From 878381a37febeb0033d9c1c4ee8262517b9e74aa Mon Sep 17 00:00:00 2001 From: John Hodge Date: Mon, 5 Aug 2013 23:25:54 +0800 Subject: [PATCH] Kernel/PTYs - Added block on user write when server is full --- KernelLand/Kernel/drv/pty.c | 55 ++++++++++++++++++++++++++++++------- 1 file changed, 45 insertions(+), 10 deletions(-) diff --git a/KernelLand/Kernel/drv/pty.c b/KernelLand/Kernel/drv/pty.c index 8b63b119..1d1bdf35 100644 --- 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) -- 2.20.1