1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
use std::future::Future;
use std::marker::PhantomData;
use std::sync::Arc;
use futures_task::{LocalFutureObj, LocalSpawn, SpawnError};
use gdnative_core::core_types::{ToVariant, Variant};
use gdnative_core::export::{FromVarargs, Method, NativeClass, Varargs};
use gdnative_core::log::{self, Site};
use gdnative_core::object::TInstance;
use crate::rt::Context;
pub trait AsyncMethod<C: NativeClass>: Send + Sync + 'static {
fn spawn_with(&self, spawner: Spawner<'_, C>);
#[inline]
fn site() -> Option<Site<'static>> {
None
}
}
pub trait StaticArgsAsyncMethod<C: NativeClass>: Send + Sync + 'static {
type Args: FromVarargs;
fn spawn_with(&self, spawner: Spawner<'_, C, Self::Args>);
#[inline]
fn site() -> Option<Site<'static>> {
None
}
}
#[derive(Clone, Copy, Default, Debug)]
pub struct StaticArgs<F> {
f: F,
}
impl<F> StaticArgs<F> {
#[inline]
pub fn new(f: F) -> Self {
StaticArgs { f }
}
}
impl<C: NativeClass, F: StaticArgsAsyncMethod<C>> AsyncMethod<C> for StaticArgs<F> {
#[inline]
fn spawn_with(&self, spawner: Spawner<'_, C>) {
let spawner = spawner.try_map_args(|mut args| match args.read_many::<F::Args>() {
Ok(parsed) => {
if let Err(err) = args.done() {
err.with_site(F::site().unwrap_or_default()).log_error();
return None;
}
Some(parsed)
}
Err(errors) => {
for err in errors {
err.with_site(F::site().unwrap_or_default()).log_error();
}
None
}
});
match spawner {
Ok(spawner) => F::spawn_with(&self.f, spawner),
Err(spawner) => spawner.spawn(|_context, _this, ()| async { Variant::nil() }),
}
}
#[inline]
fn site() -> Option<Site<'static>> {
F::site()
}
}
pub struct Spawner<'a, C: NativeClass, A = Varargs<'a>> {
sp: &'static dyn LocalSpawn,
ctx: Context,
this: TInstance<'a, C>,
args: A,
result: &'a mut Option<Result<(), SpawnError>>,
_marker: PhantomData<*const ()>,
}
impl<'a, C: NativeClass, A> Spawner<'a, C, A> {
fn try_map_args<F, R>(self, f: F) -> Result<Spawner<'a, C, R>, Spawner<'a, C, ()>>
where
F: FnOnce(A) -> Option<R>,
{
let Spawner {
sp,
ctx,
this,
args,
result,
..
} = self;
match f(args) {
Some(args) => Ok(Spawner {
sp,
ctx,
this,
args,
result,
_marker: PhantomData,
}),
None => Err(Spawner {
sp,
ctx,
this,
args: (),
result,
_marker: PhantomData,
}),
}
}
pub fn spawn<F, R>(self, f: F)
where
F: FnOnce(Arc<Context>, TInstance<'_, C>, A) -> R,
R: Future<Output = Variant> + 'static,
{
let ctx = Arc::new(self.ctx);
let future = f(Arc::clone(&ctx), self.this, self.args);
*self.result = Some(
self.sp
.spawn_local_obj(LocalFutureObj::new(Box::new(async move {
let value = future.await;
ctx.resolve(value);
}))),
);
}
}
#[derive(Clone, Copy, Default, Debug)]
pub struct Async<F> {
f: F,
}
impl<F> Async<F> {
#[inline]
pub fn new(f: F) -> Self {
Async { f }
}
}
impl<C: NativeClass, F: AsyncMethod<C>> Method<C> for Async<F> {
fn call(&self, this: TInstance<'_, C>, args: Varargs<'_>) -> Variant {
if let Some(sp) = crate::executor::local_spawn() {
let ctx = Context::new();
let func_state = ctx.func_state();
let mut result = None;
self.f.spawn_with(Spawner {
sp,
ctx,
this,
args,
result: &mut result,
_marker: PhantomData,
});
match result {
Some(Ok(())) => func_state.to_variant(),
Some(Err(err)) => {
log::error(
Self::site().unwrap_or_default(),
format_args!("unable to spawn future: {err}"),
);
Variant::nil()
}
None => {
log::error(
Self::site().unwrap_or_default(),
format_args!("implementation did not spawn a future"),
);
Variant::nil()
}
}
} else {
log::error(
Self::site().unwrap_or_default(),
"a global executor must be set before any async methods can be called on this thread",
);
Variant::nil()
}
}
fn site() -> Option<Site<'static>> {
F::site()
}
}