/* 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 #include #include #include #include #include #include #include #include #include /* * 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 #include #ifdef __cplusplus } #endif #endif /* end of include file */