From 43b7eeb5b0ad7bf701195366130ac68eeea15001 Mon Sep 17 00:00:00 2001 From: Sebastian Huber Date: Wed, 26 Feb 2020 15:58:27 +0100 Subject: c-user: Use four spaces per indent level Four spaces per indent level is used in most files. Update #3853. --- c-user/glossary.rst | 1284 +++++++++++++++++++++++++-------------------------- 1 file changed, 642 insertions(+), 642 deletions(-) (limited to 'c-user/glossary.rst') diff --git a/c-user/glossary.rst b/c-user/glossary.rst index a230d6c..67dce76 100644 --- a/c-user/glossary.rst +++ b/c-user/glossary.rst @@ -4,777 +4,777 @@ Glossary ******** .. glossary:: - :sorted: + :sorted: - active - A term used to describe an object which has been created by an - application. + active + A term used to describe an object which has been created by an + application. - aperiodic task - A task which must execute only at irregular intervals and has only a soft - deadline. + aperiodic task + A task which must execute only at irregular intervals and has only a soft + deadline. - API - An acronym for Application Programming Interface. + API + An acronym for Application Programming Interface. - application - In this document, software which makes use of RTEMS. + application + In this document, software which makes use of RTEMS. - ASR - An acronym for :term:`Asynchronous Signal Routine`. + ASR + An acronym for :term:`Asynchronous Signal Routine`. - asynchronous - Not related in order or timing to other occurrences in the system. + asynchronous + Not related in order or timing to other occurrences in the system. - Asynchronous Signal Routine - Similar to a hardware interrupt except that it is associated with a task - and is run in the context of a task. The directives provided by the - signal manager are used to service signals. + Asynchronous Signal Routine + Similar to a hardware interrupt except that it is associated with a task + and is run in the context of a task. The directives provided by the + signal manager are used to service signals. - atomic operations - Atomic operations are defined in terms of :term:`C11`. + atomic operations + Atomic operations are defined in terms of :term:`C11`. - awakened - A term used to describe a task that has been unblocked and may be - scheduled to the CPU. + awakened + A term used to describe a task that has been unblocked and may be + scheduled to the CPU. - big endian - A data representation scheme in which the bytes composing a numeric value - are arranged such that the most significant byte is at the lowest - address. + big endian + A data representation scheme in which the bytes composing a numeric value + are arranged such that the most significant byte is at the lowest + address. - bit-mapped - A data encoding scheme in which each bit in a variable is used to - represent something different. This makes for compact data - representation. + bit-mapped + A data encoding scheme in which each bit in a variable is used to + represent something different. This makes for compact data + representation. - block - A physically contiguous area of memory. + block + A physically contiguous area of memory. - blocked task - The task state entered by a task which has been previously started and - cannot continue execution until the reason for waiting has been - satisfied. Blocked tasks are not an element of the set of ready tasks of - a scheduler instance. + blocked task + The task state entered by a task which has been previously started and + cannot continue execution until the reason for waiting has been + satisfied. Blocked tasks are not an element of the set of ready tasks of + a scheduler instance. - broadcast - To simultaneously send a message to a logical set of destinations. + broadcast + To simultaneously send a message to a logical set of destinations. - Board Support Package - A collection of device initialization and control routines specific to a - particular type of board or collection of boards. + Board Support Package + A collection of device initialization and control routines specific to a + particular type of board or collection of boards. - buffer - A fixed length block of memory allocated from a partition. + buffer + A fixed length block of memory allocated from a partition. - BSP - An acronym for :term:`Board Support Package`. + BSP + An acronym for :term:`Board Support Package`. - C11 - The standard ISO/IEC 9899:2011. + C11 + The standard ISO/IEC 9899:2011. - C++11 - The standard ISO/IEC 14882:2011. + C++11 + The standard ISO/IEC 14882:2011. - calling convention - The processor and compiler dependent rules which define the mechanism - used to invoke subroutines in a high-level language. These rules define - the passing of arguments, the call and return mechanism, and the register - set which must be preserved. + calling convention + The processor and compiler dependent rules which define the mechanism + used to invoke subroutines in a high-level language. These rules define + the passing of arguments, the call and return mechanism, and the register + set which must be preserved. - Central Processing Unit - This term is equivalent to the terms processor and microprocessor. + Central Processing Unit + This term is equivalent to the terms processor and microprocessor. - chain - A data structure which allows for efficient dynamic addition and removal - of elements. It differs from an array in that it is not limited to a - predefined size. + chain + A data structure which allows for efficient dynamic addition and removal + of elements. It differs from an array in that it is not limited to a + predefined size. - cluster - We have clustered scheduling in case the set of processors of a system is - partitioned into non-empty pairwise disjoint subsets. These subsets are - called clusters. Clusters with a cardinality of one are partitions. - Each cluster is owned by exactly one scheduler instance. + cluster + We have clustered scheduling in case the set of processors of a system is + partitioned into non-empty pairwise disjoint subsets. These subsets are + called clusters. Clusters with a cardinality of one are partitions. + Each cluster is owned by exactly one scheduler instance. - coalesce - The process of merging adjacent holes into a single larger hole. - Sometimes this process is referred to as garbage collection. + coalesce + The process of merging adjacent holes into a single larger hole. + Sometimes this process is referred to as garbage collection. - Configuration Table - A table which contains information used to tailor RTEMS for a particular - application. + Configuration Table + A table which contains information used to tailor RTEMS for a particular + application. - context - All of the processor registers and operating system data structures - associated with a task. + context + All of the processor registers and operating system data structures + associated with a task. - context switch - Alternate term for task switch. Taking control of the processor from one - task and transferring it to another task. + context switch + Alternate term for task switch. Taking control of the processor from one + task and transferring it to another task. - control block - A data structure used by the executive to define and control an object. + control block + A data structure used by the executive to define and control an object. - core - When used in this manual, this term refers to the internal executive - utility functions. In the interest of application portability, the core - of the executive should not be used directly by applications. + core + When used in this manual, this term refers to the internal executive + utility functions. In the interest of application portability, the core + of the executive should not be used directly by applications. - CPU - An acronym for :term:`Central Processing Unit`. + CPU + An acronym for :term:`Central Processing Unit`. - critical section - A section of code which must be executed indivisibly. + critical section + A section of code which must be executed indivisibly. - CRT - An acronym for Cathode Ray Tube. Normally used in reference to the - man-machine interface. - - deadline - A fixed time limit by which a task must have completed a set of actions. - Beyond this point, the results are of reduced value and may even be - considered useless or harmful. - - device - A peripheral used by the application that requires special operation - software. See also device driver. - - device driver - Control software for special peripheral devices used by the application. - - directives - RTEMS' provided routines that provide support mechanisms for real-time - applications. - - dispatch - The act of loading a task's context onto the CPU and transferring control - of the CPU to that task. - - dormant - The state entered by a task after it is created and before it has been - started. - - Device Driver Table - A table which contains the entry points for each of the configured device - drivers. - - dual-ported - A term used to describe memory which can be accessed at two different - addresses. - - embedded - An application that is delivered as a hidden part of a larger system. - For example, the software in a fuel-injection control system is an - embedded application found in many late-model automobiles. + CRT + An acronym for Cathode Ray Tube. Normally used in reference to the + man-machine interface. + + deadline + A fixed time limit by which a task must have completed a set of actions. + Beyond this point, the results are of reduced value and may even be + considered useless or harmful. + + device + A peripheral used by the application that requires special operation + software. See also device driver. + + device driver + Control software for special peripheral devices used by the application. + + directives + RTEMS' provided routines that provide support mechanisms for real-time + applications. + + dispatch + The act of loading a task's context onto the CPU and transferring control + of the CPU to that task. + + dormant + The state entered by a task after it is created and before it has been + started. + + Device Driver Table + A table which contains the entry points for each of the configured device + drivers. + + dual-ported + A term used to describe memory which can be accessed at two different + addresses. + + embedded + An application that is delivered as a hidden part of a larger system. + For example, the software in a fuel-injection control system is an + embedded application found in many late-model automobiles. - envelope - A buffer provided by the MPCI layer to RTEMS which is used to pass - messages between nodes in a multiprocessor system. It typically contains - routing information needed by the MPCI. The contents of an envelope are - referred to as a packet. - - entry point - The address at which a function or task begins to execute. In C, the - entry point of a function is the function's name. - - events - A method for task communication and synchronization. The directives - provided by the event manager are used to service events. + envelope + A buffer provided by the MPCI layer to RTEMS which is used to pass + messages between nodes in a multiprocessor system. It typically contains + routing information needed by the MPCI. The contents of an envelope are + referred to as a packet. + + entry point + The address at which a function or task begins to execute. In C, the + entry point of a function is the function's name. + + events + A method for task communication and synchronization. The directives + provided by the event manager are used to service events. - exception - A synonym for interrupt. + exception + A synonym for interrupt. - executing task - The task state entered by a task after it has been given control of the - processor. In SMP configurations, a task may be registered as executing - on more than one processor for short time frames during task migration. - Blocked tasks can be executing until they issue a thread dispatch. + executing task + The task state entered by a task after it has been given control of the + processor. In SMP configurations, a task may be registered as executing + on more than one processor for short time frames during task migration. + Blocked tasks can be executing until they issue a thread dispatch. - executive - In this document, this term is used to referred to RTEMS. Commonly, an - executive is a small real-time operating system used in embedded systems. + executive + In this document, this term is used to referred to RTEMS. Commonly, an + executive is a small real-time operating system used in embedded systems. - exported - An