Implement basic version of sys_poll supporting stdin and socket, fix some deadlocks and introduce some others

crate/thread/src/thread_pool.rs

@@ -138,6 +138,7 @@ impl ThreadPool {
             (Status::Ready, _) => panic!("can not remove a process from ready queue"),
             (Status::Exited(_), _) => panic!("can not set status for a exited process"),
             (Status::Sleeping, Status::Exited(_)) => self.timer.lock().stop(Event::Wakeup(tid)),
+            (Status::Running(_), Status::Ready) => {} // to stop a thread, use stop() intead
             (_, Status::Ready) => self.scheduler.push(tid),
             _ => {}
         }

kernel/src/drivers/mod.rs

@@ -5,7 +5,7 @@ use lazy_static::lazy_static;
 use smoltcp::wire::{EthernetAddress, Ipv4Address};
 use smoltcp::socket::SocketSet;
 
-use crate::sync::{SpinNoIrqLock, Condvar, MutexGuard, SpinNoIrq};
+use crate::sync::{ThreadLock, SpinLock, Condvar, MutexGuard, SpinNoIrq};
 
 mod device_tree;
 pub mod bus;
@@ -49,14 +49,14 @@ pub trait NetDriver : Send {
 
 
 lazy_static! {
-    pub static ref DRIVERS: SpinNoIrqLock<Vec<Box<Driver>>> = SpinNoIrqLock::new(Vec::new());
+    pub static ref DRIVERS: SpinLock<Vec<Box<Driver>>> = SpinLock::new(Vec::new());
 }
 
 lazy_static! {
-    pub static ref NET_DRIVERS: SpinNoIrqLock<Vec<Box<NetDriver>>> = SpinNoIrqLock::new(Vec::new());
+    pub static ref NET_DRIVERS: ThreadLock<Vec<Box<NetDriver>>> = ThreadLock::new(Vec::new());
 }
 
-lazy_static! {
+lazy_static!{
     pub static ref SOCKET_ACTIVITY: Condvar = Condvar::new();
 }
 

kernel/src/fs/stdio.rs

@@ -11,7 +11,7 @@ use crate::sync::SpinNoIrqLock as Mutex;
 #[derive(Default)]
 pub struct Stdin {
     buf: Mutex<VecDeque<char>>,
-    pushed: Condvar,
+    pub pushed: Condvar,
 }
 
 impl Stdin {
@@ -36,6 +36,9 @@ impl Stdin {
             }
         }
     }
+    pub fn can_read(&self) -> bool {
+        self.buf.lock().len() > 0
+    }
 }
 
 #[derive(Default)]

kernel/src/process/structs.rs

@@ -23,7 +23,7 @@ pub struct Thread {
     pub proc: Arc<Mutex<Process>>,
 }
 
-#[derive(Clone)]
+#[derive(Clone, Debug)]
 pub enum SocketType {
     Raw,
     Tcp(Option<IpEndpoint>), // save local endpoint for bind()
@@ -31,7 +31,7 @@ pub enum SocketType {
     Icmp
 }
 
-#[derive(Clone)]
+#[derive(Clone, Debug)]
 pub struct SocketWrapper {
     pub handle: SocketHandle,
     pub socket_type: SocketType,
@@ -187,6 +187,14 @@ impl Thread {
         info!("temporary copy data!");
         let kstack = KernelStack::new();
 
+        let iface = &mut *(NET_DRIVERS.lock()[0]);
+        let mut sockets = iface.sockets();
+        for (_fd, file) in files.iter() {
+            if let FileLike::Socket(wrapper) = file {
+                sockets.retain(wrapper.handle);
+            }
+        }
+
 
         Box::new(Thread {
             context: unsafe { Context::new_fork(tf, kstack.top(), memory_set.token()) },

kernel/src/sync/condvar.rs

@@ -1,20 +1,31 @@
 use alloc::collections::VecDeque;
 use super::*;
 use crate::thread;
+use alloc::sync::Arc;
 
