Thread Object - Win32 Programmer's Reference

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Thread Object

The Thread performance object consists of counters that measure aspects of thread behavior. A thread is the basic object that executes instructions on a processor. All running processes have at least one thread.

Processor Time

Processor Time is the percentage of elapsed time that this thread used the processor to execute instructions. An instruction is the basic unit of execution in a processor, and a thread is the object that executes instructions. Code executed to handle some hardware interrupts and trap conditions are included in this count.

Detail Level: Novice
Counter Type: PERF_100NSEC_TIMER

% User Time
User Time is the percentage of elapsed time that this thread has spent executing code in user mode. Applications, environment subsystems, and integral subsystems execute in user mode. Code executing in user mode cannot damage the integrity of the Windows NT Executive, Kernel, and device drivers. Unlike some early operating systems, Windows NT uses process boundaries for subsystem protection in addition to the traditional protection of user and privileged modes. These subsystem processes provide additional protection. Therefore, some work done by Windows NT on behalf of your application might appear in other subsystem processes in addition to the privileged time in your process.

Detail Level: Advanced
Counter Type: PERF_100NSEC_TIMER

% Privileged Time
Privileged Time is the percentage of elapsed time that this thread has spent executing code in privileged mode. When a Windows NT system service is called, the service will often run in privileged mode in order to gain access to system-private data. Such data is protected from access by threads executing in user mode. Calls to the system can be explicit or implicit, such as page faults or interrupts. Unlike some early operating systems, Windows NT uses process boundaries for subsystem protection in addition to the traditional protection of user and privileged modes. These subsystem processes provide additional protection. Therefore, some work done by Windows NT on behalf of your application might appear in other subsystem processes in addition to the privileged time in your process.

Detail Level: Advanced
Counter Type: PERF_100NSEC_TIMER

Context Switches/sec
Context Switches/sec is the rate of switches from one thread to another. Thread switches can occur either inside of a single process or across processes. A thread switch can be caused either by one thread asking another for information, or by a thread being preempted by another, higher priority thread becoming ready to run. Unlike some early operating systems, Windows NT uses process boundaries for subsystem protection in addition to the traditional protection of user and privileged modes. These subsystem processes provide additional protection. Therefore, some work done by Windows NT on behalf of an application might appear in other subsystem processes in addition to the privileged time in the application. Switching to the subsystem process causes one context switch in the application thread. Switching back causes another context switch in the subsystem thread.

Detail Level: Advanced
Counter Type: PERF_COUNTER_COUNTER

Elapsed Time
The total elapsed time (in seconds) this thread has been running.

Detail Level: Advanced
Counter Type: PERF_ELAPSED_TIME

Priority Current
The current dynamic priority of this thread. The system can raise the thread's dynamic priority above the base priority if the thread is handling user input, or lower it towards the base priority if the thread becomes compute bound.

Detail Level: Advanced
Counter Type: PERF_COUNTER_RAWCOUNT

Priority Base
The current base priority of this thread. The system can raise the thread's dynamic priority above the base priority if the thread is handling user input, or lower it towards the base priority if the thread becomes compute bound.

Detail Level: Advanced
Counter Type: PERF_COUNTER_RAWCOUNT

Start Address
Starting virtual address for this thread.