add timeout support of poll and select

rcore-os · Aug 27, 2020 · 8335a7e · 8335a7e
1 parent 8d3f121
commit 8335a7e
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Showing 3 changed files with 44 additions and 2 deletions.
diff --git a/linux-syscall/src/file/poll.rs b/linux-syscall/src/file/poll.rs
@@ -11,6 +11,8 @@ use core::future::Future;
 use core::mem::size_of;
 use core::pin::Pin;
 use core::task::{Context, Poll};
+use core::time::Duration;
+use kernel_hal::timer_set;
 use linux_object::fs::FileDesc;
 use linux_object::time::*;
 
@@ -30,9 +32,13 @@ impl Syscall<'_> {
         #[must_use = "future does nothing unless polled/`await`-ed"]
         struct PollFuture<'a> {
             polls: &'a mut Vec<PollFd>,
+            timeout_msecs: usize,
+            begin_time_ms: usize,
             syscall: &'a Syscall<'a>,
         }
 
+        let begin_time_ms = TimeVal::now().to_msec();
+
         impl<'a> Future for PollFuture<'a> {
             type Output = SysResult;
 
@@ -72,11 +78,33 @@ impl Syscall<'_> {
                 if events > 0 {
                     return Poll::Ready(Ok(events));
                 }
+
+                if self.timeout_msecs == 0 {
+                    // no timeout, return now;
+                    return Poll::Ready(Ok(0));
+                } else {
+                    let waker = cx.waker().clone();
+                    timer_set(
+                        Duration::from_millis(self.timeout_msecs as u64),
+                        Box::new(move |_| waker.wake()),
+                    );
+                }
+
+                let current_time_ms = TimeVal::now().to_msec();
+                // infinity check
+                if self.timeout_msecs < (1 << 31)
+                    && current_time_ms - self.begin_time_ms >= self.timeout_msecs as usize
+                {
+                    return Poll::Ready(Ok(0));
+                }
+
                 Poll::Pending
             }
         }
         let future = PollFuture {
             polls: &mut polls,
+            timeout_msecs,
+            begin_time_ms,
             syscall: self,
         };
         let result = future.await;
@@ -200,12 +228,18 @@ impl Syscall<'_> {
                 if self.timeout_msecs == 0 {
                     // no timeout, return now;
                     return Poll::Ready(Ok(0));
+                } else {
+                    let waker = cx.waker().clone();
+                    timer_set(
+                        Duration::from_millis(self.timeout_msecs as u64),
+                        Box::new(move |_| waker.wake()),
+                    );
                 }
 
                 let current_time_ms = TimeVal::now().to_msec();
                 // infinity check
                 if self.timeout_msecs < (1 << 31)
-                    && current_time_ms - self.begin_time_ms > self.timeout_msecs as usize
+                    && current_time_ms - self.begin_time_ms >= self.timeout_msecs as usize
                 {
                     return Poll::Ready(Ok(0));
                 }

diff --git a/linux-syscall/test/testpoll.c b/linux-syscall/test/testpoll.c
@@ -17,12 +17,19 @@ int main(int argc, char **argv)
     int pipefd[2];
     struct timespec ts;
 
+    // test poll using pipe
     if (pipe(pipefd) == -1)
     {
         printf("pipe");
         exit(-1);
     }
 
+    // test time out
+    fds[0].fd = 0;
+    fds[0].events = POLLIN;
+    ret = poll(fds, 1, 1000);
+    assert(ret == 0);
+
     fds[0].fd = pipefd[0];
     fds[0].events = POLLIN;
     fds[1].fd = pipefd[1];

diff --git a/linux-syscall/test/testselect.c b/linux-syscall/test/testselect.c
@@ -16,9 +16,10 @@ int main(void)
 
     int pipefd[2];
 
+    // test time out 1s
     FD_ZERO(&rfds);
     FD_SET(0, &rfds);
-    tv.tv_sec = 0;
+    tv.tv_sec = 1;
     tv.tv_usec = 0;
     assert(select(1, &rfds, NULL, NULL, &tv) == 0);
     assert(!FD_ISSET(0, &rfds));