|PTHREAD_ATTR_SETGUARDSIZE(3)||Linux Programmer's Manual||PTHREAD_ATTR_SETGUARDSIZE(3)|
NAMEpthread_attr_setguardsize, pthread_attr_getguardsize - set/get guard size attribute in thread attributes object
int pthread_attr_setguardsize(pthread_attr_t *attr, size_t guardsize);
int pthread_attr_getguardsize(pthread_attr_t *attr, size_t *guardsize);
Compile and link with -pthread.
DESCRIPTIONThe pthread_attr_setguardsize() function sets the guard size attribute of the thread attributes object referred to by attr to the value specified in guardsize.
RETURN VALUEOn success, these functions return 0; on error, they return a nonzero error number.
ERRORSPOSIX.1-2001 documents an EINVAL error if attr or guardsize is invalid. On Linux these functions always succeed (but portable and future-proof applications should nevertheless handle a possible error return).
VERSIONSThese functions are provided by glibc since version 2.1.
NOTESA guard area consists of virtual memory pages that are protected to prevent read and write access. If a thread overflows its stack into the guard area, then, on most hard architectures, it receives a SIGSEGV signal, thus notifying it of the overflow. Guard areas start on page boundaries, and the guard size is internally rounded up to the system page size when creating a thread. (Nevertheless, pthread_attr_getguardsize() returns the guard size that was set by pthread_attr_setguardsize().)
BUGSAs at glibc 2.8, the NPTL threading implementation includes the guard area within the stack size allocation, rather than allocating extra space at the end of the stack, as POSIX.1 requires. (This can result in an EINVAL error from pthread_create(3) if the guard size value is too large, leaving no space for the actual stack.)
SEE ALSOmmap(2), mprotect(2), pthread_attr_init(3), pthread_attr_setstack(3), pthread_attr_setstacksize(3), pthread_create(3), pthreads(7)
COLOPHONThis page is part of release 3.53 of the Linux man-pages project. A description of the project, and information about reporting bugs, can be found at http://www.kernel.org/doc/man-pages/.