Zix

Typedefs
typedef int(*	ZixComparator) (const void *a, const void *b, void *user_data)
typedef bool(*	ZixEqualFunc) (const void *a, const void *b)
typedef void(*	ZixDestroyFunc) (void *ptr)

Enumerations
enum	ZixStatus {   ZIX_STATUS_SUCCESS , ZIX_STATUS_ERROR , ZIX_STATUS_NO_MEM , ZIX_STATUS_NOT_FOUND ,   ZIX_STATUS_EXISTS , ZIX_STATUS_BAD_ARG , ZIX_STATUS_BAD_PERMS }

Functions
static const char *	zix_strerror (const ZixStatus status)

Ring
typedef struct ZixRingImpl	ZixRing
ZixRing *	zix_ring_new (uint32_t size)
void	zix_ring_free (ZixRing *ring)
void	zix_ring_mlock (ZixRing *ring)
void	zix_ring_reset (ZixRing *ring)
uint32_t	zix_ring_read_space (const ZixRing *ring)
uint32_t	zix_ring_write_space (const ZixRing *ring)
uint32_t	zix_ring_capacity (const ZixRing *ring)
uint32_t	zix_ring_peek (ZixRing *ring, void *dst, uint32_t size)
uint32_t	zix_ring_read (ZixRing *ring, void *dst, uint32_t size)
uint32_t	zix_ring_skip (ZixRing *ring, uint32_t size)
uint32_t	zix_ring_write (ZixRing *ring, const void *src, uint32_t size)

Detailed Description

Typedef Documentation

ZixComparator

typedef int(* ZixComparator) (const void *a, const void *b, void *user_data)

Function for comparing two elements.

Definition at line 83 of file common.h.

ZixDestroyFunc

typedef void(* ZixDestroyFunc) (void *ptr)

Function to destroy an element.

Definition at line 93 of file common.h.

ZixEqualFunc

typedef bool(* ZixEqualFunc) (const void *a, const void *b)

Function for testing equality of two elements.

Definition at line 88 of file common.h.

ZixRing

typedef struct ZixRingImpl ZixRing

A lock-free ring buffer.

Thread-safe with a single reader and single writer, and realtime safe on both ends.

Definition at line 41 of file ring.h.

Enumeration Type Documentation

ZixStatus

enum ZixStatus

Enumerator
ZIX_STATUS_SUCCESS
ZIX_STATUS_ERROR
ZIX_STATUS_NO_MEM
ZIX_STATUS_NOT_FOUND
ZIX_STATUS_EXISTS
ZIX_STATUS_BAD_ARG
ZIX_STATUS_BAD_PERMS

Definition at line 55 of file common.h.

             {
   ZIX_STATUS_SUCCESS,
   ZIX_STATUS_ERROR,
   ZIX_STATUS_NO_MEM,
   ZIX_STATUS_NOT_FOUND,
   ZIX_STATUS_EXISTS,
   ZIX_STATUS_BAD_ARG,
   ZIX_STATUS_BAD_PERMS,
} ZixStatus;

Function Documentation

zix_ring_capacity()

uint32_t zix_ring_capacity

(

const ZixRing *

ring

)

Return the capacity (i.e. total write space when empty).

Definition at line 141 of file ring.cpp.

{
   return ring->size - 1;
}

References ZixRingImpl::size.

zix_ring_free()

void zix_ring_free

(

ZixRing *

ring

)

Destroy a ring.

Definition at line 86 of file ring.cpp.

{
   free(ring->buf);
   free(ring);
}

References ZixRingImpl::buf, and staffpad::vo::free().

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zix_ring_mlock()

void zix_ring_mlock

(

ZixRing *

ring

)

Lock the ring data into physical memory.

This function is NOT thread safe or real-time safe, but it should be called after zix_ring_new() to lock all ring memory to avoid page faults while using the ring (i.e. this function MUST be called first in order for the ring to be truly real-time safe).

Definition at line 93 of file ring.cpp.

{
   ZIX_MLOCK(ring, sizeof(ZixRing));
   ZIX_MLOCK(ring->buf, ring->size);
}

References ZixRingImpl::buf, ZixRingImpl::size, and ZIX_MLOCK.

Referenced by LV2AtomPortState::LV2AtomPortState().

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zix_ring_new()

ZixRing * zix_ring_new

(

uint32_t

size

)

Create a new ring.

Parameters

size	Size in bytes (note this may be rounded up).

At most size - 1 bytes may be stored in the ring at once.

Definition at line 74 of file ring.cpp.

{
   ZixRing* ring = (ZixRing*)malloc(sizeof(ZixRing));
   ring->write_head = 0;
   ring->read_head  = 0;
   ring->size       = next_power_of_two(size);
   ring->size_mask  = ring->size - 1;
   ring->buf        = (char*)malloc(ring->size);
   return ring;
}

References ZixRingImpl::buf, next_power_of_two(), ZixRingImpl::read_head, ZixRingImpl::size, size, ZixRingImpl::size_mask, and ZixRingImpl::write_head.

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zix_ring_peek()

uint32_t zix_ring_peek	(	ZixRing *	ring,
		void *	dst,
		uint32_t	size
	)

Read from the ring without advancing the read head.

