Interprocess communication

A plays a special role relative to B-D (for example, it is created before them) What do the lines between these blocks mean interprocess communication, compile-time dependencies, data flow ... 

It should be noted that different concrete architectures for one logical architecture exist in general. These may reflect a sequence of possibly different interdependent decisions of the above list, or different realization variants. For example, one concrete architecture may be equipped with a RPC and another one with a CORBA (Common Object Request Broker Architecture [877]) implementation of interprocess communication. 

If no distributed solution is desired, the independent Process COMOS PT Wrapper is resolved, i.e. the COMOS PT Wrapper is deleted, the COMOS PT HomWrapper and the COMOS PT TechWrapper are realized as local components of the Integrator Tool, and the interprocess communication between the Integrator Tool and the COMOS PT HomWrapper is substituted by a Meth-odlnvocation relation as well (cf. box 6b of Fig. 5.58). 

IF/IPC - a generalized user-system and system system interface (IF) with built-in interprocess communication channels. 

Fig. 4. Distributed memory systems. In a distributed memory architecture, the various computing devices (e.g., PCs) have their own local memory and perform calculations on distributed problems. Input data and results are exchanged via a high-performance interprocess communication network.

Multi-process SW isolation, safety Execution context OSs with pipes and sockets, e.g., UNIX with interprocess communication... 

S. Sechrest, An Introductory 4.4.bsd Interprocess Communication Tutorial (Computer Science Research Group, University of CaUfomia, Berkeley, 1993)... 

ISPS, extended to support processes and message-passing interprocess communication, and user-definable operations. 

HardwareC, a version of C extended to support processes, interprocess communication, memory modules, parameter classes (in, out, inout), architectural registers, combinational operations, and Boolean and integer variable tjrpes. 

In the field of computer science, processes, concurrency, and interprocess communication are well understood [Dijkstra68, Hoare78, Andrews83]. The execution of a set of sequential statements is called a process, and the parallel execution of two or more processes is referred to as concurrent execution. The transfer of data between two processes is called inter-process communication, and insuring that inter-process communication takes place at a mutually-agreed-upon time is called synchronization. 

The technique of partitioning is used to divide a system into a set of processes. The criteria used to partition a system can alter the extent to which interprocess communications are necessary to maintain the overall system function. System partitions are often chosen to emphasise the physical topology of the plant, the functional characteristics of a system, or the physical location of the processors. If they are chosen so that they emphasise the dominant characteristics of a system, they may give, to a first approximation, a fully decoupled system. 

In many cases the partitions lead to an apparent reduction in the complexity of the system, or allow aggregation to reduce design complexity. However, the granularity introduced by partitioning should be carefully considered because it will affect the type of system implementation. For example, as the number of parallel processes into which a computational task is partitioned is increased, so the volume of interprocess communications for control and data interchange is also increased, thus leading to a closely coupled system Implementation. 

II) Interprocess communications Is the only form of Interaction between the processes. This would take place over an Interprocess communication medium. Thus each process Is commanded to perform Its activity, and signals when It has completed Its activity. 

Interprocess communication - To suppot communication and synchronization among the concurrent processes, HardwareC suj rts both parameter passing and message passing. The former assumes the existence... 

Based on this manual approach to specifying interprocess communication, the synthesis tool must have the flexibility to specify and implement any aspect of timing or signaling that may be required. The synthesis tools have therefore been extended by adding a number of features relating to I/O and interprocess communication. 

This application controls a certain aspect of an automotive powertrain system. Due to the real-time control nature of this application and the number of concurrent timing operations, the synthesized version of the chip was implemented with ten concurrent processes. A generic diagram illustrating the flavor of the interprocess communication on this chip is shown in Figure 4, and the synthesized chip layout is shown in Figure 5. 

Eight out of ten processes were simulated individually in this design, and all worked correctly. To simulate interprocess communication, a subset of four out of the ten processes were simulated together with correct results. 

This chip provides a hardware implementation for an industry standard communications protocol for automotive data links. The synthesized version of the design required five processes, and in addition two FIFOs which serve as data buffers were added to the top level netlist manually. The FIFOs were considered a shared resource used by several of the processes, and were therefore not synthesized within any one process. Little simulation was attempted in this design. Only two of the processes were simulated individually, and no simulation involving interprocess communication was attempted on this design. 

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