Answering questions that may arise related to the meaning of portions of an IEEE standard concerning specific applications.

IEEE Standards Interpretations for IEEE Std 1003.1c™-1995 IEEE Standard for Information Technology--Portable Operating System Interface (POSIX(R)) - System Application Program Interface (API) Amendment 2: Threads Extension (C Language)

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Interpretation Request #41
Topic: pthread_cancel , pthread.h Relevant Clauses: 2.7.3, 18.2.1

pthread_cancel() is missing from ISO 9945-1:1996 2.7.3 for pthread.h. The synopsis in 18.2.1 has it in pthread.h. This is a contradiction. Proposed response: POSIX.1-1996 is unclear and allows the prototype to appear either in pthread.h or unistd.h. It is recommended that a future revision require it to be only in pthread.h since the type pthread_t is required to be defined.

Interpretation Response
The standard is clear on page 45 lines 1246-1251 that any function not listed in the table shall be in unistd.h and that unistd.h shall be included before using the function whether or not it is mentioned in the synopsis clause. It is the oppinion of the interpretations committee that this is not what the working and balloting groups intended but rather that pthread_cancel() be defined in pthread.h. This is being referred to the sponsor for consideration.

Rationale for Interpretation