Files
mlib/m-buffer.h
T
Patrick Pelissier 2e3b312fab Fix issue of recursive usage of M_GLOBAL_OPLIST_OR_DEF
Update the way to use the macro to avoid being limited by the
preprocessor limitation.
2018-09-14 20:57:55 +02:00

808 lines
46 KiB
C

/*
* M*LIB - Fixed size BUFFER & STACK interface
*
* Copyright (c) 2017-2018, Patrick Pelissier
* All rights reserved.
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are met:
* + Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* + Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND ANY
* EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
* WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
* DISCLAIMED. IN NO EVENT SHALL THE REGENTS AND CONTRIBUTORS BE LIABLE FOR ANY
* DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
* (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
* LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
* ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
* SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
#ifndef MSTARLIB_BUFFER_H
#define MSTARLIB_BUFFER_H
#include "m-core.h"
#include "m-mutex.h"
#include "m-atomic.h"
/* Define the different kind of policy a buffer can have:
* - the buffer can be either a queue (policy is FIFO) or a stack (policy is FILO),
* - if the push is blocking (waiting for the buffer to has some space) or not,
* - if the pop is blocking (waiting for the buffer to has some space) or not,
* - if both push / pop are blocking,
* - if it shall be thread safe or not (i.e. remove mutex and atomic costs),
* - if the buffer has to be init with empty elements, or if it shall init an element when it is pushed (and moved when popped),
* - if the buffer has to overwrite the last element if the buffer is full,
* - if the pop of an element is not complete until the call to pop_release (preventing push until this call).
*/
typedef enum {
BUFFER_QUEUE = 0, BUFFER_STACK = 1,
BUFFER_BLOCKING_PUSH = 0, BUFFER_UNBLOCKING_PUSH = 2,
BUFFER_BLOCKING_POP = 0, BUFFER_UNBLOCKING_POP = 4,
BUFFER_BLOCKING = 0, BUFFER_UNBLOCKING = 6,
BUFFER_THREAD_SAFE = 0, BUFFER_THREAD_UNSAFE = 8,
BUFFER_PUSH_INIT_POP_MOVE = 16,
BUFFER_PUSH_OVERWRITE = 32,
BUFFER_DEFERRED_POP = 64
} buffer_policy_e;
/* Define a lock based buffer.
USAGE: BUFFER_DEF(name, type, size_of_buffer_or_0, policy[, oplist]) */
#define BUFFER_DEF(name, type, m_size, ... ) \
BUFFERI_DEF(M_IF_NARGS_EQ1(__VA_ARGS__) \
((name, type, m_size,__VA_ARGS__, M_GLOBAL_OPLIST_OR_DEF(__VA_ARGS__)(), M_C(name,_t)), \
(name, type, m_size,__VA_ARGS__, M_C(name,_t))))
/* Define a lock-free queue for Many Producer Many Consummer
Much faster than queue of BUFFER_DEF in heavy communication scenario
Size of created queue can only a power of 2.
*/
#define QUEUE_MPMC_DEF(name, type, ...) \
QUEUEI_MPMC_DEF(M_IF_NARGS_EQ1(__VA_ARGS__) \
((name, type, __VA_ARGS__, M_GLOBAL_OPLIST_OR_DEF(__VA_ARGS__)(), M_C(name,_t)), \
(name, type, __VA_ARGS__, M_C(name,_t))))
/* Define a wait-free queue for Single Producer Single Consummer
Much faster than queue of BUFFER_DEF in heavy communication scenario
Size of created queue can only a power of 2.