object known by all nodes in a multiprocessor system. An object - created with the GLOBAL attribute will be exported. + exported + An object known by all nodes in a multiprocessor system. An object + created with the GLOBAL attribute will be exported. - external address - The address used to access dual-ported memory by all the nodes in a - system which do not own the memory. + external address + The address used to access dual-ported memory by all the nodes in a + system which do not own the memory. - FIFO - An acronym for :term:`First In First Out`. - - First In First Out - A discipline for manipulating entries in a data structure. + FIFO + An acronym for :term:`First In First Out`. + + First In First Out + A discipline for manipulating entries in a data structure. - floating point coprocessor - A component used in computer systems to enhance performance in - mathematically intensive situations. It is typically viewed as a logical - extension of the primary processor. + floating point coprocessor + A component used in computer systems to enhance performance in + mathematically intensive situations. It is typically viewed as a logical + extension of the primary processor. - freed - A resource that has been released by the application to RTEMS. - - global - An object that has been created with the GLOBAL attribute and exported to - all nodes in a multiprocessor system. + freed + A resource that has been released by the application to RTEMS. + + global + An object that has been created with the GLOBAL attribute and exported to + all nodes in a multiprocessor system. - handler - The equivalent of a manager, except that it is internal to RTEMS and - forms part of the core. A handler is a collection of routines which - provide a related set of functions. For example, there is a handler used - by RTEMS to manage all objects. + handler + The equivalent of a manager, except that it is internal to RTEMS and + forms part of the core. A handler is a collection of routines which + provide a related set of functions. For example, there is a handler used + by RTEMS to manage all objects. - hard real-time system - A real-time system in which a missed deadline causes the worked performed - to have no value or to result in a catastrophic effect on the integrity - of the system. + hard real-time system + A real-time system in which a missed deadline causes the worked performed + to have no value or to result in a catastrophic effect on the integrity + of the system. - heap - A data structure used to dynamically allocate and deallocate variable - sized blocks of memory. + heap + A data structure used to dynamically allocate and deallocate variable + sized blocks of memory. - heir task - A task is an heir if it is registered as an heir in a processor of the - system. A task can be the heir on at most one processor in the system. - In case the executing and heir tasks differ on a processor and a thread - dispatch is marked as necessary, then the next thread dispatch will make - the heir task the executing task. + heir task + A task is an heir if it is registered as an heir in a processor of the + system. A task can be the heir on at most one processor in the system. + In case the executing and heir tasks differ on a processor and a thread + dispatch is marked as necessary, then the next thread dispatch will make + the heir task the executing task. - heterogeneous - A multiprocessor computer system composed of dissimilar processors. + heterogeneous + A multiprocessor computer system composed of dissimilar processors. - homogeneous - A multiprocessor computer system composed of a single type of processor. + homogeneous + A multiprocessor computer system composed of a single type of processor. - ID - An RTEMS assigned identification tag used to access an active object. + ID + An RTEMS assigned identification tag used to access an active object. - IDLE task - A special low priority task which assumes control of the CPU when no - other task is able to execute. + IDLE task + A special low priority task which assumes control of the CPU when no + other task is able to execute. - interface - A specification of the methodology used to connect multiple independent - subsystems. + interface + A specification of the methodology used to connect multiple independent + subsystems. - internal address - The address used to access dual-ported memory by the node which owns the - memory. + internal address + The address used to access dual-ported memory by the node which owns the + memory. - interrupt - A hardware facility that causes the CPU to suspend execution, save its - status, and transfer control to a specific location. + interrupt + A hardware facility that causes the CPU to suspend execution, save its + status, and transfer control to a specific location. - interrupt level - A mask used to by the CPU to determine which pending interrupts should be - serviced. If a pending interrupt is below the current interrupt level, - then the CPU does not recognize that interrupt. + interrupt level + A mask used to by the CPU to determine which pending interrupts should be + serviced. If a pending interrupt is below the current interrupt level, + then the CPU does not recognize that interrupt. - Interrupt Service Routine - An ISR is invoked by the CPU to process a pending interrupt. + Interrupt Service Routine + An ISR is invoked by the CPU to process a pending interrupt. - I/O - An acronym for Input/Output. + I/O + An acronym for Input/Output. - ISR - An acronym for :term:`Interrupt Service Routine`. + ISR + An acronym for :term:`Interrupt Service Routine`. - kernel - In this document, this term is used as a synonym for executive. + kernel + In this document, this term is used as a synonym for executive. - list - A data structure which allows for dynamic addition and removal of - entries. It is not statically limited to a particular size. + list + A data structure which allows for dynamic addition and removal of + entries. It is not statically limited to a particular size. - little endian - A data representation scheme in which the bytes composing a numeric value - are arranged such that the least significant byte is at the lowest - address. + little endian + A data representation scheme in which the bytes composing a numeric value + are arranged such that the least significant byte is at the lowest + address. - local - An object which was created with the LOCAL attribute and is accessible - only on the node it was created and resides upon. In a single processor - configuration, all objects are local. + local + An object which was created with the LOCAL attribute and is accessible + only on the node it was created and resides upon. In a single processor + configuration, all objects are local. - local operation - The manipulation of an object which resides on the same node as the - calling task. + local operation + The manipulation of an object which resides on the same node as the + calling task. - logical address - An address used by an application. In a system without memory - management, logical addresses will equal physical addresses. + logical address + An address used by an application. In a system without memory + management, logical addresses will equal physical addresses. - loosely-coupled - A multiprocessor configuration where shared memory is not used for - communication. + loosely-coupled + A multiprocessor configuration where shared memory is not used for + communication. - major number - The index of a device driver in the Device Driver Table. + major number + The index of a device driver in the Device Driver Table. - manager - A group of related RTEMS' directives which provide access and control - over resources. + manager + A group of related RTEMS' directives which provide access and control + over resources. - MCS - An acronym for Mellor-Crummey Scott. + MCS + An acronym for Mellor-Crummey Scott. - memory pool - Used interchangeably with heap. + memory pool + Used interchangeably with heap. - message - A sixteen byte entity used to communicate between tasks. Messages are - sent to message queues and stored in message buffers. + message + A sixteen byte entity used to communicate between tasks. Messages are + sent to message queues and stored in message buffers. - message buffer - A block of memory used to store messages. + message buffer + A block of memory used to store messages. - message queue - An RTEMS object used to synchronize and communicate between tasks by - transporting messages between sending and receiving tasks. + message queue + An RTEMS object used to synchronize and communicate between tasks by + transporting messages between sending and receiving tasks. - Message Queue Control Block - A data structure associated with each message queue used by RTEMS to - manage that message queue. + Message Queue Control Block + A data structure associated with each message queue used by RTEMS to + manage that message queue. - minor number - A numeric value passed to a device driver, the exact usage of which is - driver dependent. + minor number + A numeric value passed to a device driver, the exact usage of which is + driver dependent. - mode - An entry in a task's control block that is used to determine if the task - allows preemption, timeslicing, processing of signals, and the interrupt - disable level used by the task. + mode + An entry in a task's control block that is used to determine if the task + allows preemption, timeslicing, processing of signals, and the interrupt + disable level used by the task. - MPCI - An acronym for :term:`Multiprocessor Communications Interface Layer`. + MPCI + An acronym for :term:`Multiprocessor Communications Interface Layer`. - multiprocessing - The simultaneous execution of two or more processes by a multiple - processor computer system. + multiprocessing + The simultaneous execution of two or more processes by a multiple + processor computer system. - multiprocessor - A computer with multiple CPUs available for executing applications. + multiprocessor + A computer with multiple CPUs available for executing applications. - Multiprocessor Communications Interface Layer - A set of user-provided routines which enable the nodes in a - multiprocessor system to communicate with one another. + Multiprocessor Communications Interface Layer + A set of user-provided routines which enable the nodes in a + multiprocessor system to communicate with one another. - Multiprocessor Configuration Table - The data structure defining the characteristics of the multiprocessor - target system with which RTEMS will communicate. + Multiprocessor Configuration Table + The data structure defining the characteristics of the multiprocessor + target system with which RTEMS will communicate. - multitasking - The alternation of execution amongst a group of processes on a single - CPU. A scheduling algorithm is used to determine which process executes - at which time. + multitasking + The alternation of execution amongst a group of processes on a single + CPU. A scheduling algorithm is used to determine which process executes + at which time. - mutual exclusion - A term used to describe the act of preventing other tasks from accessing - a resource simultaneously. + mutual exclusion + A term used to describe the act of preventing other tasks from accessing + a resource simultaneously. - nested - A term used to describe an ASR that occurs during another ASR or an ISR - that occurs during another ISR. + nested + A term used to describe an ASR that occurs during another ASR or an ISR + that occurs during another ISR. - node - A term used to reference a processor running RTEMS in a multiprocessor - system. + node + A term used to reference a processor running RTEMS in a multiprocessor + system. - non-existent - The state occupied by an uncreated or deleted task. - - NUMA - An acronym for Non-Uniform Memory Access. + non-existent + The state occupied by an uncreated or deleted task. + + NUMA + An acronym for Non-Uniform Memory Access. - numeric coprocessor - A component used in computer systems to enhance performance in - mathematically intensive situations. It is typically viewed as a logical - extension of the primary processor. + numeric coprocessor + A component used in computer systems to enhance performance in + mathematically intensive situations. It is typically viewed as a logical + extension of the primary processor. - object - In this document, this term is used to refer collectively to tasks, - timers, message queues, partitions, regions, semaphores, ports, and rate - monotonic