aboutsummaryrefslogtreecommitdiffstats
path: root/Alc/alcRing.c
diff options
context:
space:
mode:
Diffstat (limited to 'Alc/alcRing.c')
-rw-r--r--Alc/alcRing.c317
1 files changed, 0 insertions, 317 deletions
diff --git a/Alc/alcRing.c b/Alc/alcRing.c
deleted file mode 100644
index d72b34f1..00000000
--- a/Alc/alcRing.c
+++ /dev/null
@@ -1,317 +0,0 @@
-/**
- * OpenAL cross platform audio library
- * Copyright (C) 1999-2007 by authors.
- * This library is free software; you can redistribute it and/or
- * modify it under the terms of the GNU Library General Public
- * License as published by the Free Software Foundation; either
- * version 2 of the License, or (at your option) any later version.
- *
- * This library is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
- * Library General Public License for more details.
- *
- * You should have received a copy of the GNU Library General Public
- * License along with this library; if not, write to the
- * Free Software Foundation, Inc.,
- * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
- * Or go to http://www.gnu.org/copyleft/lgpl.html
- */
-
-#include "config.h"
-
-#include <string.h>
-#include <stdlib.h>
-
-#include "alMain.h"
-#include "threads.h"
-#include "almalloc.h"
-#include "compat.h"
-
-
-/* NOTE: This lockless ringbuffer implementation is copied from JACK, extended
- * to include an element size. Consequently, parameters and return values for a
- * size or count is in 'elements', not bytes. Additionally, it only supports
- * single-consumer/single-provider operation. */
-struct ll_ringbuffer {
- ATOMIC(size_t) write_ptr;
- ATOMIC(size_t) read_ptr;
- size_t size;
- size_t size_mask;
- size_t elem_size;
- int mlocked;
-
- alignas(16) char buf[];
-};
-
-/* Create a new ringbuffer to hold at least `sz' elements of `elem_sz' bytes.
- * The number of elements is rounded up to the next power of two. */
-ll_ringbuffer_t *ll_ringbuffer_create(size_t sz, size_t elem_sz)
-{
- ll_ringbuffer_t *rb;
- ALuint power_of_two;
-
- power_of_two = NextPowerOf2(sz);
- if(power_of_two < sz)
- return NULL;
-
- rb = al_malloc(16, sizeof(*rb) + power_of_two*elem_sz);
- if(!rb) return NULL;
-
- ATOMIC_INIT(&rb->write_ptr, 0);
- ATOMIC_INIT(&rb->read_ptr, 0);
- rb->size = power_of_two;
- rb->size_mask = rb->size - 1;
- rb->elem_size = elem_sz;
- rb->mlocked = 0;
- return rb;
-}
-
-/* Free all data associated with the ringbuffer `rb'. */
-void ll_ringbuffer_free(ll_ringbuffer_t *rb)
-{
- if(rb)
- {
-#ifdef USE_MLOCK
- if(rb->mlocked)
- munlock(rb, sizeof(*rb) + rb->size*rb->elem_size);
-#endif /* USE_MLOCK */
- al_free(rb);
- }
-}
-
-/* Lock the data block of `rb' using the system call 'mlock'. */
-int ll_ringbuffer_mlock(ll_ringbuffer_t *rb)
-{
-#ifdef USE_MLOCK
- if(!rb->mlocked && mlock(rb, sizeof(*rb) + rb->size*rb->elem_size))
- return -1;
-#endif /* USE_MLOCK */
- rb->mlocked = 1;
- return 0;
-}
-
-/* Reset the read and write pointers to zero. This is not thread safe. */
-void ll_ringbuffer_reset(ll_ringbuffer_t *rb)
-{
- ATOMIC_STORE(&rb->write_ptr, 0, almemory_order_release);
- ATOMIC_STORE(&rb->read_ptr, 0, almemory_order_release);
- memset(rb->buf, 0, rb->size*rb->elem_size);
-}
-
-/* Return the number of elements available for reading. This is the number of
- * elements in front of the read pointer and behind the write pointer. */
-size_t ll_ringbuffer_read_space(const ll_ringbuffer_t *rb)
-{
- size_t w = ATOMIC_LOAD(&CONST_CAST(ll_ringbuffer_t*,rb)->write_ptr, almemory_order_acquire);
- size_t r = ATOMIC_LOAD(&CONST_CAST(ll_ringbuffer_t*,rb)->read_ptr, almemory_order_acquire);
- return (w-r) & rb->size_mask;
-}
-/* Return the number of elements available for writing. This is the number of
- * elements in front of the write pointer and behind the read pointer. */
-size_t ll_ringbuffer_write_space(const ll_ringbuffer_t *rb)
-{
- size_t w = ATOMIC_LOAD(&CONST_CAST(ll_ringbuffer_t*,rb)->write_ptr, almemory_order_acquire);
- size_t r = ATOMIC_LOAD(&CONST_CAST(ll_ringbuffer_t*,rb)->read_ptr, almemory_order_acquire);
- return (r-w-1) & rb->size_mask;
-}
-
-/* The copying data reader. Copy at most `cnt' elements from `rb' to `dest'.
