Exam 2 Terms

Blocking receive: The receiver blocks until a message is available.

Blocking send: The sending process is blocked until the message is received by the receiving process or by the mailbox.

Bounded Buffer: Assumes a fixed buffer size. The consumer must wait if the buffer is empty and the producer must wait if the buffer is full.

Cascading Termination: If process terminates then all its children must also be terminated

Child Process: New process created

Communication Link: If process P and Q want to communicate they must send and receive messages so a communication link must exist between them. This link can be implemented in direct and indirect communication.

Context Switch: Switching the CPU to another process by performing a state save of the current process and a state restore of a different process.

Cooperating Processse: If it can affect or be affected by other processes executing in the system.

CPU-bound process: generates I/O requests infrequently, using more of its time doing computations.

Data Section: Contains global variables.

Degree of Multiprogramming: The number of processes in memory, which is controlled by long term scheduler.

Device Queue: List of processes waiting for a particular I/O device

Direct Communication: Each process that want to communicate must explicitly name the recipient or sender of the communication.

Heap: Memory that is dynamically allocated during process run time.

I/O-bound process: One that spends more of its time doing I/O than it spends doing computations.

Independent Processes: A process that cannot affect or be affected by other processes executing in the system.

Indirect Communication: the messages are sent to and received from mailboxes or ports.

Interproccess Communication: Allows process to exchange data and information.

Job Queue: consists of all processes in the system.

Long-Term Scheduler: Selects processes from ones that are kept for later execution

Medium-Term Scheduler: Sometimes is advantageous to remove processes from memory and thus reduce the degree of multiprogramming.

Message Passing: Communication takes place by means of message exchanging between the cooperating processes.

Non-Blocking receive: The receiver either a valid message or null.

Non-Blocking send: The sending process sends the message and resumes operation

Parent Process: The creating process

Process: A program in execution

Process Control Block: Contains many pieces of information associated with a specific process including these : Process State, Program counter, CPU registers, CPU scheduler info, Memory management info, accounting info, I/O status info

Process Dispatch: A process is selected for execution so it is out of ready queue.

Process Identifier (pid): unique identifier

Process Mix: Mix of I/O bound and CPU bound processes

Process Scheduler: selects an available process for program execution on CPU

Process State: Defined in part by the current activity of that process

Process State: New: The process is being created

Process State: Ready: The process is waiting to be assigned to a processor.

Process State: Running: Instructions are being executed

Process State: Terminated: The process has finished execution.

Process State: Waiting: Process is waiting for some event to occur (such as an I/O completion or reception of a signal)

Program Counter: Value that represents the current activity

Ready Queue: Processes that are residing in main memory and are ready and waiting to execute

Shared Memory (for Communication): A reigion of memory that is shared by cooperating processes is established. Processes can then exchange information by reading and writing data to the shared region.

Short-Term Scheduler: Selects among processes that are ready to execute and allocates the CPU to one of them.

Stack: Contains temporary data(such as function parameters, return addresses, and local variables),

State Restore (in Context Switch): Resume Operations

State Save(in Context Switch): Save current state of CPU

Swapping: process is swapped out and later swapped in

Text Section: The program Code

Unbounded Buffer: Places no practical limit on the size of the buffer. The consumer may have to wait for new items, but the producer can always produce new items.

Zero-capacity buffer: The queue has a maximum length of zero; thus the link cannot have any messages waiting in it. In this case, the sender must block until the recipient receives the message.