 #[derive(Default)]
 pub struct Condvar {
-    wait_queue: SpinNoIrqLock<VecDeque<thread::Thread>>,
+    wait_queue: SpinNoIrqLock<VecDeque<Arc<thread::Thread>>>,
 }
 
 impl Condvar {
     pub fn new() -> Self {
         Condvar::default()
     }
+
     pub fn _wait(&self) {
-        self.wait_queue.lock().push_back(thread::current());
+        self.wait_queue.lock().push_back(Arc::new(thread::current()));
         thread::park();
     }
+
+    pub fn wait_any(condvars: &[&Condvar]) {
+        let token = Arc::new(thread::current());
+        for condvar in condvars {
+            condvar.wait_queue.lock().push_back(token.clone());
+        }
+        thread::park();
+    }
+
     pub fn wait<'a, T, S>(&self, guard: MutexGuard<'a, T, S>) -> MutexGuard<'a, T, S>
         where S: MutexSupport
     {
@@ -23,6 +34,7 @@ impl Condvar {
         self._wait();
         mutex.lock()
     }
+
     pub fn notify_one(&self) {
         if let Some(t) = self.wait_queue.lock().pop_front() {
             t.unpark();

kernel/src/syscall/fs.rs

@@ -1,9 +1,12 @@
 //! Syscalls for file system
 
 use rcore_fs::vfs::Timespec;
+use smoltcp::socket::*;
 
 use crate::fs::*;
 use crate::memory::MemorySet;
+use crate::sync::Condvar;
+use crate::drivers::{NET_DRIVERS, SOCKET_ACTIVITY};
 
 use super::*;
 use super::net::*;
@@ -49,15 +52,68 @@ pub struct PollFd {
     revents: u16
 }
 
+const POLLIN: u16 = 0x0001;
+const POLPRI: u16 = 0x0002;
+const POLLOUT: u16 = 0x0004;
+const POLLERR: u16 = 0x0008;
+const POLLHUP: u16 = 0x0010;
+const POLLNVAL: u16 = 0x0020;
+
 pub fn sys_poll(ufds: *mut PollFd, nfds: usize, timeout_msecs: usize) -> SysResult {
     info!("poll: ufds: {:?}, nfds: {}, timeout_msecs: {:#x}", ufds, nfds, timeout_msecs);
     let mut proc = process();
     proc.memory_set.check_mut_array(ufds, nfds)?;
+
     let slice = unsafe { slice::from_raw_parts_mut(ufds, nfds) };
+    for i in 0..nfds {
+        if proc.files.get(&(slice[i].fd as usize)).is_none() {
+            return Err(SysError::EINVAL);
+        }
+    }
+    drop(proc);
+
+
+    let begin_time_ms = unsafe {crate::trap::TICK / crate::consts::USEC_PER_TICK / 1000};
+    loop {
+        let mut proc = process();
+        for i in 0..nfds {
+            match proc.files.get(&(slice[i].fd as usize)) {
+                Some(FileLike::File(_)) => {
+                    // assume it is stdin for now
+                    if (slice[i].events & POLLIN) != 0 && STDIN.can_read() {
+                        slice[i].revents = POLLIN;
+                        return Ok(0);
+                    }
+                },
+                Some(FileLike::Socket(wrapper)) => {
+                    if let SocketType::Tcp(_) = wrapper.socket_type {
+                        let iface = &mut *(NET_DRIVERS.lock()[0]);
+                        let mut sockets = iface.sockets();
+                        let mut socket = sockets.get::<TcpSocket>(wrapper.handle);
+
+                        if !socket.is_open() {
+                            slice[i].revents = POLLHUP;
+                            return Ok(0);
+                        } else if socket.can_recv() && (slice[i].events & POLLIN) != 0 {
+                            slice[i].revents = POLLIN;
+                            return Ok(0);
+                        } else if socket.can_send() && (slice[i].events & POLLOUT) != 0 {
+                            slice[i].revents = POLLIN;
+                            return Ok(0);
+                        }
+                    } else {
+                        unimplemented!()
+                    }
+                }
+                None => {
+                    slice[i].revents = POLLERR;
+                    return Ok(0);
+                }
+            }
+        }
+        Condvar::wait_any(&[&STDIN.pushed, &(*SOCKET_ACTIVITY)]);
+    }
 