Definition at line 166 of file ring.cpp.

{
   return peek_internal(ring, ring->read_head, ring->write_head, size, dst);
}

References peek_internal(), ZixRingImpl::read_head, size, and ZixRingImpl::write_head.

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zix_ring_read()

uint32_t zix_ring_read	(	ZixRing *	ring,
		void *	dst,
		uint32_t	size
	)

Read from the ring and advance the read head.

Definition at line 172 of file ring.cpp.

{
   const uint32_t r = ring->read_head;
   const uint32_t w = ring->write_head;
 
   if (peek_internal(ring, r, w, size, dst)) {
      ZIX_READ_BARRIER();
      ring->read_head = (r + size) & ring->size_mask;
      return size;
   } else {
      return 0;
   }
}

References peek_internal(), ZixRingImpl::read_head, size, ZixRingImpl::size_mask, ZixRingImpl::write_head, and ZIX_READ_BARRIER.

Referenced by LV2AtomPortState::SendToDialog(), and LV2AtomPortState::SendToInstance().

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zix_ring_read_space()

uint32_t zix_ring_read_space

(

const ZixRing *

ring

)

Return the number of bytes of space available for reading.

Definition at line 117 of file ring.cpp.

{
   return read_space_internal(ring, ring->read_head, ring->write_head);
}

References ZixRingImpl::read_head, read_space_internal(), and ZixRingImpl::write_head.

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zix_ring_reset()

void zix_ring_reset

(

ZixRing *

ring

)

Reset (empty) a ring.

This function is NOT thread-safe, it may only be called when there are no readers or writers.

Definition at line 100 of file ring.cpp.

{
   ring->write_head = 0;
   ring->read_head  = 0;
}

References ZixRingImpl::read_head, and ZixRingImpl::write_head.

zix_ring_skip()

uint32_t zix_ring_skip	(	ZixRing *	ring,
		uint32_t	size
	)

Skip data in the ring (advance read head without reading).

Definition at line 187 of file ring.cpp.

{
   const uint32_t r = ring->read_head;
   const uint32_t w = ring->write_head;
   if (read_space_internal(ring, r, w) < size) {
      return 0;
   }
 
   ZIX_READ_BARRIER();
   ring->read_head = (r + size) & ring->size_mask;
   return size;
}

References ZixRingImpl::read_head, read_space_internal(), size, ZixRingImpl::size_mask, ZixRingImpl::write_head, and ZIX_READ_BARRIER.

Referenced by LV2AtomPortState::SendToDialog(), and LV2AtomPortState::SendToInstance().

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zix_ring_write()

uint32_t zix_ring_write	(	ZixRing *	ring,
		const void *	src,
		uint32_t	size
	)

Write data to the ring.

Definition at line 201 of file ring.cpp.

{
   const uint32_t r = ring->read_head;
   const uint32_t w = ring->write_head;
   if (write_space_internal(ring, r, w) < size) {
      return 0;
   }
 
   if (w + size <= ring->size) {
      memcpy(&ring->buf[w], src, size);
      ZIX_WRITE_BARRIER();
      ring->write_head = (w + size) & ring->size_mask;
   } else {
      const uint32_t this_size = ring->size - w;
      memcpy(&ring->buf[w], src, this_size);
      memcpy(&ring->buf[0], (const char*)src + this_size, size - this_size);
      ZIX_WRITE_BARRIER();
      ring->write_head = size - this_size;
   }
 
   return size;
}

References ZixRingImpl::buf, ZixRingImpl::read_head, ZixRingImpl::size, size, ZixRingImpl::size_mask, ZixRingImpl::write_head, write_space_internal(), and ZIX_WRITE_BARRIER.

Referenced by LV2AtomPortState::ReceiveFromDialog(), and LV2AtomPortState::ReceiveFromInstance().

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zix_ring_write_space()

uint32_t zix_ring_write_space

(

const ZixRing *

ring

)

Return the number of bytes of space available for writing.

Definition at line 135 of file ring.cpp.

{
   return write_space_internal(ring, ring->read_head, ring->write_head);
}

References ZixRingImpl::read_head, ZixRingImpl::write_head, and write_space_internal().

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zix_strerror()

static const char * zix_strerror ( const ZixStatus  status )

inlinestatic

Definition at line 66 of file common.h.

{
   switch (status) {
   case ZIX_STATUS_SUCCESS:   return "Success";
   case ZIX_STATUS_ERROR:     return "Unknown error";
   case ZIX_STATUS_NO_MEM:    return "Out of memory";
   case ZIX_STATUS_NOT_FOUND: return "Not found";
   case ZIX_STATUS_EXISTS:    return "Exists";
   case ZIX_STATUS_BAD_ARG:   return "Bad argument";
   case ZIX_STATUS_BAD_PERMS: return "Bad permissions";
   }
   return "Unknown error";
}

References ZIX_STATUS_BAD_ARG, ZIX_STATUS_BAD_PERMS, ZIX_STATUS_ERROR, ZIX_STATUS_EXISTS, ZIX_STATUS_NO_MEM, ZIX_STATUS_NOT_FOUND, and ZIX_STATUS_SUCCESS.