| Flutter Impeller |

command_pool_vk.cc
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1 // Copyright 2013 The Flutter Authors. All rights reserved.
2 // Use of this source code is governed by a BSD-style license that can be
3 // found in the LICENSE file.
4
5 #include "impeller/renderer/backend/vulkan/command_pool_vk.h"
6
7 #include <memory>
8 #include <optional>
9 #include <utility>
10
11 #include "fml/thread_local.h"
12 #include "fml/trace_event.h"
13 #include "impeller/renderer/backend/vulkan/resource_manager_vk.h"
14 #include "impeller/renderer/backend/vulkan/vk.h" // IWYU pragma: keep.
15 #include "vulkan/vulkan_structs.hpp"
16
17 namespace impeller {
18
19 // Holds the command pool in a background thread, recyling it when not in use.
20 class BackgroundCommandPoolVK final {
21 public:
22 BackgroundCommandPoolVK(BackgroundCommandPoolVK&&) = default;
23
24 explicit BackgroundCommandPoolVK(
25 vk::UniqueCommandPool&& pool,
26 std::vector<vk::UniqueCommandBuffer>&& buffers,
27 std::weak_ptr<CommandPoolRecyclerVK> recycler)
28 : pool_(std::move(pool)),
29 buffers_(std::move(buffers)),
30 recycler_(std::move(recycler)) {}
31
32 ~BackgroundCommandPoolVK() {
33 auto const recycler = recycler_.lock();
34
35 // Not only does this prevent recycling when the context is being destroyed,
36 // but it also prevents the destructor from effectively being called twice;
37 // once for the original BackgroundCommandPoolVK() and once for the moved
38 // BackgroundCommandPoolVK().
39 if (!recycler) {
40 return;
41 }
42 buffers_.clear();
43
44 recycler->Reclaim(std::move(pool_));
45 }
46
47 private:
48 BackgroundCommandPoolVK(const BackgroundCommandPoolVK&) = delete;
49
50 BackgroundCommandPoolVK& operator=(const BackgroundCommandPoolVK&) = delete;
51
52 vk::UniqueCommandPool pool_;
53
54 // These are retained because the destructor of the C++ UniqueCommandBuffer
55 // wrapper type will attempt to reset the cmd buffer, and doing so may be a
56 // thread safety violation as this may happen on the fence waiter thread.
57 std::vector<vk::UniqueCommandBuffer> buffers_;
58 std::weak_ptr<CommandPoolRecyclerVK> recycler_;
59 };
60
61 CommandPoolVK::~CommandPoolVK() {
62 if (!pool_) {
63 return;
64 }
65
66 auto const context = context_.lock();
67 if (!context) {
68 return;
69 }
70 auto const recycler = context->GetCommandPoolRecycler();
71 if (!recycler) {
72 return;
73 }
74
75 auto reset_pool_when_dropped = BackgroundCommandPoolVK(
76 std::move(pool_), std::move(collected_buffers_), recycler);
77
78 UniqueResourceVKT<BackgroundCommandPoolVK> pool(
79 context->GetResourceManager(), std::move(reset_pool_when_dropped));
80 }
81
82 // TODO(matanlurey): Return a status_or<> instead of {} when we have one.
83 vk::UniqueCommandBuffer CommandPoolVK::CreateCommandBuffer() {
84 auto const context = context_.lock();
85 if (!context) {
86 return {};
87 }
88
89 Lock lock(pool_mutex_);
90 if (!pool_) {
91 return {};
92 }
93
94 auto const device = context->GetDevice();
95 vk::CommandBufferAllocateInfo info;
96 info.setCommandPool(pool_.get());
97 info.setCommandBufferCount(1u);
98 info.setLevel(vk::CommandBufferLevel::ePrimary);
99 auto [result, buffers] = device.allocateCommandBuffersUnique(info);
100 if (result != vk::Result::eSuccess) {
101 return {};
102 }
103 return std::move(buffers[0]);
104 }
105
106 void CommandPoolVK::CollectCommandBuffer(vk::UniqueCommandBuffer&& buffer) {
107 Lock lock(pool_mutex_);
108 if (!pool_) {
109 // If the command pool has already been destroyed, then its buffers have
110 // already been freed.
111 buffer.release();
112 return;
113 }
114 collected_buffers_.push_back(std::move(buffer));
115 }
116
117 void CommandPoolVK::Destroy() {
118 Lock lock(pool_mutex_);
119 pool_.reset();
120
121 // When the command pool is destroyed, all of its command buffers are freed.
