-IPC - Interprocess communication - in a multiprocessing system, many processes share fewer resources requiring ipc.
-ipc increases efficiency by allowing sharing of resources and info between processes.
-at times one process may have to wait for another process to release a shared resource.
-this wait can be arbitrarily long depending on the precise timing of resource acquisition and request.
-Race condition describes the situation above where two resources compete and wait for resources to share.
-Mutex or Mutual Exclusion is a mechanism by which Race conditions can be avoided.
-Mutex helps by isolating the resources and space for each runnable process.
-virtualization first came in 1967 in IBM cp/cms system.
-now its back full force on Intel platform.
-in future many computers will be running hypervisors on the bare metal.
-the hypervisor will create a number of vms, each with its own operating system.
-even though multicore chips are here, the os'es dont use them efficiently.
-the combination of vm and multicore chips opens new avenues.
-cloud computing enables data to be stored remotely and accessed locally.
-this is becoming more and more popular.
-The limiting factor is network speeds, not size of data.
-NT is based on DEC VMS technology.
-VMS was designed by Dave Cutler at DEC.
-NT and VMS are so strikingly similar that in the early 1990s DEC and MSFT fought lawsuits over their IP and settled out of court.
-Unix and NT (or VMS) differ mainly because the types of computers they were designed for.
-Unix was designed in 70s on small machines with limited cpu and memory power.
-Unix has 'processes' as the unit of concurrency and composition.
-NT was desgined in the early 90s when machines had more cpu and memory.
-NT has 'threads' as the unit of concurrency, dynamic libraries are unit of composition.
-NT uses fork and exec as a single operation.
-this means a single operations creates a new process and runs another program without first making a copy.
-ipc increases efficiency by allowing sharing of resources and info between processes.
-at times one process may have to wait for another process to release a shared resource.
-this wait can be arbitrarily long depending on the precise timing of resource acquisition and request.
-Race condition describes the situation above where two resources compete and wait for resources to share.
-Mutex or Mutual Exclusion is a mechanism by which Race conditions can be avoided.
-Mutex helps by isolating the resources and space for each runnable process.
-virtualization first came in 1967 in IBM cp/cms system.
-now its back full force on Intel platform.
-in future many computers will be running hypervisors on the bare metal.
-the hypervisor will create a number of vms, each with its own operating system.
-even though multicore chips are here, the os'es dont use them efficiently.
-the combination of vm and multicore chips opens new avenues.
-cloud computing enables data to be stored remotely and accessed locally.
-this is becoming more and more popular.
-The limiting factor is network speeds, not size of data.
-NT is based on DEC VMS technology.
-VMS was designed by Dave Cutler at DEC.
-NT and VMS are so strikingly similar that in the early 1990s DEC and MSFT fought lawsuits over their IP and settled out of court.
-Unix and NT (or VMS) differ mainly because the types of computers they were designed for.
-Unix was designed in 70s on small machines with limited cpu and memory power.
-Unix has 'processes' as the unit of concurrency and composition.
-NT was desgined in the early 90s when machines had more cpu and memory.
-NT has 'threads' as the unit of concurrency, dynamic libraries are unit of composition.
-NT uses fork and exec as a single operation.
-this means a single operations creates a new process and runs another program without first making a copy.
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