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
// Take a look at the license at the top of the repository in the LICENSE file.

use crate::translate::*;

use futures_channel::oneshot;
use std::future::Future;
use std::ptr;

#[derive(Debug)]
#[doc(alias = "GThreadPool")]
pub struct ThreadPool(ptr::NonNull<ffi::GThreadPool>);

unsafe impl Send for ThreadPool {}
unsafe impl Sync for ThreadPool {}

impl ThreadPool {
    #[doc(alias = "g_thread_pool_new")]
    pub fn shared(max_threads: Option<u32>) -> Result<Self, crate::Error> {
        unsafe {
            let mut err = ptr::null_mut();
            let pool = ffi::g_thread_pool_new(
                Some(spawn_func),
                ptr::null_mut(),
                max_threads.map(|v| v as i32).unwrap_or(-1),
                ffi::GFALSE,
                &mut err,
            );
            if pool.is_null() {
                Err(from_glib_full(err))
            } else {
                Ok(ThreadPool(ptr::NonNull::new_unchecked(pool)))
            }
        }
    }

    #[doc(alias = "g_thread_pool_new")]
    pub fn exclusive(max_threads: u32) -> Result<Self, crate::Error> {
        unsafe {
            let mut err = ptr::null_mut();
            let pool = ffi::g_thread_pool_new(
                Some(spawn_func),
                ptr::null_mut(),
                max_threads as i32,
                ffi::GTRUE,
                &mut err,
            );
            if pool.is_null() {
                Err(from_glib_full(err))
            } else {
                Ok(ThreadPool(ptr::NonNull::new_unchecked(pool)))
            }
        }
    }

    #[doc(alias = "g_thread_pool_push")]
    pub fn push<F: FnOnce() + Send + 'static>(&self, func: F) -> Result<(), crate::Error> {
        unsafe {
            let func: Box<dyn FnOnce() + Send + 'static> = Box::new(func);
            let func = Box::new(func);
            let mut err = ptr::null_mut();

            let func = Box::into_raw(func);
            let ret: bool = from_glib(ffi::g_thread_pool_push(
                self.0.as_ptr(),
                func as *mut _,
                &mut err,
            ));
            if ret {
                Ok(())
            } else {
                let _ = Box::from_raw(func);
                Err(from_glib_full(err))
            }
        }
    }

    pub fn push_future<T: Send + 'static, F: FnOnce() -> T + Send + 'static>(
        &self,
        func: F,
    ) -> Result<impl Future<Output = T> + Send + Sync + 'static, crate::Error> {
        let (sender, receiver) = oneshot::channel();

        self.push(move || {
            let _ = sender.send(func());
        })?;

        Ok(async move { receiver.await.expect("Dropped before executing") })
    }

    #[doc(alias = "g_thread_pool_set_max_threads")]
    pub fn set_max_threads(&self, max_threads: Option<u32>) -> Result<(), crate::Error> {
        unsafe {
            let mut err = ptr::null_mut();
            let ret: bool = from_glib(ffi::g_thread_pool_set_max_threads(
                self.0.as_ptr(),
                max_threads.map(|v| v as i32).unwrap_or(-1),
                &mut err,
            ));
            if ret {
                Ok(())
            } else {
                Err(from_glib_full(err))
            }
        }
    }

    #[doc(alias = "g_thread_pool_get_max_threads")]
    #[doc(alias = "get_max_threads")]
    pub fn max_threads(&self) -> Option<u32> {
        unsafe {
            let max_threads = ffi::g_thread_pool_get_max_threads(self.0.as_ptr());
            if max_threads == -1 {
                None
            } else {
                Some(max_threads as u32)
            }
        }
    }

    #[doc(alias = "g_thread_pool_get_num_threads")]
    #[doc(alias = "get_num_threads")]
    pub fn num_threads(&self) -> u32 {
        unsafe { ffi::g_thread_pool_get_num_threads(self.0.as_ptr()) }
    }

    #[doc(alias = "g_thread_pool_unprocessed")]
    #[doc(alias = "get_unprocessed")]
    pub fn unprocessed(&self) -> u32 {
        unsafe { ffi::g_thread_pool_unprocessed(self.0.as_ptr()) }
    }

    #[doc(alias = "g_thread_pool_set_max_unused_threads")]
    pub fn set_max_unused_threads(max_threads: Option<u32>) {
        unsafe {
            ffi::g_thread_pool_set_max_unused_threads(max_threads.map(|v| v as i32).unwrap_or(-1))
        }
    }

    #[doc(alias = "g_thread_pool_get_max_unused_threads")]
    #[doc(alias = "get_max_unused_threads")]
    pub fn max_unused_threads() -> Option<u32> {
        unsafe {
            let max_unused_threads = ffi::g_thread_pool_get_max_unused_threads();
            if max_unused_threads == -1 {
                None
            } else {
                Some(max_unused_threads as u32)
            }
        }
    }

    #[doc(alias = "g_thread_pool_get_num_unused_threads")]
    #[doc(alias = "get_num_unused_threads")]
    pub fn num_unused_threads() -> u32 {
        unsafe { ffi::g_thread_pool_get_num_unused_threads() }
    }

    #[doc(alias = "g_thread_pool_stop_unused_threads")]
    pub fn stop_unused_threads() {
        unsafe {
            ffi::g_thread_pool_stop_unused_threads();
        }
    }

    #[doc(alias = "g_thread_pool_set_max_idle_time")]
    pub fn set_max_idle_time(max_idle_time: u32) {
        unsafe { ffi::g_thread_pool_set_max_idle_time(max_idle_time) }
    }

    #[doc(alias = "g_thread_pool_get_max_idle_time")]
    #[doc(alias = "get_max_idle_time")]
    pub fn max_idle_time() -> u32 {
        unsafe { ffi::g_thread_pool_get_max_idle_time() }
    }
}

impl Drop for ThreadPool {
    fn drop(&mut self) {
        unsafe {
            ffi::g_thread_pool_free(self.0.as_ptr(), ffi::GFALSE, ffi::GTRUE);
        }
    }
}

unsafe extern "C" fn spawn_func(func: ffi::gpointer, _data: ffi::gpointer) {
    let func: Box<Box<dyn FnOnce()>> = Box::from_raw(func as *mut _);
    func()
}

#[cfg(test)]
mod tests {
    use super::*;

    #[test]
    fn test_push() {
        use std::sync::mpsc;

        let p = ThreadPool::exclusive(1).unwrap();
        let (sender, receiver) = mpsc::channel();

        p.push(move || {
            sender.send(true).unwrap();
        })
        .unwrap();

        assert_eq!(receiver.recv(), Ok(true));
    }

    #[test]
    fn test_push_future() {
        let c = crate::MainContext::new();
        let p = ThreadPool::shared(None).unwrap();

        let fut = p.push_future(|| true).unwrap();

        let res = c.block_on(fut);
        assert!(res);
    }
}