/* * M*LIB - SNAPSHOT Module * * Copyright (c) 2017-2020, 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_SNAPSHOT #define MSTARLIB_SNAPSHOT #include "m-atomic.h" #include "m-core.h" #include "m-genint.h" /* Define a Single Producer Single Consummer snapshot and its functions USAGE: SNAPSHOT_SPSC_DEF(name, type[, oplist]) */ #define SNAPSHOT_SPSC_DEF(name, ...) \ SNAPSHOTI_SPSC_DEF_P1(M_IF_NARGS_EQ1(__VA_ARGS__) \ ((name, __VA_ARGS__, M_GLOBAL_OPLIST_OR_DEF(__VA_ARGS__)() ), \ (name, __VA_ARGS__ ))) /* Define a Single Producer Multiple Consummer snapshot and its functions USAGE: SNAPSHOT_SPMC_DEF(name, type[, oplist]) */ #define SNAPSHOT_SPMC_DEF(name, ...) \ SNAPSHOTI_SPMC_DEF_P1(M_IF_NARGS_EQ1(__VA_ARGS__) \ ((name, __VA_ARGS__, M_GLOBAL_OPLIST_OR_DEF(__VA_ARGS__)() ), \ (name, __VA_ARGS__ ))) /* Define a Multiple Producer Multiple Consummer snapshot and its functions USAGE: SNAPSHOT_MPMC_DEF(name, type[, oplist]) */ #define SNAPSHOT_MPMC_DEF(name, ...) \ SNAPSHOTI_MPMC_DEF_P1(M_IF_NARGS_EQ1(__VA_ARGS__) \ ((name, __VA_ARGS__, M_GLOBAL_OPLIST_OR_DEF(__VA_ARGS__)() ), \ (name, __VA_ARGS__ ))) /* Define the oplist of a snapshot (SPSC, SPMC or MPMC). USAGE: SNAPSHOT_OPLIST(name[, oplist]) */ #define SNAPSHOT_OPLIST(...) \ SNAPSHOTI_OPLIST_P1(M_IF_NARGS_EQ1(__VA_ARGS__) \ ((__VA_ARGS__, M_GLOBAL_OPLIST_OR_DEF(__VA_ARGS__)() ), \ (__VA_ARGS__ ))) /********************************** INTERNAL ************************************/ // deferred evaluation of the input #define SNAPSHOTI_OPLIST_P1(arg) SNAPSHOTI_OPLIST_P2 arg /* Validation of the given oplist */ #define SNAPSHOTI_OPLIST_P2(name, oplist) \ M_IF_OPLIST(oplist)(SNAPSHOTI_OPLIST_P3, SNAPSHOTI_OPLIST_FAILURE)(name, oplist) /* Prepare a clean compilation failure */ #define SNAPSHOTI_OPLIST_FAILURE(name, oplist) \ ((M_LIB_ERROR(ARGUMENT_OF_SNAPSHOT_OPLIST_IS_NOT_AN_OPLIST, name, oplist))) /* Define the oplist of a snapshot */ #define SNAPSHOTI_OPLIST_P3(name, oplist) \ (INIT(M_C(name, _init)) \ ,INIT_SET(M_C(name, _init_set)) \ ,SET(M_C(name, _set)) \ ,CLEAR(M_C(name, _clear)) \ ,TYPE(M_C(name, _t)) \ ,SUBTYPE(M_C(name_, type_t)) \ ,OPLIST(oplist) \ ,M_IF_METHOD(INIT_MOVE, oplist)(INIT_MOVE(M_C(name, _init_move)),) \ ,M_IF_METHOD(MOVE, oplist)(MOVE(M_C(name, _move)),) \ ) /******************************** INTERNAL SPSC **********************************/ /* Flag defining the atomic state of a snapshot: * - r: Index of the read buffer Range [0..2] * - w: Index of the write buffer Range [0..2] * - f: Next index of the write buffer when a shot is taken Range [0..2] * - b: Boolean indicating that the read buffer shall be updated * all fields packed in an unsigned char type. */ #define SNAPSHOTI_SPSC_FLAG(r, w, f, b) \ ((unsigned char)( ( (r) << 4) | ((w) << 2) | ((f)) | ((b) << 6))) #define SNAPSHOTI_SPSC_R(flags) \ (((unsigned int) (flags) >> 4) & 0x03u) #define SNAPSHOTI_SPSC_W(flags) \ (((unsigned int) (flags) >> 2) & 0x03u) #define SNAPSHOTI_SPSC_F(flags) \ (((unsigned int) (flags) >> 0) & 0x03u) #define SNAPSHOTI_SPSC_B(flags) \ (((unsigned int) (flags) >> 6) & 0x01u) /* NOTE: Due to atomic_load only accepting non-const pointer, we can't have any const in the interface. */ #define SNAPSHOTI_SPSC_FLAGS_CONTRACT(flags) \ assert(SNAPSHOTI_SPSC_R(flags) != SNAPSHOTI_SPSC_W(flags) \ && SNAPSHOTI_SPSC_R(flags) != SNAPSHOTI_SPSC_F(flags) \ && SNAPSHOTI_SPSC_W(flags) != SNAPSHOTI_SPSC_F(flags)) #define SNAPSHOTI_SPSC_CONTRACT(snap) do { \ assert((snap) != NULL); \ unsigned char f = atomic_load (&(snap)->flags); \ SNAPSHOTI_SPSC_FLAGS_CONTRACT(f); \ } while (0) // A snapshot is basically an atomic triple buffer (Lock Free) // between a single producer thread and a single consummer thread. #define SNAPSHOTI_SPSC_MAX_BUFFER 3 // Defered evaluation of the arguments. #define SNAPSHOTI_SPSC_DEF_P1(arg) SNAPSHOTI_SPSC_DEF_P2 arg /* Validate the oplist before going further */ #define SNAPSHOTI_SPSC_DEF_P2(name, type, oplist) \ M_IF_OPLIST(oplist)(SNAPSHOTI_SPSC_DEF_P3, SNAPSHOTI_SPSC_DEF_FAILURE)(name, type, oplist) /* Stop processing with a compilation failure */ #define SNAPSHOTI_SPSC_DEF_FAILURE(name, type, oplist) \ M_STATIC_FAILURE(M_LIB_NOT_AN_OPLIST, "(SNAPSHOT_SPSC_DEF): the given argument is not a valid oplist: " #oplist) #define SNAPSHOTI_SPSC_DEF_P3(name, type, oplist) \ \ /* Create an aligned type to avoid false sharing between threads */ \ typedef struct M_C(name, _aligned_type_s) { \ type x; \ M_CACHELINE_ALIGN(align, type); \ } M_C(name, _aligned_type_t); \ \ typedef struct M_C(name, _s) { \ M_C(name, _aligned_type_t) data[SNAPSHOTI_SPSC_MAX_BUFFER]; \ atomic_uchar flags; \ } M_C(name, _t)[1]; \ typedef struct M_C(name, _s) *M_C(name, _ptr); \ typedef const struct M_C(name, _s) *M_C(name, _srcptr); \ \ typedef type M_C(name, _type_t); \ \ M_CHECK_COMPATIBLE_OPLIST(name, 1, type, oplist) \ \ static inline void M_C(name, _init)(M_C(name, _t) snap) \ { \ assert(snap != NULL); \ for(int i = 0; i < SNAPSHOTI_SPSC_MAX_BUFFER; i++) { \ M_CALL_INIT(oplist, snap->data[i].x); \ } \ atomic_init (&snap->flags, SNAPSHOTI_SPSC_FLAG(0, 1, 2, 0)); \ SNAPSHOTI_SPSC_CONTRACT(snap); \ } \ \ static inline void M_C(name, _clear)(M_C(name, _t) snap) \ { \ SNAPSHOTI_SPSC_CONTRACT(snap); \ for(int i = 0; i < SNAPSHOTI_SPSC_MAX_BUFFER; i++) { \ M_CALL_CLEAR(oplist, snap->data[i].x); \ } \ } \ \ static inline void M_C(name, _init_set)(M_C(name, _t) snap, \ M_C(name, _t) org) \ { \ SNAPSHOTI_SPSC_CONTRACT(org); \ assert(snap != NULL && snap != org); \ for(int i = 0; i < SNAPSHOTI_SPSC_MAX_BUFFER; i++) { \ M_CALL_INIT_SET(oplist, snap->data[i].x, org->data[i].x); \ } \ atomic_init (&snap->flags, atomic_load(&org->flags)); \ SNAPSHOTI_SPSC_CONTRACT(snap); \ } \ \ static inline void M_C(name, _set)(M_C(name, _t) snap, \ M_C(name, _t) org) \ { \ SNAPSHOTI_SPSC_CONTRACT(snap); \ SNAPSHOTI_SPSC_CONTRACT(org); \ for(int i = 0; i < SNAPSHOTI_SPSC_MAX_BUFFER; i++) { \ M_CALL_SET(oplist, snap->data[i].x, org->data[i].x); \ } \ atomic_init (&snap->flags, atomic_load(&org->flags)); \ SNAPSHOTI_SPSC_CONTRACT(snap); \ } \ \ M_IF_METHOD(INIT_MOVE, oplist)( \ static inline void M_C(name, _init_move)(M_C(name, _t) snap, \ M_C(name, _t) org) \ { \ SNAPSHOTI_SPSC_CONTRACT(org); \ assert(snap != NULL && snap != org); \ for(int i = 0; i < SNAPSHOTI_SPSC_MAX_BUFFER; i++) { \ M_CALL_INIT_MOVE(oplist, snap->data[i].x, org->data[i].x); \ } \ atomic_store (&snap->flags, atomic_load(&org->flags)); \ atomic_store (&org->flags, SNAPSHOTI_SPSC_FLAG(0,0,0,0) ); \ SNAPSHOTI_SPSC_CONTRACT(snap); \ } \ ,) /* IF_METHOD (INIT_MOVE) */ \ \ M_IF_METHOD(MOVE, oplist)( \ static inline void M_C(name, _move)(M_C(name, _t) snap, \ M_C(name, _t) org) \ { \ SNAPSHOTI_SPSC_CONTRACT(snap); \ SNAPSHOTI_SPSC_CONTRACT(org); \ assert(snap != org); \ for(int i = 0; i < SNAPSHOTI_SPSC_MAX_BUFFER; i++) { \ M_CALL_MOVE(oplist, snap->data[i].x, org->data[i].x); \ } \ atomic_store (&snap->flags, atomic_load(&org->flags)); \ atomic_store (&org->flags, SNAPSHOTI_SPSC_FLAG(0,0,0,0) ); \ SNAPSHOTI_SPSC_CONTRACT(snap); \ } \ ,) /* IF_METHOD (MOVE) */ \ \ \ static inline type *M_C(name, _write)(M_C(name, _t) snap) \ { \ SNAPSHOTI_SPSC_CONTRACT(snap); \ unsigned char nextFlags, origFlags = atomic_load (&snap->flags); \ /* Atomic CAS operation */ \ do { \ /* Swap F and W buffer, setting exchange flag */ \ nextFlags = SNAPSHOTI_SPSC_FLAG(SNAPSHOTI_SPSC_R(origFlags), \ SNAPSHOTI_SPSC_F(origFlags), \ SNAPSHOTI_SPSC_W(origFlags), 1); \ /* exponential backoff is not needed as there can't be more \ than 2 threads which try to update the data. */ \ } while (!atomic_compare_exchange_weak (&snap->flags, &origFlags, \ nextFlags)); \ /* Return new write buffer for new updating */ \ return &snap->data[SNAPSHOTI_SPSC_W(nextFlags)].x; \ } \ \ static inline type const *M_C(name, _read)(M_C(name, _t) snap) \ { \ SNAPSHOTI_SPSC_CONTRACT(snap); \ unsigned char nextFlags, origFlags = atomic_load (&snap->flags); \ /* Atomic CAS operation */ \ do { \ /* If no exchange registered, do nothing and keep the same */ \ if (!SNAPSHOTI_SPSC_B(origFlags)) { \ nextFlags = origFlags; \ break; \ } \ /* Swap R and F buffer, clearing