1 /*
2 *
3 * Copyright 2017 gRPC authors.
4 *
5 * Licensed under the Apache License, Version 2.0 (the "License");
6 * you may not use this file except in compliance with the License.
7 * You may obtain a copy of the License at
8 *
9 * http://www.apache.org/licenses/LICENSE-2.0
10 *
11 * Unless required by applicable law or agreed to in writing, software
12 * distributed under the License is distributed on an "AS IS" BASIS,
13 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
14 * See the License for the specific language governing permissions and
15 * limitations under the License.
16 *
17 */
18
19 #include <grpc/support/port_platform.h>
20
21 #include "src/core/lib/gprpp/arena.h"
22
23 #include <string.h>
24 #include <new>
25
26 #include <grpc/support/alloc.h>
27 #include <grpc/support/atm.h>
28 #include <grpc/support/log.h>
29 #include <grpc/support/sync.h>
30
31 #include "src/core/lib/gpr/alloc.h"
32 #include "src/core/lib/gprpp/memory.h"
33
34 namespace {
35
ArenaStorage(size_t initial_size)36 void* ArenaStorage(size_t initial_size) {
37 static constexpr size_t base_size =
38 GPR_ROUND_UP_TO_ALIGNMENT_SIZE(sizeof(grpc_core::Arena));
39 initial_size = GPR_ROUND_UP_TO_ALIGNMENT_SIZE(initial_size);
40 size_t alloc_size = base_size + initial_size;
41 static constexpr size_t alignment =
42 (GPR_CACHELINE_SIZE > GPR_MAX_ALIGNMENT &&
43 GPR_CACHELINE_SIZE % GPR_MAX_ALIGNMENT == 0)
44 ? GPR_CACHELINE_SIZE
45 : GPR_MAX_ALIGNMENT;
46 return gpr_malloc_aligned(alloc_size, alignment);
47 }
48
49 } // namespace
50
51 namespace grpc_core {
52
~Arena()53 Arena::~Arena() {
54 Zone* z = last_zone_;
55 while (z) {
56 Zone* prev_z = z->prev;
57 z->~Zone();
58 gpr_free_aligned(z);
59 z = prev_z;
60 }
61 }
62
Create(size_t initial_size)63 Arena* Arena::Create(size_t initial_size) {
64 return new (ArenaStorage(initial_size)) Arena(initial_size);
65 }
66
CreateWithAlloc(size_t initial_size,size_t alloc_size)67 std::pair<Arena*, void*> Arena::CreateWithAlloc(size_t initial_size,
68 size_t alloc_size) {
69 static constexpr size_t base_size =
70 GPR_ROUND_UP_TO_ALIGNMENT_SIZE(sizeof(Arena));
71 auto* new_arena =
72 new (ArenaStorage(initial_size)) Arena(initial_size, alloc_size);
73 void* first_alloc = reinterpret_cast<char*>(new_arena) + base_size;
74 return std::make_pair(new_arena, first_alloc);
75 }
76
Destroy()77 size_t Arena::Destroy() {
78 size_t size = total_used_.Load(MemoryOrder::RELAXED);
79 this->~Arena();
80 gpr_free_aligned(this);
81 return size;
82 }
83
AllocZone(size_t size)84 void* Arena::AllocZone(size_t size) {
85 // If the allocation isn't able to end in the initial zone, create a new
86 // zone for this allocation, and any unused space in the initial zone is
87 // wasted. This overflowing and wasting is uncommon because of our arena
88 // sizing hysteresis (that is, most calls should have a large enough initial
89 // zone and will not need to grow the arena).
90 static constexpr size_t zone_base_size =
91 GPR_ROUND_UP_TO_ALIGNMENT_SIZE(sizeof(Zone));
92 size_t alloc_size = zone_base_size + size;
93 Zone* z = new (gpr_malloc_aligned(alloc_size, GPR_MAX_ALIGNMENT)) Zone();
94 {
95 gpr_spinlock_lock(&arena_growth_spinlock_);
96 z->prev = last_zone_;
97 last_zone_ = z;
98 gpr_spinlock_unlock(&arena_growth_spinlock_);
99 }
100 return reinterpret_cast<char*>(z) + zone_base_size;
101 }
102
103 } // namespace grpc_core
104