122 // Handles allocated from that pool are now invalid and must be discarded.
123 for (auto& buffer : collected_buffers_) {
124 buffer.release();
125 }
126 collected_buffers_.clear();
127 }
128
129 // Associates a resource with a thread and context.
130 using CommandPoolMap =
131 std::unordered_map<uint64_t, std::shared_ptr<CommandPoolVK>>;
132 FML_THREAD_LOCAL fml::ThreadLocalUniquePtr<CommandPoolMap> tls_command_pool_map;
133
134 // Map each context to a list of all thread-local command pools associated
135 // with that context.
136 static Mutex g_all_pools_map_mutex;
137 static std::unordered_map<const ContextVK*,
138 std::vector<std::weak_ptr<CommandPoolVK>>>
139 g_all_pools_map IPLR_GUARDED_BY(g_all_pools_map_mutex);
140
141 // TODO(matanlurey): Return a status_or<> instead of nullptr when we have one.
142 std::shared_ptr<CommandPoolVK> CommandPoolRecyclerVK::Get() {
143 auto const strong_context = context_.lock();
144 if (!strong_context) {
145 return nullptr;
146 }
147
148 // If there is a resource in used for this thread and context, return it.
149 if (!tls_command_pool_map.get()) {
150 tls_command_pool_map.reset(new CommandPoolMap());
151 }
152 CommandPoolMap& pool_map = *tls_command_pool_map.get();
153 auto const hash = strong_context->GetHash();
154 auto const it = pool_map.find(hash);
155 if (it != pool_map.end()) {
156 return it->second;
157 }
158
159 // Otherwise, create a new resource and return it.
160 auto pool = Create();
161 if (!pool) {
162 return nullptr;
163 }
164
165 auto const resource =
166 std::make_shared<CommandPoolVK>(std::move(*pool), context_);
167 pool_map.emplace(hash, resource);
168
169 {
170 Lock all_pools_lock(g_all_pools_map_mutex);
171 g_all_pools_map[strong_context.get()].push_back(resource);
172 }
173
174 return resource;
175 }
176
177 // TODO(matanlurey): Return a status_or<> instead of nullopt when we have one.
178 std::optional<vk::UniqueCommandPool> CommandPoolRecyclerVK::Create() {
179 // If we can reuse a command pool, do so.
180 if (auto pool = Reuse()) {
181 return pool;
182 }
183
184 // Otherwise, create a new one.
185 auto context = context_.lock();
186 if (!context) {
187 return std::nullopt;
188 }
189 vk::CommandPoolCreateInfo info;
190 info.setQueueFamilyIndex(context->GetGraphicsQueue()->GetIndex().family);
191 info.setFlags(vk::CommandPoolCreateFlagBits::eTransient);
192
193 auto device = context->GetDevice();
194 auto [result, pool] = device.createCommandPoolUnique(info);
195 if (result != vk::Result::eSuccess) {
196 return std::nullopt;
197 }
198 return std::move(pool);
199 }
200
201 std::optional<vk::UniqueCommandPool> CommandPoolRecyclerVK::Reuse() {
202 // If there are no recycled pools, return nullopt.
203 Lock recycled_lock(recycled_mutex_);
204 if (recycled_.empty()) {
205 return std::nullopt;
206 }
207
208 // Otherwise, remove and return a recycled pool.
209 auto pool = std::move(recycled_.back());
210 recycled_.pop_back();
211 return std::move(pool);
212 }
213
214 void CommandPoolRecyclerVK::Reclaim(vk::UniqueCommandPool&& pool) {
215 // Reset the pool on a background thread.
216 auto strong_context = context_.lock();
217 if (!strong_context) {
218 return;
219 }
220 auto device = strong_context->GetDevice();
221 device.resetCommandPool(pool.get());
222
223 // Move the pool to the recycled list.
224 Lock recycled_lock(recycled_mutex_);
225 recycled_.push_back(std::move(pool));
226 }
227
228 CommandPoolRecyclerVK::~CommandPoolRecyclerVK() {
229 // Ensure all recycled pools are reclaimed before this is destroyed.
230 Dispose();
231 }
232
233 void CommandPoolRecyclerVK::Dispose() {
234 CommandPoolMap* pool_map = tls_command_pool_map.get();
235 if (pool_map) {
236 pool_map->clear();
237 }
238 }
239
240 void CommandPoolRecyclerVK::DestroyThreadLocalPools(const ContextVK* context) {
241 // Delete the context's entry in this thread's command pool map.
