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author | 2016-03-25 17:07:29 -0700 | |
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committer | 2016-03-25 17:07:29 -0700 | |
commit | f23078cbd302d32649537eedda1769c5685228d8 (patch) | |
tree | b0bb46845658e5b8256868d102076226aa10215e /src/core/lib/transport/metadata.c | |
parent | f3d76384351039266e250aacf97c90d5b0c07dca (diff) |
Stage #1 of core breakup: move everything under lib
Diffstat (limited to 'src/core/lib/transport/metadata.c')
-rw-r--r-- | src/core/lib/transport/metadata.c | 698 |
1 files changed, 698 insertions, 0 deletions
diff --git a/src/core/lib/transport/metadata.c b/src/core/lib/transport/metadata.c new file mode 100644 index 0000000000..7ed28feca8 --- /dev/null +++ b/src/core/lib/transport/metadata.c @@ -0,0 +1,698 @@ +/* + * + * Copyright 2015-2016, Google Inc. + * 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. + * * Neither the name of Google Inc. nor the names of its + * contributors may be used to endorse or promote products derived from + * this software without specific prior written permission. + * + * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS 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 COPYRIGHT + * OWNER 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. + * + */ + +#include "src/core/transport/metadata.h" + +#include <assert.h> +#include <stddef.h> +#include <string.h> + +#include <grpc/compression.h> +#include <grpc/support/alloc.h> +#include <grpc/support/atm.h> +#include <grpc/support/log.h> +#include <grpc/support/string_util.h> +#include <grpc/support/time.h> + +#include "src/core/iomgr/iomgr_internal.h" +#include "src/core/profiling/timers.h" +#include "src/core/support/murmur_hash.h" +#include "src/core/support/string.h" +#include "src/core/transport/chttp2/bin_encoder.h" +#include "src/core/transport/static_metadata.h" + +/* There are two kinds of mdelem and mdstr instances. + * Static instances are declared in static_metadata.{h,c} and + * are initialized by grpc_mdctx_global_init(). + * Dynamic instances are stored in hash tables on grpc_mdctx, and are backed + * by internal_string and internal_element structures. + * Internal helper functions here-in (is_mdstr_static, is_mdelem_static) are + * used to determine which kind of element a pointer refers to. + */ + +#define INITIAL_STRTAB_CAPACITY 4 +#define INITIAL_MDTAB_CAPACITY 4 + +#ifdef GRPC_METADATA_REFCOUNT_DEBUG +#define DEBUG_ARGS , const char *file, int line +#define FWD_DEBUG_ARGS , file, line +#define REF_MD_LOCKED(shard, s) ref_md_locked((shard), (s), __FILE__, __LINE__) +#else +#define DEBUG_ARGS +#define FWD_DEBUG_ARGS +#define REF_MD_LOCKED(shard, s) ref_md_locked((shard), (s)) +#endif + +#define TABLE_IDX(hash, log2_shards, capacity) \ + (((hash) >> (log2_shards)) % (capacity)) +#define SHARD_IDX(hash, log2_shards) ((hash) & ((1 << (log2_shards)) - 1)) + +typedef void (*destroy_user_data_func)(void *user_data); + +/* Shadow structure for grpc_mdstr for non-static values */ +typedef struct internal_string { + /* must be byte compatible with grpc_mdstr */ + gpr_slice