*/
#define QUEUE_SPSC_DEF(name, type, ...) \
QUEUEI_SPSC_DEF(M_IF_NARGS_EQ1(__VA_ARGS__) \
((name, type, __VA_ARGS__, M_GLOBAL_OPLIST_OR_DEF(__VA_ARGS__)(), M_C(name,_t)), \
(name, type, __VA_ARGS__, M_C(name,_t))))
/********************************** INTERNAL ************************************/
#define BUFFERI_IF_CTE_SIZE(m_size) M_IF(M_BOOL(m_size))
#define BUFFERI_SIZE(m_size) BUFFERI_IF_CTE_SIZE(m_size) (m_size, v->size)
#define BUFFERI_POLICY_P(policy, val) \
(((policy) & (val)) != 0)
#define BUFFERI_CONTRACT(buffer, size) do { \
assert (buffer != NULL); \
assert (buffer->data != NULL); \
}while (0)
#define BUFFERI_PROTECTED_CONTRACT(buffer, size) do { \
assert (atomic_load(&buffer->number[0]) <= BUFFERI_SIZE(size)); \
} while (0)
#define BUFFERI_DEF(arg) BUFFERI_DEF2 arg
#define BUFFERI_DEF2(name, type, m_size, policy, oplist, buffer_t) \
\
typedef struct M_C(name, _s) { \
m_mutex_t mutexPush; /* MUTEX used for pushing elements */ \
size_t idx_prod; /* Index of the production threads */ \
size_t overwrite; /* Number of overwritten values */ \
m_cond_t there_is_data; /* condition raised when there is data */ \
m_cond_t there_is_room_for_data; /* Cond. raised when there is room */ \
m_mutex_t mutexPop; /* MUTEX used for popping elements */ \
size_t idx_cons; /* Index of the consumption threads */ \
BUFFERI_IF_CTE_SIZE(m_size)( ,size_t size;) /* Size of the buffer */ \
/* number[0] := Number of elements in the buffer */ \
/* number[1] := [OPTION] Number of elements being deferred in the buffer */ \
atomic_ulong number[1 + BUFFERI_POLICY_P(policy, BUFFER_DEFERRED_POP)]; \
/* If fixed size, array of elements, otherwise pointer to element */ \
BUFFERI_IF_CTE_SIZE(m_size)(type data[m_size], type *data); \
} buffer_t[1]; \
typedef struct M_C(name, _s) *M_C(name, _ptr); \
typedef const struct M_C(name, _s) *M_C(name, _srcptr); \
\
static inline void \
M_C(name, _init)(buffer_t v, size_t size) \
{ \
BUFFERI_IF_CTE_SIZE(m_size)(assert(size == m_size), v->size = size); \
v->idx_prod = v->idx_cons = v->overwrite = 0; \
atomic_init (&v->number[0], 0UL); \
if (BUFFERI_POLICY_P(policy, BUFFER_DEFERRED_POP)) \
atomic_init (&v->number[1], 0UL); \
if (!BUFFERI_POLICY_P((policy), BUFFER_THREAD_UNSAFE)) { \
m_mutex_init(v->mutexPush); \
m_mutex_init(v->mutexPop); \
m_cond_init(v->there_is_data); \
m_cond_init(v->there_is_room_for_data); \
} else \
assert(BUFFERI_POLICY_P((policy), BUFFER_UNBLOCKING)); \
BUFFERI_IF_CTE_SIZE(m_size)( , \
v->data = M_CALL_REALLOC(oplist, type, NULL, BUFFERI_SIZE(m_size)); \
if (v->data == NULL) { \
M_MEMORY_FULL (BUFFERI_SIZE(m_size)*sizeof(type)); \
return; \
} \
) \
if (!BUFFERI_POLICY_P((policy), BUFFER_PUSH_INIT_POP_MOVE)) { \
for(size_t i = 0; i < size; i++) { \
M_CALL_INIT(oplist, v->data[i]); \
} \
} \
BUFFERI_CONTRACT(v,m_size); \
} \
\
static inline void \
M_C(name, _int_clear_obj)(buffer_t v) \
{ \
BUFFERI_CONTRACT(v,m_size); \
if (!BUFFERI_POLICY_P((policy), BUFFER_PUSH_INIT_POP_MOVE)) { \
for(size_t i = 0; i < BUFFERI_SIZE(m_size); i++) { \
M_CALL_CLEAR(oplist, v->data[i]); \
} \
} else { \
size_t i = BUFFERI_POLICY_P((policy), BUFFER_STACK) ? 0 : v->idx_cons; \
while (i != v->idx_prod) { \
M_CALL_CLEAR(oplist, v->data[i]); \
i++; \
if (!BUFFERI_POLICY_P((policy), BUFFER_STACK) && i >= BUFFERI_SIZE(m_size)) \
