What is the process management in windows 7?

Answer 1

Every process contains one or more threads, and the Windows thread is the basic executable unit; see the next chapter for a threads introduction. Threads are scheduled on the basis of the usual factors: availability of resources such as CPUs and physical memory, priority, fairness, and so on. Windows has long supported multiprocessor systems, so threads can be allocated to separate processors within a computer.

From the programmer's perspective, each Windows process includes resources such as the following components:

• One or more threads.
• A virtual address space that is distinct from other processes' address spaces. Note that shared memory-mapped files share physical memory, but the sharing processes will probably use different virtual addresses to access the mapped file.
• One or more code segments, including code in DLLs.
• One or more data segments containing global variables.
• Environment strings with environment variable information, such as the current search path.
• The process heap.
• Resources such as open handles and other heaps.

Each thread in a process shares code, global variables, environment strings, and resources. Each thread is independently scheduled, and a thread has the following elements:

• A stack for procedure calls, interrupts, exception handlers, and automatic storage.
• Thread Local Storage (TLS)-An arraylike collection of pointers giving each thread the ability to allocate storage to create its own unique data environment.
• An argument on the stack, from the creating thread, which is usually unique for each thread.
• A context structure, maintained by the kernel, with machine register values.

Figure 6-1 shows a process with several threads. This figure is schematic and does not indicate actual memory addresses, nor is it drawn to scale.

Figure 6-1 A Process and Its Threads