Priority Scheduler

Cargo.lock

@@ -256,9 +256,9 @@ checksum = "f9fbbcab51052fe104eb5e5d351cf728d30a5be1fe14d9be8a3b097481fb97de"
 
 [[package]]
 name = "libredox"
-version = "0.1.14"
+version = "0.1.16"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "1744e39d1d6a9948f4f388969627434e31128196de472883b39f148769bfe30a"
+checksum = "e02f3bb43d335493c96bf3fd3a321600bf6bd07ed34bc64118e9293bdffea46c"
 dependencies = [
  "bitflags",
  "libc",
@@ -472,9 +472,9 @@ dependencies = [
 
 [[package]]
 name = "redox_syscall"
-version = "0.7.3"
+version = "0.7.4"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "6ce70a74e890531977d37e532c34d45e9055d2409ed08ddba14529471ed0be16"
+checksum = "f450ad9c3b1da563fb6948a8e0fb0fb9269711c9c73d9ea1de5058c79c8d643a"
 dependencies = [
  "bitflags",
 ]

Cargo.toml

@@ -67,8 +67,8 @@ bitflags = "2"
 ioslice = { version = "0.6", default-features = false }
 plain = "0.2"
 redox-path = "0.3"
-redox_protocols = { package = "libredox", version = "0.1.14", default-features = false, features = ["protocol"] }
-redox_syscall = "0.7.3"
+redox_protocols = { package = "libredox", version = "0.1.16", default-features = false, features = ["protocol"] }
+redox_syscall = "0.7.4"
 
 [build-dependencies]
 cc = "1"

redox-rt/src/proc.rs

@@ -1119,7 +1119,7 @@ pub fn new_child_process(args: &ForkArgs<'_>) -> Result<NewChildProc> {
                 pid: 0,
                 euid: 0,
                 egid: 0,
-                ens: 1,
+                prio: !0, // Value is overwritten later
                 debug_name: {
                     let mut buf = [0; 32];
                     let src = b"[init]";

redox-rt/src/sys.rs

@@ -110,6 +110,37 @@ pub fn posix_getppid() -> u32 {
     this_proc_call(&mut [], CallFlags::empty(), &[ProcCall::Getppid as u64]).expect("cannot fail")
         as u32
 }
+
+#[inline]
+pub fn posix_setpriority(which: i32, who: u32, prio: u32) -> Result<(), syscall::Error> {
+    if which != 0 {
+        return Err(syscall::Error::new(syscall::EINVAL)); // TODO: Add support for PRIO_PGRP and PRIO_PROCESS
+    }
+
+    this_proc_call(
+        &mut [],
+        CallFlags::empty(),
+        &[ProcCall::SetProcPriority as u64, who as u64, prio as u64],
+    )?;
+
+    Ok(())
+}
+
+#[inline]
+pub fn posix_getpriority(which: i32, who: u32) -> Result<u32, syscall::Error> {
+    if which != 0 {
+        return Err(syscall::Error::new(syscall::EINVAL));
+    }
+
+    let res = this_proc_call(
+        &mut [],
+        CallFlags::empty(),
+        &[ProcCall::GetProcPriority as u64, who as u64],
+    )?;
+
+    Ok(res as u32)
+}
+
 #[inline]
 pub unsafe fn sys_futex_wait(addr: *mut u32, val: u32, deadline: Option<&TimeSpec>) -> Result<()> {
     wrapper(true, false, || {

src/platform/redox/mod.rs

@@ -634,8 +634,13 @@ impl Pal for Sys {
     }
 
     fn getpriority(which: c_int, who: id_t) -> Result<c_int> {
-        todo_skip!(0, "getpriority({}, {}): not implemented", which, who);
-        Err(Errno(ENOSYS))
+        match redox_rt::sys::posix_getpriority(which, who as u32) {
+            Ok(kernel_prio) => {
+                let posix_prio = (kernel_prio as i32 * -1) + 40 as i32;
+                Ok(posix_prio)
+            }
+            Err(e) => Err(Errno(e.errno)),
+        }
     }
 
     fn getrandom(buf: &mut [u8], flags: c_uint) -> Result<usize> {
@@ -1197,15 +1202,13 @@ impl Pal for Sys {
     }
 
     fn setpriority(which: c_int, who: id_t, prio: c_int) -> Result<()> {
-        // TODO
-        todo_skip!(
-            0,
-            "setpriority({}, {}, {}): not implemented",
-            which,
-            who,
-            prio
-        );
-        Err(Errno(ENOSYS))
+        let clamped_prio = prio.clamp(-20, 19);
+        let kernel_prio = (20 + clamped_prio) as u32;
+
+        match redox_rt::sys::posix_setpriority(which, who as u32, kernel_prio) {
+            Ok(_) => Ok(()),
+            Err(e) => Err(Errno(e.errno)),
+        }
     }
 
     fn setsid() -> Result<c_int> {