rename ring_buffer to ringbuffer and remove previous attempt

1 files changed, 0 insertions, 174 deletions

diff --git a/lf_ring_buffer.c b/lf_ring_buffer.c
deleted file mode 100644
index 606e29a..0000000
--- a/lf_ring_buffer.c
+++ /dev/null
@@ -1,174 +0,0 @@
-/*
- * File     : lf_ring_buffer.c
- * Author   : Jérémy Zurcher  <jeremy@asynk.ch>
- * Date     : 05/01/010
- * License  :
- *
- *  Permission is hereby granted, free of charge, to any person obtaining
- *  a copy of this software and associated documentation files (the
- *  "Software"), to deal in the Software without restriction, including
- *  without limitation the rights to use, copy, modify, merge, publish,
- *  distribute, sublicense, and/or sell copies of the Software, and to
- *  permit persons to whom the Software is furnished to do so, subject to
- *  the following conditions:
- *  
- *  The above copyright notice and this permission notice shall be
- *  included in all copies or substantial portions of the Software.
- *  
- *  THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
- *  EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
- *  MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
- *  NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
- *  LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
- *  OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
- *  WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
- *
- */
-
-#include "lf_ring_buffer.h"
-#include "lf_portable_cas.h"
-#include <stdlib.h>
-#include <string.h>
-#include <time.h>
-
-//#define DEBUG_LFRB_KO 1
-//#define DEBUG_LFRB_CAS 1
-//#define DEBUG_LFRB 1
-
-#ifdef DEBUG_LFRB
-    #include <stdio.h>
-    #define _LOG_KO_( ... ) fprintf(stdout,__VA_ARGS__)
-    #define _LOG_CAS_( ... ) fprintf(stdout,__VA_ARGS__)
-#elif defined DEBUG_LFRB_CAS
-    #include <stdio.h>
-    #define _LOG_KO_( ... )
-    #define _LOG_CAS_( ... ) fprintf(stdout,__VA_ARGS__)
-#elif defined DEBUG_LFRB_KO
-    #include <stdio.h>
-    #define _LOG_KO_( ... ) fprintf(stdout,__VA_ARGS__)
-    #define _LOG_CAS_( ... )
-#else
-    #define _LOG_KO_( ... )
-    #define _LOG_CAS_( ... )
-#endif
-
-#define BACKOFF_NANO_SLEEP  100000
-
-/* initialize an empty lf_ring_buffer struct */
-lf_ring_buffer_t* lf_ring_buffer_create( size_t n_buf ) {
-    /* alloc ring_buffer struct */
-    lf_ring_buffer_t *r = malloc(sizeof(lf_ring_buffer_t));
-    if(r==NULL) return NULL;
-    /* */
-    r->buffer = malloc(LFRB_BUFFER_SIZE*n_buf);
-    if(r->buffer==NULL) {
-        free(r);
-        return NULL;
-    }
-    memset(r->buffer,0,LFRB_BUFFER_SIZE*n_buf);
-    r->n_buf = n_buf;
-    r->read_from = -1;
-    r->write_to = 0;
-    return r;
-}
-
-/* destroy an lf_ring_buffer strcture */
-void lf_ring_buffer_destroy( lf_ring_buffer_t *r ) {
-    free(r->buffer);
-    free(r);
-}
-
-/* return 1 if is empty */
-int lf_ring_buffer_empty( lf_ring_buffer_t *r ) { return r->read_from==-1; }
-
-/* write data into the ring buffer */
-int lf_ring_buffer_write( lf_ring_buffer_t *r, void *data, int flags ) {
-    int write_to, read_from, next;
-    struct timespec backoff;
-    int backoff_time = BACKOFF_NANO_SLEEP;
-    /* reserve a buffer */
-    for(;;){
-        write_to = r->write_to;
-        read_from = r->read_from;
-        if(LFRB_IS_AVAILABLE( r->buffer[write_to] ) ) {
-            /* read_from==write_to means that the buffer is full and that a writer thread which at first reserved this buffer
-             * hasn't had enough CPU cycles to call MARK_AS_FILLED
-             */
-            if( read_from!=write_to ) {
-                next = write_to+1;
-                if (next==r->n_buf) next=0;
-                /* what might have happend between IS_AVAILABLE and now :
-                * - a writter has reserved this buffer => write_to has moved => CAS fails
-                * - a reader has consumed a buffer => read_from has moved => we've got more space
-                */
-                _LOG_CAS_( "write: CAS %d %d %d\n", r->write_to, write_to, next );
-                if( CompareAndSwapInt( &r->write_to, write_to, next ) ) {
-                    /* !!!!!!!!!!!!!! WARNING !!!!!!!!!!!!!!!!!