periods. All RTEMS objects have IDs and user-assigned names. + object + In this document, this term is used to refer collectively to tasks, + timers, message queues, partitions, regions, semaphores, ports, and rate + monotonic periods. All RTEMS objects have IDs and user-assigned names. - object-oriented - A term used to describe systems with common mechanisms for utilizing a - variety of entities. Object-oriented systems shield the application from - implementation details. + object-oriented + A term used to describe systems with common mechanisms for utilizing a + variety of entities. Object-oriented systems shield the application from + implementation details. - operating system - The software which controls all the computer's resources and provides the - base upon which application programs can be written. + operating system + The software which controls all the computer's resources and provides the + base upon which application programs can be written. - overhead - The portion of the CPUs processing power consumed by the operating - system. + overhead + The portion of the CPUs processing power consumed by the operating + system. - packet - A buffer which contains the messages passed between nodes in a - multiprocessor system. A packet is the contents of an envelope. + packet + A buffer which contains the messages passed between nodes in a + multiprocessor system. A packet is the contents of an envelope. - partition - An RTEMS object which is used to allocate and deallocate fixed size - blocks of memory from an dynamically specified area of memory. + partition + An RTEMS object which is used to allocate and deallocate fixed size + blocks of memory from an dynamically specified area of memory. - partition - Clusters with a cardinality of one are partitions. + partition + Clusters with a cardinality of one are partitions. - Partition Control Block - A data structure associated with each partition used by RTEMS to manage - that partition. + Partition Control Block + A data structure associated with each partition used by RTEMS to manage + that partition. - pending - A term used to describe a task blocked waiting for an event, message, - semaphore, or signal. + pending + A term used to describe a task blocked waiting for an event, message, + semaphore, or signal. - periodic task - A task which must execute at regular intervals and comply with a hard - deadline. + periodic task + A task which must execute at regular intervals and comply with a hard + deadline. - physical address - The actual hardware address of a resource. + physical address + The actual hardware address of a resource. - poll - A mechanism used to determine if an event has occurred by periodically - checking for a particular status. Typical events include arrival of - data, completion of an action, and errors. + poll + A mechanism used to determine if an event has occurred by periodically + checking for a particular status. Typical events include arrival of + data, completion of an action, and errors. - pool - A collection from which resources are allocated. + pool + A collection from which resources are allocated. - portability - A term used to describe the ease with which software can be rehosted on - another computer. + portability + A term used to describe the ease with which software can be rehosted on + another computer. - posting - The act of sending an event, message, semaphore, or signal to a task. + posting + The act of sending an event, message, semaphore, or signal to a task. - preempt - The act of forcing a task to relinquish the processor and dispatching to - another task. + preempt + The act of forcing a task to relinquish the processor and dispatching to + another task. - priority - A mechanism used to represent the relative importance of an element in a - set of items. RTEMS uses priority to determine which task should - execute. + priority + A mechanism used to represent the relative importance of an element in a + set of items. RTEMS uses priority to determine which task should + execute. - priority boosting - A simple approach to extend the priority inheritance protocol for - clustered scheduling is priority boosting. In case a mutex is owned by a - task of another cluster, then the priority of the owner task is raised to - an artificially high priority, the pseudo-interrupt priority. + priority boosting + A simple approach to extend the priority inheritance protocol for + clustered scheduling is priority boosting. In case a mutex is owned by a + task of another cluster, then the priority of the owner task is raised to + an artificially high priority, the pseudo-interrupt priority. - priority inheritance - An algorithm that calls for the lower priority task holding a resource to - have its priority increased to that of the highest priority task blocked - waiting for that resource. This avoids the problem of priority - inversion. + priority inheritance + An algorithm that calls for the lower priority task holding a resource to + have its priority increased to that of the highest priority task blocked + waiting for that resource. This avoids the problem of priority + inversion. - priority inversion - A form of indefinite postponement which occurs when a high priority tasks - requests access to shared resource currently allocated to low priority - task. The high priority task must block until the low priority task - releases the resource. + priority inversion + A form of indefinite postponement which occurs when a high priority tasks + requests access to shared resource currently allocated to low priority + task. The high priority task must block until the low priority task + releases the resource. - processor utilization - The percentage of processor time used by a task or a set of tasks. + processor utilization + The percentage of processor time used by a task or a set of tasks. - proxy - An RTEMS control structure used to represent, on a remote node, a task - which must block as part of a remote operation. - - Proxy Control Block - A data structure associated with each proxy used by RTEMS to manage that - proxy. - - PTCB - An acronym for :term:`Partition Control Block`. - - PXCB - An acronym for :term:`Proxy Control Block`. - - quantum - The application defined unit of time in which the processor is allocated. - - queue - Alternate term for message queue. - - QCB - An acronym for :term:`Message Queue Control Block`. - - ready task - A task occupies this state when it is available to be given control of a - processor. A ready task has no processor assigned. The scheduler - decided that other tasks are currently more important. A task that is - ready to execute and has a processor assigned is called scheduled. + proxy + An RTEMS control structure used to represent, on a remote node, a task + which must block as part of a remote operation. + + Proxy Control Block + A data structure associated with each proxy used by RTEMS to manage that + proxy. + + PTCB + An acronym for :term:`Partition Control Block`. + + PXCB + An acronym for :term:`Proxy Control Block`. + + quantum + The application defined unit of time in which the processor is allocated. + + queue + Alternate term for message queue. + + QCB + An acronym for :term:`Message Queue Control Block`. + + ready task + A task occupies this state when it is available to be given control of a + processor. A ready task has no processor assigned. The scheduler + decided that other tasks are currently more important. A task that is + ready to execute and has a processor assigned is called scheduled. - real-time - A term used to describe systems which are characterized by requiring - deterministic response times to external stimuli. The external stimuli - require that the response occur at a precise time or the response is - incorrect. - - reentrant - A term used to describe routines which do not modify themselves or global - variables. - - region - An RTEMS object which is used to allocate and deallocate variable size - blocks of memory from a dynamically specified area of memory. - - Region Control Block - A data structure associated with each region used by RTEMS to manage that - region. - - registers - Registers are locations physically located within a component, typically - used for device control or general purpose storage. - - remote - Any object that does not reside on the local node. - - remote operation - The manipulation of an object which does not reside on the same node as - the calling task. - - return code - Also known as error code or return value. - - resource - A hardware or software entity to which access must be controlled. - - resume - Removing a task from the suspend state. If the task's state is ready - following a call to the ``rtems_task_resume`` directive, then the task is - available for scheduling. - - return code - A value returned by RTEMS directives to indicate the completion status of - the directive. - - RNCB - An acronym for :term:`Region Control Block`. - - round-robin - A task scheduling discipline in which tasks of equal priority are - executed in the order in which they are made ready. - - RS-232 - A standard for serial communications. - - running - The state of a rate monotonic timer while it is being used to delineate a - period. The timer exits this state by either expiring or being canceled. - - schedulable - A set of tasks which can be guaranteed to meet their deadlines based upon - a specific scheduling algorithm. + real-time + A term used to describe systems which are characterized by requiring + deterministic response times to external stimuli. The external stimuli + require that the response occur at a precise time or the response is + incorrect. + + reentrant + A term used to describe routines which do not modify themselves or global + variables. + + region + An RTEMS object which is used to allocate and deallocate variable size + blocks of memory from a dynamically specified area of memory. + + Region Control Block + A data structure associated with each region used by RTEMS to manage that + region. + + registers + Registers are locations physically located within a component, typically + used for device control or general purpose storage. + + remote + Any object that does not reside on the local node. + + remote operation + The manipulation of an object which does not reside on the same node as + the calling task. + + return code + Also known as error code or return value. + + resource + A hardware or software entity to which access must be controlled. + + resume + Removing a task from the suspend state. If the task's state is ready + following a call to the ``rtems_task_resume`` directive, then the task is + available for scheduling. + + return code + A value returned by RTEMS directives to indicate the completion status of + the directive. + + RNCB + An acronym for :term:`Region Control Block`. + + round-robin + A task scheduling discipline in which tasks of equal priority are + executed in the order in which they are made ready. + + RS-232 + A standard for serial communications. + + running + The state of a rate monotonic timer while it is being used to delineate a + period. The timer exits this state by either expiring or being canceled. + + schedulable + A set of tasks which can be guaranteed to meet their deadlines based upon + a specific scheduling algorithm. - schedule - The process of choosing which task should next enter the executing state. - - scheduled task - A task is scheduled if it is allowed to execute and has a processor - assigned. Such a task executes currently on a processor or is about to - start execution. A task about to start execution it is an heir task on - exactly one processor in the system. - - scheduler - A scheduler or scheduling algorithm allocates processors to a subset of - its set of ready tasks. So it manages access to the processor resource. - Various algorithms exist to choose the tasks allowed to use a processor - out of the set of ready tasks. One method is to assign each task a - priority number and assign the tasks with the lowest priority number to - one processor of the set of processors owned by a scheduler instance. + schedule + The process of choosing which task should next enter the executing state. + + scheduled task + A task is scheduled if it is allowed to execute and has a processor + assigned. Such a task executes currently on a processor or is about to + start execution. A task about to start execution it is an heir task on + exactly one processor in the system. + + scheduler + A scheduler or scheduling algorithm allocates processors to a subset of + its