pthread_join (BPX1PTJ, BPX4PTJ) — Wait on a thread

Function

The pthread_join callable service obtains the termination status for a specific thread. The pthread_join service waits only if the thread has not ended, is not in a detached state, and is not currently joined by another thread.

Requirements

Operation	Environment
Authorization:	Supervisor state or problem state, any PSW key
Dispatchable unit mode:	Task
Cross memory mode:	PASN = HASN
AMODE (BPX1PTJ):	31-bit
AMODE (BPX4PTJ):	64-bit
ASC mode:	Primary mode
Interrupt status:	Enabled for interrupts
Locks:	Unlocked
Control parameters:	All parameters must be addressable by the caller and in the primary address space.

Format

The syntax format is as follows:

CALL BPX1PTJ,(Thread_ID,
              Status_field_address,
              Return_value,
              Return_code,
              Reason_code)

AMODE 64 callers use BPX4PTJ with the same parameters. The Status_field_address parameter is a doubleword.

Parameters

Thread_ID

Supplied parameter

Type:: Character string
Length:: 8 bytes

The name of an 8-byte field that contains the thread ID for the target thread that is to be waited upon.

Status_field_address

Supplied parameter

Type:: Address
Length:: Fullword (doubleword)

The name of a fullword (doubleword) field that contains the address of a status field in which to return the exit status of the thread that is specified by the thread ID value. If this field is zero, the thread exit status is not returned.

Return_Value

Returned parameter

Type:: Integer
Length:: Fullword

The name of a fullword in which the pthread_join service returns 0 if the request is successful, or -1 if it is not successful.

Return_Code

Returned parameter

Type:: Integer
Length:: Fullword

The name of a fullword in which the pthread_join service stores the return code. The pthread_join service returns Return_code only if Return_value is -1. For a list of return code values, see Return codes (errnos) in z/OS UNIX System Services Messages and Codes. The pthread_join service can return one of the following values in the Return_code parameter:

Return code	Explanation
EINTR	The calling process received a signal before the completion of an event that would cause the pthread_join service to return. The service was interrupted by a signal. In this case, the value contained in Status_field_address is undefined.
EINVAL	The value that was specified by thread ID is not valid; it does not contain a value that is consistent with thread IDs managed by the system. The following reason code can accompany this return code: JRLightWeightThread.
ESRCH	The value that was specified by thread ID does not refer to a thread that is undetached. The following reason codes can accompany this return code: JRThreadNotFound, JRAlreadyJoined, and JRAlreadyDetached.
EDEADLK	A deadlock was detected; or the value specified by thread ID refers to the calling thread. The following reason codes can accompany this return code: JRJoinLoop and JRJoinToSelf.

Reason_Code

Returned parameter

Type:: Integer
Length:: Fullword

The name of a fullword in which the pthread_join service stores the reason code. The pthread_join service returns Reason_code only if Return_value is -1. Reason_code further qualifies the Return_code value. For a list of reason codes, see Reason codes in z/OS UNIX System Services Messages and Codes.

Usage notes

The pthread_join service can be called repeatedly for a thread until the thread is detached. However, a thread can be the target of only one pthread_join at a time.
In AMODE 31, the status field pointed to by Status_Field_Addr is 4 bytes. In AMODE 64, the status field is 8 bytes. See pthread_create (BPX1PTC, BPX4PTC) — Create a thread for further information.
When pthread_join is issued for a non-pthread-created thread that has ended, that thread will only be found if it exited via pthread_exit_and_get.

pthread_join (BPX1PTJ, BPX4PTJ) — Wait on a thread

Function

Requirements

Format

Parameters

Usage notes

Related services

Characteristics and restrictions

Examples