242 if (tls_command_pool_map.get()) {
243 tls_command_pool_map.get()->erase(context->GetHash());
244 }
245
246 // Destroy all other thread-local CommandPoolVK instances associated with
247 // this context.
248 Lock all_pools_lock(g_all_pools_map_mutex);
249 auto found = g_all_pools_map.find(context);
250 if (found != g_all_pools_map.end()) {
251 for (auto& weak_pool : found->second) {
252 auto pool = weak_pool.lock();
253 if (!pool) {
254 continue;
255 }
256 // Delete all objects held by this pool. The destroyed pool will still
257 // remain in its thread's TLS map until that thread exits.
258 pool->Destroy();
259 }
260 g_all_pools_map.erase(found);
261 }
262 }
263
264 } // namespace impeller
impeller::CommandPoolMap
std::unordered_map< uint64_t, std::shared_ptr< CommandPoolVK > > CommandPoolMap
Definition: command_pool_vk.cc:131
impeller::CommandPoolVK::~CommandPoolVK
~CommandPoolVK()
Definition: command_pool_vk.cc:61
impeller::CommandPoolRecyclerVK::DestroyThreadLocalPools
static void DestroyThreadLocalPools(const ContextVK *context)
Clean up resources held by all per-thread command pools associated with the given context.
Definition: command_pool_vk.cc:240
impeller::IPLR_GUARDED_BY
static std::unordered_map< const ContextVK *, std::vector< std::weak_ptr< CommandPoolVK > > > g_all_pools_map IPLR_GUARDED_BY(g_all_pools_map_mutex)
impeller::BackgroundCommandPoolVK::~BackgroundCommandPoolVK
~BackgroundCommandPoolVK()
Definition: command_pool_vk.cc:32
impeller::UniqueResourceVKT
A unique handle to a resource which will be reclaimed by the specified resource manager.
Definition: resource_manager_vk.h:145
impeller::BackgroundCommandPoolVK::BackgroundCommandPoolVK
BackgroundCommandPoolVK(vk::UniqueCommandPool &&pool, std::vector< vk::UniqueCommandBuffer > &&buffers, std::weak_ptr< CommandPoolRecyclerVK > recycler)
Definition: command_pool_vk.cc:24
impeller::Lock
Definition: thread.h:75
impeller::BackgroundCommandPoolVK::BackgroundCommandPoolVK
BackgroundCommandPoolVK(BackgroundCommandPoolVK &&)=default
impeller::ContextVK::GetHash
uint64_t GetHash() const
Definition: context_vk.h:57
vk.h
impeller::CommandPoolVK::CollectCommandBuffer
void CollectCommandBuffer(vk::UniqueCommandBuffer &&buffer)
Collects the given |vk::CommandBuffer| to be retained.
Definition: command_pool_vk.cc:106
command_pool_vk.h
impeller::g_all_pools_map_mutex
static Mutex g_all_pools_map_mutex
Definition: command_pool_vk.cc:136
impeller::CommandPoolRecyclerVK::Get
std::shared_ptr< CommandPoolVK > Get()
Gets a command pool for the current thread.
Definition: command_pool_vk.cc:142
impeller::CommandPoolVK::Destroy
void Destroy()
Delete all Vulkan objects in this command pool.
Definition: command_pool_vk.cc:117
impeller::CommandPoolRecyclerVK::Reclaim
void Reclaim(vk::UniqueCommandPool &&pool)
Returns a command pool to be reset on a background thread.
Definition: command_pool_vk.cc:214
impeller::CommandPoolRecyclerVK::~CommandPoolRecyclerVK
~CommandPoolRecyclerVK()
Definition: command_pool_vk.cc:228
impeller::CommandPoolRecyclerVK::Dispose
void Dispose()
Clears all recycled command pools to let them be reclaimed.
Definition: command_pool_vk.cc:233
impeller::CommandPoolVK::CreateCommandBuffer
vk::UniqueCommandBuffer CreateCommandBuffer()
Creates and returns a new |vk::CommandBuffer|.
Definition: command_pool_vk.cc:83
impeller::ContextVK
Definition: context_vk.h:40
impeller::tls_command_pool_map
FML_THREAD_LOCAL fml::ThreadLocalUniquePtr< CommandPoolMap > tls_command_pool_map
Definition: command_pool_vk.cc:132
resource_manager_vk.h
std
Definition: comparable.h:95
impeller::BackgroundCommandPoolVK
Definition: command_pool_vk.cc:20
impeller
Definition: aiks_context.cc:10