Implement sigsuspend.

src/platform/linux/signal.rs

@@ -155,8 +155,10 @@ impl PalSignal for Sys {
         .map(|_| ())
     }
 
-    fn sigsuspend(set: &sigset_t) -> c_int {
-        unsafe { e(syscall!(RT_SIGSUSPEND, set as *const sigset_t, NSIG / 8)) as c_int }
+    fn sigsuspend(set: &sigset_t) -> Errno {
+        unsafe {
+            e_raw(syscall!(RT_SIGSUSPEND, set as *const sigset_t, NSIG / 8)).expect_err("must fail")
+        }
     }
 
     unsafe fn sigtimedwait(

src/platform/pal/signal.rs

@@ -37,7 +37,7 @@ pub trait PalSignal: Pal {
         oset: Option<&mut sigset_t>,
     ) -> Result<(), Errno>;
 
-    fn sigsuspend(set: &sigset_t) -> c_int;
+    fn sigsuspend(set: &sigset_t) -> Errno; // always fails
 
     unsafe fn sigtimedwait(set: *const sigset_t, sig: *mut siginfo_t, tp: *const timespec)
         -> c_int;

src/platform/redox/signal.rs

@@ -246,7 +246,7 @@ impl PalSignal for Sys {
     }
 
     fn sigpending(set: &mut sigset_t) -> Result<(), Errno> {
-        *set = redox_rt::signal::currently_pending();
+        *set = redox_rt::signal::currently_pending_blocked();
         Ok(())
     }
 
@@ -264,20 +264,11 @@ impl PalSignal for Sys {
         })
     }
 
-    fn sigsuspend(set: &sigset_t) -> c_int {
-        //TODO: correct implementation
-        let mut oset = sigset_t::default();
-        if let Err(err) = redox_rt::signal::set_sigmask(Some(*set), Some(&mut oset)) {
-            Errno::from(err).sync();
-            return -1;
+    fn sigsuspend(set: &sigset_t) -> Errno {
+        match redox_rt::signal::wait_with_mask(*set) {
+            Ok(_) => unreachable!(),
+            Err(err) => err.into(),
         }
-        //TODO: wait for signal
-        Self::sched_yield();
-        if let Err(err) = redox_rt::signal::set_sigmask(Some(oset), None) {
-            Errno::from(err).sync();
-            return -1;
-        }
-        0
     }
 
     unsafe fn sigtimedwait(