How can we differentiate a thread from a process

Question

How can we differentiate a thread from a process ? As we know that thread is smallest unit of program.

Jignesh Trivedi · Answer

hi A process is a collection of virtual memory space code data and system resources. A thread is code that is to be serially executed within a process. A processor executes threads not processes so each application has at least one process and a process always has at least one thread of execution known as the primary thread. A process can have multiple threads in addition to the primary thread. Thread Process Threads share the address space of the process thatcreated it processes have their own address. Threads have direct access to the data segment of its process processes have their own copy of the data segment of the parent process Threads can directly communicate with other threads of its process processes must use interprocess communication to communicate with sibling processes. Threads have almost no overhead processes have considerable overhead. New threads are easily created new processes require duplication of the parent process. Changes to the main thread (cancellation priority change etc.) may affect the behavior of the other threads of the process changes to the parent process does not affect child processes. hope this will help you.

Nattudurai Eswaramurthy · Answer

Process Each process provides the resources needed to execute a program. A process has a virtual address space executable code open handles to system objects a security context a unique process identifier environment variables a priority class minimum and maximum working set sizes and at least one thread of execution. Each process is started with a single thread often called the primary thread but can create additional threads from any of its threads. Thread A thread is the entity within a process that can be scheduled for execution. All threads of a process share its virtual address space and system resources. In addition each thread maintains exception handlers a scheduling priority thread local storage a unique thread identifier and a set of structures the system will use to save the thread context until it is scheduled. The thread context includes the thread's set of machine registers the kernel stack a thread environment block and a user stack in the address space of the thread's process. Threads can also have their own security context which can be used for impersonating clients. you can find help from the following MSDN article : http://msdn.microsoft.com/en-us/library/ms681917 (VS.85).aspx