Threads

• A thread of execution results from a fork of a computer program into two or more concurrently running tasks

• The Linux kernel schedules threads asynchronously

• A thread exists within a process.
• Threads are a finer-grained unit of execution than processes. When you invoke a program, Linux creates a new process and in that process creates a single thread, which runs the program sequentially.
• Thread can create additional threads; all these threads run the same program in the same process, but each thread may be executing a different part of the program at any given time.
• All threads within a process share the same address space.
• The creating and the created thread share the same memory space, file descriptors, and other system resources as the original. If one thread changes the value of a variable, for instance, the other thread subsequently will see the modified value.Similarly, if one thread closes a file descriptor, other threads may not read from or write to that file descriptor