i = 0; \
} \
} \
v->idx_prod = v->idx_cons = 0; \
atomic_store_explicit (&v->number[0], 0UL, memory_order_relaxed); \
if (BUFFERI_POLICY_P(policy, BUFFER_DEFERRED_POP)) \
atomic_store_explicit(&v->number[1], 0UL, memory_order_relaxed); \
BUFFERI_CONTRACT(v,m_size); \
} \
\
static inline void \
M_C(name, _clear)(buffer_t v) \
{ \
BUFFERI_CONTRACT(v,m_size); \
M_C(name, _int_clear_obj)(v); \
BUFFERI_IF_CTE_SIZE(m_size)( , \
M_CALL_FREE(oplist, v->data); \
v->data = NULL; \
) \
v->overwrite = 0; \
if (!BUFFERI_POLICY_P((policy), BUFFER_THREAD_UNSAFE)) { \
m_mutex_clear(v->mutexPush); \
m_mutex_clear(v->mutexPop); \
m_cond_clear(v->there_is_data); \
m_cond_clear(v->there_is_room_for_data); \
} \
} \
\
static inline void \
M_C(name, _clean)(buffer_t v) \
{ \
BUFFERI_CONTRACT(v,m_size); \
if (!BUFFERI_POLICY_P((policy), BUFFER_THREAD_UNSAFE)) { \
m_mutex_lock(v->mutexPush); \
m_mutex_lock(v->mutexPop); \
} \
BUFFERI_PROTECTED_CONTRACT(v, m_size); \
if (BUFFERI_POLICY_P((policy), BUFFER_PUSH_INIT_POP_MOVE)) \
M_C(name, _int_clear_obj)(v); \
v->idx_prod = v->idx_cons = 0; \
atomic_store_explicit (&v->number[0], 0UL, memory_order_relaxed); \
if (BUFFERI_POLICY_P(policy, BUFFER_DEFERRED_POP)) \
atomic_store_explicit(&v->number[1], 0UL, memory_order_relaxed); \
if (!BUFFERI_POLICY_P((policy), BUFFER_THREAD_UNSAFE)) { \
m_cond_broadcast(v->there_is_room_for_data); \
m_mutex_unlock(v->mutexPop); \
m_mutex_unlock(v->mutexPush); \
} \
BUFFERI_CONTRACT(v,m_size); \
} \
\
static inline bool \
M_C(name, _empty_p)(buffer_t v) \
{ \
BUFFERI_CONTRACT(v,m_size); \
/* If the buffer has been configured with deferred pop \
we considered the queue as empty when the number of \
deferred pop has reached 0, not the number of items in the \
buffer is 0. */ \
if (BUFFERI_POLICY_P(policy, BUFFER_DEFERRED_POP)) \
return atomic_load_explicit (&v->number[1], memory_order_relaxed) == 0; \
else \
return atomic_load_explicit (&v->number[0], memory_order_relaxed) == 0; \
} \
\
static inline bool \
M_C(name, _full_p)(buffer_t v) \
{ \
BUFFERI_CONTRACT(v,m_size); \
return atomic_load_explicit (&v->number[0], memory_order_relaxed) \
== BUFFERI_SIZE(m_size); \
} \
\
static inline size_t \
M_C(name, _size)(buffer_t v) \
{ \
BUFFERI_CONTRACT(v,m_size); \
return atomic_load_explicit (&v->number[0], memory_order_relaxed); \
} \
\
static inline bool \
M_C(name, _push_blocking)(buffer_t v, type const data, bool blocking) \
{ \
BUFFERI_CONTRACT(v,m_size); \
\
/* BUFFER lock */ \
if (!BUFFERI_POLICY_P((policy), BUFFER_THREAD_UNSAFE)) { \
m_mutex_lock(v->mutexPush); \
while (!BUFFERI_POLICY_P((policy), BUFFER_PUSH_OVERWRITE) \
&& M_C(name, _full_p)(v)) { \
if (!blocking) { \
m_mutex_unlock(v->mutexPush); \
return false; \
} \
m_cond_wait(v->there_is_room_for_data, v->mutexPush); \
} \
} else if (!BUFFERI_POLICY_P((policy), BUFFER_PUSH_OVERWRITE) \
&& M_C(name, _full_p)(v)) \
return false; \
BUFFERI_PROTECTED_CONTRACT(v, m_size); \
\
size_t previousSize, idx = v->idx_prod; \
/* INDEX computation if we have to overwrite the last element */ \
if (M_UNLIKELY (BUFFERI_POLICY_P((policy), BUFFER_PUSH_OVERWRITE) \
&& M_C(name, _full_p)(v))) { \
v->overwrite++; \
/* Let's overwrite the last element */ \
/* Compute the index of the last push element */ \
idx--; \
