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Benefits of multithreading Because each thread runs independently, multithreading your code can: Improve application responsiveness Any program in which many activities are not dependent upon each other can be redesigned so that each activity is fired off as a thread. For example, a GUI in which you are performing one activity while starting up another will show improved performance when implemented with threads. Use multiprocessors more efficiently Typically, applications that express concurrency requirements with threads need not take into account the number of available processors. The performance of the application improves transparently with additional processors. Numerical algorithms and applications with a high degree of paralleism, such as matrix multiplications, can run much faster when implemented with threads on a multiprocessor. Improve your program structure Many programs are more efficiently structured as multiple independent or semi-independent units of execution instead of as a single, monolithic thread. Multithreaded programs can be more adaptive to variations in user demands than are single threaded programs. Use fewer system resources Programs that use two or more processes that access common data through shared memory are applying more than one thread of control. However, each process has a full address space and operating systems state. The cost of creating and maintaining this large amount of state makes each process much more expensive than a thread in both time and space. In addition, the inherent separation between processes can require a major effort by the programmer to communicate between the threads in different processes or to synchronize their actions. Improve performance The operation of creating a new process is over 30 times as expensive as creating an unbound thread, and about 5 times the cost of creating a bound thread consisting of both a thread and a LWP (Solaris). LinuxThreads: find some benchmarks! |