set of ready tasks. So it manages access to the processor resource. + Various algorithms exist to choose the tasks allowed to use a processor + out of the set of ready tasks. One method is to assign each task a + priority number and assign the tasks with the lowest priority number to + one processor of the set of processors owned by a scheduler instance. - scheduler instance - A scheduler instance is a scheduling algorithm with a corresponding - context to store its internal state. Each processor in the system is - owned by at most one scheduler instance. The processor to scheduler - instance assignment is determined at application configuration time. See - :ref:`Configuring a System`. - - segments - Variable sized memory blocks allocated from a region. - - semaphore - An RTEMS object which is used to synchronize tasks and provide mutually - exclusive access to resources. - - Semaphore Control Block - A data structure associated with each semaphore used by RTEMS to manage - that semaphore. - - shared memory - Memory which is accessible by multiple nodes in a multiprocessor system. - - signal - An RTEMS provided mechanism to communicate asynchronously with a task. - Upon reception of a signal, the ASR of the receiving task will be - invoked. - - signal set - A thirty-two bit entity which is used to represent a task's collection of - pending signals and the signals sent to a task. - - SMCB - An acronym for :term:`Semaphore Control Block`. - - SMP - An acronym for Symmetric Multiprocessing. - - SMP locks - The SMP locks ensure mutual exclusion on the lowest level and are a - replacement for the sections of disabled interrupts. Interrupts are - usually disabled while holding an SMP lock. They are implemented using - atomic operations. Currently a ticket lock is used in RTEMS. - - SMP barriers - The SMP barriers ensure that a defined set of independent threads of - execution on a set of processors reaches a common synchronization point - in time. They are implemented using atomic operations. Currently a - sense barrier is used in RTEMS. - - soft real-time system - A real-time system in which a missed deadline does not compromise the - integrity of the system. - - sporadic task - A task which executes at irregular intervals and must comply with a hard - deadline. A minimum period of time between successive iterations of the - task can be guaranteed. - - stack - A data structure that is managed using a Last In First Out (LIFO) - discipline. Each task has a stack associated with it which is used to - store return information and local variables. - - status code - Also known as error code or return value. - - suspend - A term used to describe a task that is not competing for the CPU because it - has had a ``rtems_task_suspend`` directive. - - synchronous - Related in order or timing to other occurrences in the system. - - system call - In this document, this is used as an alternate term for directive. - - target - The system on which the application will ultimately execute. - - TAS - An acronym for Test-And-Set. - - task - A logically complete thread of execution. It consists normally of a set - of registers and a stack. The scheduler assigns processors to a subset - of the ready tasks. The terms task and thread are synonym in RTEMS. The - term task is used throughout the Classic API, however, internally in the - operating system implementation and the POSIX API the term thread is - used. - - Task Control Block - A data structure associated with each task used by RTEMS to manage that - task. - - task migration - Task migration happens in case a task stops execution on one processor - and resumes execution on another processor. - - task processor affinity - The set of processors on which a task is allowed to execute. + scheduler instance + A scheduler instance is a scheduling algorithm with a corresponding + context to store its internal state. Each processor in the system is + owned by at most one scheduler instance. The processor to scheduler + instance assignment is determined at application configuration time. See + :ref:`Configuring a System`. + + segments + Variable sized memory blocks allocated from a region. + + semaphore + An RTEMS object which is used to synchronize tasks and provide mutually + exclusive access to resources. + + Semaphore Control Block + A data structure associated with each semaphore used by RTEMS to manage + that semaphore. + + shared memory + Memory which is accessible by multiple nodes in a multiprocessor system. + + signal + An RTEMS provided mechanism to communicate asynchronously with a task. + Upon reception of a signal, the ASR of the receiving task will be + invoked. + + signal set + A thirty-two bit entity which is used to represent a task's collection of + pending signals and the signals sent to a task. + + SMCB + An acronym for :term:`Semaphore Control Block`. + + SMP + An acronym for Symmetric Multiprocessing. + + SMP locks + The SMP locks ensure mutual exclusion on the lowest level and are a + replacement for the sections of disabled interrupts. Interrupts are + usually disabled while holding an SMP lock. They are implemented using + atomic operations. Currently a ticket lock is used in RTEMS. + + SMP barriers + The SMP barriers ensure that a defined set of independent threads of + execution on a set of processors reaches a common synchronization point + in time. They are implemented using atomic operations. Currently a + sense barrier is used in RTEMS. + + soft real-time system + A real-time system in which a missed deadline does not compromise the + integrity of the system. + + sporadic task + A task which executes at irregular intervals and must comply with a hard + deadline. A minimum period of time between successive iterations of the + task can be guaranteed. + + stack + A data structure that is managed using a Last In First Out (LIFO) + discipline. Each task has a stack associated with it which is used to + store return information and local variables. + + status code + Also known as error code or return value. + + suspend + A term used to describe a task that is not competing for the CPU because it + has had a ``rtems_task_suspend`` directive. + + synchronous + Related in order or timing to other occurrences in the system. + + system call + In this