if (!BUFFERI_POLICY_P((policy), BUFFER_STACK)) { \
idx = idx >= BUFFERI_SIZE(m_size) ? BUFFERI_SIZE(m_size)-1 : idx; \
} \
/* Update data in the buffer */ \
M_CALL_SET(oplist, v->data[idx], data); \
previousSize = BUFFERI_SIZE(m_size); \
\
} else { \
\
/* Add a new item in the buffer */ \
/* PUSH data in the buffer */ \
if (!BUFFERI_POLICY_P((policy), BUFFER_PUSH_INIT_POP_MOVE)) { \
M_CALL_SET(oplist, v->data[idx], data); \
} else { \
M_CALL_INIT_SET(oplist, v->data[idx], data); \
} \
\
/* Increment production INDEX of the buffer */ \
idx++; \
if (!BUFFERI_POLICY_P((policy), BUFFER_STACK)) { \
idx = (idx == BUFFERI_SIZE(m_size)) ? 0 : idx; \
} \
v->idx_prod = idx; \
\
/* number[] is the only variable which can be modified by both \
the consummer thread which has the pop lock and the producer \
thread which has the push lock. As such, it has to be handled \
like an atomic variable. */ \
/* Increment number of elements of the buffer */ \
previousSize = atomic_fetch_add (&v->number[0], 1UL); \
if (BUFFERI_POLICY_P((policy), BUFFER_DEFERRED_POP)) { \
previousSize = atomic_fetch_add (&v->number[1], 1UL); \
} \
} \
\
/* BUFFER unlock */ \
if (!BUFFERI_POLICY_P((policy), BUFFER_THREAD_UNSAFE)) { \
m_mutex_unlock(v->mutexPush); \
/* If the number of items in the buffer was 0, some consummer \
may be waiting. Signal to them the availibility of the data \
We cannot only signal one thread. */ \
if (previousSize == 0) { \
m_mutex_lock(v->mutexPop); \
m_cond_broadcast(v->there_is_data); \
m_mutex_unlock(v->mutexPop); \
} \
} \
\
BUFFERI_CONTRACT(v,m_size); \
return true; \
} \
\
static inline bool \
M_C(name, _pop_blocking)(type *data, buffer_t v, bool blocking) \
{ \
BUFFERI_CONTRACT(v,m_size); \
assert (data != NULL); \
\
/* BUFFER lock */ \
if (!BUFFERI_POLICY_P((policy), BUFFER_THREAD_UNSAFE)) { \
m_mutex_lock(v->mutexPop); \
while (M_C(name, _empty_p)(v)) { \
if (!blocking) { \
m_mutex_unlock(v->mutexPop); \
return false; \
} \
m_cond_wait(v->there_is_data, v->mutexPop); \
} \
} else if (M_C(name, _empty_p)(v)) \
return false; \
BUFFERI_PROTECTED_CONTRACT(v, m_size); \
\
/* POP data from the buffer and update INDEX */ \
if (!BUFFERI_POLICY_P((policy), BUFFER_STACK)) { \
/* FIFO queue */ \
if (!BUFFERI_POLICY_P((policy), BUFFER_PUSH_INIT_POP_MOVE)) { \
M_CALL_SET(oplist, *data, v->data[v->idx_cons]); \
} else { \
M_DO_INIT_MOVE (oplist, *data, v->data[v->idx_cons]); \
} \
v->idx_cons = (v->idx_cons == BUFFERI_SIZE(m_size)-1) ? 0 : (v->idx_cons + 1); \
} else { \
/* STACK queue */ \
v->idx_prod --; \
if (!BUFFERI_POLICY_P((policy), BUFFER_PUSH_INIT_POP_MOVE)) { \
M_CALL_SET(oplist, *data, v->data[v->idx_prod]); \
} else { \
M_DO_INIT_MOVE (oplist, *data, v->data[v->idx_prod]); \
} \
} \
\
/* number[] is the only variable which can be modified by both \
the consummer thread which has the pop lock and the producer \
thread which has the push lock. As such, it has to be handled \
like an atomic variable. */ \
/* Decrement number of elements in the buffer */ \
size_t previousSize; \
if (!BUFFERI_POLICY_P((policy), BUFFER_DEFERRED_POP)) { \
previousSize = atomic_fetch_sub (&v->number[0], 1UL); \
} else { \
atomic_fetch_sub (&v->number[1], 1UL); \
} \
\
/* BUFFER unlock */ \
if (!BUFFERI_POLICY_P((policy), BUFFER_THREAD_UNSAFE)) { \
