A thread that was created either using pthread_create() with the detachstate attribute not set to PTHREAD_CREATE_DETACHED or using thrd_create(), and for which neither pthread_detach() nor pthread_join() has been called and returned zero, and neither thrd_detach() nor thrd_join() has been called and returned <tt>thrd_success</tt>.

<small>Note: The pthread_attr_setdetachstate(), pthread_create(), pthread_detach(), pthread_join(), thrd_create(), thrd_detach(), and thrd_join() functions are defined in detail in the System Interfaces volume of POSIX.1-202x.</small>

A single flow of control within a process. Each thread has its own thread ID, scheduling priority and policy, errno value, floating point environment, thread-specific key/value bindings, and the required system resources to support a flow of control. Anything whose address can be determined by a thread, including but not limited to static variables, storage obtained via malloc(), directly addressable storage obtained through implementation-defined functions, and automatic variables, are accessible to all live threads in the same process.

<small>Note: The malloc() function is defined in detail in the System Interfaces volume of POSIX.1-202x.</small>

A single flow of control within a process. Each thread has its own thread ID, scheduling priority and policy, errno value, floating point environment, thread-specific key/value bindings, and the required system resources to support a flow of control. Anything whose address may be determined by a thread, including but not limited to static variables, storage obtained via malloc(), directly addressable storage obtained through implementation-defined functions, and automatic variables, are accessible to all live threads in the same process.

<small>Note: The malloc() function is defined in detail in the System Interfaces volume of POSIX.1-202x.</small>

A live thread (see [xref to Live Thread]) or a zombie thread (see [xref to Zombie Thread]). The lifetime of a thread is described in [xref to Thread Lifetime].

The period of time that begins when a thread is created and ends when its thread ID is returned to the process.

See also Live Thread in [xref to Live Thread], Thread Termination in [xref to Thread Termination], and Zombie Thread in [xref to Zombie Thread].

<small>Note: Thread creation is defined in detail in the descriptions of the pthread_create() and thrd_create() functions in the System Interfaces volume of POSIX.1-202x.</small>

Thread termination occurs when a thread executes pthread_exit() or thrd_exit(), when it returns from the start_routine function passed to pthread_create() or from the func function passed to thrd_create(), or when it acts on a cancellation request initiated by pthread_cancel().

<small>Note: The pthread_cancel(), pthread_create(), pthread_exit(), thrd_create(), and thrd_exit() functions are defined in detail in the System Interfaces volume of POSIX.1-202x.</small>

The remains of a joinable live thread (see [xref to Joinable Thread] and [xref to Live Thread]) after it terminates (see [xref to Thread Termination]) and before it has been joined with pthread_join() or thrd_join() or detached with pthread_detach() or thrd_detach().

<small>Note: The pthread_detach(), pthread_join(), thrd_detach(), and thrd_join() functions are defined in detail in the System Interfaces volume of POSIX.1-202x.</small>

The lifetime of a thread ID ends after the thread terminates if it was created using pthread_create() with the detachstate attribute set to PTHREAD_CREATE_DETACHED or if pthread_detach(), pthread_join(), thrd_detach(), or thrd_join() has been called for that thread.

The lifetime of a thread ID ends after the later of thread termination (see [xref to Thread Termination]) and the point when the thread is no longer joinable (see [xref to Joinable Thread]).

It shall not be an error to request cancellation of a zombie thread.

Historical implementations varied on the result of a pthread_cancel() with a thread ID indicating a zombie thread. Some indicated success with nothing further to do because the thread had already terminated, while others gave an error of [ESRCH]. Since the definition of thread lifetime in this standard covers zombie threads, the [ESRCH] error as described is inappropriate in this case and implementations that give this error do not conform.

If thread has not terminated, pthread_detach() shall not cause it to terminate.

If thread has not terminated, pthread_detach() shall not cause it to terminate, but shall prevent the thread from becoming a zombie thread when it does terminate.

a thread that has exited but remains unjoined

a zombie thread

It shall not be an error if thread is a zombie thread.

Existing implementations vary on the result of a pthread_kill() with a thread ID indicating an inactive thread (a terminated thread that has not been detached or joined). Some indicate success on such a call, while others give an error of [ESRCH]. Since the definition of thread lifetime in this volume of POSIX.1-202x covers inactive threads, the [ESRCH] error as described is inappropriate in this case.

Historical implementations varied on the result of a pthread_kill() with a thread ID indicating a zombie thread. Some indicated success on such a call, while others gave an error of [ESRCH]. Since the definition of thread lifetime in this volume of POSIX.1-202x covers zombie threads, the [ESRCH] error as described is inappropriate in this case and implementations that give this error do not conform.

A future version of this standard may require that pthread_kill() not fail with [ESRCH] in the case of sending signals to an inactive thread (a terminated thread not yet detached or joined), even though no signal will be delivered because the thread is no longer running.

None.