Context switch

This paper deals with the recovery after a fault. Thus, no fault injection experiments are carried out. On each context switch, we take a checkpoint, holding the architectural state of the processor. We first clarify two terms A rollback means that the state at time i... 

For other shared resources, such as the Level 2 (L2) cache, the system implementation needs to ensure that system predictability and determinism is not affected by changes in the contents of the L2 cache due to application behaviour, which could lead to variations in the partition context switch time, known as jitter. This is normally addressed by invalidating and flushing the cache at the end of a... 

The XML Parser is a simple context-based parser. In each context there are two callback functions that are used for opening and closing markup tags. During the parsing, these functions are called to initialize the RSI array and the safety rule trees. Context switching is performed inside the callback function according to the parsed XML tag. 

It would not be efficient to always check aU invariants on all data structures. Hence, a data object can have two states, open and closed. The convention is that a thread only may change objects it owns and that it may force a check on all invariants by wrapping an object, that is by moving it from open to closed. Ignoring volatile variables, a property that VCC enforces in verification is that members of a closed struct cannot be modified by the program. In addition, if an object is closed, its invariants are guaranteed to hold. That is relevant in a concurrent setting when a context switch may occur. 

No task attributes The rtems task variable add routine is never used (No Dependence => Ada.Task Attributes). In addition, all tasks are created with attribute RTEMS FLOATING POINT, even if floating point instructions are not used, so the context switch time is as similar as possible for all tasks. 

The execution time of Interrupt Service Routines (ISR) is not recorded, however just the interrupt for the RTEMS clock tick is enabled (configured to 100 Hz). All the other nominal interrupts are masked to reduce unpredictability (device polling is always used). Furthermore, every time the clock tick is received the MILB task is scheduled, so this ISR overhead is finally attributed to this task, which has the highest priority. In addition, the predictability impact of not being able to use freeze-on-interrupt in the caches is greatly reduced as every time an interrupt arrives a context switch wiU be performed anyway. 

Since every single activation of each task for the complete test is recorded, it is possible to automatically compute the interference time of each task activation by subtracting the execution time of the different time spans where a thread preempts it (set of tasks directly preempting task i during the activation k, denoted by dp(i, k), but not those tasks indirectly preempting task t). This time value is approximate because it does not take into account the context switch, but is close enough for our schedulability analysis. 

Besides the use of the two described techniques for recording the execution time of every task and critical section, the RapiTime tool was also used to obtain the actual worst-case execution times. This hybrid tool is based on collecting timestamps of functional blocks during test runs, and then using static analysis to compute the worst-case path of each task or critical section, even if it has never been exercised during the tests. To obtain these execution timestamps from the IXV OBSW test suite, each functional block was instrumented with an invalid SPARC instruction interpreted by the SVF (similar approach to the SVF traces but with even less overhead), as well as inside the RTEMS context switch hook to separate the timestamps per task. 

In addition, since the breakpointing technique provides complete observability of any instruction of the OBSW without noticeable overhead, we intend to perform a more detailed timing analysis in the future [11], e.g. monitoring every interrupt execution, and other sources of blocking like context switch routines or those... 

The bus system of a switchgear assembly, its interconnecting links and wires are the protected type components, whereas an interrupter (breaker, switch or a fuse) may be a protecting or protected type, depending upon their application and location in the circuit. A contactor and an OCR are therefore protected devices in the same context, for they provide no short-time protection. A protecting device may become protected when it is also provided with a back-up protection. 

Ii is seen ihai ihe surge frequency during current chopping may rarely exceed 20 kHz and which, in the context of switching. surges, may be considered as low-frequency oscillations, easy to handle and interrupt. 

The first set of case studies illustrates errors due to the inadequate design of the human-machine interface (HMI). The HMI is the boundary across which information is transmitted between the process and the plant worker. In the context of process control, the HMI may consist of analog displays such as chart records and dials, or modem video display unit (VDU) based control systems. Besides display elements, the HMI also includes controls such as buttons and switches, or devices such as trackballs in the case of computer controlled systems. The concept of the HMI can also be extended to include all means of conveying information to the worker, including the labeling of control equipment components and chemical containers. Further discussion regarding the HMI is provided in Chapter 2. This section contains examples of deficiencies in the display of process information, in various forms of labeling, and the use of inappropriate instrumentation scales. 

Melanocortin peptides are potent anti-inflammatory agents displaying beneficial effects in diseases ranging from cardiovascular to arthritis to obesity to name a few. Within an inflammatory context, they have the ability to switch off early production of cytokines and at later stages they increase levels of anti-inflammatory proteins that lead to the resolution of the host inflammatory response potentially restoring homeostasis to the tissue. They could eventually be viewed as an alternative to glucocorticoids, as their mode of action often resembles that seen... 

Transition path sampling can also be helpful in the calculation of free energies in the context of fast-switching methods described in Chap. 5. As shown by Jarzynski [12], equilibrium free energies can be computed from the work performed on a system in repeated transformations carried out arbitrarily far from equilibrium. From a computational point of view, this remarkable theorem is attractive because it promises efficient free energy calculations due to the reduced cost of... 

Perhaps that s tme in this case. But indeterminate state charts will be important when we discuss components. This component may be combined with a wide variety of others, including ones not yet known of so we actually don t know what the causes are, only what the possible outcomes can be. This situation might happen if we allowed our phone instrument to be connected to a new kind of switching system. As long as we have a way of reusing this underspecified model and adding to it in another context, it is worthwhile to make this separation. 

These results imply that the type of behavior exhibited by a given system is not necessarily an intrinsic property of the system. It may, in fact, be possible in many cases to switch between two types of behavior by control of the reaction conditions, as it is for 124 and 129. In the context of this review the interesting aspect is that in such cases one would be able to determine whether the conformation of the product is determined by structural mimicry in the parent phase or by the intermolecular interactions in the crystal of the product. 

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