From 3832b25f308279539a3748bafdc5056d16e4b291 Mon Sep 17 00:00:00 2001 From: Chris Robinson Date: Thu, 11 Jan 2018 09:16:28 -0800 Subject: Move the ringbuffer declarations to a separate header And rename alcRing.c to ringbuffer.c for consistency. --- Alc/alcRing.c | 317 ---------------------------------------------------------- 1 file changed, 317 deletions(-) delete mode 100644 Alc/alcRing.c (limited to 'Alc/alcRing.c') 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 -#include - -#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; - } -} -- cgit v1.2.3