Kernel/PTYs - Added block on user write when server is full

[tpg/acess2.git] / KernelLand / Kernel / drv / pty.c

diff --git a/KernelLand/Kernel/drv/pty.c b/KernelLand/Kernel/drv/pty.c
index 8b63b11..1d1bdf3 100644 (file)
--- a/KernelLand/Kernel/drv/pty.c
+++ b/KernelLand/Kernel/drv/pty.c
@@ -532,6 +532,8 @@ _select:
        Mutex_Acquire(&pty->InputMutex);
        Length = _rb_read(pty->InputData, INPUT_RINGBUFFER_LEN, &pty->InputReadPos, &pty->InputWritePos,
                Buffer, Length);
+       if( Length && pty->ServerNode )
+               VFS_MarkFull(pty->ServerNode, 0);
        Mutex_Release(&pty->InputMutex);
 
        if(pty->InputReadPos == pty->InputWritePos)
@@ -559,19 +561,29 @@ size_t PTY_WriteClient(tVFS_Node *Node, off_t Offset, size_t Length, const void
        }       
 
        // Write to either FIFO or directly to output function
-       if( pty->OutputFcn )
-       {
+       if( pty->OutputFcn ) {
                pty->OutputFcn(pty->OutputHandle, Length, Buffer);
+               return Length;
        }
-       else
-       {
-               // Write to output ringbuffer
-               Length = _rb_write(pty->OutputData, OUTPUT_RINGBUFFER_LEN,
-                       &pty->OutputReadPos, &pty->OutputWritePos,
-                       Buffer, Length);
-               VFS_MarkAvaliable(pty->ServerNode, 1);
+       
+       // FIFO
+       tTime   timeout_z, *timeout = (Flags & VFS_IOFLAG_NOBLOCK) ? &timeout_z : NULL;
+        int    rv;
+       
+       rv = VFS_SelectNode(Node, VFS_SELECT_WRITE, timeout, "PTY_WriteClient");
+       if(!rv ) {
+               errno = (timeout ? EWOULDBLOCK : EINTR);
+               return -1;
        }
        
+       // Write to output ringbuffer
+       Length = _rb_write(pty->OutputData, OUTPUT_RINGBUFFER_LEN,
+               &pty->OutputReadPos, &pty->OutputWritePos,
+               Buffer, Length);
+       VFS_MarkAvaliable(pty->ServerNode, 1);
+       if( (pty->OutputWritePos + 1) % OUTPUT_RINGBUFFER_LEN == pty->OutputReadPos )
+               VFS_MarkFull(Node, 1);
+       
        return Length;
 }
 
@@ -605,6 +617,10 @@ void PTY_CloseClient(tVFS_Node *Node)
 size_t PTY_ReadServer(tVFS_Node *Node, off_t Offset, size_t Length, void *Buffer, Uint Flags)
 {
        tPTY *pty = Node->ImplPtr;
+       if( !pty ) {
+               errno = EIO;
+               return -1;
+       }
 
        // TODO: Prevent two servers fighting over client's output      
        if( pty->OutputFcn )
@@ -634,7 +650,26 @@ size_t PTY_ReadServer(tVFS_Node *Node, off_t Offset, size_t Length, void *Buffer
 //\! Write to the client's input
 size_t PTY_WriteServer(tVFS_Node *Node, off_t Offset, size_t Length, const void *Buffer, Uint Flags)
 {
-       return PTY_SendInput(Node->ImplPtr, Buffer, Length);
+       tPTY    *pty = Node->ImplPtr;
+       if( !pty ) {
+               errno = EIO;
+               return -1;
+       }
+
+       tTime   timeout_z = 0, *timeout = (Flags & VFS_IOFLAG_NOBLOCK) ? &timeout_z : NULL;
+       int rv = VFS_SelectNode(Node, VFS_SELECT_WRITE, timeout, "PTY_WriteServer");
+       if(!rv) {
+               errno = (timeout ? EWOULDBLOCK : EINTR);
+               return -1;
+       }
+       size_t  used = 0;
+       do {
+               used += PTY_SendInput(Node->ImplPtr, Buffer, Length);
+       } while( used < Length && !(Flags & VFS_IOFLAG_NOBLOCK) );
+       
+       if( (pty->InputWritePos+1)%INPUT_RINGBUFFER_LEN == pty->InputReadPos )
+               VFS_MarkFull(Node, 1);
+       return used;
 }
 
 void PTY_CloseServer(tVFS_Node *Node)