1 // Copyright 2021 The Pigweed Authors
2 //
3 // Licensed under the Apache License, Version 2.0 (the "License"); you may not
4 // use this file except in compliance with the License. You may obtain a copy of
5 // the License at
6 //
7 //     https://www.apache.org/licenses/LICENSE-2.0
8 //
9 // Unless required by applicable law or agreed to in writing, software
10 // distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
11 // WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
12 // License for the specific language governing permissions and limitations under
13 // the License.
14 #pragma once
15 
16 #include <mutex>
17 
18 #include "FreeRTOS.h"
19 #include "pw_assert/assert.h"
20 #include "pw_interrupt/context.h"
21 #include "pw_sync/thread_notification.h"
22 #include "task.h"
23 
24 namespace pw::sync {
25 namespace backend {
26 
27 static_assert(configUSE_TASK_NOTIFICATIONS != 0,
28               "Task Notifications aren't enabled.");
29 
30 }  // namespace backend
31 
ThreadNotification()32 inline ThreadNotification::ThreadNotification()
33     : native_type_{
34           .blocked_thread = nullptr,
35           .notified = false,
36       } {}
37 
38 inline ThreadNotification::~ThreadNotification() = default;
39 
try_acquire()40 inline bool ThreadNotification::try_acquire() {
41   // Enforce the pw::sync::ThreadNotification IRQ contract.
42   PW_DASSERT(!interrupt::InInterruptContext());
43   std::lock_guard lock(native_type_.shared_spin_lock);
44   const bool notified = native_type_.notified;
45   native_type_.notified = false;
46   return notified;
47 }
48 
49 inline ThreadNotification::native_handle_type
native_handle()50 ThreadNotification::native_handle() {
51   return native_type_;
52 }
53 
54 }  // namespace pw::sync
55