nonblock stdin for mgba keyboard support

kernel/src/fs/file.rs

@@ -19,6 +19,7 @@ pub struct OpenOptions {
     pub write: bool,
     /// Before each write, the file offset is positioned at the end of the file.
     pub append: bool,
+    pub nonblock: bool,
 }
 
 #[derive(Debug)]
@@ -48,7 +49,17 @@ impl FileHandle {
         if !self.options.read {
             return Err(FsError::InvalidParam); // FIXME: => EBADF
         }
-        let len = self.inode.read_at(offset, buf)?;
+        let mut len : usize = 0;
+        if !self.options.nonblock {   // block
+            loop {
+                len = self.inode.read_at(offset, buf)?;
+                if len > 0 {
+                    break;
+                }
+            }
+        }else{
+            len = self.inode.read_at(offset, buf)?;
+        }
         Ok(len)
     }
 
@@ -123,6 +134,13 @@ impl FileHandle {
     pub fn inode(&self) -> Arc<INode> {
         self.inode.clone()
     }
+
+    pub fn fcntl(&mut self, cmd: usize, arg: usize) -> Result<()> {
+        if arg == 2048 && cmd == 4 {
+            self.options.nonblock = true;
+        }
+        Ok(())
+    }
 }
 
 impl fmt::Debug for FileHandle {

kernel/src/fs/file_like.rs

@@ -56,6 +56,16 @@ impl FileLike {
         };
         Ok(status)
     }
+
+    pub fn fcntl(&mut self, cmd: usize, arg: usize) -> SysResult {
+        match self {
+            FileLike::File(file) => file.fcntl(cmd, arg)?,
+            FileLike::Socket(socket) => {
+                //TODO
+            }
+        }
+        Ok(0)
+    }
 }
 
 impl fmt::Debug for FileLike {

kernel/src/fs/stdio.rs

@@ -35,8 +35,7 @@ impl Stdin {
             match buf_lock.pop_front() {
                 Some(c) => return c,
                 None => {
-                    //self.pushed.wait(buf_lock);
-                    return 0 as char;
+                    self.pushed.wait(buf_lock);
                 }
             }
         }
@@ -92,8 +91,12 @@ macro_rules! impl_inode {
 
 impl INode for Stdin {
     fn read_at(&self, offset: usize, buf: &mut [u8]) -> Result<usize> {
-        buf[0] = self.pop() as u8;
-        Ok(1)
+        if self.can_read() {
+            buf[0] = self.pop() as u8;
+            Ok(1)
+        }else{
+            Ok(0)
+        }
     }
     fn write_at(&self, _offset: usize, _buf: &[u8]) -> Result<usize> {
         unimplemented!()

kernel/src/process/structs.rs

@@ -260,6 +260,7 @@ impl Thread {
                     read: true,
                     write: false,
                     append: false,
+                    nonblock: false,
                 },
                 String::from("stdin"),
             )),
@@ -272,6 +273,7 @@ impl Thread {
                     read: false,
                     write: true,
                     append: false,
+                    nonblock: false,
                 },
                 String::from("stdout"),
             )),
@@ -284,6 +286,7 @@ impl Thread {
                     read: false,
                     write: true,
                     append: false,
+                    nonblock: false,
                 },
                 String::from("stderr"),
             )),

kernel/src/syscall/fs.rs

@@ -703,6 +703,7 @@ impl Syscall<'_> {
                 read: true,
                 write: false,
                 append: false,
+                nonblock: false,
             },
             String::from("pipe_r:[]"),
         )));
@@ -713,6 +714,7 @@ impl Syscall<'_> {
                 read: false,
                 write: true,
                 append: false,
+                nonblock: false,
             },
             String::from("pipe_w:[]"),
         )));
@@ -828,6 +830,16 @@ impl Syscall<'_> {
         );
         return Ok(total_written);
     }
+
+    pub fn sys_fcntl(&mut self, fd : usize, cmd : usize, arg : usize) -> SysResult{
+        info!(
+            "fcntl: fd: {}, cmd: {:x}, arg: {}",
+            fd, cmd, arg
+        );
+        let mut proc = self.process();
+        let file_like = proc.get_file_like(fd)?;
+        file_like.fcntl(cmd, arg)
+    }
 }
 
 impl Process {
@@ -978,6 +990,7 @@ impl OpenFlags {
             read: self.readable(),
             write: self.writable(),
             append: self.contains(OpenFlags::APPEND),
+            nonblock: false,
         }
     }
 }

kernel/src/syscall/mod.rs

@@ -99,7 +99,10 @@ impl Syscall<'_> {
             SYS_READV => self.sys_readv(args[0], args[1] as *const IoVec, args[2]),
             SYS_WRITEV => self.sys_writev(args[0], args[1] as *const IoVec, args[2]),
             SYS_SENDFILE => self.sys_sendfile(args[0], args[1], args[2] as *mut usize, args[3]),
-            SYS_FCNTL => self.unimplemented("fcntl", Ok(0)),
+            SYS_FCNTL => {
+                info!("SYS_FCNTL : {} {} {} {}", args[0], args[1], args[2], args[3]);
+                self.sys_fcntl(args[0], args[1], args[2])
+            },
             SYS_FLOCK => self.unimplemented("flock", Ok(0)),
             SYS_FSYNC => self.sys_fsync(args[0]),
             SYS_FDATASYNC => self.sys_fdatasync(args[0]),