proc: WaitProcess + Spawn

src/main.rs

@@ -67,7 +67,7 @@ pub fn kernel_main() {
     let file = node.open(OpenOptions::READ, FileMode::empty()).unwrap();
 
     {
-        let user_init = proc::exec::load_elf(file, &["/init"]).unwrap();
+        let user_init = proc::exec::load_elf(file, &["/init", "xxx"]).unwrap();
         let mut io = user_init.io.lock();
         io.set_ioctx(ioctx);
         drop(io);

src/proc/io.rs

@@ -66,4 +66,8 @@ impl ProcessIo {
     pub fn ioctx(&mut self) -> &mut IoContext {
         self.ioctx.as_mut().unwrap()
     }
+
+    pub fn handle_exit(&mut self) {
+        self.files.clear();
+    }
 }

src/proc/wait.rs

@@ -32,6 +32,8 @@ struct Timeout {
     deadline: Duration,
 }
 
+pub static PROCESS_EXIT_WAIT: Wait = Wait::new("process-exit");
+
 impl Wait {
     /// Constructs a new wait notification channel
     pub const fn new(name: &'static str) -> Self {

src/syscall/mod.rs

@@ -4,10 +4,11 @@ use core::{mem::MaybeUninit, time::Duration};
 use abi::{
     error::Error,
     io::{DirectoryEntry, FileAttr, FileMode, OpenOptions, RawFd, SeekFrom},
+    process::{SpawnOption, SpawnOptions},
     syscall::SyscallFunction,
 };
 use alloc::rc::Rc;
-use vfs::{Read, ReadDirectory, Seek, VnodeKind, VnodeRef, Write};
+use vfs::{IoContext, Read, ReadDirectory, Seek, VnodeKind, VnodeRef, Write};
 use yggdrasil_abi::{
     error::SyscallResult,
     io::{MountOptions, UnmountOptions},
@@ -16,9 +17,13 @@ use yggdrasil_abi::{
 use crate::{
     fs,
     mem::table::{PageAttributes, VirtualMemoryManager},
-    proc::{io::ProcessIo, wait},
+    proc::{
+        self,
+        io::ProcessIo,
+        wait::{self, PROCESS_EXIT_WAIT},
+    },
     sync::IrqSafeSpinlockGuard,
-    task::process::Process,
+    task::{process::Process, ProcessId},
 };
 
 mod arg;
@@ -267,6 +272,58 @@ fn syscall_handler(func: SyscallFunction, args: &[u64]) -> Result<usize, Error>
                 file_borrow.seek(pos).map(|v| v as usize)
             })
         }
+        SyscallFunction::Spawn => {
+            let options = arg_user_ref::<SpawnOptions>(args[0] as usize)?;
+
+            debugln!("Spawn {:#?}", options);
+
+            run_with_io(|mut io| {
+                let node = io.ioctx().find(None, options.program, true, true)?;
+
+                // Setup a new process from the file
+                let file = node.open(OpenOptions::READ, FileMode::empty())?;
+                let child = proc::exec::load_elf(file, options.arguments)?;
+                let pid = child.id() as u32;
+
+                // Inherit root from the creator
+                let child_ioctx = IoContext::new(io.ioctx().root().clone());
+
+                {
+                    let mut child_io = child.io.lock();
+
+                    for opt in options.optional {
+                        if let SpawnOption::InheritFile { source, child } = opt {
+                            let src_file = io.file(*source)?;
+                            child_io.set_file(*child, src_file)?;
+                        }
+                    }
+                }
+
+                child.enqueue_somewhere();
+
+                Ok(pid as _)
+            })
+        }
+        SyscallFunction::WaitProcess => {
+            let pid = args[0] as ProcessId;
+            let status = arg_user_mut::<i32>(args[1] as _)?;
+            debugln!("WaitProcess #{}", pid);
+
+            let target = Process::get(pid).ok_or(Error::DoesNotExist)?;
+
+            loop {
+                if let Some(exit_status) = target.get_exit_status() {
+                    *status = exit_status;
+                    break Ok(0);
+                }
+
+                // Suspend and wait for signal
+                match PROCESS_EXIT_WAIT.wait(Some(Duration::from_secs(3))) {
+                    Ok(()) | Err(Error::TimedOut) => (),
+                    Err(_) => todo!(),
+                }
+            }
+        }
     }
 }
 

