xref: /aosp_15_r20/external/pigweed/pw_async_basic/fake_dispatcher.cc (revision 61c4878ac05f98d0ceed94b57d316916de578985)
1 // Copyright 2023 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 
15 #include "pw_async/fake_dispatcher.h"
16 
17 #include "pw_async/task.h"
18 #include "pw_log/log.h"
19 
20 using namespace std::chrono_literals;
21 
22 namespace pw::async::test::backend {
23 
NativeFakeDispatcher(Dispatcher & dispatcher)24 NativeFakeDispatcher::NativeFakeDispatcher(Dispatcher& dispatcher)
25     : dispatcher_(dispatcher) {}
26 
~NativeFakeDispatcher()27 NativeFakeDispatcher::~NativeFakeDispatcher() {
28   RequestStop();
29   DrainTaskQueue();
30 }
31 
RunUntilIdle()32 bool NativeFakeDispatcher::RunUntilIdle() {
33   bool tasks_ran = ExecuteDueTasks();
34   if (stop_requested_) {
35     tasks_ran |= DrainTaskQueue();
36   }
37   return tasks_ran;
38 }
39 
RunUntil(chrono::SystemClock::time_point end_time)40 bool NativeFakeDispatcher::RunUntil(chrono::SystemClock::time_point end_time) {
41   bool tasks_ran = false;
42   while (!task_queue_.empty() && task_queue_.front().due_time() <= end_time &&
43          !stop_requested_) {
44     now_ = task_queue_.front().due_time();
45     tasks_ran |= ExecuteDueTasks();
46   }
47 
48   if (stop_requested_) {
49     tasks_ran |= DrainTaskQueue();
50     return tasks_ran;
51   }
52 
53   if (now_ < end_time) {
54     now_ = end_time;
55   }
56   return tasks_ran;
57 }
58 
RunFor(chrono::SystemClock::duration duration)59 bool NativeFakeDispatcher::RunFor(chrono::SystemClock::duration duration) {
60   return RunUntil(now() + duration);
61 }
62 
ExecuteDueTasks()63 bool NativeFakeDispatcher::ExecuteDueTasks() {
64   bool task_ran = false;
65   while (!task_queue_.empty() && task_queue_.front().due_time() <= now() &&
66          !stop_requested_) {
67     ::pw::async::backend::NativeTask& task = task_queue_.front();
68     task_queue_.pop_front();
69 
70     Context ctx{&dispatcher_, &task.task_};
71     task(ctx, OkStatus());
72 
73     task_ran = true;
74   }
75   return task_ran;
76 }
77 
RequestStop()78 void NativeFakeDispatcher::RequestStop() {
79   PW_LOG_DEBUG("stop requested");
80   stop_requested_ = true;
81 }
82 
DrainTaskQueue()83 bool NativeFakeDispatcher::DrainTaskQueue() {
84   bool task_ran = false;
85   while (!task_queue_.empty()) {
86     ::pw::async::backend::NativeTask& task = task_queue_.front();
87     task_queue_.pop_front();
88 
89     PW_LOG_DEBUG("running cancelled task");
90     Context ctx{&dispatcher_, &task.task_};
91     task(ctx, Status::Cancelled());
92 
93     task_ran = true;
94   }
95   return task_ran;
96 }
97 
Post(Task & task)98 void NativeFakeDispatcher::Post(Task& task) { PostAt(task, now()); }
99 
PostAfter(Task & task,chrono::SystemClock::duration delay)100 void NativeFakeDispatcher::PostAfter(Task& task,
101                                      chrono::SystemClock::duration delay) {
102   PostAt(task, now() + delay);
103 }
104 
PostAt(Task & task,chrono::SystemClock::time_point time)105 void NativeFakeDispatcher::PostAt(Task& task,
106                                   chrono::SystemClock::time_point time) {
107   PW_LOG_DEBUG("posting task");
108   PostTaskInternal(task.native_type(), time);
109 }
110 
Cancel(Task & task)111 bool NativeFakeDispatcher::Cancel(Task& task) {
112   return task_queue_.remove(task.native_type());
113 }
114 
PostTaskInternal(::pw::async::backend::NativeTask & task,chrono::SystemClock::time_point time_due)115 void NativeFakeDispatcher::PostTaskInternal(
116     ::pw::async::backend::NativeTask& task,
117     chrono::SystemClock::time_point time_due) {
118   if (!task.unlisted()) {
119     if (task.due_time() <= time_due) {
120       // No need to repost a task that was already queued to run.
121       return;
122     }
123     // The task needs its time updated, so we have to move it to
124     // a different part of the list.
125     task.unlist();
126   }
127   task.set_due_time(time_due);
128   auto it_front = task_queue_.begin();
129   auto it_behind = task_queue_.before_begin();
130   while (it_front != task_queue_.end() && time_due >= it_front->due_time()) {
131     ++it_front;
132     ++it_behind;
133   }
134   task_queue_.insert_after(it_behind, task);
135 }
136 
137 }  // namespace pw::async::test::backend
138