NAME
vrb_resize - create a new virtual ring buffer
LIBRARY
-lvrb
SYNOPSIS
#include <vrb.h>
vrb_p vrb_resize(size_t size, const char *name);
DESCRIPTION
vrb_resize changes the size of a virtual ring buffer if the data in the
source buffer will fit in the requested space.
ARGUMENTS
vrb_p vrb
specifies the ring buffer which will be resized.
size_t size
specifies the requested minimum buffer size to be allocated. The given
value will be rounded up to the nearest or equal whole multiple of the
system page size. The virtual ring buffer is implemented by mapping
two adjacent blocks of memory to the same memory object. Thus, twice
as much virtual address space will be used and the specified size must
be less than half of the available virtual address space for this
process.
const char *name
specifies an optional name of a file to be used as backing store via
mmap(2) in a mounted filesystem in which the process has write
permission. If the named file cannot be opened for write, an error
will occur. If NULL is given, swap space will be used as backing store
via shmat(2).
RETURN VALUE
int
On success, 0 is returned. Otherwise, -1 is returned.
ERRORS
If an error is returned, then errno will have one of the following
values:
ENOSPC The data in the current virtual ring buffer will not fit into
the requested space.
EINVAL A buffer size was requested which is too large for address space
allocation arithmetic.
ENOMEM Out of memory allocating the virtual ring buffer structure.
- An errno value set by a failing system call.
SEE ALSO
vrb(3), vrb_capacity(3), vrb_data_len(3), vrb_data_ptr(3),
vrb_destroy(3), vrb_get(3), vrb_get_min(3), vrb_give(3), vrb_init(3),
vrb_init_opt(3), vrb_is_empty(3), vrb_is_full(3), vrb_is_not_empty(3),
vrb_is_not_full(3), vrb_move(3), vrb_new(3), vrb_new_opt(3),
vrb_put(3), vrb_put_all(3), vrb_read(3), vrb_read_min(3),
vrb_space_len(3), vrb_space_ptr(3), vrb_take(3), vrb_uninit(3),
vrb_write(3), vrb_write_min(3)