"Mohan gupta" writes:

can anyone please tell me how is sheduling between the threads is done in boost ::thread are there any system calls involved or just its the appilcation of repeated function calls or something else

Boost thread uses the OS API to launch the threads, and then leaves it up to the OS to schedule the threads. Obviously the use of synchronizing mechanisms such as mutexes and condition variables will affect this scheduling. Anthony -- Anthony Williams | Just Software Solutions Ltd Custom Software Development | http://www.justsoftwaresolutions.co.uk Registered in England, Company Number 5478976. Registered Office: 15 Carrallack Mews, St Just, Cornwall, TR19 7UL