exchange flag */ \ nextFlags = SNAPSHOTI_SPSC_FLAG(SNAPSHOTI_SPSC_F(origFlags), \ SNAPSHOTI_SPSC_W(origFlags), \ SNAPSHOTI_SPSC_R(origFlags), 0); \ /* exponential backoff is not needed as there can't be more \ than 2 threads which try to update the data. */ \ } while (!atomic_compare_exchange_weak (&snap->flags, &origFlags, \ nextFlags)); \ /* Return current read buffer */ \ return M_CONST_CAST(type, &snap->data[SNAPSHOTI_SPSC_R(nextFlags)].x); \ } \ \ static inline bool M_C(name, _updated_p)(M_C(name, _t) snap) \ { \ SNAPSHOTI_SPSC_CONTRACT(snap); \ unsigned char flags = atomic_load (&snap->flags); \ return SNAPSHOTI_SPSC_B(flags); \ } \ \ static inline type *M_C(name, _get_write_buffer)(M_C(name, _t) snap) \ { \ SNAPSHOTI_SPSC_CONTRACT(snap); \ unsigned char flags = atomic_load(&snap->flags); \ return &snap->data[SNAPSHOTI_SPSC_W(flags)].x; \ } \ \ static inline type const *M_C(name, _get_read_buffer)(M_C(name, _t) snap) \ { \ SNAPSHOTI_SPSC_CONTRACT(snap); \ unsigned char flags = atomic_load(&snap->flags); \ return M_CONST_CAST(type, &snap->data[SNAPSHOTI_SPSC_R(flags)].x); \ } \ /******************************** INTERNAL SPMC **********************************/ #define SNAPSHOTI_SPMC_INT_FLAG(w, n) ( ((w) << 1) | (n) ) #define SNAPSHOTI_SPMC_INT_FLAG_W(f) ((f) >> 1) #define SNAPSHOTI_SPMC_INT_FLAG_N(f) ((f) & 1) // 2 more buffer than the number of readers are needed #define SNAPSHOTI_SPMC_EXTRA_BUFFER 2 #define SNAPSHOTI_SPMC_MAX_READER (GENINT_MAX_ALLOC-SNAPSHOTI_SPMC_EXTRA_BUFFER) /* structure to handle SPMC snapshot but return an unique index in the buffer array. - lastNext: last published written index + next flag (format SNAPSHOTI_SPMC_INT_FLAG) - currentWrite: the index being currently written. - n : number of readers - cptTab: ref counter array - freeList: a pool of free integers. */ typedef struct snapshot_mrsw_int_s { atomic_uint lastNext; unsigned int currentWrite; size_t n; atomic_uint *cptTab; genint_t freeList; } snapshot_mrsw_int_t[1]; // can't check currentWrite due to potential data race on it #define SNAPSHOTI_SPMC_INT_CONTRACT(s) do { \ assert (s != NULL); \ assert (s->n > 0 && s->n <= SNAPSHOTI_SPMC_MAX_READER); \ assert ((size_t)SNAPSHOTI_SPMC_INT_FLAG_W(atomic_load(&s->lastNext)) \ <= s->n + SNAPSHOTI_SPMC_EXTRA_BUFFER); \ assert (s->cptTab != NULL); \ } while (0) static inline void snapshot_mrsw_int_init(snapshot_mrsw_int_t s, size_t n) { assert (s != NULL); assert (n >= 1 && n <= SNAPSHOTI_SPMC_MAX_READER); s->n = n; n += SNAPSHOTI_SPMC_EXTRA_BUFFER; atomic_uint *ptr = M_MEMORY_REALLOC (atomic_uint, NULL, n); if (M_UNLIKELY (ptr == NULL)) { M_MEMORY_FULL(sizeof (atomic_uint) * n); return; } s->cptTab = ptr; for(size_t i = 0; i < n; i++) atomic_init(&s->cptTab[i], 0U); genint_init (s->freeList, (unsigned int) n); // Get a free buffer and set it as available for readers unsigned int w = genint_pop(s->freeList); assert (w != GENINT_ERROR); atomic_store(&s->cptTab[w], 1U); atomic_init(&s->lastNext, SNAPSHOTI_SPMC_INT_FLAG(w, true)); // Get working buffer s->currentWrite = genint_pop(s->freeList); assert (s->currentWrite != GENINT_ERROR); atomic_store(&s->cptTab[s->currentWrite], 1U); SNAPSHOTI_SPMC_INT_CONTRACT(s); } static inline void snapshot_mrsw_int_clear(snapshot_mrsw_int_t s) { SNAPSHOTI_SPMC_INT_CONTRACT(s); M_MEMORY_FREE (s->cptTab); genint_clear(s->freeList); s->cptTab = NULL; s->n = 0; } static inline unsigned int snapshot_mrsw_int_get_write_idx(snapshot_mrsw_int_t s) { SNAPSHOTI_SPMC_INT_CONTRACT(s); return s->currentWrite; } static inline unsigned int snapshot_mrsw_int_size(snapshot_mrsw_int_t s) { SNAPSHOTI_SPMC_INT_CONTRACT(s); return (unsigned int) s->n; } static inline unsigned int snapshot_mrsw_int_write_idx(snapshot_mrsw_int_t s, unsigned int idx) { SNAPSHOTI_SPMC_INT_CONTRACT(s); unsigned int newNext, previous = atomic_load(&s->lastNext); do { newNext = SNAPSHOTI_SPMC_INT_FLAG(idx, true); } while (!atomic_compare_exchange_weak(&s->lastNext, &previous, newNext)); if (SNAPSHOTI_SPMC_INT_FLAG_N(previous)) { // Reuse previous buffer as it was not used by any reader idx = SNAPSHOTI_SPMC_INT_FLAG_W(previous); // Some other read threads may already have try to reserve this index // So atomic_load(&s->cptTab[idx]) can be greater than 1. // However they will fail to ack it in lastNext, and remove their reservation later } else { // Free the write index idx = SNAPSHOTI_SPMC_INT_FLAG_W(previous); unsigned int c = atomic_fetch_sub(&s->cptTab[idx], 1U); assert (c != 0 && c <= s->n + 1); // Get a new buffer. if (c != 1) { // If someone else keeps a ref on the buffer, we can't reuse it // get another free one. idx = genint_pop(s->freeList); assert(idx != GENINT_ERROR); } assert (idx < s->n + SNAPSHOTI_SPMC_EXTRA_BUFFER); assert (atomic_load(&s->cptTab[idx]) == 0); atomic_store(&s->cptTab[idx], 1U); } SNAPSHOTI_SPMC_INT_CONTRACT(s); return idx; } static inline unsigned int snapshot_mrsw_int_write(snapshot_mrsw_int_t s) { s->currentWrite = snapshot_mrsw_int_write_idx(s, s->currentWrite); SNAPSHOTI_SPMC_INT_CONTRACT(s); return s->currentWrite; } static inline unsigned int snapshot_mrsw_int_write_start(snapshot_mrsw_int_t s) { SNAPSHOTI_SPMC_INT_CONTRACT(s); // Get a new buffer. unsigned int idx = genint_pop(s->freeList); assert (idx != GENINT_ERROR); assert (idx < s->n + SNAPSHOTI_SPMC_EXTRA_BUFFER); assert (atomic_load(&s->cptTab[idx]) == 0); atomic_store(&s->cptTab[idx], 