slice; + uint32_t hash; + + /* private only data */ + gpr_atm refcnt; + + uint8_t has_base64_and_huffman_encoded; + gpr_slice_refcount refcount; + + gpr_slice base64_and_huffman; + + struct internal_string *bucket_next; +} internal_string; + +/* Shadow structure for grpc_mdelem for non-static elements */ +typedef struct internal_metadata { + /* must be byte compatible with grpc_mdelem */ + internal_string *key; + internal_string *value; + + /* private only data */ + gpr_atm refcnt; + + gpr_mu mu_user_data; + gpr_atm destroy_user_data; + gpr_atm user_data; + + struct internal_metadata *bucket_next; +} internal_metadata; + +typedef struct strtab_shard { + gpr_mu mu; + internal_string **strs; + size_t count; + size_t capacity; +} strtab_shard; + +typedef struct mdtab_shard { + gpr_mu mu; + internal_metadata **elems; + size_t count; + size_t capacity; + size_t free; +} mdtab_shard; + +#define LOG2_STRTAB_SHARD_COUNT 5 +#define LOG2_MDTAB_SHARD_COUNT 4 +#define STRTAB_SHARD_COUNT ((size_t)(1 << LOG2_STRTAB_SHARD_COUNT)) +#define MDTAB_SHARD_COUNT ((size_t)(1 << LOG2_MDTAB_SHARD_COUNT)) + +/* hash seed: decided at initialization time */ +static uint32_t g_hash_seed; +static int g_forced_hash_seed = 0; + +/* linearly probed hash tables for static element lookup */ +static grpc_mdstr *g_static_strtab[GRPC_STATIC_MDSTR_COUNT * 2]; +static grpc_mdelem *g_static_mdtab[GRPC_STATIC_MDELEM_COUNT * 2]; +static size_t g_static_strtab_maxprobe; +static size_t g_static_mdtab_maxprobe; + +static strtab_shard g_strtab_shard[STRTAB_SHARD_COUNT]; +static mdtab_shard g_mdtab_shard[MDTAB_SHARD_COUNT]; + +static void gc_mdtab(mdtab_shard *shard); + +void grpc_test_only_set_metadata_hash_seed(uint32_t seed) { + g_hash_seed = seed; + g_forced_hash_seed = 1; +} + +void grpc_mdctx_global_init(void) { + size_t i, j; + if (!g_forced_hash_seed) { + g_hash_seed = (uint32_t)gpr_now(GPR_CLOCK_REALTIME).tv_nsec; + } + g_static_strtab_maxprobe = 0; + g_static_mdtab_maxprobe = 0; + /* build static tables */ + memset(g_static_mdtab, 0, sizeof(g_static_mdtab)); + memset(g_static_strtab, 0, sizeof(g_static_strtab)); + for (i = 0; i < GRPC_STATIC_MDSTR_COUNT; i++) { + grpc_mdstr *elem = &grpc_static_mdstr_table[i]; + const char *str = grpc_static_metadata_strings[i]; + uint32_t hash = gpr_murmur_hash3(str, strlen(str), g_hash_seed); + *(gpr_slice *)&elem->slice = gpr_slice_from_static_string(str); + *(uint32_t *)&elem->hash = hash; + for (j = 0;; j++) { + size_t idx = (hash + j) % GPR_ARRAY_SIZE(g_static_strtab); + if (g_static_strtab[idx] == NULL) { + g_static_strtab[idx] = &grpc_static_mdstr_table[i]; + break; + } + } + if (j > g_static_strtab_maxprobe) { + g_static_strtab_maxprobe = j; + } + } + for (i = 0; i < GRPC_STATIC_MDELEM_COUNT; i++) { + grpc_mdelem *elem = &grpc_static_mdelem_table[i]; + grpc_mdstr *key = + &grpc_static_mdstr_table[grpc_static_metadata_elem_indices[2 * i + 0]]; + grpc_mdstr *value = + &grpc_static_mdstr_table[grpc_static_metadata_elem_indices[2 * i + 1]]; + uint32_t hash = GRPC_MDSTR_KV_HASH(key->hash, value->hash); + *(grpc_mdstr **)&elem->key = key; + *(grpc_mdstr **)&elem->value = value; + for (j = 0;; j++) { + size_t idx = (hash + j) % GPR_ARRAY_SIZE(g_static_mdtab); + if (g_static_mdtab[idx] == NULL) { + g_static_mdtab[idx] = elem; + break; + } + } + if (j > g_static_mdtab_maxprobe) { + g_static_mdtab_maxprobe = j; + } + } + /* initialize shards */ + for (i = 0; i < STRTAB_SHARD_COUNT; i++) { + strtab_shard *shard = &g_strtab_shard[i]; + gpr_mu_init(&shard->mu); + shard->count = 0; + shard->capacity = INITIAL_STRTAB_CAPACITY; + shard->strs = gpr_malloc(sizeof(*shard->strs) * shard->capacity); + memset(shard->strs, 0, sizeof(*shard->strs) * shard->capacity); + } + for (i = 0; i < MDTAB_SHARD_COUNT; i++) { + mdtab_shard *shard = &g_mdtab_shard[i]; + gpr_mu_init(&shard->mu); + shard->count = 0; + shard->free = 0; + shard->capacity = INITIAL_MDTAB_CAPACITY; + shard->elems = gpr_malloc(sizeof(*shard->elems) * shard->capacity); + memset(shard->elems, 0, sizeof(*shard->elems) * shard->capacity); + } +} + +void grpc_mdctx_global_shutdown(void) { + size_t i; + for (i = 0; i < MDTAB_SHARD_COUNT; i++) { + mdtab_shard *shard = &g_mdtab_shard[i]; + gpr_mu_destroy(&shard->mu); + gc_mdtab(shard); + /* TODO(ctiller): GPR_ASSERT(shard->count == 0); */ + if (shard->count != 0) { + gpr_log(GPR_DEBUG, "WARNING: %d metadata elements were leaked", + shard->count); + if (grpc_iomgr_abort_on_leaks()) { + abort(); + } + } + gpr_free(shard->elems); + } + for (i = 0; i < STRTAB_SHARD_COUNT; i++) { + strtab_shard *shard = &g_strtab_shard[i]; + gpr_mu_destroy(&shard->mu); + /* TODO(ctiller): GPR_ASSERT(shard->count == 0); */ + if (shard->count != 0) { + gpr_log(GPR_DEBUG, "WARNING: %d metadata strings were leaked", + shard->count); + if (grpc_iomgr_abort_on_leaks()) { + abort(); + } + } + gpr_free(shard->strs); + } +} + +static int is_mdstr_static(grpc_mdstr *s) { + return s >= &grpc_static_mdstr_table[0] && + s < &grpc_static_mdstr_table[GRPC_STATIC_MDSTR_COUNT]; +} + +static int is_mdelem_static(grpc_mdelem *e) { + return e >= &grpc_static_mdelem_table[0] && + e < &grpc_static_mdelem_table[GRPC_STATIC_MDELEM_COUNT]; +} + +static void ref_md_locked(mdtab_shard *shard, + internal_metadata *md DEBUG_ARGS) { +#ifdef GRPC_METADATA_REFCOUNT_DEBUG + gpr_log(file, line, GPR_LOG_SEVERITY_DEBUG, + "ELM REF:%p:%d->%d: '%s' = '%s'", md, + gpr_atm_no_barrier_load(&md->refcnt), + gpr_atm_no_barrier_load(&md->refcnt) + 1, + grpc_mdstr_as_c_string((grpc_mdstr *)md->key), + grpc_mdstr_as_c_string((grpc_mdstr *)md->value)); +#endif + if (0 == gpr_atm_no_barrier_fetch_add(&md->refcnt, 2)) { + shard->free--; + } else { + GPR_ASSERT(1 != gpr_atm_no_barrier_fetch_add(&md->refcnt, -1)); + } +} + +static void grow_strtab(strtab_shard *shard) { + size_t capacity = shard->capacity * 2; + size_t i; + internal_string **strtab; + internal_string *s, *next; + + GPR_TIMER_BEGIN("grow_strtab", 0); + + strtab = gpr_malloc(sizeof(internal_string *) * capacity); + memset(strtab, 0, sizeof(internal_string *) * capacity); + + for (i = 0; i < shard->capacity; i++) { + for (s = shard->strs[i]; s; s = next) { + size_t idx = TABLE_IDX(s->hash, LOG2_STRTAB_SHARD_COUNT, capacity); + next = s->bucket_next; + s->bucket_next = strtab[idx]; + strtab[idx] = s; + } + } + + gpr_free(shard->strs); + shard->strs = strtab; + shard->capacity = capacity; + + GPR_TIMER_END("grow_strtab", 0); +} + +static void internal_destroy_string(strtab_shard *shard, internal_string *is) { + internal_string **prev_next; + internal_string *cur; + GPR_TIMER_BEGIN("internal_destroy_string", 0); + if (is->has_base64_and_huffman_encoded) { + gpr_slice_unref(is->base64_and_huffman); + } + for (prev_next = &shard->strs[TABLE_IDX(is->hash, LOG2_STRTAB_SHARD_COUNT, + shard->capacity)], + cur = *prev_next; + cur != is; prev_next = &cur->bucket_next, cur = cur->bucket_next) + ; + *prev_next = cur->bucket_next; + shard->count--; + gpr_free(is); + GPR_TIMER_END("internal_destroy_string", 0); +} + +static void slice_ref(void *p) { + internal_string *is = + (internal_string *)((char *)p - offsetof(internal_string, refcount)); + GRPC_MDSTR_REF((grpc_mdstr *)(is)); +} + +static void slice_unref(void *p) { + internal_string *is = + (internal_string *)((char *)p - offsetof(internal_string, refcount)); + GRPC_MDSTR_UNREF((grpc_mdstr *)(is)); +} + +grpc_mdstr *grpc_mdstr_from_string(const char *str) { + return grpc_mdstr_from_buffer((const uint8_t *)str, strlen(str)); +} + +grpc_mdstr *grpc_mdstr_from_slice(gpr_slice slice) { + grpc_mdstr *result = grpc_mdstr_from_buffer(GPR_SLICE_START_PTR(slice), + GPR_SLICE_LENGTH(slice)); + gpr_slice_unref(slice); + return result; +} + +grpc_mdstr *grpc_mdstr_from_buffer(const uint8_t *buf, size_t length) { + uint32_t hash = gpr_murmur_hash3(buf, length, g_hash_seed); + internal_string *s; + strtab_shard *shard = + &g_strtab_shard[SHARD_IDX(hash, LOG2_STRTAB_SHARD_COUNT)]; + size_t i; + size_t idx; + + GPR_TIMER_BEGIN("grpc_mdstr_from_buffer", 0); + + /* search for a static string */ + for (i = 0; i <= g_static_strtab_maxprobe; i++) { + grpc_mdstr *ss; + idx = (hash + i) % GPR_ARRAY_SIZE(g_static_strtab); + ss = g_static_strtab[idx]; + if (ss == NULL) break; + if (ss->hash == hash && GPR_SLICE_LENGTH(ss->slice) == length && + 0 == memcmp(buf, GPR_SLICE_START_PTR(ss->slice), length)) { + GPR_TIMER_END("grpc_mdstr_from_buffer", 0); + return ss; + } + } + + gpr_mu_lock(&shard->mu); + + /* search for an existing string */ + idx = TABLE_IDX(hash, LOG2_STRTAB_SHARD_COUNT, shard->capacity); + for (s = shard->strs[idx]; s; s = s->bucket_next) { + if (s->hash == hash && GPR_SLICE_LENGTH(s->slice) == length && + 0 == memcmp(buf, GPR_SLICE_START_PTR(s->slice), length)) { + GRPC_MDSTR_REF((grpc_mdstr *)s); + gpr_mu_unlock(&shard->mu); + GPR_TIMER_END("grpc_mdstr_from_buffer", 0); + return (grpc_mdstr *)s; + } + } + + /* not found: create a new string */ + if (length + 1 < GPR_SLICE_INLINED_SIZE) { + /* string data goes directly into the slice */ + s = gpr_malloc(sizeof(internal_string)); + gpr_atm_rel_store(&s->refcnt, 2); + s->slice.refcount = NULL; + memcpy(s->slice.data.inlined.bytes, buf, length); + s->slice.data.inlined.bytes[length] = 0; + s->slice.data.inlined.length = (uint8_t)length; + } else { + /* string data goes after the internal_string header, and we +1 for null + terminator */ + s = gpr_malloc(sizeof(internal_string) + length + 1); + gpr_atm_rel_store(&s->refcnt, 2); + s->refcount.ref = slice_ref; + s->refcount.unref = slice_unref; + s->slice.refcount = &s->refcount; + s->slice.data.refcounted.bytes = (uint8_t *)(s + 1); + s->slice.data.refcounted.length = length; + memcpy(s->slice.data.refcounted.bytes, buf, length); + /* add a null terminator for cheap c string conversion when desired */ + s->slice.data.refcounted.bytes[length] = 0; + } + s->has_base64_and_huffman_encoded = 0; + s->hash = hash; + s->bucket_next = shard->strs[idx]; + shard->strs[idx] = s; + + shard->count++; + + if (shard->count > shard->capacity * 2) { + grow_strtab(shard); + } + + gpr_mu_unlock(&shard->mu); + GPR_TIMER_END("grpc_mdstr_from_buffer", 0); + + return (grpc_mdstr *)s; +} + +static void gc_mdtab(mdtab_shard *shard) { + size_t i; + internal_metadata **prev_next; + internal_metadata *md, *next; + + GPR_TIMER_BEGIN("gc_mdtab", 0); + for (i = 0; i < shard->capacity; i++) { + prev_next = &shard->elems[i]; + for (md = shard->elems[i]; md; md = next) { + void *user_data = (void *)gpr_atm_no_barrier_load(&md->user_data); + next = md->bucket_next; + if (gpr_atm_acq_load(&md->refcnt) == 0) { + GRPC_MDSTR_UNREF((grpc_mdstr *)md->key); + GRPC_MDSTR_UNREF((grpc_mdstr *)md->value); + if (md->user_data) { + ((destroy_user_data_func)gpr_atm_no_barrier_load( + &md->destroy_user_data))(user_data); + } + gpr_free(md); + *prev_next = next; + shard->free--; + shard->count--; + } else { + prev_next = &md->bucket_next; + } + } + } + GPR_TIMER_END("gc_mdtab", 0); +} + +static void grow_mdtab(mdtab_shard *shard) { + size_t capacity = shard->capacity * 2; + size_t i; + internal_metadata **mdtab; + internal_metadata *md, *next; + uint32_t hash; + + GPR_TIMER_BEGIN("grow_mdtab", 0); + + mdtab = gpr_malloc(sizeof(internal_metadata *) * capacity); + memset(mdtab, 0, sizeof(internal_metadata *) * capacity); + + for (i = 0; i < shard->capacity; i++) { + for (md = shard->elems[i]; md; md = next) { + size_t idx; + hash = GRPC_MDSTR_KV_HASH(md->key->hash, md->value->hash); + next = md->bucket_next; + idx = TABLE_IDX(hash, LOG2_MDTAB_SHARD_COUNT, capacity); + md->bucket_next = mdtab[idx]; + mdtab[idx] = md; + } + } + + gpr_free(shard->elems); + shard->elems = mdtab; + shard->capacity = capacity; + + GPR_TIMER_END("grow_mdtab", 0); +} + +static void rehash_mdtab(mdtab_shard *shard) { + if (shard->free > shard->capacity / 4) { + gc_mdtab(shard); + } else { + grow_mdtab(shard); + } +} + +grpc_mdelem *grpc_mdelem_from_metadata_strings(grpc_mdstr *mkey, + grpc_mdstr *mvalue) { + internal_string *key = (internal_string *)mkey; + internal_string *value = (internal_string *)mvalue; + uint32_t hash = GRPC_MDSTR_KV_HASH(mkey->hash, mvalue->hash); + internal_metadata *md; + mdtab_shard *shard = &g_mdtab_shard[SHARD_IDX(hash, LOG2_MDTAB_SHARD_COUNT)]; + size_t i; + size_t idx; + + GPR_TIMER_BEGIN("grpc_mdelem_from_metadata_strings", 0); + + if (is_mdstr_static(mkey) && is_mdstr_static(mvalue)) { + for (i = 0; i <= g_static_mdtab_maxprobe; i++) { + grpc_mdelem *smd; + idx = (hash + i) % GPR_ARRAY_SIZE(g_static_mdtab); + smd = g_static_mdtab[idx]; + if (smd == NULL) break; + if (smd->key == mkey && smd->value == mvalue) { + GPR_TIMER_END("grpc_mdelem_from_metadata_strings", 0); + return smd; + } + } + } + + gpr_mu_lock(&shard->mu); + + idx = TABLE_IDX(hash, LOG2_MDTAB_SHARD_COUNT, shard->capacity); + /* search for an existing pair */ + for (md = shard->elems[idx]; md; md = md->bucket_next) { + if (md->key == key && md->value == value) { + REF_MD_LOCKED(shard, md); + GRPC_MDSTR_UNREF((grpc_mdstr *)key); + GRPC_MDSTR_UNREF((grpc_mdstr *)value); + gpr_mu_unlock(&shard->mu); + GPR_TIMER_END("grpc_mdelem_from_metadata_strings", 0); + return (grpc_mdelem *)md; + } + } + + /* not found: create a new pair */ + md = gpr_malloc(sizeof(internal_metadata)); + gpr_atm_rel_store(&md->refcnt, 2); + md->key = key; + md->value = value; + md->user_data = 0; + md->destroy_user_data = 0; + md->bucket_next = shard->elems[idx]; + shard->elems[idx] = md; + gpr_mu_init(&md->mu_user_data); +#ifdef GRPC_METADATA_REFCOUNT_DEBUG + gpr_log(GPR_DEBUG, "ELM NEW:%p:%d: '%s' = '%s'", md, + gpr_atm_no_barrier_load(&md->refcnt), + grpc_mdstr_as_c_string((grpc_mdstr *)md->key), + grpc_mdstr_as_c_string((grpc_mdstr *)md->value)); +#endif + shard->count++; + + if (shard->count > shard->capacity * 2) { + rehash_mdtab(shard); + } + + gpr_mu_unlock(&shard->mu); + + GPR_TIMER_END("grpc_mdelem_from_metadata_strings", 0); + + return (grpc_mdelem *)md; +} + +grpc_mdelem *grpc_mdelem_from_strings(const char *key, const char *value) { + return grpc_mdelem_from_metadata_strings(grpc_mdstr_from_string(key), + grpc_mdstr_from_string(value)); +} + +grpc_mdelem *grpc_mdelem_from_slices(gpr_slice key, gpr_slice value) { + return grpc_mdelem_from_metadata_strings(grpc_mdstr_from_slice(key), + grpc_mdstr_from_slice(value)); +} + +grpc_mdelem *grpc_mdelem_from_string_and_buffer(const char *key, + const uint8_t *value, + size_t value_length) { + return grpc_mdelem_from_metadata_strings( + grpc_mdstr_from_string(key), grpc_mdstr_from_buffer(value, value_length)); +} + +grpc_mdelem *grpc_mdelem_ref(grpc_mdelem *gmd DEBUG_ARGS) { + internal_metadata *md = (internal_metadata *)gmd; + if (is_mdelem_static(gmd)) return gmd; +#ifdef GRPC_METADATA_REFCOUNT_DEBUG + gpr_log(file, line, GPR_LOG_SEVERITY_DEBUG, + "ELM REF:%p:%d->%d: '%s' = '%s'", md, + gpr_atm_no_barrier_load(&md->refcnt), + gpr_atm_no_barrier_load(&md->refcnt) + 1, + grpc_mdstr_as_c_string((grpc_mdstr *)md->key), + grpc_mdstr_as_c_string((grpc_mdstr *)md->value)); +#endif + /* we can assume the ref count is >= 1 as the application is calling + this function - meaning that no adjustment to mdtab_free is necessary, + simplifying the logic here to be just an atomic increment */ + /* use C assert to have this removed in opt builds */ + assert(gpr_atm_no_barrier_load(&md->refcnt) >= 2); + gpr_atm_no_barrier_fetch_add(&md->refcnt, 1); + return gmd; +} + +void grpc_mdelem_unref(grpc_mdelem *gmd DEBUG_ARGS) { + internal_metadata *md = (internal_metadata *)gmd; + if (!md) return; + if (is_mdelem_static(gmd)) return; +#ifdef GRPC_METADATA_REFCOUNT_DEBUG + gpr_log(file, line, GPR_LOG_SEVERITY_DEBUG, + "ELM