document, this is used as an alternate term for directive. + + target + The system on which the application will ultimately execute. + + TAS + An acronym for Test-And-Set. + + task + A logically complete thread of execution. It consists normally of a set + of registers and a stack. The scheduler assigns processors to a subset + of the ready tasks. The terms task and thread are synonym in RTEMS. The + term task is used throughout the Classic API, however, internally in the + operating system implementation and the POSIX API the term thread is + used. + + Task Control Block + A data structure associated with each task used by RTEMS to manage that + task. + + task migration + Task migration happens in case a task stops execution on one processor + and resumes execution on another processor. + + task processor affinity + The set of processors on which a task is allowed to execute. - task switch - Alternate terminology for context switch. Taking control of the - processor from one task and given to another. + task switch + Alternate terminology for context switch. Taking control of the + processor from one task and given to another. - TCB - An acronym for :term:`Task Control Block`. + TCB + An acronym for :term:`Task Control Block`. - thread - This term has the same meaning as :term:`task`. + thread + This term has the same meaning as :term:`task`. - thread dispatch - The thread dispatch transfers control of the processor from the currently - executing thread to the heir thread of the processor. + thread dispatch + The thread dispatch transfers control of the processor from the currently + executing thread to the heir thread of the processor. - tick - The basic unit of time used by RTEMS. It is a user-configurable number - of microseconds. The current tick expires when a clock tick directive is - invoked. + tick + The basic unit of time used by RTEMS. It is a user-configurable number + of microseconds. The current tick expires when a clock tick directive is + invoked. - tightly-coupled - A multiprocessor configuration system which communicates via shared - memory. + tightly-coupled + A multiprocessor configuration system which communicates via shared + memory. - timeout - An argument provided to a number of directives which determines the - maximum length of time an application task is willing to wait to acquire - the resource if it is not immediately available. + timeout + An argument provided to a number of directives which determines the + maximum length of time an application task is willing to wait to acquire + the resource if it is not immediately available. - timer - An RTEMS object used to invoke subprograms at a later time. + timer + An RTEMS object used to invoke subprograms at a later time. - Timer Control Block - A data structure associated with each timer used by RTEMS to manage that - timer. + Timer Control Block + A data structure associated with each timer used by RTEMS to manage that + timer. - timeslicing - A task scheduling discipline in which tasks of equal priority are - executed for a specific period of time before being preempted by another - task. + timeslicing + A task scheduling discipline in which tasks of equal priority are + executed for a specific period of time before being preempted by another + task. - timeslice - The application defined unit of time in which the processor is allocated. + timeslice + The application defined unit of time in which the processor is allocated. - TLS - An acronym for Thread-Local Storage :cite:`Drepper:2013:TLS`. TLS is - available in :term:`C11` and :term:`C++11`. The support for TLS depends - on the CPU port :cite:`RTEMS:CPU`. + TLS + An acronym for Thread-Local Storage :cite:`Drepper:2013:TLS`. TLS is + available in :term:`C11` and :term:`C++11`. The support for TLS depends + on the CPU port :cite:`RTEMS:CPU`. - TMCB - An acronym for :term:`Timer Control Block`. + TMCB + An acronym for :term:`Timer Control Block`. - transient overload - A temporary rise in system activity which may cause deadlines to be - missed. Rate Monotonic Scheduling can be used to determine if all - deadlines will be met under transient overload. + transient overload + A temporary rise in system activity which may cause deadlines to be + missed. Rate Monotonic Scheduling can be used to determine if all + deadlines will be met under transient overload. - TTAS - An acronym for Test and Test-And-Set. + TTAS + An acronym for Test and Test-And-Set. - user extensions - Software routines provided by the application to enhance the - functionality of RTEMS. + user extensions + Software routines provided by the application to enhance the + functionality of RTEMS. - User Extension Table - A table which contains the entry points for each user extensions. + User Extension Table + A table which contains the entry points for each user extensions. - User Initialization Tasks Table - A table which contains the information needed to create and start each of - the user initialization tasks. + User Initialization Tasks Table + A table which contains the information needed to create and start each of + the user initialization tasks. - user-provided - These terms are used to designate any software routines which must be - written by the application designer. + user-provided + These terms are used to designate any software routines which must be + written by the application designer. - user-supplied - This term has the same meaning as :term:`user-provided`. + user-supplied + This term has the same meaning as :term:`user-provided`. - vector - Memory pointers used by the processor to fetch the address of routines - which will handle various exceptions and interrupts. + vector + Memory pointers used by the processor to fetch the address of routines + which will handle various exceptions and interrupts. - wait queue - The list of tasks blocked pending the release of a particular resource. - Message queues, regions, and semaphores have a wait queue associated with - them. + wait queue + The list of tasks blocked pending the release of a particular resource. + Message queues, regions, and semaphores have a wait queue associated with + them. - yield - When a task voluntarily releases control of the processor. + yield + When a task voluntarily releases control of the processor. -- cgit v1.2.3