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author | 2017-03-17 13:02:03 -0700 | |
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committer | 2017-03-17 16:00:17 -0700 | |
commit | 9bc0d8200ec17ababe4c9cd6134a2cb7465365a6 (patch) | |
tree | 14ac57b2410205774b345de360b0886033d7d433 /src/core/lib/support/arena.c | |
parent | cabb1517e5ac3cdbe59415678d4f0d284f9fabda (diff) | |
parent | 40a947ef93aeddca3b606613f628d4d09f094e77 (diff) |
Merge remote-tracking branch 'upstream/master' into cares_bazel_rule
Diffstat (limited to 'src/core/lib/support/arena.c')
-rw-r--r-- | src/core/lib/support/arena.c | 98 |
1 files changed, 98 insertions, 0 deletions
diff --git a/src/core/lib/support/arena.c b/src/core/lib/support/arena.c new file mode 100644 index 0000000000..7bcb983f24 --- /dev/null +++ b/src/core/lib/support/arena.c @@ -0,0 +1,98 @@ +/* + * + * Copyright 2017, 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/lib/support/arena.h" +#include <grpc/support/alloc.h> +#include <grpc/support/atm.h> +#include <grpc/support/log.h> +#include <grpc/support/useful.h> + +#define ROUND_UP_TO_ALIGNMENT_SIZE(x) \ + (((x) + GPR_MAX_ALIGNMENT - 1u) & ~(GPR_MAX_ALIGNMENT - 1u)) + +typedef struct zone { + size_t size_begin; + size_t size_end; + gpr_atm next_atm; +} zone; + +struct gpr_arena { + gpr_atm size_so_far; + zone initial_zone; +}; + +gpr_arena *gpr_arena_create(size_t initial_size) { + initial_size = ROUND_UP_TO_ALIGNMENT_SIZE(initial_size); + gpr_arena *a = gpr_zalloc(sizeof(gpr_arena) + initial_size); + a->initial_zone.size_end = initial_size; + return a; +} + +size_t gpr_arena_destroy(gpr_arena *arena) { + gpr_atm size = gpr_atm_no_barrier_load(&arena->size_so_far); + zone *z = (zone *)gpr_atm_no_barrier_load(&arena->initial_zone.next_atm); + gpr_free(arena); + while (z) { + zone *next_z = (zone *)gpr_atm_no_barrier_load(&z->next_atm); + gpr_free(z); + z = next_z; + } + return (size_t)size; +} + +void *gpr_arena_alloc(gpr_arena *arena, size_t size) { + size = ROUND_UP_TO_ALIGNMENT_SIZE(size); + size_t start = + (size_t)gpr_atm_no_barrier_fetch_add(&arena->size_so_far, size); + zone *z = &arena->initial_zone; + while (start > z->size_end) { + zone *next_z = (zone *)gpr_atm_acq_load(&z->next_atm); + if (next_z == NULL) { + size_t next_z_size = (size_t)gpr_atm_no_barrier_load(&arena->size_so_far); + next_z = gpr_zalloc(sizeof(zone) + next_z_size); + next_z->size_begin = z->size_end; + next_z->size_end = z->size_end + next_z_size; + if (!gpr_atm_rel_cas(&z->next_atm, (gpr_atm)NULL, (gpr_atm)next_z)) { + gpr_free(next_z); + next_z = (zone *)gpr_atm_acq_load(&z->next_atm); + } + } + z = next_z; + } + if (start + size > z->size_end) { + return gpr_arena_alloc(arena, size); + } + GPR_ASSERT(start >= z->size_begin); + GPR_ASSERT(start + size <= z->size_end); + return ((char *)(z + 1)) + start - z->size_begin; +} |