UNREF:%p:%d->%d: '%s' = '%s'", md, + gpr_atm_no_barrier_load(&md->refcnt), + gpr_atm_no_barrier_load(&md->refcnt) - 1, + grpc_mdstr_as_c_string((grpc_mdstr *)md->key), + grpc_mdstr_as_c_string((grpc_mdstr *)md->value)); +#endif + if (2 == gpr_atm_full_fetch_add(&md->refcnt, -1)) { + uint32_t hash = GRPC_MDSTR_KV_HASH(md->key->hash, md->value->hash); + mdtab_shard *shard = + &g_mdtab_shard[SHARD_IDX(hash, LOG2_MDTAB_SHARD_COUNT)]; + GPR_TIMER_BEGIN("grpc_mdelem_unref.to_zero", 0); + gpr_mu_lock(&shard->mu); + if (1 == gpr_atm_no_barrier_load(&md->refcnt)) { + shard->free++; + gpr_atm_no_barrier_store(&md->refcnt, 0); + } + gpr_mu_unlock(&shard->mu); + GPR_TIMER_END("grpc_mdelem_unref.to_zero", 0); + } +} + +const char *grpc_mdstr_as_c_string(grpc_mdstr *s) { + return (const char *)GPR_SLICE_START_PTR(s->slice); +} + +grpc_mdstr *grpc_mdstr_ref(grpc_mdstr *gs DEBUG_ARGS) { + internal_string *s = (internal_string *)gs; + if (is_mdstr_static(gs)) return gs; + GPR_ASSERT(gpr_atm_full_fetch_add(&s->refcnt, 1) != 0); + return gs; +} + +void grpc_mdstr_unref(grpc_mdstr *gs DEBUG_ARGS) { + internal_string *s = (internal_string *)gs; + if (is_mdstr_static(gs)) return; + if (2 == gpr_atm_full_fetch_add(&s->refcnt, -1)) { + strtab_shard *shard = + &g_strtab_shard[SHARD_IDX(s->hash, LOG2_STRTAB_SHARD_COUNT)]; + gpr_mu_lock(&shard->mu); + if (1 == gpr_atm_no_barrier_load(&s->refcnt)) { + internal_destroy_string(shard, s); + } + gpr_mu_unlock(&shard->mu); + } +} + +void *grpc_mdelem_get_user_data(grpc_mdelem *md, void (*destroy_func)(void *)) { + internal_metadata *im = (internal_metadata *)md; + void *result; + if (is_mdelem_static(md)) { + return (void *)grpc_static_mdelem_user_data[md - grpc_static_mdelem_table]; + } + if (gpr_atm_acq_load(&im->destroy_user_data) == (gpr_atm)destroy_func) { + return (void *)gpr_atm_no_barrier_load(&im->user_data); + } else { + return NULL; + } + return result; +} + +void grpc_mdelem_set_user_data(grpc_mdelem *md, void (*destroy_func)(void *), + void *user_data) { + internal_metadata *im = (internal_metadata *)md; + GPR_ASSERT(!is_mdelem_static(md)); + GPR_ASSERT((user_data == NULL) == (destroy_func == NULL)); + gpr_mu_lock(&im->mu_user_data); + if (gpr_atm_no_barrier_load(&im->destroy_user_data)) { + /* user data can only be set once */ + gpr_mu_unlock(&im->mu_user_data); + if (destroy_func != NULL) { + destroy_func(user_data); + } + return; + } + gpr_atm_no_barrier_store(&im->user_data, (gpr_atm)user_data); + gpr_atm_rel_store(&im->destroy_user_data, (gpr_atm)destroy_func); + gpr_mu_unlock(&im->mu_user_data); +} + +gpr_slice grpc_mdstr_as_base64_encoded_and_huffman_compressed(grpc_mdstr *gs) { + internal_string *s = (internal_string *)gs; + gpr_slice slice; + strtab_shard *shard = + &g_strtab_shard[SHARD_IDX(s->hash, LOG2_STRTAB_SHARD_COUNT)]; + gpr_mu_lock(&shard->mu); + if (!s->has_base64_and_huffman_encoded) { + s->base64_and_huffman = + grpc_chttp2_base64_encode_and_huffman_compress(s->slice); + s->has_base64_and_huffman_encoded = 1; + } + slice = s->base64_and_huffman; + gpr_mu_unlock(&shard->mu); + return slice; +} |