upipe/uring.h header reference

Upipe ring of buffers More

• upipe/ubase.h
• upipe/uatomic.h

• struct uring
• struct uring_elem
• typedef [...] uring_fifo
• typedef [...] uring_fifo_val
• typedef [...] uring_index
• typedef [...] uring_lifo
• typedef [...] uring_lifo_val

• void * uring_elem_get(struct uring *uring, uring_index index)
• void uring_elem_set(struct uring *uring, uring_index index, void *opaque)
• void uring_fifo_clean(struct uring *uring, uring_fifo *fifo_p)
• void uring_fifo_init(struct uring *uring, uring_fifo *fifo_p)
• uring_index uring_fifo_pop(struct uring *uring, uring_fifo *fifo_p)
• void uring_fifo_push(struct uring *uring, uring_fifo *fifo_p, uring_index index)
• uring_lifo_val uring_init(struct uring *uring, uint16_t length, void *extra)
• void uring_lifo_clean(struct uring *uring, uring_lifo *lifo_p)
• void uring_lifo_init(struct uring *uring, uring_lifo *lifo_p, uring_lifo_val lifo)
• uring_index uring_lifo_pop(struct uring *uring, uring_lifo *lifo_p)
• void uring_lifo_push(struct uring *uring, uring_lifo *lifo_p, uring_index index)

• URING_FIFO_NULL
• URING_INDEX_NULL
• URING_LIFO_NULL
• uring_sizeof

This API defines rings of structures for use in LIFOs and FIFOs.

This macro is declared in upipe/uring.h source file, line 252.

This macro represents a (NULL, NULL) FIFO descriptor.

This macro is declared in upipe/uring.h source file, line 48.

This macro represents a NULL index position.

This macro is declared in upipe/uring.h source file, line 131.

This macro represents a NULL LIFO descriptor.

This macro is declared in upipe/uring.h source file, line 32.

This struct is declared in upipe/uring.h source file, line 62.

This struct defines a ring of elements.

This struct is declared in upipe/uring.h source file, line 52.

This struct defines an element in the ring.

This function is declared in upipe/uring.h source file, line 110.

This function gets the opaque of a uring element.

Parameter list:

• uring: pointer to uring structure
• index: index of the element in the ring

The return value is opaque associated with the element, or NULL

This function is declared in upipe/uring.h source file, line 97.

This function sets the opaque of a uring element.

Parameter list:

• uring: pointer to uring structure
• index: index of the element in the ring
• opaque: opaque to associate with the element

This typedef is declared in upipe/uring.h source file, line 250.

This typedef defines an atomic structure describing a FIFO, based on uring_fifo_val.

This function is declared in upipe/uring.h source file, line 434.

This function cleans up a FIFO.

Parameter list:

• uring: pointer to uring structure
• fifo_p: pointer to the FIFO descriptor

This function is declared in upipe/uring.h source file, line 424.

This function initializes a FIFO.

Parameter list:

• uring: pointer to uring structure
• fifo_p: pointer to the FIFO descriptor

This function is declared in upipe/uring.h source file, line 352.

This function pops an element from the head of a FIFO.

Parameter list:

• uring: pointer to uring structure
• fifo_p: pointer to the FIFO descriptor

The return value is index of the first FIFO element, or URING_INDEX_NULL

This function is declared in upipe/uring.h source file, line 403.

This function pushes an element into the tail of a FIFO in a thread-safe manner.

Parameter list:

• uring: pointer to uring structure
• fifo_p: pointer to the FIFO descriptor
• index: index of the element to push

This typedef is declared in upipe/uring.h source file, line 245.

This typedef defines a multiplexed structure from two element indexes (head and tail) and associated tags. The bit-field definition is:

This typedef is declared in upipe/uring.h source file, line 46.

This typedef defines the position of an element in the uring array.

This function is declared in upipe/uring.h source file, line 450.

This function initializes a ring. By default all elements are chained, and the first element is the head of the chain.

Parameter list:

• uring: pointer to uring structure
• length: number of elements in the ring
• extra: mandatory extra space allocated by the caller, with the size returned by uring_sizeof

The return value is uring LIFO descriptor of the first element, for use in uring_lifo_init

This typedef is declared in upipe/uring.h source file, line 129.

This typedef defines an atomic structure describing a LIFO, based on uring_lifo_val.

This function is declared in upipe/uring.h source file, line 188.

This function cleans up a LIFO.

Parameter list:

• uring: pointer to uring structure
• lifo_p: pointer to the LIFO descriptor

This function is declared in upipe/uring.h source file, line 178.

This function initializes a LIFO.

Parameter list:

• uring: pointer to uring structure
• lifo_p: pointer to the LIFO descriptor
• lifo: LIFO value returned by uring_init, or URING_LIFO_NULL

This function is declared in upipe/uring.h source file, line 200.

This function pops an element from a LIFO.

Parameter list:

• uring: pointer to uring structure
• lifo_p: pointer to the LIFO descriptor

The return value is index of the first LIFO element, or URING_INDEX_NULL

This function is declared in upipe/uring.h source file, line 225.

This function pushes an element into a LIFO.

Parameter list:

• uring: pointer to uring structure
• lifo_p: pointer to the LIFO descriptor
• index: index of the element to push

This typedef is declared in upipe/uring.h source file, line 124.

This typedef defines a multiplexed structure from an element index (top) and a tag incremented at each use of the element. This is to avoid the ABA problem in concurrent operations. The bit-field definition is:

This macro is declared in upipe/uring.h source file, line 73.

This macro returns the required size of extra data space for uring.

Parameter list:

• length: number of elements in the ring

The return value is size in octets to allocate

This function is for internal use only.

This function is declared in upipe/uring.h source file, line 83.

This function returns a pointer to an element from an index.

Parameter list:

• index: of the element in the ring

The return value is pointer to the element in the ring

This function is for internal use only.

This function is declared in upipe/uring.h source file, line 328.

This function finds in a chained list of elements the one pointing to a given index.

Parameter list:

• uring: pointer to uring structure
• start: index of the first element of the list
• find: index to find

The return value is index of the element pointing to find, or URING_INDEX_NULL if not found

This function is for internal use only.

This function is declared in upipe/uring.h source file, line 311.

This function returns the index of the head element of a FIFO descriptor

Parameter list:

• fifo: FIFO multiplexed structure

The return value is index of the head element in the ring

This function is for internal use only.

This function is declared in upipe/uring.h source file, line 298.

This function returns the index of the tail element of a FIFO descriptor.

Parameter list:

• fifo: FIFO multiplexed structure

The return value is index of the tail element in the ring

This function is for internal use only.

This function is declared in upipe/uring.h source file, line 281.

This function sets the index of the head element of a FIFO descriptor.

Parameter list:

• fifo_p: pointer to uring FIFO multiplexed structure
• index: index of the head element in the ring

This function is for internal use only.

This function is declared in upipe/uring.h source file, line 263.

This function sets the index of the tail element of a FIFO descriptor.

Parameter list:

• fifo_p: pointer to uring FIFO multiplexed structure
• index: index of the tail element in the ring

This function is for internal use only.

This function is declared in upipe/uring.h source file, line 160.

This function returns a LIFO value (multiplexed tag and index) for a given element index. There is no memory barrier in this function because we assume it's been done by the caller.

Parameter list:

• uring: pointer to uring structure
• index: index of the element in the ring

The return value is uring LIFO multiplexed structure

This function is for internal use only.

This function is declared in upipe/uring.h source file, line 141.

This function returns the index of an element from a LIFO value.

Parameter list:

• lifo: uring LIFO multiplexed structure

The return value is index of the element in the ring