priority_Control 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,
Priority_Control new_priority
);
/*
* _Thread_Evaluate_mode
*
* DESCRIPTION:
*
* This routine XXX
*/
boolean _Thread_Evaluate_mode( void );
/*
* _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
);
/*
* _Thread_Is_proxy_blocking
*
* DESCRIPTION:
*
* This function returns TRUE if the status code is equal to the
* status which indicates that a proxy is blocking, and FALSE otherwise.
*/
STATIC INLINE boolean _Thread_Is_proxy_blocking (
unsigned32 code
);
/*
* _Thread_Internal_allocate
*
* DESCRIPTION:
*
* This routine allocates an internal thread.
*/
STATIC INLINE Thread_Control *_Thread_Internal_allocate( void );
/*
* _Thread_Internal_free
*
* DESCRIPTION:
*
* This routine frees an internal thread.
*/
STATIC INLINE void _Thread_Internal_free (
Thread_Control *the_task
);
/*
* _Thread_Idle_body
*
* DESCRIPTION:
*
* This routine is the body of the system idle thread.
*/
#if (CPU_PROVIDES_IDLE_THREAD_BODY == FALSE)
Thread _Thread_Idle_body(
unsigned32 ignored
);
#endif
#include <rtems/score/thread.inl>
#include <rtems/score/threadmp.h>
#ifdef __cplusplus
}
#endif
#endif
/* end of include file */
