vrb_get_min(3) [debian man page]

vrb_get_min(3)						      VRB Programmer's Manual						    vrb_get_min(3)

NAME

       vrb_get_min - get minimum data from a VRB

LIBRARY

       -lvrb

SYNOPSIS

       #include <vrb.h>

       size_t vrb_get_min(vrb_p vrb, char *target, size_t minsize, size_t maxsize);

DESCRIPTION

       vrb_get_min Get data from a virtual ring buffer and copy it to the space provider by the caller only if the minimum specified amount can be
       copied.	If less data than the minimum is available, then no data is copied.

ARGUMENTS

       vrb_p vrb
       specifies which virtual ring buffer.

       char *target
       specifies the location where to copy the data to.

       size_t minsize
       specifies the minimum length of data that must be available to be copied.

       size_t maxsize
       specifies the maximum length of data that can be obtained from the virtual ring buffer.

RETURN VALUE

       size_t
       The actual length of data copied is returned, which can be any value from the minimum size to the maximum size, or 0.

ERRORS

       If an error is returned, then errno will have the following value:

       EINVAL An invalid virtual ring buffer pointer was specified, or the minimum request exceeds the buffer capacity and thus can never be  sat-
	      isfied.

SEE ALSO

       vrb(3),	 vrb_capacity(3),   vrb_data_len(3),  vrb_data_ptr(3),	vrb_destroy(3),  vrb_get(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_resize(3), vrb_space_len(3), vrb_space_ptr(3), vrb_take(3), vrb_uninit(3), vrb_write(3),
       vrb_write_min(3)

vrb								    2002-09-30							    vrb_get_min(3)

vrb_new(3)						      VRB Programmer's Manual							vrb_new(3)

NAME

       vrb_new - create a new virtual ring buffer

LIBRARY

       -lvrb

SYNOPSIS

       #include <vrb.h>

       vrb_p vrb_new(size_t size, const char *name);

DESCRIPTION

       vrb_new creates a new instance of a virtual ring buffer.

       A  virtual ring buffer is a character FIFO queue with the special property that any sequence of characters in the buffer may be accessed as
       a single contiguous block of memory, eliminating the need to split any sequence to handle a buffer wraparound.

ARGUMENTS

       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 temporary name pattern or an actual 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 name string ends in "XXXXXX" then mkstemp(3) will be used to make the file unique.   Other-
       wise  it  will  be  used as is.	If the named file already exists or otherwise 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

       vrb_p
       On success, a handle (pointer) to the newly created virtual ring buffer is returned.  On error, NULL is returned.

ERRORS

       If an error is returned, then errno will have one of the following values:

       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_opt(3),  vrb_put(3),
       vrb_put_all(3), vrb_read(3), vrb_read_min(3), vrb_resize(3), vrb_space_len(3), vrb_space_ptr(3), vrb_take(3), vrb_uninit(3),  vrb_write(3),
       vrb_write_min(3)

vrb								    2002-09-30								vrb_new(3)