m_mutex_unlock(v->mutexPop); \
/* If the number of items in the buffer was the max, some producer \
may be waiting. Signal to them the availibility of the free room \
We cannot only signal one thread. */ \
if ((!BUFFERI_POLICY_P((policy), BUFFER_DEFERRED_POP)) \
&& previousSize == BUFFERI_SIZE(m_size)) { \
m_mutex_lock(v->mutexPush); \
m_cond_broadcast(v->there_is_room_for_data); \
m_mutex_unlock(v->mutexPush); \
} \
} \
\
BUFFERI_CONTRACT(v,m_size); \
return true; \
} \
\
\
static inline bool \
M_C(name, _push)(buffer_t v, type const data) \
{ \
return M_C(name, _push_blocking)(v, data, \
!BUFFERI_POLICY_P((policy), BUFFER_UNBLOCKING_PUSH)); \
} \
\
static inline bool \
M_C(name, _pop)(type *data, buffer_t v) \
{ \
return M_C(name, _pop_blocking)(data, v, \
!BUFFERI_POLICY_P((policy), BUFFER_UNBLOCKING_POP)); \
} \
\
static inline size_t \
M_C(name, _overwrite)(const buffer_t v) \
{ \
return v->overwrite; \
} \
\
static inline size_t \
M_C(name, _capacity)(const buffer_t v) \
{ \
(void) v; /* may be unused */ \
return BUFFERI_SIZE(m_size); \
} \
\
static inline void \
M_C(name, _pop_release)(buffer_t v) \
{ \
/* Decrement the effective number of elements in the buffer */ \
if (BUFFERI_POLICY_P((policy), BUFFER_DEFERRED_POP)) { \
size_t previousSize = atomic_fetch_sub (&v->number[0], 1UL); \
if (previousSize == BUFFERI_SIZE(m_size)) { \
m_mutex_lock(v->mutexPush); \
m_cond_broadcast(v->there_is_room_for_data); \
m_mutex_unlock(v->mutexPush); \
} \
} \
} \
/* Definition of a a QUEUE for Many Produccer / Many Consummer
for high bandwidth scenario:
* lock-free,
* wait-free but only because it accepts to fail spuriously,
* quite fast
* no blocking calls.
* only queue (no stack)
* size of queue is always a power of 2
* no overwriting.
*/
#define QUEUEI_MPMC_DEF(arg) QUEUEI_MPMC_DEF2 arg
#ifdef NDEBUG
# define QUEUEI_MPMC_CONTRACT(v) /* nothing */
#else
# define QUEUEI_MPMC_CONTRACT(v) do { \
assert (v != 0); \
assert (v->Tab != NULL); \
unsigned int _r = atomic_load(&v->ConsoIdx); \
unsigned int _w = atomic_load(&v->ProdIdx); \
_r = atomic_load(&v->ConsoIdx); \
assert (_r > _w || _w-_r <= v->size); \
assert (M_POWEROF2_P(v->size)); \
} while (0)
#endif
#define QUEUEI_MPMC_DEF2(name, type, policy, oplist, buffer_t) \
\
/* The sequence number of an element will be equal to either \
- 2* the index of the production which creates it, \
- 1 + 2* the index of the consumption which consummes it \
In case of overflow, as there is no order comparison but only \
equal comparison, there is no special issue. \
Each element is put in a separate cache line to avoid false \
sharing. \
*/ \
typedef struct M_C(name, _el_s) { \
atomic_uint seq; /* Can only increase until overflow */ \
type x; \
char align[M_ALIGN_FOR_CACHELINE_EXCLUSION > sizeof(atomic_uint)+sizeof(type) ? M_ALIGN_FOR_CACHELINE_EXCLUSION - sizeof(atomic_uint)-sizeof(type) : 1]; \
} M_C(name, _el_t); \
\
/* If there is only one producer and one consummer, then they won't \
typically use the same cache line, increasing performance. */ \
typedef struct M_C(name, _s) { \
atomic_uint ProdIdx; /* Can only increase until overflow */ \
char align1[M_ALIGN_FOR_CACHELINE_EXCLUSION]; \
atomic_uint ConsoIdx; /* Can only increase until overflow */ \
char align2[M_ALIGN_FOR_CACHELINE_EXCLUSION]; \
