diff options
Diffstat (limited to 'cpukit/score/include/rtems/score/schedulercbs.h')
| -rw-r--r-- | cpukit/score/include/rtems/score/schedulercbs.h | 327 |
1 files changed, 327 insertions, 0 deletions
diff --git a/cpukit/score/include/rtems/score/schedulercbs.h b/cpukit/score/include/rtems/score/schedulercbs.h new file mode 100644 index 0000000000..4cc00a65de --- /dev/null +++ b/cpukit/score/include/rtems/score/schedulercbs.h @@ -0,0 +1,327 @@ +/** + * @file rtems/score/schedulercbs.h + * + * This include file contains all the constants and structures associated + * with the manipulation of threads for the CBS scheduler. + */ + +/* + * Copryight (c) 2011 Petr Benes. + * Copyright (C) 2011 On-Line Applications Research Corporation (OAR). + * + * The license and distribution terms for this file may be + * found in the file LICENSE in this distribution or at + * http://www.rtems.com/license/LICENSE. + * + * $Id$ + */ + +#ifndef _RTEMS_SCORE_SCHEDULERCBS_H +#define _RTEMS_SCORE_SCHEDULERCBS_H + +#include <rtems/score/chain.h> +#include <rtems/score/priority.h> +#include <rtems/score/scheduler.h> +#include <rtems/score/rbtree.h> +#include <rtems/score/scheduleredf.h> +#include <rtems/rtems/signal.h> +#include <rtems/rtems/timer.h> +#include <rtems/score/thread.h> + +#ifdef __cplusplus +extern "C" { +#endif + +/** + * @addtogroup ScoreScheduler + * + */ +/**@{*/ + +/** + * Entry points for the Constant Bandwidth Server Scheduler. + * + * @note: The CBS scheduler is an enhancement of EDF scheduler, + * therefor some routines are similar. + */ +#define SCHEDULER_CBS_ENTRY_POINTS \ + { \ + _Scheduler_EDF_Initialize, /* initialize entry point */ \ + _Scheduler_EDF_Schedule, /* schedule entry point */ \ + _Scheduler_EDF_Yield, /* yield entry point */ \ + _Scheduler_EDF_Block, /* block entry point */ \ + _Scheduler_CBS_Unblock, /* unblock entry point */ \ + _Scheduler_EDF_Allocate, /* allocate entry point */ \ + _Scheduler_EDF_Free, /* free entry point */ \ + _Scheduler_EDF_Update, /* update entry point */ \ + _Scheduler_EDF_Enqueue, /* enqueue entry point */ \ + _Scheduler_EDF_Enqueue_first, /* enqueue_first entry point */ \ + _Scheduler_EDF_Extract, /* extract entry point */ \ + _Scheduler_EDF_Priority_compare, /* compares two priorities */ \ + _Scheduler_CBS_Release_job, /* new period of task */ \ + _Scheduler_priority_Tick /* tick entry point */ \ + } + +/* Return values for CBS server. */ +#define SCHEDULER_CBS_OK 0 +#define SCHEDULER_CBS_ERROR_GENERIC -16 +#define SCHEDULER_CBS_ERROR_NO_MEMORY -17 +#define SCHEDULER_CBS_ERROR_INVALID_PARAMETER -18 +#define SCHEDULER_CBS_ERROR_UNAUTHORIZED -19 +#define SCHEDULER_CBS_ERROR_UNIMPLEMENTED -20 +#define SCHEDULER_CBS_ERROR_MISSING_COMPONENT -21 +#define SCHEDULER_CBS_ERROR_INCONSISTENT_STATE -22 +#define SCHEDULER_CBS_ERROR_SYSTEM_OVERLOAD -23 +#define SCHEDULER_CBS_ERROR_INTERNAL_ERROR -24 +#define SCHEDULER_CBS_ERROR_NOT_FOUND -25 +#define SCHEDULER_CBS_ERROR_FULL -26 +#define SCHEDULER_CBS_ERROR_EMPTY -27 +#define SCHEDULER_CBS_ERROR_NOSERVER SCHEDULER_CBS_ERROR_NOT_FOUND + +/** Maximum number of simultaneous servers. */ +extern uint32_t _Scheduler_CBS_Maximum_servers; + +/** Server id. */ +typedef uint32_t Scheduler_CBS_Server_id; + +/** Callback function invoked when a budget overrun of a task occurs. */ +typedef void (*Scheduler_CBS_Budget_overrun)( + Scheduler_CBS_Server_id server_id +); + +/** + * This structure handles server parameters. + */ +typedef struct { + /** Relative deadline of the server. */ + time_t deadline; + /** Budget (computation time) of the server. */ + time_t budget; +} Scheduler_CBS_Parameters; + +/** + * This structure represents a time server. + */ +typedef struct { + /** + * Task id. + * + * @note: The current implementation of CBS handles only one task per server. + */ + rtems_id task_id; + /** Server paramenters. */ + Scheduler_CBS_Parameters parameters; + /** Callback function invoked when a budget overrun occurs. */ + Scheduler_CBS_Budget_overrun cbs_budget_overrun; +} Scheduler_CBS_Server; + +/** + * This structure handles CBS specific data of a thread. + */ +typedef struct { + /** EDF scheduler specific data of a task. */ + Scheduler_EDF_Per_thread edf_per_thread; + /** CBS server specific data of a task. */ + Scheduler_CBS_Server *cbs_server; +} Scheduler_CBS_Per_thread; + + +/** + * List of servers. The @a Scheduler_CBS_Server is the index to the array + * of pointers to @a _Scheduler_CBS_Server_list. + */ +Scheduler_CBS_Server **_Scheduler_CBS_Server_list; + +/** + * @brief Scheduler CBS Unblock + * + * This routine adds @a the_thread to the scheduling decision, that is, + * adds it to the ready queue and updates any appropriate scheduling + * variables, for example the heir thread. + * + * It is checked whether the remaining budget is sufficient. If not, the + * thread continues as a new job in order to protect concurrent threads. + * + * @note This has to be asessed as missed deadline of the current job. + * + * @param[in] the_thread will be unblocked. + */ +void _Scheduler_CBS_Unblock( + Thread_Control *the_thread +); + +/** + * @brief Scheduler CBS Release job + * + * This routine is called when a new job of task is released. + * It is called only from Rate Monotonic manager in the beginning + * of new period. Deadline has to be shifted and budget replenished. + * + * @param[in] the_thread is the owner of the job. + * @param[in] length of the new job from now. If equal to 0, + * the job was cancelled or deleted. + */ + +void _Scheduler_CBS_Release_job ( + Thread_Control *the_thread, + uint32_t length +); + +/** + * @brief _Scheduler_CBS_Initialize + * + * Initializes the CBS library. + * + * @return status code. + */ +int _Scheduler_CBS_Initialize(void); + +/** + * @brief _Scheduler_CBS_Attach_thread + * + * Attach a task to an already existing server. + * + * @return status code. + */ +int _Scheduler_CBS_Attach_thread ( + Scheduler_CBS_Server_id server_id, + rtems_id task_id +); + +/** + * @brief _Scheduler_CBS_Detach_thread + * + * Detach from the CBS Server. + * + * @return status code. + */ +int _Scheduler_CBS_Detach_thread ( + Scheduler_CBS_Server_id server_id, + rtems_id task_id +); + +/** + * @brief _Scheduler_CBS_Cleanup + * + * Cleanup resources associated to the CBS Library. + * + * @return status code. + */ +int _Scheduler_CBS_Cleanup (void); + +/** + * @brief _Scheduler_CBS_Create_server + * + * Create a new server with specified parameters. + * + * @return status code. + */ +int _Scheduler_CBS_Create_server ( + Scheduler_CBS_Parameters *params, + Scheduler_CBS_Budget_overrun budget_overrun_callback, + rtems_id *server_id +); + +/** + * @brief _Scheduler_CBS_Destroy_server + * + * Detach all tasks from a server and destroy it. + * + * @return status code. + */ +int _Scheduler_CBS_Destroy_server ( + Scheduler_CBS_Server_id server_id +); + +/** + * @brief _Scheduler_CBS_Get_approved_budget + * + * Retrieve the budget that has been approved for the subsequent + * server instances. + * + * @return status code. + */ +int _Scheduler_CBS_Get_approved_budget ( + Scheduler_CBS_Server_id server_id, + time_t *approved_budget +); + +/** + * @brief _Scheduler_CBS_Get_remaining_budget + * + * Retrieve remaining budget for the current server instance. + * + * @return status code. + */ +int _Scheduler_CBS_Get_remaining_budget ( + Scheduler_CBS_Server_id server_id, + time_t *remaining_budget +); + +/** + * @brief _Scheduler_CBS_Get_execution_time + * + * Retrieve time info relative to the current server. + * + * @return status code. + */ +int _Scheduler_CBS_Get_execution_time ( + Scheduler_CBS_Server_id server_id, + time_t *exec_time, + time_t *abs_time +); + +/** + * @brief _Scheduler_CBS_Get_parameters + * + * Retrieve CBS scheduling parameters. + * + * @return status code. + */ +int _Scheduler_CBS_Get_parameters ( + Scheduler_CBS_Server_id server_id, + Scheduler_CBS_Parameters *params +); + +/** + * @brief _Scheduler_CBS_Get_server_id + * + * Get a thread server id, or SCHEDULER_CBS_ERROR_NOT_FOUND if it is not + * attached to any server. + * + * @return status code. + */ +int _Scheduler_CBS_Get_server_id ( + rtems_id task_id, + Scheduler_CBS_Server_id *server_id +); + +/** + * @brief _Scheduler_CBS_Set_parameters + * + * Change CBS scheduling parameters. + * + * @return status code. + */ +int _Scheduler_CBS_Set_parameters ( + Scheduler_CBS_Server_id server_id, + Scheduler_CBS_Parameters *parameters +); + +/** + * @brief Scheduler CBS Budget overrun + * + * This routine is invoked when a limited time quantum is exceeded. + */ +void _Scheduler_CBS_Budget_callout( + Thread_Control *the_thread +); + +#ifdef __cplusplus +} +#endif + +/**@}*/ + +#endif +/* end of include file */ |