-    // emulate it for now
-    use core::time::Duration;
-    thread::sleep(Duration::from_millis(timeout_msecs as u64));
     Ok(nfds as isize)
 }
 

kernel/src/syscall/mod.rs

@@ -13,6 +13,7 @@ use crate::fs::FileHandle;
 use crate::process::*;
 use crate::thread;
 use crate::util;
+use crate::arch::cpu;
 
 use self::fs::*;
 use self::mem::*;
@@ -30,6 +31,9 @@ mod net;
 
 /// System call dispatcher
 pub fn syscall(id: usize, args: [usize; 6], tf: &mut TrapFrame) -> isize {
+    let pid = cpu::id();
+    let tid = processor().tid();
+    debug!("{}:{} syscall id {} begin", pid, tid, id);
     let ret = match id {
         // file
         000 => sys_read(args[0], args[1] as *mut u8, args[2]),
@@ -163,7 +167,7 @@ pub fn syscall(id: usize, args: [usize; 6], tf: &mut TrapFrame) -> isize {
             crate::trap::error(tf);
         }
     };
-    debug!("syscall id {} ret with {:?}", id, ret);
+    debug!("{}:{} syscall id {} ret with {:?}", pid, tid, id, ret);
     match ret {
         Ok(code) => code,
         Err(err) => -(err as isize),

kernel/src/syscall/net.rs

@@ -182,7 +182,6 @@ pub fn sys_connect(fd: usize, addr: *const u8, addrlen: usize) -> SysResult {
 
     let mut proc = process();
     proc.memory_set.check_ptr(addr)?;
-    let iface = &mut *(NET_DRIVERS.lock()[0]);
 
     let mut dest = None;
     let mut port = 0;
@@ -197,6 +196,8 @@ pub fn sys_connect(fd: usize, addr: *const u8, addrlen: usize) -> SysResult {
 
     let wrapper = proc.get_socket(fd)?;
     if let SocketType::Tcp(_) = wrapper.socket_type {
+        let mut drivers = NET_DRIVERS.lock();
+        let iface = &mut *(drivers[0]);
         let mut sockets = iface.sockets();
         let mut socket = sockets.get::<TcpSocket>(wrapper.handle);
 
@@ -207,19 +208,28 @@ pub fn sys_connect(fd: usize, addr: *const u8, addrlen: usize) -> SysResult {
                 // avoid deadlock
                 drop(socket);
                 drop(sockets);
+                drop(iface);
+                drop(drivers);
 
                 // wait for connection result
                 loop {
+                    let mut drivers = NET_DRIVERS.lock();
+                    let iface = &mut *(drivers[0]);
                     iface.poll();
 
                     let mut sockets = iface.sockets();
                     let mut socket = sockets.get::<TcpSocket>(wrapper.handle);
                     if socket.state() == TcpState::SynSent {
                         // still connecting
-                        SOCKET_ACTIVITY._wait()
+                        drop(socket);
+                        drop(sockets);
+                        drop(iface);
+                        drop(drivers);
+                        debug!("poll for connection wait");
+                        SOCKET_ACTIVITY._wait();
                     } else if socket.state() == TcpState::Established {
                         break Ok(0);
-                    } else if socket.state() == TcpState::Closed {
+                    } else {
                         break Err(SysError::ECONNREFUSED);
                     }
                 }
@@ -515,18 +525,17 @@ pub fn sys_recvfrom(
 
 pub fn sys_close_socket(proc: &mut Process, fd: usize, handle: SocketHandle) -> SysResult {
     let iface = &mut *(NET_DRIVERS.lock()[0]);
-    let mut socket = iface.sockets().remove(handle);
-    match socket {
-        Socket::Tcp(ref mut tcp_socket) => {
-            tcp_socket.close();
-        }
-        _ => {}
-    }
-
+    let mut sockets = iface.sockets();
+    sockets.release(handle);
+    sockets.prune();
     Ok(0)
 }
 
 pub fn sys_bind(fd: usize, addr: *const u8, len: usize) -> SysResult {
+    info!(
+        "sys_bind: fd: {} addr: {:?} len: {}",
+        fd, addr, len
+    );
     let mut proc = process();
     proc.memory_set.check_array(addr, len)?;
 