-                     * - if the ring is empty before this write operation (r->read_from==-1 or latest idx)
-                     * - and n_buf other threads execute this same function before the next CAS is finished
-                     * then, the last thread will :
-                     * - see this buffer as available
-                     * - and see the ring as empty instead of full !!!!!
-                     * so it will ends with two threads writing on this buffer
-                     */
-                    if(r->read_from==-1) CompareAndSwapInt( &r->read_from, -1, write_to );
-                    break;
-                }
-            } else {
-                _LOG_KO_("write: ring full %d %d\n",r->read_from,idx);
-                if(IS_NOT_BLOCKING(flags)) return -1;
-                backoff.tv_sec = 0;
-                backoff.tv_nsec = backoff_time;
-                nanosleep(&backoff,NULL);
-            }
-        } else {
-            _LOG_KO_("write: buffer not available\n");
-            if(IS_NOT_BLOCKING(flags)) return -1;
-            backoff.tv_sec = 0;
-            backoff.tv_nsec = backoff_time;
-            nanosleep(&backoff,NULL);
-        }
-        backoff_time += BACKOFF_NANO_SLEEP;
-    }
-    /* fill this buffer and mark it as filled */
-    memcpy( LFRB_DATA_PTR(r->buffer[write_to]), data, LFRB_DATA_SIZE );
-    LFRB_MARK_AS_FILLED( r->buffer[write_to] );
-    return 0;
-}
-
-/* read data from the ring buffer */
-int lf_ring_buffer_read( lf_ring_buffer_t *r, void *data, int flags ) {
-    int write_to, read_from, next;
-    struct timespec backoff;
-    int backoff_time = BACKOFF_NANO_SLEEP;
-    for(;;) {
-        write_to = r->write_to;
-        read_from = r->read_from;
-        if( !(LFRB_IS_AVAILABLE( r->buffer[read_from] )) && read_from!=-1 ) {
-            next = read_from+1;
-            if (next==r->n_buf) next=0;
-            /* will do bad things if data dst buffer is too small !! */
-            memcpy( data, LFRB_DATA_PTR(r->buffer[read_from]), LFRB_DATA_SIZE );
-            _LOG_CAS_( "read: CAS %d %d %d\n", r->read_from, read_from, next );
-            if( CompareAndSwapInt( &r->read_from, read_from, next ) ) {
-                if(r->read_from==r->write_to) {
-                    /* the buffer is empty but writers will see it as full */
-                    _LOG_CAS_( "read: empty CAS %d %d %d\n", r->read_from, next, -1 );
-                    CompareAndSwapInt( &r->read_from, next, -1 );
-                }
-                break;
-            }
-        }
-
-        _LOG_KO_("read: ring empty\n");
-        if(IS_NOT_BLOCKING(flags)) return -1;
-        backoff.tv_sec = 0;
-        backoff.tv_nsec = backoff_time;
-        nanosleep(&backoff,NULL);
-        backoff_time += BACKOFF_NANO_SLEEP;
-    }
-    /* finish the read process */
-    LFRB_MARK_AS_READ( r->buffer[read_from] );
-    return 0;
-}
-