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ck_array.h
(3.06 KB)
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ck_backoff.h
(1.84 KB)
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ck_barrier.h
(5.31 KB)
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ck_bitmap.h
(12.25 KB)
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ck_brlock.h
(6.47 KB)
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ck_bytelock.h
(5.3 KB)
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ck_cc.h
(3.68 KB)
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ck_cohort.h
(5.64 KB)
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ck_elide.h
(8.74 KB)
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ck_epoch.h
(7.82 KB)
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ck_fifo.h
(12.87 KB)
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ck_hp.h
(3.31 KB)
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ck_hp_fifo.h
(5.99 KB)
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ck_hp_stack.h
(3.08 KB)
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ck_hs.h
(4.46 KB)
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ck_ht.h
(6.51 KB)
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ck_limits.h
(1.77 KB)
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ck_malloc.h
(1.57 KB)
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ck_md.h
(3.91 KB)
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ck_pflock.h
(3.68 KB)
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ck_pr.h
(31.64 KB)
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ck_queue.h
(15.78 KB)
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ck_rhs.h
(4.41 KB)
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ck_ring.h
(16.8 KB)
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ck_rwcohort.h
(11.17 KB)
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ck_rwlock.h
(6.15 KB)
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ck_sequence.h
(3.35 KB)
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ck_spinlock.h
(2.46 KB)
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ck_stack.h
(9.03 KB)
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ck_stdbool.h
(1.42 KB)
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ck_stddef.h
(1.42 KB)
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ck_stdint.h
(1.55 KB)
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ck_stdlib.h
(1.42 KB)
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ck_string.h
(1.42 KB)
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ck_swlock.h
(5.09 KB)
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ck_tflock.h
(3.9 KB)
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gcc
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spinlock
Editing: ck_bytelock.h
/* * Copyright 2010-2015 Samy Al Bahra. * All rights reserved. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * 2. 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 AUTHOR 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 AUTHOR OR 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 CK_BYTELOCK_H #define CK_BYTELOCK_H /* * The implementations here are derived from the work described in: * Dice, D. and Shavit, N. 2010. TLRW: return of the read-write lock. * In Proceedings of the 22nd ACM Symposium on Parallelism in Algorithms * and Architectures (Thira, Santorini, Greece, June 13 - 15, 2010). * SPAA '10. ACM, New York, NY, 284-293. */ #include <ck_cc.h> #include <ck_md.h> #include <ck_pr.h> #include <ck_stdbool.h> #include <ck_stddef.h> #include <ck_limits.h> struct ck_bytelock { unsigned int owner; unsigned int n_readers; uint8_t readers[CK_MD_CACHELINE - sizeof(unsigned int) * 2] CK_CC_ALIGN(8); }; typedef struct ck_bytelock ck_bytelock_t; #define CK_BYTELOCK_INITIALIZER { 0, 0, {0} } #define CK_BYTELOCK_UNSLOTTED UINT_MAX CK_CC_INLINE static void ck_bytelock_init(struct ck_bytelock *bytelock) { unsigned int i; bytelock->owner = 0; bytelock->n_readers = 0; for (i = 0; i < sizeof bytelock->readers; i++) bytelock->readers[i] = false; ck_pr_barrier(); return; } #ifdef CK_F_PR_LOAD_64 #define CK_BYTELOCK_LENGTH sizeof(uint64_t) #define CK_BYTELOCK_LOAD ck_pr_load_64 #define CK_BYTELOCK_TYPE uint64_t #elif defined(CK_F_PR_LOAD_32) #define CK_BYTELOCK_LENGTH sizeof(uint32_t) #define CK_BYTELOCK_LOAD ck_pr_load_32 #define CK_BYTELOCK_TYPE uint32_t #else #error Unsupported platform. #endif CK_CC_INLINE static void ck_bytelock_write_lock(struct ck_bytelock *bytelock, unsigned int slot) { CK_BYTELOCK_TYPE *readers = (void *)bytelock->readers; unsigned int i; /* Announce upcoming writer acquisition. */ while (ck_pr_cas_uint(&bytelock->owner, 0, slot) == false) ck_pr_stall(); /* If we are slotted, we might be upgrading from a read lock. */ if (slot <= sizeof bytelock->readers) ck_pr_store_8(&bytelock->readers[slot - 1], false); /* * Wait for slotted readers to drain out. This also provides the * lock acquire semantics. */ ck_pr_fence_atomic_load(); for (i = 0; i < sizeof(bytelock->readers) / CK_BYTELOCK_LENGTH; i++) { while (CK_BYTELOCK_LOAD(&readers[i]) != false) ck_pr_stall(); } /* Wait for unslotted readers to drain out. */ while (ck_pr_load_uint(&bytelock->n_readers) != 0) ck_pr_stall(); ck_pr_fence_lock(); return; } #undef CK_BYTELOCK_LENGTH #undef CK_BYTELOCK_LOAD #undef CK_BYTELOCK_TYPE CK_CC_INLINE static void ck_bytelock_write_unlock(struct ck_bytelock *bytelock) { ck_pr_fence_unlock(); ck_pr_store_uint(&bytelock->owner, 0); return; } CK_CC_INLINE static void ck_bytelock_read_lock(struct ck_bytelock *bytelock, unsigned int slot) { if (ck_pr_load_uint(&bytelock->owner) == slot) { ck_pr_store_8(&bytelock->readers[slot - 1], true); ck_pr_fence_strict_store(); ck_pr_store_uint(&bytelock->owner, 0); return; } /* Unslotted threads will have to use the readers counter. */ if (slot > sizeof bytelock->readers) { for (;;) { ck_pr_inc_uint(&bytelock->n_readers); ck_pr_fence_atomic_load(); if (ck_pr_load_uint(&bytelock->owner) == 0) break; ck_pr_dec_uint(&bytelock->n_readers); while (ck_pr_load_uint(&bytelock->owner) != 0) ck_pr_stall(); } ck_pr_fence_lock(); return; } slot -= 1; for (;;) { #ifdef CK_F_PR_FAA_8 ck_pr_fas_8(&bytelock->readers[slot], true); ck_pr_fence_atomic_load(); #else ck_pr_store_8(&bytelock->readers[slot], true); ck_pr_fence_store_load(); #endif /* * If there is no owner at this point, our slot has * already been published and it is guaranteed no * write acquisition will succeed until we drain out. */ if (ck_pr_load_uint(&bytelock->owner) == 0) break; ck_pr_store_8(&bytelock->readers[slot], false); while (ck_pr_load_uint(&bytelock->owner) != 0) ck_pr_stall(); } ck_pr_fence_lock(); return; } CK_CC_INLINE static void ck_bytelock_read_unlock(struct ck_bytelock *bytelock, unsigned int slot) { ck_pr_fence_unlock(); if (slot > sizeof bytelock->readers) ck_pr_dec_uint(&bytelock->n_readers); else ck_pr_store_8(&bytelock->readers[slot - 1], false); return; } #endif /* CK_BYTELOCK_H */
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