From: Mathieu Desnoyers Date: Sun, 27 Sep 2009 04:02:21 +0000 (-0400) Subject: urcu-ht: work in progress RCU hash table X-Git-Tag: v0.7.0~43^2~247 X-Git-Url: https://git.lttng.org./?a=commitdiff_plain;h=ab7d5fc6ff3128b5699e1871e9726f4e79b8f2e6;p=userspace-rcu.git urcu-ht: work in progress RCU hash table Signed-off-by: Mathieu Desnoyers --- diff --git a/Makefile.inc b/Makefile.inc index 9d566b7..7a5ed3f 100644 --- a/Makefile.inc +++ b/Makefile.inc @@ -8,7 +8,7 @@ all: checkarch liburcu.so urcu.o \ liburcu-mb.so urcu-mb.o \ liburcu-defer.so urcu-defer.o \ urcu-yield.o \ - urcu-hash.o \ + urcu-ht.o \ subdirs checkarch: diff --git a/tests/Makefile.inc b/tests/Makefile.inc index f62256b..4e85352 100644 --- a/tests/Makefile.inc +++ b/tests/Makefile.inc @@ -16,6 +16,7 @@ URCU_SIGNAL_YIELD=${LIBDIR}/urcu-yield.o ${LIBDIR}/urcu.h URCU_MB=${LIBDIR}/urcu-mb.o ${LIBDIR}/urcu.h URCU_QSBR=${LIBDIR}/urcu-qsbr.o ${LIBDIR}/urcu-qsbr.h URCU_MB_DEFER=${LIBDIR}/urcu-mb.o ${LIBDIR}/urcu-defer.o ${LIBDIR}/urcu.h +URCU_HT=${LIBDIR}/urcu-mb.o ${LIBDIR}/urcu-defer.o ${LIBDIR}/urcu-ht.o ${LIBDIR}/urcu.h all: test_urcu test_urcu_dynamic_link test_urcu_timing \ test_rwlock_timing test_rwlock test_perthreadlock_timing \ @@ -24,7 +25,7 @@ all: test_urcu test_urcu_dynamic_link test_urcu_timing \ urcutorture-yield test_mutex test_looplen test_urcu_gc \ test_urcu_gc_mb test_qsbr_gc test_qsbr_lgc test_urcu_lgc \ test_urcu_lgc_mb test_qsbr_dynamic_link test_urcu_mb_defer \ - test_atomic + test_atomic test_ht api.h: ${APIHEADER} cp -f ${APIHEADER} api.h @@ -112,6 +113,9 @@ urcutorture-yield: urcutorture.c ${URCU_SIGNAL_YIELD} rcutorture.h api.h test_atomic: test_atomic.c ../arch_atomic.h $(CC) ${CFLAGS} $(LDFLAGS) -o $@ $(SRC_DEP) +test_ht: test_ht.c ${URCU_HT} + $(CC) ${CFLAGS} $(LDFLAGS) -o $@ $(SRC_DEP) + ,PHONY: clean clean: diff --git a/tests/test_ht.c b/tests/test_ht.c new file mode 100644 index 0000000..12b210e --- /dev/null +++ b/tests/test_ht.c @@ -0,0 +1,434 @@ +/* + * test_ht.c + * + * Userspace RCU library - test program + * + * Copyright February 2009 - Mathieu Desnoyers + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; either version 2 of the License, or + * (at your option) any later version. + * + * 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 along + * with this program; if not, write to the Free Software Foundation, Inc., + * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA. + */ + +#define _GNU_SOURCE +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include "../urcu-ht.h" + +#include "../arch.h" + +/* Make this big enough to include the POWER5+ L3 cacheline size of 256B */ +#define CACHE_LINE_SIZE 4096 + +/* hardcoded number of CPUs */ +#define NR_CPUS 16384 + +#if defined(_syscall0) +_syscall0(pid_t, gettid) +#elif defined(__NR_gettid) +static inline pid_t gettid(void) +{ + return syscall(__NR_gettid); +} +#else +#warning "use pid as tid" +static inline pid_t gettid(void) +{ + return getpid(); +} +#endif + +#ifndef DYNAMIC_LINK_TEST +#define _LGPL_SOURCE +#else +#define debug_yield_read() +#endif +#include "../urcu.h" + +static struct rcu_ht *test_ht; + +struct test_array { + int a; +}; + +static volatile int test_go, test_stop; + +static unsigned long wdelay; + +static struct test_array *test_rcu_pointer; + +static unsigned long duration; + +/* read-side C.S. duration, in loops */ +static unsigned long rduration; + +static inline void loop_sleep(unsigned long l) +{ + while(l-- != 0) + cpu_relax(); +} + +static int verbose_mode; + +#define