nshmget(3) [osf1 man page]

nshmget(3)						     Library Functions Manual							nshmget(3)

NAME

       nshmget - Returns (or creates) the ID for a shared memory region (libnuma library)

SYNOPSIS

       #include <numa.h> #include <sys/shm.h>

       int nshmget(
	       key_t key,
	       size_t size,
	       int shmflg,
	       memalloc_attr_t *attr );

PARAMETERS

       Specifies  the  key  that  identifies the shared memory region. The value for the key parameter can be IPC_PRIVATE or a random number other
       than zero (0). If the value of key is IPC_PRIVATE, it can be used to assure the return of a new, unused shared  memory  region.	 Specifies
       the  minimum  number  of  bytes	to allocate for the region.  Specifies the creation flags. See shmget(2) for a description of these flags.
       Points to a memory allocation policy and attributes structure. If the specified key does not exist, and a shared memory region is  created,
       these attributes will be assigned to the memory object created to manage the shared memory region.

DESCRIPTION

       If the attr argument is NULL, the nshmget() function behaves identically to the shmget() function.

       If the attr argument is non-NULL, it points to a memory allocation policy and attributes structure that specifies where the pages should be
       allocated for a newly created shared memory region. To change the policy of an existing shared memory region, use the nmadvise()function.

       If the mattr_policy member of the structure pointed to by attr is MPOL_DIRECTED and the mattr_rad  member  is  RAD_NONE,  the  system  will
       choose  the  Resource  Affinity Domain (RAD) where the pages of the shared memory region will be allocated from among the RADs specified in
       the mattr_radset member of *attr.  If the mattr_radset member is the empty set, the system will select a RAD for  the  memory  object  from
       among all of the RADs in the caller's partition, and the overflow set will be the empty set.

RETURN VALUES

       Success.  Failure. In this case, errno is set to indicate the error.

ERRORS

       In  addition  to  the  error  conditions for the shmget() function, the nshmget()function sets errno to one of the specified values for the
       specified condition: A non-NULL attr argument points to an invalid address.  The structure pointed to by  the  attr  argument  contains	an
       invalid memory allocation policy or invalid RAD. The striped allocation was requested with a stride of 0.

SEE ALSO

       Functions: shmget(2), nmadvise(3), numa_intro(3)

       Files: numa_types(4), shmid_ds(4)

																	nshmget(3)

Check Out this Related Man Page

SHMGET(2)						      BSD System Calls Manual							 SHMGET(2)

NAME

     shmget -- get shared memory area identifier

SYNOPSIS

     #include <sys/shm.h>

     int
     shmget(key_t key, size_t size, int shmflg);

DESCRIPTION

     shmget() returns the shared memory identifier associated with the key key.

     A shared memory segment is created if either key is equal to IPC_PRIVATE, or key does not have a shared memory segment identifier associated
     with it, and the IPC_CREAT bit is set in shmflg.

     If a new shared memory segment is created, the data structure associated with it (the shmid_ds structure, see shmctl(2)) is initialized as
     follows:

     o	 shm_perm.cuid and shm_perm.uid are set to the effective uid of the calling process.

     o	 shm_perm.gid and shm_perm.cgid are set to the effective gid of the calling process.

     o	 shm_perm.mode is set to the lower 9 bits of shmflg.

     o	 shm_lpid, shm_nattch, shm_atime, and shm_dtime are set to 0

     o	 shm_ctime is set to the current time.

     o	 shm_segsz is set to the value of size.

     o	 The ftok(3) function may be used to generate a key from a pathname.

RETURN VALUES

     Upon successful completion a positive shared memory segment identifier is returned.  Otherwise, -1 is returned and the global variable errno
     is set to indicate the error.

ERRORS

     The shmget() system call will fail if:

     [EACCES]		A shared memory segment is already associated with key and the caller has no permission to access it.

     [EEXIST]		Both IPC_CREAT and IPC_EXCL are set in shmflg, and a shared memory segment is already associated with key.

     [EINVAL]		No shared memory segment is to be created, and a shared memory segment exists for key, but the size of the segment associ-
			ated with it is less than size, which is non-zero.

     [ENOENT]		IPC_CREAT was not set in shmflg and no shared memory segment associated with key was found.

     [ENOMEM]		There is not enough memory left to created a shared memory segment of the requested size.

     [ENOSPC]		A new shared memory identifier could not be created because the system limit for the number of shared memory identifiers
			has been reached.

LEGACY SYNOPSIS

     #include <sys/types.h>
     #include <sys/ipc.h>
     #include <sys/shm.h>

     int
     shmget(key_t key, int size, int shmflg);

     All of these include files are necessary.	The type of size has changed.

SEE ALSO

     ftok(3), shmat(2), shmctl(2), shmdt(2), compat(5)

BSD
								  August 17, 1995							       BSD

Linux and UNIX Man Pages

nshmget(3) [osf1 man page]

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