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pthread_attr_init(3) [osf1 man page]

pthread_attr_init(3)					     Library Functions Manual					      pthread_attr_init(3)

NAME
pthread_attr_init - Initializes a thread attributes object. LIBRARY
DECthreads POSIX 1003.1c Library (libpthread.so) SYNOPSIS
#include <pthread.h> int pthread_attr_init( pthread_attr_t *attr,); STANDARDS
Interfaces documented on this reference page conform to industry standards as follows: IEEE Std 1003.1c-1995, POSIX System Application Program Interface PARAMETERS
Address of a thread attributes object to be initialized. DESCRIPTION
This routine initializes the thread attributes object specified by the attr argument with a set of default attribute values. A thread attributes object is used to specify the attributes of one or more threads when they are created. The attributes object created by this routine is used only in calls to the pthread_create(3) routine. The following routines change individual attributes of an initialized thread attributes object: pthread_attr_setdetachstate pthread_attr_setguardsize_np pthread_attr_setinheritsched pthread_attr_setschedparam pthread_attr_setschedpolicy pthread_attr_setscope pthread_attr_setstackaddr pthread_attr_setstacksize The attributes of the thread attributes object are initialized to default values. The default value of each attribute is discussed in the reference description for each routine listed above. When a thread attributes object is used to create a thread, the object's attribute values determine the characteristics of the new thread. Thus, attributes objects act as additional arguments to thread creation. Changing the attributes of a thread attributes object does not affect any threads that were previously created using that attributes object. You can use the same thread attributes object in successive calls to pthread_create(3), from any thread. (However, you cannot use the same value of the stack address attribute to create multiple threads that might run concurrently; threads cannot share a stack.) If more than one thread might change the attributes in a shared attributes object, your program must use a mutex to protect the integrity of the attributes object's contents. When you set the scheduling policy or scheduling parameters, or both, in a thread attributes object, you must disable scheduling inheri- tance if you want the scheduling attributes you set to be used at thread creation. To disable scheduling inheritance, before creating the new thread use the pthread_attr_setinheritsched routine to specify the value PTHREAD_EXPLICIT_SCHED for the inherit argument. RETURN VALUES
If an error condition occurs, the thread attributes object cannot be used, and this routine returns an integer value indicating the type of error. Possible return values are as follows: Successful completion. The value specified by attr is not a valid thread attributes object. Insufficient memory exists to initialize the thread attributes object. ERRORS
None RELATED INFORMATION
Functions: pthread_attr_destroy(3), pthread_attr_setdetachstate(3), pthread_attr_setguardsize(3), pthread_attr_setinheritsched(3), pthread_attr_setschedparam(3), pthread_attr_setschedpolicy(3), pthread_attr_setscope(3), pthread_attr_setstackaddr(3), pthread_attr_set- stacksize(3), pthread_create(3) Manuals: Guide to DECthreads and Programmer's Guide delim off pthread_attr_init(3)

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pthread_attr_getguardsize(3)				     Library Functions Manual				      pthread_attr_getguardsize(3)

NAME
pthread_attr_getguardsize - Obtains the guardsize attribute of the specified thread attributes object. LIBRARY
DECthreads POSIX 1003.1c Library (libpthread.so) SYNOPSIS
#include <pthread.h> int pthread_attr_getguardsize( const pthread_attr_t *attr, size_t *guardsize); STANDARDS
Interfaces documented on this reference page conform to industry standards as follows: IEEE Std 1003.1c-1995, POSIX System Application Program Interface PARAMETERS
Address of the thread attributes object whose guardsize attribute is obtained. Receives the value of the guardsize attribute of the thread attributes object specified by attr. DESCRIPTION
This routine obtains the value of the guardsize attribute of the thread attributes object specified in the attr argument and stores it in the location specified by the guardsize argument. The specified attributes object must already be initialized at the time this routine is called. When creating a thread, use a thread attributes object to specify nondefault values for thread attributes. The guardsize attribute of a thread attributes object specifies the minimum size (in bytes) of the guard area for the stack of a new thread. A guard area can help a multithreaded program detect overflow of a thread's stack. A guard area is a region of no-access memory that DEC- threads allocates at the overflow end of the thread's stack. When any thread attempts to access a memory location within this region, a memory addressing violation occurs. NOTES
The value of the guardsize attribute of a particular thread attributes object does not necessarily correspond to the actual size of the guard area of any existing thread in your multithreaded program. RETURN VALUES
If an error condition occurs, this routine returns an integer value indicating the type of error. Possible return values are as follows: Successful completion. The value specified by attr does not refer to an existing thread attributes object. ERRORS
None RELATED INFORMATION
Functions: pthread_attr_init(3), pthread_attr_setguardsize(3), pthread_attr_setstacksize(3), pthread_create(3) Manuals: Guide to DECthreads and Programmer's Guide delim off pthread_attr_getguardsize(3)
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