printf_verbose(fmt, args...) \ + do { \ + if (verbose_mode) \ + printf(fmt, args); \ + } while (0) + +static unsigned int cpu_affinities[NR_CPUS]; +static unsigned int next_aff = 0; +static int use_affinity = 0; + +pthread_mutex_t affinity_mutex = PTHREAD_MUTEX_INITIALIZER; + +static void set_affinity(void) +{ + cpu_set_t mask; + int cpu; + int ret; + + if (!use_affinity) + return; + + ret = pthread_mutex_lock(&affinity_mutex); + if (ret) { + perror("Error in pthread mutex lock"); + exit(-1); + } + cpu = cpu_affinities[next_aff++]; + ret = pthread_mutex_unlock(&affinity_mutex); + if (ret) { + perror("Error in pthread mutex unlock"); + exit(-1); + } + CPU_ZERO(&mask); + CPU_SET(cpu, &mask); + sched_setaffinity(0, sizeof(mask), &mask); +} + +/* + * returns 0 if test should end. + */ +static int test_duration_write(void) +{ + return !test_stop; +} + +static int test_duration_read(void) +{ + return !test_stop; +} + +static unsigned long long __thread nr_writes; +static unsigned long long __thread nr_reads; + +static unsigned int nr_readers; +static unsigned int nr_writers; + +pthread_mutex_t rcu_copy_mutex = PTHREAD_MUTEX_INITIALIZER; + +void rcu_copy_mutex_lock(void) +{ + int ret; + ret = pthread_mutex_lock(&rcu_copy_mutex); + if (ret) { + perror("Error in pthread mutex lock"); + exit(-1); + } +} + +void rcu_copy_mutex_unlock(void) +{ + int ret; + + ret = pthread_mutex_unlock(&rcu_copy_mutex); + if (ret) { + perror("Error in pthread mutex unlock"); + exit(-1); + } +} + +/* + * malloc/free are reusing memory areas too quickly, which does not let us + * test races appropriately. Use a large circular array for allocations. + * ARRAY_SIZE is larger than nr_writers, which insures we never run over our tail. + */ +#define ARRAY_SIZE (1048576 * nr_writers) +#define ARRAY_POISON 0xDEADBEEF +static int array_index; +static struct test_array *test_array; + +static struct test_array *test_array_alloc(void) +{ + struct test_array *ret; + int index; + + rcu_copy_mutex_lock(); + index = array_index % ARRAY_SIZE; + assert(test_array[index].a == ARRAY_POISON || + test_array[index].a == 0); + ret = &test_array[index]; + array_index++; + if (array_index == ARRAY_SIZE) + array_index = 0; + rcu_copy_mutex_unlock(); + return ret; +} + +static void test_array_free(struct test_array *ptr) +{ + if (!ptr) + return; + rcu_copy_mutex_lock(); + ptr->a = ARRAY_POISON; + rcu_copy_mutex_unlock(); +} + +void *thr_reader(void *_count) +{ + unsigned long long *count = _count; + struct test_array *local_ptr; + + printf_verbose("thread_begin %s, thread id : %lx, tid %lu\n", + "reader", pthread_self(), (unsigned long)gettid()); + + set_affinity(); + + rcu_register_thread(); + + while (!test_go) + { + } + smp_mb(); + + for (;;) { + rcu_read_lock(); + local_ptr = rcu_dereference(test_rcu_pointer); + debug_yield_read(); + if (local_ptr) + assert(local_ptr->a == 8); + if (unlikely(rduration)) + loop_sleep(rduration); + rcu_read_unlock(); + nr_reads++; + if (unlikely(!test_duration_read())) + break; + } + + rcu_unregister_thread(); + + *count = nr_reads; + printf_verbose("thread_end %s, thread id : %lx, tid %lu\n", + "reader", pthread_self(), (unsigned long)gettid()); + return ((void*)1); + +} + +void *thr_writer(void *_count) +{ + unsigned long long *count = _count; + struct test_array *new, *old; + + printf_verbose("thread_begin %s, thread id : %lx, tid %lu\n", + "writer", pthread_self(), (unsigned long)gettid()); + + set_affinity(); + + while (!test_go) + { + } + smp_mb(); + + for (;;) { + new = test_array_alloc(); + new->a = 8; + old = rcu_publish_content(&test_rcu_pointer, new); + if (old) + old->a = 0; + test_array_free(old); + nr_writes++; + if (unlikely(!test_duration_write())) + break; + if (unlikely(wdelay)) + loop_sleep(wdelay); + } + + printf_verbose("thread_end %s, thread id : %lx, tid %lu\n", + "writer", pthread_self(), (unsigned long)gettid()); + *count = nr_writes; + return ((void*)2); +} + +void show_usage(int argc, char **argv) +{ + printf("Usage : %s nr_readers nr_writers duration (s)", argv[0]); +#ifdef DEBUG_YIELD + printf(" [-r] [-w] (yield reader and/or writer)"); +#endif + printf(" [-d delay] (writer period (us))"); + printf(" [-c duration] (reader C.S. duration (in loops))"); + printf(" [-v] (verbose output)"); + printf(" [-a cpu#] [-a cpu#]... (affinity)"); + printf("\n"); +} + +int main(int argc, char **argv) +{ + int err; + pthread_t *tid_reader, *tid_writer; + void *tret; + unsigned long long *count_reader, *count_writer; + unsigned long long tot_reads = 0, tot_writes = 0; + int i, a; + + if (argc < 4) { + show_usage(argc, argv); + return -1; + } + + err = sscanf(argv[1], "%u", &nr_readers); + if (err != 1) { + show_usage(argc, argv); + return -1; + } + + err = sscanf(argv[2], "%u", &nr_writers); + if (err != 1) { + show_usage(argc, argv); + return -1; + } + + err = sscanf(argv[3], "%lu", &duration); + if (err != 1) { + show_usage(argc, argv); + return -1; + } + + for (i = 4; i < argc; i++) { + if (argv[i][0] != '-') + continue; + switch (argv[i][1]) { +#ifdef DEBUG_YIELD + case 'r': + yield_active |= YIELD_READ; + break; + case 'w': + yield_active |= YIELD_WRITE; + break; +#endif + case 'a': + if (argc < i + 2) { + show_usage(argc, argv); + return -1; + } + a = atoi(argv[++i]); + cpu_affinities[next_aff++] = a; + use_affinity = 1; + printf_verbose("Adding CPU %d affinity\n", a); + break; + case 'c': + if (argc < i + 2) { + show_usage(argc, argv); + return -1; + } + rduration = atol(argv[++i]); + break; + case 'd': + if (argc < i + 2) { + show_usage(argc, argv); + return -1; + } + wdelay = atol(argv[++i]); + break; + case 'v': + verbose_mode = 1; + break; + } + } + + printf_verbose("running test for %lu seconds, %u readers, %u writers.\n", + duration, nr_readers, nr_writers); + printf_verbose("Writer delay : %lu loops.\n", wdelay); + printf_verbose("Reader duration : %lu loops.\n", rduration); + printf_verbose("thread %-6s, thread id : %lx, tid %lu\n", + "main", pthread_self(), (unsigned long)gettid()); + + test_array = malloc(sizeof(*test_array) * ARRAY_SIZE); + tid_reader = malloc(sizeof(*tid_reader) * nr_readers); + tid_writer = malloc(sizeof(*tid_writer) * nr_writers); + count_reader = malloc(sizeof(*count_reader) * nr_readers); + count_writer = malloc(sizeof(*count_writer) * nr_writers); + test_ht = ht_new(stupid_hash, free); + next_aff = 0; + + for (i = 0; i < nr_readers; i++) { + err = pthread_create(&tid_reader[i], NULL, thr_reader, + &count_reader[i]); + if (err != 0) + exit(1); + } + for (i = 0; i < nr_writers; i++) { + err = pthread_create(&tid_writer[i], NULL, thr_writer, + &count_writer[i]); + if (err != 0) + exit(1); + } + + smp_mb(); + + test_go = 1; + + sleep(duration); + + test_stop = 1; + + for (i = 0; i < nr_readers; i++) { + err = pthread_join(tid_reader[i], &tret); + if (err != 0) + exit(1); + tot_reads += count_reader[i]; + } + for (i = 0; i < nr_writers; i++) { + err = pthread_join(tid_writer[i], &tret); + if (err != 0) + exit(1); + tot_writes += count_writer[i]; + } + ht_destroy(test_ht); + + printf_verbose("total