M_C(name, _el_t) *Tab; \
unsigned int size; \
} buffer_t[1]; \
\
static inline bool \
M_C(name, _push)(buffer_t table, type x) \
{ \
QUEUEI_MPMC_CONTRACT(table); \
unsigned int idx = atomic_load_explicit(&table->ProdIdx, \
memory_order_relaxed); \
const unsigned int i = idx & (table->size -1); \
const unsigned int seq = atomic_load_explicit(&table->Tab[i].seq, \
memory_order_acquire); \
if (M_UNLIKELY (2*(idx - table->size) + 1 != seq)) { \
/* Buffer full (or unlikely preemption). Can not push */ \
return false; \
} \
if (M_UNLIKELY (!atomic_compare_exchange_strong_explicit(&table->ProdIdx, \
&idx, idx+1, memory_order_relaxed, memory_order_relaxed))) { \
/* Thread has been preempted by another one. */ \
return false; \
} \
if (!BUFFERI_POLICY_P((policy), BUFFER_PUSH_INIT_POP_MOVE)) { \
M_CALL_SET(oplist, table->Tab[i].x, x); \
} else { \
M_CALL_INIT_SET(oplist, table->Tab[i].x, x); \
} \
atomic_store_explicit(&table->Tab[i].seq, 2*idx, memory_order_release); \
QUEUEI_MPMC_CONTRACT(table); \
return true; \
} \
\
static inline bool \
M_C(name, _pop)(type *ptr, buffer_t table) \
{ \
QUEUEI_MPMC_CONTRACT(table); \
assert (ptr != NULL); \
unsigned int iC = atomic_load_explicit(&table->ConsoIdx, \
memory_order_relaxed); \
const unsigned int i = (iC & (table->size -1)); \
const unsigned int seq = atomic_load_explicit(&table->Tab[i].seq, \
memory_order_acquire); \
if (seq != 2 * iC) { \
/* Nothing in buffer to consumme (or unlikely preemption) */ \
return false; \
} \
if (M_UNLIKELY (!atomic_compare_exchange_strong_explicit(&table->ConsoIdx, \
&iC, iC+1, memory_order_relaxed, memory_order_relaxed))) { \
/* Thread has been preempted by another one */ \
return false; \
} \
if (!BUFFERI_POLICY_P((policy), BUFFER_PUSH_INIT_POP_MOVE)) { \
M_CALL_SET(oplist, *ptr, table->Tab[i].x); \
} else { \
M_DO_INIT_MOVE (oplist, *ptr, table->Tab[i].x); \
} \
atomic_store_explicit(&table->Tab[i].seq, 2*iC + 1, memory_order_release); \
QUEUEI_MPMC_CONTRACT(table); \
return true; \
} \
\
static inline void \
M_C(name, _init)(buffer_t buffer, size_t size) \
{ \
assert (buffer != NULL); \
assert( M_POWEROF2_P(size)); \
assert (size < UINT_MAX); \
assert(((policy) & (BUFFER_STACK|BUFFER_THREAD_UNSAFE|BUFFER_PUSH_OVERWRITE)) == 0); \
atomic_init(&buffer->ProdIdx, (unsigned int) size); \
atomic_init(&buffer->ConsoIdx, (unsigned int) size); \
buffer->size = size; \
buffer->Tab = M_CALL_REALLOC(oplist, M_C(name, _el_t), NULL, size); \
if (buffer->Tab == NULL) { \
M_MEMORY_FULL (size*sizeof(M_C(name, _el_t) )); \
return; \
} \
for(unsigned int j = 0; j < size; j++) { \
atomic_init(&buffer->Tab[j].seq, 2*j+1U); \
if (!BUFFERI_POLICY_P((policy), BUFFER_PUSH_INIT_POP_MOVE)) { \
M_CALL_INIT(oplist, buffer->Tab[j].x); \
} \
} \
QUEUEI_MPMC_CONTRACT(buffer); \
} \
\
static inline void \
M_C(name, _clear)(buffer_t buffer) \
{ \
QUEUEI_MPMC_CONTRACT(buffer); \
if (!BUFFERI_POLICY_P((policy), BUFFER_PUSH_INIT_POP_MOVE)) { \
for(unsigned int j = 0; j < buffer->size; j++) { \
M_CALL_CLEAR(oplist, buffer->Tab[j].x); \
} \
} else { \
unsigned int iP = atomic_load_explicit(&buffer->ProdIdx, memory_order_relaxed); \
unsigned int i = iP & (buffer->size -1); \
unsigned int iC = atomic_load_explicit(&buffer->ConsoIdx, memory_order_relaxed); \
unsigned int j = iC & (buffer->size -1); \