1U); SNAPSHOTI_SPMC_INT_CONTRACT(s); return idx; } static inline void snapshot_mrsw_int_write_end(snapshot_mrsw_int_t s, unsigned int idx) { SNAPSHOTI_SPMC_INT_CONTRACT(s); unsigned int newNext, previous = atomic_load(&s->lastNext); do { newNext = SNAPSHOTI_SPMC_INT_FLAG(idx, true); } while (!atomic_compare_exchange_weak(&s->lastNext, &previous, newNext)); // Free the previous write buffer idx = SNAPSHOTI_SPMC_INT_FLAG_W(previous); unsigned int c = atomic_fetch_sub(&s->cptTab[idx], 1U); assert (c != 0 && c <= s->n + 1); if (c == 1) { genint_push(s->freeList, idx); } SNAPSHOTI_SPMC_INT_CONTRACT(s); } static inline unsigned int snapshot_mrsw_int_read_start(snapshot_mrsw_int_t s) { SNAPSHOTI_SPMC_INT_CONTRACT(s); unsigned int idx, previous; reload: // Load the last published index + Next flag previous = atomic_load(&s->lastNext); while (true) { // Get the last published index idx = SNAPSHOTI_SPMC_INT_FLAG_W(previous); // Load the number of threads using this index unsigned int c = atomic_load(&s->cptTab[idx]); assert (c <= s->n + 1); // Reserve the index if it still being reserved by someone else if (M_UNLIKELY (c == 0 || !atomic_compare_exchange_strong(&s->cptTab[idx], &c, c+1))) goto reload; // Try to ack it unsigned int newNext = SNAPSHOTI_SPMC_INT_FLAG(idx, false); reforce: if (M_LIKELY (atomic_compare_exchange_strong(&s->lastNext, &previous, newNext))) break; // We have been preempted by another thread if (idx == SNAPSHOTI_SPMC_INT_FLAG_W(previous)) { // This is still ok if the index has not changed // We can get previous to true again if the writer has recycled the index, // while we reserved it, and the reader get prempted until its CAS. if (M_UNLIKELY (SNAPSHOTI_SPMC_INT_FLAG_N(previous) == true)) goto reforce; break; } // Free the reserved index as we failed it to ack it c = atomic_fetch_sub(&s->cptTab[idx], 1U); assert (c != 0 && c <= s->n+1); if (c == 1) { genint_push(s->freeList, idx); } } SNAPSHOTI_SPMC_INT_CONTRACT(s); return idx; } static inline void snapshot_mrsw_int_read_end(snapshot_mrsw_int_t s, unsigned int idx) { SNAPSHOTI_SPMC_INT_CONTRACT(s); assert (idx < s->n + SNAPSHOTI_SPMC_EXTRA_BUFFER); // Decrement reference counter of the buffer unsigned int c = atomic_fetch_sub(&s->cptTab[idx], 1U); assert (c != 0 && c <= s->n+1); if (c == 1) { // Buffer no longer used by any reader thread. // Push back index in free list genint_push(s->freeList, idx); } SNAPSHOTI_SPMC_INT_CONTRACT(s); } #define SNAPSHOTI_SPMC_CONTRACT(snap) do { \ assert (snap != NULL); \ assert (snap->data != NULL); \ } while (0) // Defered evaluation #define SNAPSHOTI_SPMC_DEF_P1(arg) SNAPSHOTI_SPMC_DEF_P2 arg /* Validate the oplist before going further */ #define