- * Returns the actual number of elements copied. */
-size_t ll_ringbuffer_read(ll_ringbuffer_t *rb, char *dest, size_t cnt)
-{
- size_t read_ptr;
- size_t free_cnt;
- size_t cnt2;
- size_t to_read;
- size_t n1, n2;
-
- free_cnt = ll_ringbuffer_read_space(rb);
- if(free_cnt == 0) return 0;
-
- to_read = (cnt > free_cnt) ? free_cnt : cnt;
- read_ptr = ATOMIC_LOAD(&rb->read_ptr, almemory_order_relaxed) & rb->size_mask;
-
- cnt2 = read_ptr + to_read;
- if(cnt2 > rb->size)
- {
- n1 = rb->size - read_ptr;
- n2 = cnt2 & rb->size_mask;
- }
- else
- {
- n1 = to_read;
- n2 = 0;
- }
-
- memcpy(dest, &rb->buf[read_ptr*rb->elem_size], n1*rb->elem_size);
- read_ptr += n1;
- if(n2)
- {
- memcpy(dest + n1*rb->elem_size, &rb->buf[(read_ptr&rb->size_mask)*rb->elem_size],
- n2*rb->elem_size);
- read_ptr += n2;
- }
- ATOMIC_STORE(&rb->read_ptr, read_ptr, almemory_order_release);
- return to_read;
-}
-
-/* The copying data reader w/o read pointer advance. Copy at most `cnt'
- * elements from `rb' to `dest'. Returns the actual number of elements copied.
- */
-size_t ll_ringbuffer_peek(ll_ringbuffer_t *rb, char *dest, size_t cnt)
-{
- size_t free_cnt;
- size_t cnt2;
- size_t to_read;
- size_t n1, n2;
- size_t read_ptr;
-
- free_cnt = ll_ringbuffer_read_space(rb);
- if(free_cnt == 0) return 0;
-
- to_read = (cnt > free_cnt) ? free_cnt : cnt;
- read_ptr = ATOMIC_LOAD(&rb->read_ptr, almemory_order_relaxed) & rb->size_mask;
-
- cnt2 = read_ptr + to_read;
- if(cnt2 > rb->size)
- {
- n1 = rb->size - read_ptr;
- n2 = cnt2 & rb->size_mask;
- }
- else
- {
- n1 = to_read;
- n2 = 0;
- }
-
- memcpy(dest, &rb->buf[read_ptr*rb->elem_size], n1*rb->elem_size);
- if(n2)
- {
- read_ptr += n1;
- memcpy(dest + n1*rb->elem_size, &rb->buf[(read_ptr&rb->size_mask)*rb->elem_size],
- n2*rb->elem_size);
- }
- return to_read;
-}
-
-/* The copying data writer. Copy at most `cnt' elements to `rb' from `src'.