while (i != j) { \
M_CALL_CLEAR(oplist, buffer->Tab[j].x); \
j++; \
if (j >= buffer->size) \
j = 0; \
} \
} \
M_CALL_FREE(oplist, buffer->Tab); \
buffer->Tab = NULL; /* safer */ \
} \
\
static inline size_t \
M_C(name, _size)(buffer_t table) \
{ \
QUEUEI_MPMC_CONTRACT(table); \
const unsigned int iC = atomic_load_explicit(&table->ConsoIdx, memory_order_relaxed); \
const unsigned int iP = atomic_load_explicit(&table->ProdIdx, memory_order_acquire); \
/* We return an approximation as we can't read both iC & iP atomically \
As we read producer index after consummer index, \
and they are atomic variables without reordering \
producer index is always greater or equal than consumer index \
(or on overflow occurs, in which case as we compute with modulo \
arithmetic, the right result is computed). \
We may return a result which is greater than the size of the queue \
if the function is interrupted a long time between reading iC & \
iP. the function is not protected against it. \
*/ \
return iP-iC; \
} \
\
static inline size_t \
M_C(name, _capacity)(buffer_t v) \
{ \
QUEUEI_MPMC_CONTRACT(v); \
return v->size; \
} \
\
static inline bool \
M_C(name, _empty_p)(buffer_t v) \
{ \
return M_C(name, _size) (v) == 0; \
} \
\
static inline bool \
M_C(name, _full_p)(buffer_t v) \
{ \
return M_C(name, _size)(v) >= v->size; \
} \
/* Definition of a a QUEUE for Single Produccer / Single Consummer
for high bandwidth scenario:
* wait-free,
* quite fast
* no blocking calls.
* only queue (no stack)
* size of queue is always a power of 2
* no overwriting.
*/
#define QUEUEI_SPSC_DEF(arg) QUEUEI_SPSC_DEF2 arg
#ifdef NDEBUG
#define QUEUEI_SPSC_CONTRACT(table) do { } while (0)
#else
#define QUEUEI_SPSC_CONTRACT(table) do { \
assert (table != NULL); \
unsigned int _r = atomic_load(&table->consoIdx); \
unsigned int _w = atomic_load(&table->prodIdx); \
/* Due to overflow we don't have assert (_r <= _w); */ \
_r = atomic_load(&table->consoIdx); \
assert (_r > _w || _w-_r <= table->size); \
assert (M_POWEROF2_P(table->size)); \
} while (0)
#endif
#define QUEUEI_SPSC_DEF2(name, type, policy, oplist, buffer_t) \
\
typedef struct M_C(name, _el_s) { \
type x; \
} M_C(name, _el_t); \
\
typedef struct M_C(name, _s) { \
atomic_uint consoIdx; /* Can only increase until overflow */ \
unsigned int size; \
M_C(name, _el_t) *Tab; \
char align[M_ALIGN_FOR_CACHELINE_EXCLUSION > sizeof(atomic_uint) +sizeof(size_t) + sizeof(void*) ? M_ALIGN_FOR_CACHELINE_EXCLUSION - sizeof(atomic_uint) -sizeof(size_t)-sizeof(void*): 1]; \
atomic_uint prodIdx; /* Can only increase until overflow */ \
} buffer_t[1]; \
\
static inline bool \
M_C(name, _push)(buffer_t table, type x) \
{ \
QUEUEI_SPSC_CONTRACT(table); \
unsigned int r = atomic_load_explicit(&table->consoIdx, \
memory_order_relaxed); \
unsigned int w = atomic_load_explicit(&table->prodIdx, \
memory_order_acquire); \
if (w-r >= table->size) \
return false; \
unsigned int i = w & (table->size -1); \
if (!BUFFERI_POLICY_P((policy), BUFFER_PUSH_INIT_POP_MOVE)) { \
M_CALL_SET(oplist, table->Tab[i].x, x); \
} else { \
M_CALL_INIT_SET(oplist, table->Tab[i].x, x); \
} \
atomic_store_explicit(&table->prodIdx, w+1, memory_order_release); \
QUEUEI_SPSC_CONTRACT(table); \
return true; \
} \
\
static inline bool \
M_C(name, _pop)(type *ptr, buffer_t table) \