src/task/process.rs

@@ -9,7 +9,7 @@ use crate::{
     mem::table::AddressSpace,
     proc::{
         io::ProcessIo,
-        wait::{Wait, WaitStatus},
+        wait::{Wait, WaitStatus, PROCESS_EXIT_WAIT},
     },
     sync::{IrqGuard, IrqSafeSpinlock},
     util::OneTimeInit,
@@ -34,6 +34,7 @@ pub enum ProcessState {
 struct ProcessInner {
     pending_wait: Option<&'static Wait>,
     wait_status: WaitStatus,
+    exit_status: i32,
 }
 
 /// Process data and state structure
@@ -65,6 +66,7 @@ impl Process {
             inner: IrqSafeSpinlock::new(ProcessInner {
                 pending_wait: None,
                 wait_status: WaitStatus::Done,
+                exit_status: 0,
             }),
             space,
             io: IrqSafeSpinlock::new(ProcessIo::new()),
@@ -115,6 +117,11 @@ impl Process {
         self.space.as_ref().unwrap()
     }
 
+    /// Returns the address space of the task, if one is set
+    pub fn get_address_space(&self) -> Option<&AddressSpace> {
+        self.space.as_ref()
+    }
+
     /// Selects a suitable CPU queue and submits the process for execution.
     ///
     /// # Panics
@@ -212,28 +219,69 @@ impl Process {
         self.inner.lock().wait_status = status;
     }
 
+    pub fn get_exit_status(&self) -> Option<i32> {
+        if self.state() == ProcessState::Terminated {
+            Some(self.inner.lock().exit_status)
+        } else {
+            None
+        }
+    }
+
     /// Returns the [Process] currently executing on local CPU, None if idling.
     pub fn get_current() -> Option<Rc<Self>> {
         let queue = Cpu::local().queue();
         queue.current_process()
     }
 
+    pub fn get(pid: ProcessId) -> Option<Rc<Self>> {
+        PROCESSES.lock().get(pid).cloned()
+    }
+
     /// Wraps [Process::get_current()] for cases when the caller is absolutely sure there is a
     /// running process (e.g. the call itself comes from a process).
     pub fn current() -> Rc<Self> {
         Self::get_current().unwrap()
     }
 
-    /// Terminate a process
-    pub fn exit(&self, status: usize) {
-        let current_state = self.state.swap(ProcessState::Terminated, Ordering::SeqCst);
+    pub fn handle_exit(&self) {
+        // Queue lock is still held
+        assert_eq!(self.state(), ProcessState::Terminated);
 
+        // TODO cancel Wait if a process was killed while suspended?
+        {
+            let inner = self.inner.lock();
+            debugln!(
+                "Handling exit of #{} with status {}",
+                self.id(),
+                inner.exit_status
+            );
+
+            // TODO cleanup address space
+            // if let Some(space) = self.get_address_space() {
+            // }
+
+            self.io.lock().handle_exit();
+        }
+
+        // Notify any waiters we're done
+        PROCESS_EXIT_WAIT.wakeup_all();
+    }
+
+    /// Terminate a process
+    pub fn exit(&self, status: i32) {
+        self.inner.lock().exit_status = status;
+        let current_state = self.state.swap(ProcessState::Terminated, Ordering::SeqCst);
         debugln!("Process {} exited with code {}", self.id(), status);
 
         match current_state {
-            ProcessState::Suspended => (),
+            ProcessState::Suspended => {
+                todo!();
+            }
             ProcessState::Ready => todo!(),
-            ProcessState::Running => unsafe { Cpu::local().queue().yield_cpu() },
+            ProcessState::Running => {
+                self.handle_exit();
+                unsafe { Cpu::local().queue().yield_cpu() }
+            }
             ProcessState::Terminated => todo!(),
         }
     }