number of reads : %llu, writes %llu\n", tot_reads, + tot_writes); + printf("SUMMARY %-25s testdur %4lu nr_readers %3u rdur %6lu " + "nr_writers %3u " + "wdelay %6lu nr_reads %12llu nr_writes %12llu nr_ops %12llu\n", + argv[0], duration, nr_readers, rduration, + nr_writers, wdelay, tot_reads, tot_writes, + tot_reads + tot_writes); + test_array_free(test_rcu_pointer); + free(test_array); + free(tid_reader); + free(tid_writer); + free(count_reader); + free(count_writer); + return 0; +} diff --git a/urcu-hash.c b/urcu-hash.c deleted file mode 100644 index 1267af5..0000000 --- a/urcu-hash.c +++ /dev/null @@ -1,230 +0,0 @@ - -#define _LGPL_SOURCE -#include -#include -#include -#include -#include -#include -#include -#include - -#define HASH_SIZE 4096 - -typedef unsigned long (*ht_hash_fct)(void *key); - -struct rcu_ht_node; - -struct rcu_ht_node { - struct rcu_ht_node *next; - void *key; - void *data; -}; - -struct rcu_ht { - struct rcu_ht_node *tbl[HASH_SIZE]; - ht_hash_fct hash_fct; - void (*free_fct)(void *data); /* fct to free data */ -}; - -struct rcu_ht *ht_new(ht_hash_fct hash_fct, void (*free_fct)(void *data)); - -void ht_delete_all(struct rcu_ht *ht); - -int ht_destroy(struct rcu_ht *ht); - -void *ht_lookup(struct rcu_ht *ht, void *key); - -int ht_add(struct rcu_ht *ht, void *key, void *data); - -int ht_delete(struct rcu_ht *ht, void *key); - -void *ht_steal(struct rcu_ht *ht, void *key); - - -/* Implementation */ - -static unsigned long stupid_hash(void *key) -{ - return (unsigned long)key % HASH_SIZE; -} - -struct rcu_ht *ht_new(ht_hash_fct hash_fct, void (*free_fct)(void *data)) -{ - struct rcu_ht *ht; - - ht = calloc(1, sizeof(struct rcu_ht)); - ht->hash_fct = hash_fct; - ht->free_fct = free_fct; -} - -/* delete all elements */ -void ht_delete_all(struct rcu_ht *ht) -{ - unsigned long i; - struct rcu_ht_node **prev, *node; - - for (i = 0; i < HASH_SIZE; i++) { - rcu_read_lock(); - - prev = &ht->tbl[i]; - node = rcu_dereference(*prev); - /* - * Cut the head, therefore whole bucket will be unused - * after GP. (except for concurrent additions) - */ - rcu_assign_pointer(prev, NULL); - for (;;) { - if (likely(!node)) { - break; - } - prev = &node->next; - if (node->data) - call_rcu(ht->free_fct, node->data); - call_rcu(free, node); - node = rcu_dereference(*prev); - } - rcu_read_unlock(); - } -} - -/* - * Should only be called when no more concurrent readers nor writers can - * possibly access the table. - */ -int ht_destroy(struct rcu_ht *ht) -{ - ht_delete_all(ht); - free(ht); -} - -void *ht_lookup(struct rcu_ht *ht, void *key) -{ - unsigned long hash; - struct rcu_ht_node *node; - void *ret; - - hash = ht->hash_fct(key); - - rcu_read_lock(); - node = rcu_dereference(ht->tbl[hash]); - for (;;) { - if (likely(!node)) { - ret = NULL; - break; - } - if (node->key == key) { - ret = node->data; - break; - } - node = rcu_dereference(node->next); - } - rcu_read_unlock(); -} - -/* - * Will re-try until either: - * - The key is already there (-EEXIST) - * - We successfully add the key at the head of a table bucket. - */ -int ht_add(struct rcu_ht *ht, void *key, void *data) -{ - struct rcu_ht_node *node, *old_head, *new_head; - unsigned long hash; - int ret = 0; - - new_head = calloc(1, sizeof(struct rcu_ht_node)); - new_head->key = key; - new_head->data = data; - hash = ht->hash_fct(key); - - /* here comes the fun and tricky part. - * Add at the beginning with a cmpxchg. - * Hold a read lock between the moment the first