{ \
QUEUEI_SPSC_CONTRACT(table); \
assert (ptr != NULL); \
unsigned int w = atomic_load_explicit(&table->prodIdx, \
memory_order_relaxed); \
unsigned int r = atomic_load_explicit(&table->consoIdx, \
memory_order_acquire); \
if (w-r == 0) \
return false; \
unsigned int i = r & (table->size -1); \
if (!BUFFERI_POLICY_P((policy), BUFFER_PUSH_INIT_POP_MOVE)) { \
M_CALL_SET(oplist, *ptr , table->Tab[i].x); \
} else { \
M_DO_INIT_MOVE (oplist, *ptr, table->Tab[i].x); \
} \
atomic_store_explicit(&table->consoIdx, r+1, memory_order_release); \
QUEUEI_SPSC_CONTRACT(table); \
return true; \
} \
\
static inline size_t \
M_C(name, _size)(buffer_t table) \
{ \
QUEUEI_SPSC_CONTRACT(table); \
unsigned int r = atomic_load_explicit(&table->consoIdx, \
memory_order_relaxed); \
unsigned int w = atomic_load_explicit(&table->prodIdx, \
memory_order_acquire); \
/* We return an approximation as we can't read both r & w atomically \
As we read producer index after consummer index, \
and they are atomic variables without reordering \
producer index is always greater or equal than consumer index \
(or on overflow occurs, in which case as we compute with modulo \
arithmetic, the right result is computed). \
We may return a result which is greater than the size of the queue \
if the function is interrupted a long time between reading the \
indexs. The function is not protected against it. \
*/ \
return w-r; \
} \
\
static inline size_t \
M_C(name, _capacity)(buffer_t v) \
{ \
return v->size; \
} \
\
static inline bool \
M_C(name, _empty_p)(buffer_t v) \
{ \
return M_C(name, _size) (v) == 0; \
} \
\
static inline bool \
M_C(name, _full_p)(buffer_t v) \
{ \
return M_C(name, _size)(v) >= v->size; \
} \
\
static inline void \
M_C(name, _init)(buffer_t buffer, size_t size) \
{ \
assert (buffer != NULL); \
assert( M_POWEROF2_P(size)); \
assert (size < UINT_MAX); \
assert(((policy) & (BUFFER_STACK|BUFFER_THREAD_UNSAFE|BUFFER_PUSH_OVERWRITE)) == 0); \
atomic_init(&buffer->prodIdx, (unsigned int) size); \
atomic_init(&buffer->consoIdx, (unsigned int) size); \
buffer->size = size; \
buffer->Tab = M_CALL_REALLOC(oplist, M_C(name, _el_t), NULL, size); \
if (buffer->Tab == NULL) { \
M_MEMORY_FULL (size*sizeof(M_C(name, _el_t) )); \
return; \
} \
if (!BUFFERI_POLICY_P((policy), BUFFER_PUSH_INIT_POP_MOVE)) { \
for(size_t j = 0; j < size; j++) { \
M_CALL_INIT(oplist, buffer->Tab[j].x); \
} \
} \
QUEUEI_SPSC_CONTRACT(buffer); \
} \
\
static inline void \
M_C(name, _clear)(buffer_t buffer) \
{ \
QUEUEI_SPSC_CONTRACT(buffer); \
if (!BUFFERI_POLICY_P((policy), BUFFER_PUSH_INIT_POP_MOVE)) { \
for(unsigned int j = 0; j < buffer->size; j++) { \
M_CALL_CLEAR(oplist, buffer->Tab[j].x); \
} \
} else { \
unsigned int iP = atomic_load_explicit(&buffer->prodIdx, memory_order_relaxed); \
unsigned int i = iP & (buffer->size -1); \
unsigned int iC = atomic_load_explicit(&buffer->consoIdx, memory_order_relaxed); \
unsigned int j = iC & (buffer->size -1); \
while (i != j) { \
M_CALL_CLEAR(oplist, buffer->Tab[j].x); \
j++; \
if (j >= buffer->size) \
j = 0; \
} \
} \
M_CALL_FREE(oplist, buffer->Tab); \
buffer->Tab = NULL; /* safer */ \
} \
\
// NOTE: SET & INIT_SET are deliberatly missing. TBC if it the right way.
// NOTE: There is no oplist defined for this container.
#endif