@@ -545,7 +554,7 @@ pub fn sys_bind(fd: usize, addr: *const u8, len: usize) -> SysResult {
     }
 
     let iface = &mut *(NET_DRIVERS.lock()[0]);
-    let wrapper = proc.get_socket_mut(fd)?;
+    let wrapper = &mut proc.get_socket_mut(fd)?;
     if let SocketType::Tcp(_) = wrapper.socket_type {
         wrapper.socket_type = SocketType::Tcp(Some(IpEndpoint::new(host.unwrap(), port)));
         Ok(0)
@@ -555,6 +564,10 @@ pub fn sys_bind(fd: usize, addr: *const u8, len: usize) -> SysResult {
 }
 
 pub fn sys_listen(fd: usize, backlog: usize) -> SysResult {
+    info!(
+        "sys_listen: fd: {} backlog: {}",
+        fd, backlog
+    );
     // smoltcp tcp sockets do not support backlog
     // open multiple sockets for each connection
     let mut proc = process();
@@ -575,6 +588,10 @@ pub fn sys_listen(fd: usize, backlog: usize) -> SysResult {
 }
 
 pub fn sys_accept(fd: usize, addr: *mut u8, addr_len: *mut u32) -> SysResult {
+    info!(
+        "sys_accept: fd: {} addr: {:?} addr_len: {:?}",
+        fd, addr, addr_len
+    );
     // smoltcp tcp sockets do not support backlog
     // open multiple sockets for each connection
     let mut proc = process();
@@ -584,16 +601,17 @@ pub fn sys_accept(fd: usize, addr: *mut u8, addr_len: *mut u32) -> SysResult {
 
         let max_addr_len = unsafe { *addr_len } as usize;
         if max_addr_len < size_of::<SockaddrIn>() {
+            debug!("length too short {}", max_addr_len);
             return Err(SysError::EINVAL);
         }
 
         proc.memory_set.check_mut_array(addr, max_addr_len)?;
     }
 
-    let iface = &mut *(NET_DRIVERS.lock()[0]);
     let wrapper = proc.get_socket_mut(fd)?;
     if let SocketType::Tcp(Some(endpoint)) = wrapper.socket_type {
         loop {
+            let iface = &mut *(NET_DRIVERS.lock()[0]);
             let mut sockets = iface.sockets();
             let mut socket = sockets.get::<TcpSocket>(wrapper.handle);
 
@@ -617,7 +635,7 @@ pub fn sys_accept(fd: usize, addr: *mut u8, addr_len: *mut u32) -> SysResult {
                         fd,
                         FileLike::Socket(SocketWrapper {
                             handle: tcp_handle,
-                            socket_type: SocketType::Tcp(None),
+                            socket_type: SocketType::Tcp(Some(endpoint)),
                         }),
                     )
                     .unwrap();
@@ -634,14 +652,21 @@ pub fn sys_accept(fd: usize, addr: *mut u8, addr_len: *mut u32) -> SysResult {
             // avoid deadlock
             drop(socket);
             drop(sockets);
+            drop(iface);
             SOCKET_ACTIVITY._wait()
         }
     } else {
+        debug!("bad socket type {:?}", wrapper);
         Err(SysError::EINVAL)
     }
 }
 
 pub fn sys_getsockname(fd: usize, addr: *mut u8, addr_len: *mut u32) -> SysResult {
+    info!(
+        "sys_getsockname: fd: {} addr: {:?} addr_len: {:?}",
+        fd, addr, addr_len
+    );
+
     // smoltcp tcp sockets do not support backlog
     // open multiple sockets for each connection
     let mut proc = process();