SNAPSHOTI_SPMC_DEF_P2(name, type, oplist) \ M_IF_OPLIST(oplist)(SNAPSHOTI_SPMC_DEF_P3, SNAPSHOTI_SPMC_DEF_FAILURE)(name, type, oplist) /* Stop processing with a compilation failure */ #define SNAPSHOTI_SPMC_DEF_FAILURE(name, type, oplist) \ M_STATIC_FAILURE(M_LIB_NOT_AN_OPLIST, "(SNAPSHOT_SPMC_DEF): the given argument is not a valid oplist: " #oplist) #define SNAPSHOTI_SPMC_DEF_P3(name, type, oplist) \ \ /* Create an aligned type to avoid false sharing between threads */ \ typedef struct M_C(name, _aligned_type_s) { \ type x; \ M_CACHELINE_ALIGN(align, type); \ } M_C(name, _aligned_type_t); \ \ typedef struct M_C(name, _s) { \ M_C(name, _aligned_type_t) *data; \ snapshot_mrsw_int_t core; \ } M_C(name, _t)[1]; \ \ typedef type M_C(name, _type_t); \ \ M_CHECK_COMPATIBLE_OPLIST(name, 1, type, oplist) \ \ static inline void M_C(name, _init)(M_C(name, _t) snap, size_t nReader) \ { \ assert (snap != NULL); \ assert (nReader > 0 && nReader <= SNAPSHOTI_SPMC_MAX_READER); \ snap->data = M_CALL_REALLOC(oplist, M_C(name, _aligned_type_t), \ NULL, nReader+SNAPSHOTI_SPMC_EXTRA_BUFFER); \ if (M_UNLIKELY (snap->data == NULL)) { \ M_MEMORY_FULL(sizeof(M_C(name, _aligned_type_t)) * \ (nReader+SNAPSHOTI_SPMC_EXTRA_BUFFER)); \ return; \ } \ for(size_t i = 0; i < nReader + SNAPSHOTI_SPMC_EXTRA_BUFFER; i++) { \ M_CALL_INIT(oplist, snap->data[i].x); \ } \ snapshot_mrsw_int_init(snap->core, nReader); \ SNAPSHOTI_SPMC_CONTRACT(snap); \ } \ \ static inline void M_C(name, _clear)(M_C(name, _t) snap) \ { \ SNAPSHOTI_SPMC_CONTRACT(snap); \ size_t nReader = snapshot_mrsw_int_size(snap->core); \ for(size_t i = 0; i < nReader + SNAPSHOTI_SPMC_EXTRA_BUFFER; i++) { \ M_CALL_CLEAR(oplist, snap->data[i].x); \ } \ M_CALL_FREE(oplist, snap->data); \ snapshot_mrsw_int_clear(snap->core); \ } \ \ static inline type *M_C(name, _write)(M_C(name, _t) snap) \ { \ SNAPSHOTI_SPMC_CONTRACT(snap); \ const unsigned int idx = snapshot_mrsw_int_write(snap->core); \ return &snap->data[idx].x; \ } \ \ static inline type const *M_C(name, _read_start)(M_C(name, _t) snap) \ { \ SNAPSHOTI_SPMC_CONTRACT(snap); \ const unsigned int idx = snapshot_mrsw_int_read_start(snap->core); \ return M_CONST_CAST(type, &snap->data[idx].x); \ } \ \ static inline void M_C(name, _read_end)(M_C(name, _t) snap, type const *old) \ { \ SNAPSHOTI_SPMC_CONTRACT(snap); \ assert (old != NULL); \ const M_C(name, _aligned_type_t) *oldx; \ oldx = M_CTYPE_FROM_FIELD(M_C(name, _aligned_type_t), old, type, x); \ assert (oldx >= snap->data); \ assert (oldx < snap->data + snap->core->n+SNAPSHOTI_SPMC_EXTRA_BUFFER); \ assert(snap->core->n+SNAPSHOTI_SPMC_EXTRA_BUFFER < UINT_MAX); \ const unsigned int idx = (unsigned int) (oldx - snap->data); \ snapshot_mrsw_int_read_end(snap->core, idx); \ } \ \ static inline type *M_C(name, _get_write_buffer)(M_C(name, _t) snap) \ { \ SNAPSHOTI_SPMC_CONTRACT(snap); \ const unsigned int idx = snapshot_mrsw_int_get_write_idx(snap->core); \ return &snap->data[idx].x; \ } \ \ //FIXME: Evaluate the needs for the methods _set_, _init_set. /******************************** INTERNAL MPMC **********************************/ // MPMC is built upon SPMC // Defered evaluation #define SNAPSHOTI_MPMC_DEF_P1(arg) SNAPSHOTI_MPMC_DEF_P2 arg /* Validate the oplist before going further */ #define SNAPSHOTI_MPMC_DEF_P2(name, type, oplist) \ M_IF_OPLIST(oplist)(SNAPSHOTI_MPMC_DEF_P3, SNAPSHOTI_MPMC_DEF_FAILURE)(name, type, oplist) /* Stop processing with a compilation failure */ #define SNAPSHOTI_MPMC_DEF_FAILURE(name, type, oplist) \ M_STATIC_FAILURE(M_LIB_NOT_AN_OPLIST, "(SNAPSHOT_MPMC_DEF): the given argument is not a valid oplist: " #oplist) #define SNAPSHOTI_MPMC_DEF_P3(name, type, oplist) \ \ SNAPSHOTI_SPMC_DEF_P1((M_C(name, _mrsw), type, oplist)) \ \ typedef struct M_C(name, _s) { \ M_C(name, _mrsw_t) core; \ } M_C(name, _t)[1]; \ \ typedef type M_C(name, _type_t); \ \ M_CHECK_COMPATIBLE_OPLIST(name, 1, type, oplist) \ \ static inline void M_C(name, _init)(M_C(name, _t) snap, size_t nReader, size_t nWriter) \ { \ M_C(name, _mrsw_init)(snap->core, nReader + nWriter -1 ); \ unsigned int idx = snap->core->core->currentWrite; \ snap->core->core->currentWrite = GENINT_ERROR; \ snapshot_mrsw_int_write_end(snap->core->core, idx); \ } \ \ static inline void M_C(name, _clear)(M_C(name, _t) snap) \ { \ M_C(name, _mrsw_clear)(snap->core); \ } \ \ static inline type *M_C(name, _write_start)(M_C(name, _t) snap) \ { \ SNAPSHOTI_SPMC_CONTRACT(snap->core); \ const unsigned int idx = snapshot_mrsw_int_write_start(snap->core->core); \ return &snap->core->data[idx].x; \ } \ \ static inline void M_C(name, _write_end)(M_C(name, _t) snap, type *old) \ { \ SNAPSHOTI_SPMC_CONTRACT(snap->core); \ const M_C(name, _mrsw_aligned_type_t) *oldx; \ oldx = M_CTYPE_FROM_FIELD(M_C(name, _mrsw_aligned_type_t), old, type, x); \ assert (oldx >= snap->core->data); \ assert (oldx < snap->core->data + snap->core->core->n + SNAPSHOTI_SPMC_EXTRA_BUFFER); \ assert(snap->core->core->n+SNAPSHOTI_SPMC_EXTRA_BUFFER < UINT_MAX); \ const unsigned int idx = (unsigned int) (oldx - snap->core->data); \ snapshot_mrsw_int_write_end(snap->core->core, idx); \ } \ \ static inline type const *M_C(name, _read_start)(M_C(name, _t) snap) \ { \ return M_C(name, _mrsw_read_start)(snap->core); \ } \ \ static inline void M_C(name, _read_end)(M_C(name, _t) snap, type const *old) \ { \ M_C(name, _mrsw_read_end)(snap->core, old); \ } \ \ //TODO: _set_, _init_set #endif