element is read - * and the nodes traversal (to find duplicates). This ensures - * the head pointer has not been reclaimed when cmpxchg is done. - * Always adding at the head ensures that we would have to - * re-try if a new item has been added concurrently. So we ensure that - * we never add duplicates. */ -retry: - rcu_read_lock(); - - old_head = node = rcu_dereference(ht->tbl[hash]); - for (;;) { - if (likely(!node)) { - break; - } - if (node->key == key) { - ret = -EEXIST; - goto end; - } - node = rcu_dereference(node->next); - } - if (rcu_cmpxchg_pointer(&ht->tbl[hash], old_head, new_head) != old_head) - goto restart; -end: - rcu_read_unlock(); - - return ret; - - /* restart loop, release and re-take the read lock to be kind to GP */ -restart: - rcu_read_unlock(); - goto retry; -} - -/* - * Restart until we successfully remove the entry, or no entry is left - * ((void *)(unsigned long)-ENOENT). - */ -struct rcu_ht_node *ht_steal(struct rcu_ht *ht, void *key); -{ - struct rcu_ht_node **prev, *node; - unsigned long hash; - - hash = ht->hash_fct(key); - -retry: - rcu_read_lock(); - - prev = &ht->tbl[hash]; - node = rcu_dereference(*prev); - for (;;) { - if (likely(!node)) { - node = (void *)(unsigned long)-ENOENT; - goto end; - } - if (node->key == key) { - break; - } - prev = &node->next; - node = rcu_dereference(*prev); - } - /* Found it ! pointer to object is in "prev" */ - if (rcu_cmpxchg_pointer(prev, node, node->next) != node) - goto restart; -end: - rcu_read_unlock(); - - return node; - - /* restart loop, release and re-take the read lock to be kind to GP */ -restart: - rcu_read_unlock(); - goto retry; -} - -int ht_delete(struct rcu_ht *ht, void *key) -{ - struct rcu_ht_node *node; - - node = ht_steal(ht, key); - if (node) { - if (free_fct && node->data) - call_rcu(ht->free_fct, node->data); - call_rcu(free, node); - return 0; - } else { - return -ENOENT; - } -} diff --git a/urcu-ht.c b/urcu-ht.c new file mode 100644 index 0000000..8edfae3 --- /dev/null +++ b/urcu-ht.c @@ -0,0 +1,216 @@ + +#define _LGPL_SOURCE +#include +#include +#include +#include +#include +#include +#include +#include +#include + +struct rcu_ht_node; + +struct rcu_ht_node { + struct rcu_ht_node *next; + void *key; + void *data; +}; + +struct rcu_ht { + struct rcu_ht_node *tbl[HASH_SIZE]; + ht_hash_fct hash_fct; + void (*free_fct)(void *data); /* fct to free data */ +}; + +struct rcu_ht *ht_new(ht_hash_fct hash_fct, void (*free_fct)(void *data)) +{ + struct rcu_ht *ht; + + ht = calloc(1, sizeof(struct rcu_ht)); + ht->hash_fct = hash_fct; + ht->free_fct = free_fct; + return ht; +} + +/* delete all elements */ +void ht_delete_all(struct rcu_ht *ht) +{ + unsigned long i; + struct rcu_ht_node **prev, *node; + + for (i = 0; i < HASH_SIZE; i++) { + rcu_read_lock(); + + prev = &ht->tbl[i]; + node = rcu_dereference(*prev); + /* + * Cut the head, therefore whole bucket will be unused + * after GP. (except for concurrent additions) + */ + rcu_assign_pointer(prev, NULL); + for (;;) { + if (likely(!node)) { + break; + } + prev = &node->next; + if (node->data) + call_rcu(ht->free_fct, node->data); + call_rcu(free, node); + node = rcu_dereference(*prev); + } + rcu_read_unlock(); + } +} + +/* + * Should only be called when no more concurrent readers nor writers can + * possibly access the table. + */ +void ht_destroy(struct rcu_ht *ht) +{ + ht_delete_all(ht); + free(ht); +} + +void *ht_lookup(struct rcu_ht *ht, void *key) +{ + unsigned long hash; + struct rcu_ht_node *node; + void *ret; + + hash = ht->hash_fct(key); + + rcu_read_lock(); + node = rcu_dereference(ht->tbl[hash]); + for (;;) { + if (likely(!node)) { + ret = NULL; + break; + } + if (node->key == key) { + ret = node->data; + break; + } + node = rcu_dereference(node->next); + } + rcu_read_unlock(); + + return ret; +} + +/* + * Will re-try until either: + * - The key is already there (-EEXIST) + * - We successfully add the key at the head of a table bucket. + */ +int ht_add(struct rcu_ht *ht, void *key, void *data) +{ + struct rcu_ht_node *node, *old_head, *new_head; + unsigned long hash; + int ret = 0; + + new_head = calloc(1, sizeof(struct rcu_ht_node)); + new_head->key = key; + new_head->data = data; + hash = ht->hash_fct(key); + + /* here comes the fun and tricky part. + * Add at the beginning with a cmpxchg. + * Hold a read lock between the moment the first element is read + * and the nodes traversal (to find duplicates). This ensures + * the head pointer has not been reclaimed when cmpxchg is done. + * Always adding at the head ensures that we would have to + * re-try if a new item has been added concurrently. So we ensure that + * we never add duplicates. */ +retry: + rcu_read_lock(); + + old_head = node = rcu_dereference(ht->tbl[hash]); + for (;;) { + if (likely(!node)) { + break; + } + if (node->key == key) { + ret = -EEXIST; + goto end; + } + node = rcu_dereference(node->next); + } + if (rcu_cmpxchg_pointer(&ht->tbl[hash], old_head, new_head) != old_head) + goto restart; +end: + rcu_read_unlock(); + + return ret; + + /* restart loop, release and re-take the read lock to be kind to GP */ +restart: + rcu_read_unlock(); + goto retry; +} + +/* + * Restart until we successfully remove the entry, or no entry is left + * ((void *)(unsigned long)-ENOENT). + */ +void *ht_steal(struct rcu_ht *ht, void *key) +{ + struct rcu_ht_node **prev, *node; + unsigned long hash; + void *data; + + hash = ht->hash_fct(key); + +retry: + rcu_read_lock(); + + prev = &ht->tbl[hash]; + node = rcu_dereference(*prev); + for (;;) { + if (likely(!node)) { + data = (void *)(unsigned long)-ENOENT; + goto end; + } + if (node->key == key) { + break; + } + prev = &node->next; + node = rcu_dereference(*prev); + } + /* Found it ! pointer to object is in "prev" */ + if (rcu_cmpxchg_pointer(prev, node, node->next) != node) + goto restart; +end: + rcu_read_unlock(); + + data = node->data; + call_rcu(free, node); + + return data; + + /* restart loop, release and re-take the read lock to be kind to GP */ +restart: + rcu_read_unlock(); + goto retry; +} + +int ht_delete(struct rcu_ht *ht, void *key) +{ + void *data; + + data = ht_steal(ht, key); + if (data) { + if (ht->free_fct && data) + call_rcu(ht->free_fct, data); + return 0; + } else { + return -ENOENT; + } +} + +unsigned long stupid_hash(void *key) +{ + return (unsigned long)key % HASH_SIZE; +} diff --git a/urcu-ht.h b/urcu-ht.h new file mode 100644 index 0000000..0cbd1e6 --- /dev/null +++ b/urcu-ht.h @@ -0,0 +1,23 @@ +#ifndef _URCU_HT_H +#define _URCU_HT_H + +#define HASH_SIZE 4096 +typedef unsigned long (*ht_hash_fct)(void *key); + +struct rcu_ht *ht_new(ht_hash_fct hash_fct, void (*free_fct)(void *data)); + +void ht_delete_all(struct rcu_ht *ht); + +void ht_destroy(struct rcu_ht *ht); + +void *ht_lookup(struct rcu_ht *ht, void *key); + +int ht_add(struct rcu_ht *ht, void *key, void *data); + +int ht_delete(struct rcu_ht *ht, void *key); + +void *ht_steal(struct rcu_ht *ht, void *key); + +unsigned long stupid_hash(void *key); + +#endif /* _URCU_HT_H */