vrb_space_ptr
returns the pointer to the beginning of the contiguous block of
empty space within the virtual ring buffer where data may be placed.
The pointer has meaning only if there is space in the buffer.
If there is no space in the buffer, an arbitrary pointer is
returned that must not be used.
Use
vrb_space_len(3)
or
vrb_is_full(3)
to determine if
vrb_space_ptr(3)
has a meaningful pointer.
The caller may access all of this space, and should call
vrb_give(3)
to indicate how much data has been placed into
the buffer.
ARGUMENTS
vrb_p vrb
specifies the virtual ring buffer to obtain the empty space pointer from.
If a NULL or invalid pointer is given, results are unpredictable
and are likely to be disasterous.
RETURN VALUE
size_t
The pointer to the empty space in the virtual ring buffer is returned.