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suricata/src/util-ringbuffer.h

137 lines
4.8 KiB
C

/* Copyright (C) 2007-2010 Open Information Security Foundation
*
* You can copy, redistribute or modify this Program under the terms of
* the GNU General Public License version 2 as published by the Free
* Software Foundation.
*
* This program 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 General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* version 2 along with this program; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
* 02110-1301, USA.
*/
/**
* \file
*
* \author Victor Julien <victor@inliniac.net>
*
* See the .c file for a full explanation.
*/
#ifndef __UTIL_RINGBUFFER_H__
#include "util-atomic.h"
#include "threads.h"
/** When the ringbuffer is full we have two options, either we spin & sleep
* or we use a pthread condition to wait.
*
* \warning this approach isn't working due to a race condition between the
* time it takes for a thread to enter the condwait and the
* signalling. I've obverved the following case: T1 sees that the
* ringbuffer is empty, so it decides to start the wait condition.
* While it is acquiring the lock and entering the wait, T0 puts a
* number of items in the buffer. For each of these it signals T1.
* However, as that thread isn't in the "wait" mode yet, the signals
* are lost. T0 now is done as well and enters it's own wait
* condition. T1 completes it's "wait" initialization. It waits for
* signals, but T0 won't be able to send them as it's waiting itself.
*/
//#define RINGBUFFER_MUTEX_WAIT
/** \brief ring buffer api
*
* Ring buffer api for a single writer and a single reader. It uses a
* read and write pointer. Only the read ptr needs atomic updating.
*/
#define RING_BUFFER_8_SIZE 256
typedef struct RingBuffer8_ {
SC_ATOMIC_DECLARE(unsigned char, write); /**< idx where we put data */
SC_ATOMIC_DECLARE(unsigned char, read); /**< idx where we read data */
uint8_t shutdown;
#ifdef RINGBUFFER_MUTEX_WAIT
SCCondT wait_cond;
SCMutex wait_mutex;
#endif /* RINGBUFFER_MUTEX_WAIT */
SCSpinlock spin; /**< lock protecting writes for multi writer mode*/
void *array[RING_BUFFER_8_SIZE];
} RingBuffer8;
#define RING_BUFFER_16_SIZE 65536
typedef struct RingBuffer16_ {
SC_ATOMIC_DECLARE(unsigned short, write); /**< idx where we put data */
SC_ATOMIC_DECLARE(unsigned short, read); /**< idx where we read data */
uint8_t shutdown;
#ifdef RINGBUFFER_MUTEX_WAIT
SCCondT wait_cond;
SCMutex wait_mutex;
#endif /* RINGBUFFER_MUTEX_WAIT */
SCSpinlock spin; /**< lock protecting writes for multi writer mode*/
void *array[RING_BUFFER_16_SIZE];
} RingBuffer16;
RingBuffer8 *RingBuffer8Init(void);
void RingBuffer8Destroy(RingBuffer8 *);
RingBuffer16 *RingBufferInit(void);
void RingBufferDestroy(RingBuffer16 *);
int RingBufferIsEmpty(RingBuffer16 *);
int RingBufferIsFull(RingBuffer16 *);
uint16_t RingBufferSize(RingBuffer16 *);
void RingBuffer8Shutdown(RingBuffer8 *);
void RingBufferShutdown(RingBuffer16 *);
void RingBufferWait(RingBuffer16 *rb);
/** Single Reader, Single Writer ring buffer, fixed at
* 256 items so we can use unsigned char's that just
* wrap around */
void *RingBufferSrSw8Get(RingBuffer8 *);
int RingBufferSrSw8Put(RingBuffer8 *, void *);
/** Multiple Reader, Single Writer ring buffer, fixed at
* 256 items so we can use unsigned char's that just
* wrap around */
void *RingBufferMrSw8Get(RingBuffer8 *);
int RingBufferMrSw8Put(RingBuffer8 *, void *);
/** Multiple Reader, Single Writer ring buffer, fixed at
* 65536 items so we can use unsigned shorts that just
* wrap around */
void *RingBufferMrSwGet(RingBuffer16 *);
int RingBufferMrSwPut(RingBuffer16 *, void *);
/** Single Reader, Single Writer ring buffer, fixed at
* 65536 items so we can use unsigned shorts that just
* wrap around */
void *RingBufferSrSwGet(RingBuffer16 *);
int RingBufferSrSwPut(RingBuffer16 *, void *);
/** Multiple Reader, Multi Writer ring buffer, fixed at
* 256 items so we can use unsigned char's that just
* wrap around */
void *RingBufferMrMw8Get(RingBuffer8 *);
int RingBufferMrMw8Put(RingBuffer8 *, void *);
/** Multiple Reader, Multi Writer ring buffer, fixed at
* 65536 items so we can use unsigned char's that just
* wrap around */
void *RingBufferMrMwGet(RingBuffer16 *);
void *RingBufferMrMwGetNoWait(RingBuffer16 *);
int RingBufferMrMwPut(RingBuffer16 *, void *);
void *RingBufferSrMw8Get(RingBuffer8 *);
int RingBufferSrMw8Put(RingBuffer8 *, void *);
void DetectRingBufferRegisterTests(void);
#endif /* __UTIL_RINGBUFFER_H__ */