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/* vim:ts=8:sts=4:sw=4:noai:noexpandtab
*
* basic transmit window.
*
* Copyright (c) 2006 Miru Limited.
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2.1 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
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this library; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*/
#ifndef __PGM_IMPL_TXW_H__
#define __PGM_IMPL_TXW_H__
typedef struct pgm_txw_state_t pgm_txw_state_t;
typedef struct pgm_txw_t pgm_txw_t;
#include <impl/framework.h>
PGM_BEGIN_DECLS
/* must be smaller than PGM skbuff control buffer */
struct pgm_txw_state_t {
uint32_t unfolded_checksum; /* first 32-bit word must be checksum */
unsigned waiting_retransmit:1; /* in retransmit queue */
unsigned retransmit_count:15;
unsigned nak_elimination_count:16;
uint8_t pkt_cnt_requested; /* # parity packets to send */
uint8_t pkt_cnt_sent; /* # parity packets already sent */
};
struct pgm_txw_t {
const pgm_tsi_t* restrict tsi;
/* option: lockless atomics */
volatile uint32_t lead;
volatile uint32_t trail;
pgm_queue_t retransmit_queue;
pgm_rs_t rs;
uint8_t tg_sqn_shift;
struct pgm_sk_buff_t* restrict parity_buffer;
/* Advance with data */
pgm_time_t adv_ivl_expiry;
unsigned increment_window_naks;
unsigned adv_secs; /* TXW_ADV_SECS */
unsigned adv_sqns; /* TXW_ADV_SECS in sequences */
unsigned is_fec_enabled:1;
unsigned adv_mode:1; /* 0 = advance by time, 1 = advance by data */
size_t size; /* window content size in bytes */
unsigned alloc; /* length of pdata[] */
#if defined(__STDC_VERSION__) && (__STDC_VERSION__ >= 199901L)
/* C99 flexible array, sizeof() invalid */
struct pgm_sk_buff_t* pdata[];
#elif !defined(__STDC_VERSION__) || defined(__cplusplus)
/* C90 and older */
struct pgm_sk_buff_t* pdata[1];
#else
/* GNU C variable-length object */
struct pgm_sk_buff_t* pdata[0];
#endif
};
PGM_GNUC_INTERNAL pgm_txw_t* pgm_txw_create (const pgm_tsi_t*const, const uint16_t, const uint32_t, const unsigned, const ssize_t, const bool, const uint8_t, const uint8_t) PGM_GNUC_WARN_UNUSED_RESULT;
PGM_GNUC_INTERNAL void pgm_txw_shutdown (pgm_txw_t*const);
PGM_GNUC_INTERNAL void pgm_txw_add (pgm_txw_t*const restrict, struct pgm_sk_buff_t*const restrict);
PGM_GNUC_INTERNAL struct pgm_sk_buff_t* pgm_txw_peek (const pgm_txw_t*const, const uint32_t) PGM_GNUC_WARN_UNUSED_RESULT;
PGM_GNUC_INTERNAL bool pgm_txw_retransmit_push (pgm_txw_t*const, const uint32_t, const bool, const uint8_t) PGM_GNUC_WARN_UNUSED_RESULT;
PGM_GNUC_INTERNAL struct pgm_sk_buff_t* pgm_txw_retransmit_try_peek (pgm_txw_t*const) PGM_GNUC_WARN_UNUSED_RESULT;
PGM_GNUC_INTERNAL void pgm_txw_retransmit_remove_head (pgm_txw_t*const);
PGM_GNUC_INTERNAL uint32_t pgm_txw_get_unfolded_checksum (const struct pgm_sk_buff_t*const) PGM_GNUC_PURE;
PGM_GNUC_INTERNAL void pgm_txw_set_unfolded_checksum (struct pgm_sk_buff_t*const, const uint32_t);
PGM_GNUC_INTERNAL void pgm_txw_inc_retransmit_count (struct pgm_sk_buff_t*const);
PGM_GNUC_INTERNAL bool pgm_txw_retransmit_is_empty (const pgm_txw_t*const) PGM_GNUC_WARN_UNUSED_RESULT;
/* declare for GCC attributes */
static inline size_t pgm_txw_max_length (const pgm_txw_t*const) PGM_GNUC_WARN_UNUSED_RESULT;
static inline uint32_t pgm_txw_length (const pgm_txw_t*const) PGM_GNUC_WARN_UNUSED_RESULT;
static inline size_t pgm_txw_size (const pgm_txw_t*const) PGM_GNUC_WARN_UNUSED_RESULT;
static inline bool pgm_txw_is_empty (const pgm_txw_t* const) PGM_GNUC_WARN_UNUSED_RESULT;
static inline bool pgm_txw_is_full (const pgm_txw_t* const) PGM_GNUC_WARN_UNUSED_RESULT;
static inline uint32_t pgm_txw_lead (const pgm_txw_t* const) PGM_GNUC_WARN_UNUSED_RESULT;
static inline uint32_t pgm_txw_lead_atomic (const pgm_txw_t* const) PGM_GNUC_WARN_UNUSED_RESULT;
static inline uint32_t pgm_txw_next_lead (const pgm_txw_t* const) PGM_GNUC_WARN_UNUSED_RESULT;
static inline uint32_t pgm_txw_trail (const pgm_txw_t* const) PGM_GNUC_WARN_UNUSED_RESULT;
static inline uint32_t pgm_txw_trail_atomic (const pgm_txw_t* const) PGM_GNUC_WARN_UNUSED_RESULT;
static inline
size_t
pgm_txw_max_length (
const pgm_txw_t*const window
)
{
pgm_assert (NULL != window);
return window->alloc;
}
static inline
uint32_t
pgm_txw_length (
const pgm_txw_t*const window
)
{
pgm_assert (NULL != window);
return ( 1 + window->lead ) - window->trail;
}
static inline
size_t
pgm_txw_size (
const pgm_txw_t*const window
)
{
pgm_assert (NULL != window);
return window->size;
}
static inline
bool
pgm_txw_is_empty (
const pgm_txw_t*const window
)
{
pgm_assert (NULL != window);
return (0 == pgm_txw_length (window));
}
static inline
bool
pgm_txw_is_full (
const pgm_txw_t*const window
)
{
pgm_assert (NULL != window);
return (pgm_txw_length (window) == pgm_txw_max_length (window));
}
static inline
uint32_t
pgm_txw_lead (
const pgm_txw_t*const window
)
{
pgm_assert (NULL != window);
return window->lead;
}
/* atomics may rely on global variables and so cannot be defined __pure__ */
static inline
uint32_t
pgm_txw_lead_atomic (
const pgm_txw_t*const window
)
{
pgm_assert (NULL != window);
return pgm_atomic_read32 (&window->lead);
}
static inline
uint32_t
pgm_txw_next_lead (
const pgm_txw_t*const window
)
{
pgm_assert (NULL != window);
return (uint32_t)(pgm_txw_lead (window) + 1);
}
static inline
uint32_t
pgm_txw_trail (
const pgm_txw_t*const window
)
{
pgm_assert (NULL != window);
return window->trail;
}
static inline
uint32_t
pgm_txw_trail_atomic (
const pgm_txw_t*const window
)
{
pgm_assert (NULL != window);
return pgm_atomic_read32 (&window->trail);
}
PGM_END_DECLS
#endif /* __PGM_IMPL_TXW_H__ */
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