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Diffstat (limited to 'cpukit/include/rtems/score/schedulernode.h')
| -rw-r--r-- | cpukit/include/rtems/score/schedulernode.h | 217 |
1 files changed, 217 insertions, 0 deletions
diff --git a/cpukit/include/rtems/score/schedulernode.h b/cpukit/include/rtems/score/schedulernode.h new file mode 100644 index 0000000000..d62e983853 --- /dev/null +++ b/cpukit/include/rtems/score/schedulernode.h @@ -0,0 +1,217 @@ +/* + * Copyright (c) 2014, 2016 embedded brains GmbH. All rights reserved. + * + * embedded brains GmbH + * Dornierstr. 4 + * 82178 Puchheim + * Germany + * <rtems@embedded-brains.de> + * + * The license and distribution terms for this file may be + * found in the file LICENSE in this distribution or at + * http://www.rtems.org/license/LICENSE. + */ + +#ifndef _RTEMS_SCORE_SCHEDULERNODE_H +#define _RTEMS_SCORE_SCHEDULERNODE_H + +#include <rtems/score/basedefs.h> +#include <rtems/score/chain.h> +#include <rtems/score/priority.h> +#include <rtems/score/smplockseq.h> + +struct _Thread_Control; + +#ifdef __cplusplus +extern "C" { +#endif /* __cplusplus */ + +#if defined(RTEMS_SMP) +/** + * @brief The scheduler node requests. + */ +typedef enum { + /** + * @brief The scheduler node is not on the list of pending requests. + */ + SCHEDULER_NODE_REQUEST_NOT_PENDING, + + /** + * @brief There is a pending scheduler node request to add this scheduler + * node to the Thread_Control::Scheduler::Scheduler_nodes chain. + */ + SCHEDULER_NODE_REQUEST_ADD, + + /** + * @brief There is a pending scheduler node request to remove this scheduler + * node from the Thread_Control::Scheduler::Scheduler_nodes chain. + */ + SCHEDULER_NODE_REQUEST_REMOVE, + + /** + * @brief The scheduler node is on the list of pending requests, but nothing + * should change. + */ + SCHEDULER_NODE_REQUEST_NOTHING, + +} Scheduler_Node_request; +#endif + +typedef struct Scheduler_Node Scheduler_Node; + +/** + * @brief Scheduler node for per-thread data. + */ +struct Scheduler_Node { +#if defined(RTEMS_SMP) + /** + * @brief Chain node for usage in various scheduler data structures. + * + * Strictly, this is the wrong place for this field since the data structures + * to manage scheduler nodes belong to the particular scheduler + * implementation. Currently, all SMP scheduler implementations use chains + * or red-black trees. The node is here to simplify things, just like the + * object node in the thread control block. + */ + union { + Chain_Node Chain; + RBTree_Node RBTree; + } Node; + + /** + * @brief The sticky level determines if this scheduler node should use an + * idle thread in case this node is scheduled and the owner thread is + * blocked. + */ + int sticky_level; + + /** + * @brief The thread using this node. + * + * This is either the owner or an idle thread. + */ + struct _Thread_Control *user; + + /** + * @brief The idle thread claimed by this node in case the sticky level is + * greater than zero and the thread is block or is scheduled on another + * scheduler instance. + * + * This is necessary to ensure the priority ceiling protocols work across + * scheduler boundaries. + */ + struct _Thread_Control *idle; +#endif + + /** + * @brief The thread owning this node. + */ + struct _Thread_Control *owner; + +#if defined(RTEMS_SMP) + /** + * @brief Block to register and manage this scheduler node in the thread + * control block of the owner of this scheduler node. + */ + struct { + /** + * @brief Node to add this scheduler node to + * Thread_Control::Scheduler::Wait_nodes. + */ + Chain_Node Wait_node; + + /** + * @brief Node to add this scheduler node to + * Thread_Control::Scheduler::Scheduler_nodes or a temporary remove list. + */ + union { + /** + * @brief The node for Thread_Control::Scheduler::Scheduler_nodes. + */ + Chain_Node Chain; + + /** + * @brief The next pointer for a temporary remove list. + * + * @see _Thread_Scheduler_process_requests(). + */ + Scheduler_Node *next; + } Scheduler_node; + + /** + * @brief Link to the next scheduler node in the + * Thread_Control::Scheduler::requests list. + */ + Scheduler_Node *next_request; + + /** + * @brief The current scheduler node request. + */ + Scheduler_Node_request request; + } Thread; +#endif + + /** + * @brief Thread wait support block. + */ + struct { + Priority_Aggregation Priority; + } Wait; + + /** + * @brief The thread priority information used by the scheduler. + * + * The thread priority is manifest in two independent areas. One area is the + * user visible thread priority along with a potential thread queue. The + * other is the scheduler. During a thread priority change, the user visible + * thread priority and the thread queue are first updated and the thread + * priority value here is changed. Once this is done the scheduler is + * notified via the update priority operation, so that it can update its + * internal state and honour a new thread priority value. + */ + struct { + /** + * @brief The thread priority value of this scheduler node. + * + * The producer of this value is _Thread_Change_priority(). The consumer + * is the scheduler via the unblock and update priority operations. + * + * This priority control consists of two parts. One part is the plain + * priority value (most-significant 63 bits). The other part is the + * least-significant bit which indicates if the thread should be appended + * (bit set) or prepended (bit cleared) to its priority group, see + * SCHEDULER_PRIORITY_APPEND(). + */ + Priority_Control value; + +#if defined(RTEMS_SMP) + /** + * @brief Sequence lock to synchronize priority value updates. + */ + SMP_sequence_lock_Control Lock; +#endif + } Priority; +}; + +#if defined(RTEMS_SMP) +/** + * @brief The size of a scheduler node. + * + * This value is provided via <rtems/confdefs.h>. + */ +extern const size_t _Scheduler_Node_size; +#endif + +#if defined(RTEMS_SMP) +#define SCHEDULER_NODE_OF_THREAD_WAIT_NODE( node ) \ + RTEMS_CONTAINER_OF( node, Scheduler_Node, Thread.Wait_node ) + +#define SCHEDULER_NODE_OF_THREAD_SCHEDULER_NODE( node ) \ + RTEMS_CONTAINER_OF( node, Scheduler_Node, Thread.Scheduler_node.Chain ) +#endif + +#ifdef __cplusplus +} +#endif /* __cplusplus */ + +#endif /* _RTEMS_SCORE_SCHEDULERNODE_H */ |