diff options
| -rw-r--r-- | accel/tcg/translate-all.c | 2 | ||||
| -rw-r--r-- | include/qemu/qht.h | 7 | ||||
| -rw-r--r-- | tests/qht-bench.c | 4 | ||||
| -rw-r--r-- | tests/test-qht.c | 8 | ||||
| -rw-r--r-- | util/qht.c | 27 |
5 files changed, 32 insertions, 16 deletions
diff --git a/accel/tcg/translate-all.c b/accel/tcg/translate-all.c index f39123bd5a..1695f8c352 100644 --- a/accel/tcg/translate-all.c +++ b/accel/tcg/translate-all.c @@ -1242,7 +1242,7 @@ static void tb_link_page(TranslationBlock *tb, tb_page_addr_t phys_pc, /* add in the hash table */ h = tb_hash_func(phys_pc, tb->pc, tb->flags, tb->cflags & CF_HASH_MASK, tb->trace_vcpu_dstate); - qht_insert(&tb_ctx.htable, tb, h); + qht_insert(&tb_ctx.htable, tb, h, NULL); #ifdef CONFIG_USER_ONLY if (DEBUG_TB_CHECK_GATE) { diff --git a/include/qemu/qht.h b/include/qemu/qht.h index 5f03a0f4cb..1fb9116fa0 100644 --- a/include/qemu/qht.h +++ b/include/qemu/qht.h @@ -70,6 +70,7 @@ void qht_destroy(struct qht *ht); * @ht: QHT to insert to * @p: pointer to be inserted * @hash: hash corresponding to @p + * @existing: address where the pointer to an existing entry can be copied to * * Attempting to insert a NULL @p is a bug. * Inserting the same pointer @p with different @hash values is a bug. @@ -78,9 +79,11 @@ void qht_destroy(struct qht *ht); * inserted into the hash table. * * Returns true on success. - * Returns false if the @p-@hash pair already exists in the hash table. + * Returns false if there is an existing entry in the table that is equivalent + * (i.e. ht->cmp matches and the hash is the same) to @p-@h. If @existing + * is !NULL, a pointer to this existing entry is copied to it. */ -bool qht_insert(struct qht *ht, void *p, uint32_t hash); +bool qht_insert(struct qht *ht, void *p, uint32_t hash, void **existing); /** * qht_lookup_custom - Look up a pointer using a custom comparison function. diff --git a/tests/qht-bench.c b/tests/qht-bench.c index c94ac25158..f492b3a20a 100644 --- a/tests/qht-bench.c +++ b/tests/qht-bench.c @@ -163,7 +163,7 @@ static void do_rw(struct thread_info *info) bool written = false; if (qht_lookup(&ht, p, hash) == NULL) { - written = qht_insert(&ht, p, hash); + written = qht_insert(&ht, p, hash, NULL); } if (written) { stats->in++; @@ -322,7 +322,7 @@ static void htable_init(void) r = xorshift64star(r); p = &keys[r & (init_range - 1)]; hash = h(*p); - if (qht_insert(&ht, p, hash)) { + if (qht_insert(&ht, p, hash, NULL)) { break; } retries++; diff --git a/tests/test-qht.c b/tests/test-qht.c index b069881342..dda6a067be 100644 --- a/tests/test-qht.c +++ b/tests/test-qht.c @@ -27,11 +27,17 @@ static void insert(int a, int b) for (i = a; i < b; i++) { uint32_t hash; + void *existing; + bool inserted; arr[i] = i; hash = i; - qht_insert(&ht, &arr[i], hash); + inserted = qht_insert(&ht, &arr[i], hash, NULL); + g_assert_true(inserted); + inserted = qht_insert(&ht, &arr[i], hash, &existing); + g_assert_false(inserted); + g_assert_true(existing == &arr[i]); } } diff --git a/util/qht.c b/util/qht.c index 487e9237bc..c138777a9c 100644 --- a/util/qht.c +++ b/util/qht.c @@ -511,9 +511,9 @@ void *qht_lookup(struct qht *ht, const void *userp, uint32_t hash) } /* call with head->lock held */ -static bool qht_insert__locked(struct qht *ht, struct qht_map *map, - struct qht_bucket *head, void *p, uint32_t hash, - bool *needs_resize) +static void *qht_insert__locked(struct qht *ht, struct qht_map *map, + struct qht_bucket *head, void *p, uint32_t hash, + bool *needs_resize) { struct qht_bucket *b = head; struct qht_bucket *prev = NULL; @@ -523,8 +523,9 @@ static bool qht_insert__locked(struct qht *ht, struct qht_map *map, do { for (i = 0; i < QHT_BUCKET_ENTRIES; i++) { if (b->pointers[i]) { - if (unlikely(b->pointers[i] == p)) { - return false; + if (unlikely(b->hashes[i] == hash && + ht->cmp(b->pointers[i], p))) { + return b->pointers[i]; } } else { goto found; @@ -553,7 +554,7 @@ static bool qht_insert__locked(struct qht *ht, struct qht_map *map, atomic_set(&b->hashes[i], hash); atomic_set(&b->pointers[i], p); seqlock_write_end(&head->sequence); - return true; + return NULL; } static __attribute__((noinline)) void qht_grow_maybe(struct qht *ht) @@ -577,25 +578,31 @@ static __attribute__((noinline)) void qht_grow_maybe(struct qht *ht) qemu_mutex_unlock(&ht->lock); } -bool qht_insert(struct qht *ht, void *p, uint32_t hash) +bool qht_insert(struct qht *ht, void *p, uint32_t hash, void **existing) { struct qht_bucket *b; struct qht_map *map; bool needs_resize = false; - bool ret; + void *prev; /* NULL pointers are not supported */ qht_debug_assert(p); b = qht_bucket_lock__no_stale(ht, hash, &map); - ret = qht_insert__locked(ht, map, b, p, hash, &needs_resize); + prev = qht_insert__locked(ht, map, b, p, hash, &needs_resize); qht_bucket_debug__locked(b); qemu_spin_unlock(&b->lock); if (unlikely(needs_resize) && ht->mode & QHT_MODE_AUTO_RESIZE) { qht_grow_maybe(ht); } - return ret; + if (likely(prev == NULL)) { + return true; + } + if (existing) { + *existing = prev; + } + return false; } static inline bool qht_entry_is_last(struct qht_bucket *b, int pos) |