- * Returns the actual number of elements copied. */
-size_t ll_ringbuffer_write(ll_ringbuffer_t *rb, const char *src, size_t cnt)
-{
- size_t write_ptr;
- size_t free_cnt;
- size_t cnt2;
- size_t to_write;
- size_t n1, n2;
-
- free_cnt = ll_ringbuffer_write_space(rb);
- if(free_cnt == 0) return 0;
-
- to_write = (cnt > free_cnt) ? free_cnt : cnt;
- write_ptr = ATOMIC_LOAD(&rb->write_ptr, almemory_order_relaxed) & rb->size_mask;
-
- cnt2 = write_ptr + to_write;
- if(cnt2 > rb->size)
- {
- n1 = rb->size - write_ptr;
- n2 = cnt2 & rb->size_mask;
- }
- else
- {
- n1 = to_write;
- n2 = 0;
- }
-
- memcpy(&rb->buf[write_ptr*rb->elem_size], src, n1*rb->elem_size);
- write_ptr += n1;
- if(n2)
- {
- memcpy(&rb->buf[(write_ptr&rb->size_mask)*rb->elem_size], src + n1*rb->elem_size,
- n2*rb->elem_size);
- write_ptr += n2;
- }
- ATOMIC_STORE(&rb->write_ptr, write_ptr, almemory_order_release);
- return to_write;
-}
-
-/* Advance the read pointer `cnt' places. */
-void ll_ringbuffer_read_advance(ll_ringbuffer_t *rb, size_t cnt)
-{
- ATOMIC_ADD(&rb->read_ptr, cnt, almemory_order_acq_rel);
-}
-
-/* Advance the write pointer `cnt' places. */
-void ll_ringbuffer_write_advance(ll_ringbuffer_t *rb, size_t cnt)
-{
- ATOMIC_ADD(&rb->write_ptr, cnt, almemory_order_acq_rel);
-}
-
-/* The non-copying data reader. `vec' is an array of two places. Set the values
- * at `vec' to hold the current readable data at `rb'. If the readable data is
- * in one segment the second segment has zero length. */
-void ll_ringbuffer_get_read_vector(const ll_ringbuffer_t *rb, ll_ringbuffer_data_t * vec)
-{
- size_t free_cnt;
- size_t cnt2;
- size_t w, r;
-
- w = ATOMIC_LOAD(&CONST_CAST(ll_ringbuffer_t*,rb)->write_ptr, almemory_order_acquire);
- r = ATOMIC_LOAD(&CONST_CAST(ll_ringbuffer_t*,rb)->read_ptr, almemory_order_acquire);
- w &= rb->size_mask;
- r &= rb->size_mask;
- free_cnt = (w-r) & rb->size_mask;
-
- cnt2 = r + free_cnt;
- if(cnt2 > rb->size)
- {
- /* Two part vector: the rest of the buffer after the current write ptr,
- * plus some from the start of the buffer. */
- vec[0].buf = (char*)&rb->buf[r*rb->elem_size];
- vec[0].len = rb->size - r;
- vec[1].buf = (char*)rb->buf;
- vec[1].len = cnt2 & rb->size_mask;
- }
- else
- {
- /* Single part vector: just the rest of the buffer */
- vec[0].buf = (char*)&rb->buf[r*rb->elem_size];
- vec[0].len = free_cnt;
- vec[1].buf = NULL;
- vec[1].len = 0;
- }
-}
-
-/* The non-copying data writer. `vec' is an array of two places. Set the values
- * at `vec' to hold the current writeable data at `rb'. If the writeable data
- * is in one segment the second segment has zero length. */
-void ll_ringbuffer_get_write_vector(const ll_ringbuffer_t *rb, ll_ringbuffer_data_t *vec)
-{
- size_t free_cnt;
- size_t cnt2;
- size_t w, r;
-
- w = ATOMIC_LOAD(&CONST_CAST(ll_ringbuffer_t*,rb)->write_ptr, almemory_order_acquire);
- r = ATOMIC_LOAD(&CONST_CAST(ll_ringbuffer_t*,rb)->read_ptr, almemory_order_acquire);
- w &= rb->size_mask;
- r &= rb->size_mask;
- free_cnt = (r-w-1) & rb->size_mask;
-
- cnt2 = w + free_cnt;
- if(cnt2 > rb->size)
- {
- /* Two part vector: the rest of the buffer after the current write ptr,
- * plus some from the start of the buffer. */
- vec[0].buf = (char*)&rb->buf[w*rb->elem_size];
- vec[0].len = rb->size - w;
- vec[1].buf = (char*)rb->buf;
- vec[1].len = cnt2 & rb->size_mask;
- }
- else
- {
- vec[0].buf = (char*)&rb->buf[w*rb->elem_size];
- vec[0].len = free_cnt;
- vec[1].buf = NULL;
- vec[1].len = 0;
- }
-}
generated by cgit v1.2.3 (git 2.39.1) at 2024-11-29 19:43:41 +0000