RE: What is the difference between process and thread....
Creation of new process requires new resources and Address space whereas the thread can be created in the same address space of the process which not only saves space and resources but are also easy to create and delete,and many threads can exhists in a process.
RE: What is the difference between process and thread....
Parent & child process have different Code, Data & Test segments. But two threads of the same process share the Code & Data segments and have separate stacks.
RE: What is the difference between process and thread....
A thread is a stream of instructions which can be scheduled independently(i.e it has its own program counter and stack).But a thread shares its resources like program code,directories and global data with the calling process.A process on the other hand has its own copy of both resources and scheduling information.A process can have many threads,basically threads are called light weight processes.
RE: What is the difference between process and thread?...
Differences Between Threads and Processes
Threads share the address space of the process that created 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 inter-process 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.
Threads can exercise considerable control over threads of the same process; processes can only exercise control over child processes.
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.
Both have an id, set of registers, state, priority, and scheduling policy.
Both have attributes that describe the entity to the OS.
Both have an information block.
Both share resources with the parent process.
Both function as independent entities from the parent process.
The creator can exercise some control over the thread or process.
Both can change their attributes.
Both can create new resources.
Neither can access the resources of another process.
RE: What is the difference between process and thread?
Operating system is aware of process, it can see the processes. But operating system is NOT aware of thread, do not see them.
Threads are only visible in processes, created by the user within user space. Think like process is a bucket for threads and a process may have multiple threads.
**And most importantly if there is no process there can not be any thread.**
