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pthread_rwlockattr_getpshared(3) [linux man page]

PTHREAD_RWLOCKATTR_GETPSHARED(P)			     POSIX Programmer's Manual				  PTHREAD_RWLOCKATTR_GETPSHARED(P)

NAME
pthread_rwlockattr_getpshared, pthread_rwlockattr_setpshared - get and set the process-shared attribute of the read-write lock attributes object SYNOPSIS
#include <pthread.h> int pthread_rwlockattr_getpshared(const pthread_rwlockattr_t * restrict attr, int *restrict pshared); int pthread_rwlockattr_setpshared(pthread_rwlockattr_t *attr, int pshared); DESCRIPTION
The pthread_rwlockattr_getpshared() function shall obtain the value of the process-shared attribute from the initialized attributes object referenced by attr. The pthread_rwlockattr_setpshared() function shall set the process-shared attribute in an initialized attributes object referenced by attr. The process-shared attribute shall be set to PTHREAD_PROCESS_SHARED to permit a read-write lock to be operated upon by any thread that has access to the memory where the read-write lock is allocated, even if the read-write lock is allocated in memory that is shared by multiple processes. If the process-shared attribute is PTHREAD_PROCESS_PRIVATE, the read-write lock shall only be operated upon by threads created within the same process as the thread that initialized the read-write lock; if threads of differing processes attempt to operate on such a read-write lock, the behavior is undefined. The default value of the process-shared attribute shall be PTHREAD_PROCESS_PRIVATE. Additional attributes, their default values, and the names of the associated functions to get and set those attribute values are implemen- tation-defined. RETURN VALUE
Upon successful completion, the pthread_rwlockattr_getpshared() function shall return zero and store the value of the process-shared attribute of attr into the object referenced by the pshared parameter. Otherwise, an error number shall be returned to indicate the error. If successful, the pthread_rwlockattr_setpshared() function shall return zero; otherwise, an error number shall be returned to indicate the error. ERRORS
The pthread_rwlockattr_getpshared() and pthread_rwlockattr_setpshared() functions may fail if: EINVAL The value specified by attr is invalid. The pthread_rwlockattr_setpshared() function may fail if: EINVAL The new value specified for the attribute is outside the range of legal values for that attribute. These functions shall not return an error code of [EINTR]. The following sections are informative. EXAMPLES
None. APPLICATION USAGE
None. RATIONALE
None. FUTURE DIRECTIONS
None. SEE ALSO
pthread_rwlock_destroy() , pthread_rwlockattr_destroy() , pthread_rwlockattr_init() , the Base Definitions volume of IEEE Std 1003.1-2001, <pthread.h> COPYRIGHT
Portions of this text are reprinted and reproduced in electronic form from IEEE Std 1003.1, 2003 Edition, Standard for Information Technol- ogy -- Portable Operating System Interface (POSIX), The Open Group Base Specifications Issue 6, Copyright (C) 2001-2003 by the Institute of Electrical and Electronics Engineers, Inc and The Open Group. In the event of any discrepancy between this version and the original IEEE and The Open Group Standard, the original IEEE and The Open Group Standard is the referee document. The original Standard can be obtained online at http://www.opengroup.org/unix/online.html . IEEE
/The Open Group 2003 PTHREAD_RWLOCKATTR_GETPSHARED(P)

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pthread_rwlockattr_getpshared(3C)                                                                                pthread_rwlockattr_getpshared(3C)

NAME
pthread_rwlockattr_getpshared, pthread_rwlockattr_setpshared - get or set process-shared attribute of read-write lock attributes object SYNOPSIS
cc -mt [ flag... ] file... -lpthread [ library... ] #include <pthread.h> int pthread_rwlockattr_getpshared(const pthread_rwlockattr_t *restrict attr, int *restrict pshared); int pthread_rwlockattr_setpshared(pthread_rwlockattr_t *attr, int pshared); The process-shared attribute is set to PTHREAD_PROCESS_SHARED to permit a read-write lock to be operated upon by any thread that has access to the memory where the read-write lock is allocated, even if the read-write lock is allocated in memory that is shared by multiple processes. If the process-shared attribute is PTHREAD_PROCESS_PRIVATE, the read-write lock will only be operated upon by threads created within the same process as the thread that initialised the read-write lock; if threads of differing processes attempt to operate on such a read-write lock, the behaviour is undefined. The default value of the process-shared attribute is PTHREAD_PROCESS_PRIVATE. The pthread_rwlockattr_getpshared() function obtains the value of the process-shared attribute from the initialised attributes object ref- erenced by attr. The pthread_rwlockattr_setpshared() function is used to set the process-shared attribute in an initialised attributes object referenced by attr. If successful, the pthread_rwlockattr_setpshared() function returns 0. Otherwise, an error number is returned to indicate the error. Upon successful completion, the pthread_rwlockattr_getpshared() returns 0 and stores the value of the process-shared attribute of attr into the object referenced by the pshared parameter. Otherwise an error number is returned to indicate the error. The pthread_rwlockattr_getpshared() and pthread_rwlockattr_setpshared() functions will fail if: EINVAL The value specified by attr or pshared is invalid. See attributes(5) for descriptions of the following attributes: +-----------------------------+-----------------------------+ | ATTRIBUTE TYPE | ATTRIBUTE VALUE | +-----------------------------+-----------------------------+ |Interface Stability |Standard | +-----------------------------+-----------------------------+ |MT-Level |MT-Safe | +-----------------------------+-----------------------------+ pthread_rwlock_init(3C), pthread_rwlock_rdlock(3C), pthread_rwlock_unlock(3C), pthread_rwlock_wrlock(3C), pthread_rwlockattr_init(3C), attributes(5), standards(5) 23 Mar 2005 pthread_rwlockattr_getpshared(3C)
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