From 5347b94bbd7455453754fd79b6aaa64aa368ce59 Mon Sep 17 00:00:00 2001
From: Lars Op den Kamp <lars@opdenkamp.eu>
Date: Thu, 29 Mar 2012 11:53:41 +0200
Subject: [PATCH] win32: implemented timeouts in serial socket reads

---
 src/lib/platform/sockets/serialport.h   |  6 ++++
 src/lib/platform/windows/os-socket.h    |  2 ++
 src/lib/platform/windows/serialport.cpp | 38 +++++++++++++++----------
 3 files changed, 31 insertions(+), 15 deletions(-)

diff --git a/src/lib/platform/sockets/serialport.h b/src/lib/platform/sockets/serialport.h
index bdd05b9..fb4be19 100644
--- a/src/lib/platform/sockets/serialport.h
+++ b/src/lib/platform/sockets/serialport.h
@@ -71,6 +71,9 @@ namespace PLATFORM
     public:
       CSerialSocket(const CStdString &strName, uint32_t iBaudrate, SerialDataBits iDatabits = SERIAL_DATA_BITS_EIGHT, SerialStopBits iStopbits = SERIAL_STOP_BITS_ONE, SerialParity iParity = SERIAL_PARITY_NONE) :
           CCommonSocket<serial_socket_t>(INVALID_SERIAL_SOCKET_VALUE, strName),
+#ifdef __WINDOWS__
+          m_iCurrentTimeout(0),
+#endif
           m_bIsOpen(false),
           m_iBaudrate(iBaudrate),
           m_iDatabits(iDatabits),
@@ -96,6 +99,9 @@ namespace PLATFORM
     protected:
   #ifndef __WINDOWS__
       struct termios  m_options;
+  #else
+      bool SetTimeouts(serial_socket_t socket, int* iError, DWORD iTimeout);
+      DWORD           m_iCurrentTimeout;
   #endif
 
       bool            m_bIsOpen;
diff --git a/src/lib/platform/windows/os-socket.h b/src/lib/platform/windows/os-socket.h
index 5174cba..86750c5 100644
--- a/src/lib/platform/windows/os-socket.h
+++ b/src/lib/platform/windows/os-socket.h
@@ -95,6 +95,8 @@ namespace PLATFORM
 
   inline ssize_t SerialSocketRead(serial_socket_t socket, int *iError, void* data, size_t len, uint64_t iTimeoutMs /*= 0*/)
   {
+    *iError = 0;
+
     if (len != (DWORD)len)
     {
       *iError = EINVAL;
diff --git a/src/lib/platform/windows/serialport.cpp b/src/lib/platform/windows/serialport.cpp
index c0cdd93..fe91725 100644
--- a/src/lib/platform/windows/serialport.cpp
+++ b/src/lib/platform/windows/serialport.cpp
@@ -48,11 +48,14 @@ void FormatWindowsError(int iErrorCode, CStdString &strMessage)
   }
 }
 
-bool SetTimeouts(serial_socket_t socket, int* iError, bool bBlocking)
+bool CSerialSocket::SetTimeouts(serial_socket_t socket, int* iError, DWORD iTimeout)
 {
   if (socket == INVALID_HANDLE_VALUE)
 	  return false;
 
+  if (iTimeout == m_iCurrentTimeout)
+    return true;
+
   COMMTIMEOUTS cto;
   if (!GetCommTimeouts(socket, &cto))
   {
@@ -60,18 +63,9 @@ bool SetTimeouts(serial_socket_t socket, int* iError, bool bBlocking)
     return false;
   }
 
-  if (bBlocking)
-  {
-    cto.ReadIntervalTimeout         = 0;
-    cto.ReadTotalTimeoutConstant    = 0;
-    cto.ReadTotalTimeoutMultiplier  = 0;
-  }
-  else
-  {
-    cto.ReadIntervalTimeout         = MAXDWORD;
-    cto.ReadTotalTimeoutConstant    = 0;
-    cto.ReadTotalTimeoutMultiplier  = 0;
-  }
+  cto.ReadIntervalTimeout         = 0;
+  cto.ReadTotalTimeoutConstant    = iTimeout;
+  cto.ReadTotalTimeoutMultiplier  = 0;
 
   if (!SetCommTimeouts(socket, &cto))
   {
@@ -79,6 +73,7 @@ bool SetTimeouts(serial_socket_t socket, int* iError, bool bBlocking)
     return false;
   }
 
+  m_iCurrentTimeout = iTimeout;
   return true;
 }
 
@@ -103,7 +98,20 @@ ssize_t CSerialSocket::Write(void* data, size_t len)
 
 ssize_t CSerialSocket::Read(void* data, size_t len, uint64_t iTimeoutMs /* = 0 */)
 {
-  return IsOpen() ? SerialSocketRead(m_socket, &m_iError, data, len, iTimeoutMs) : -1;
+  if (IsOpen())
+  {
+    DWORD iTimeout((DWORD)iTimeoutMs);
+    if (iTimeout != iTimeoutMs)
+      return -1;
+
+    int iError(0);
+    if (!SetTimeouts(m_socket, &iError, iTimeout))
+      return -1;
+
+    return SerialSocketRead(m_socket, &m_iError, data, len, iTimeoutMs);
+  }
+
+  return -1;
 }
 
 bool CSerialSocket::Open(uint64_t iTimeoutMs /* = 0 */)
@@ -153,7 +161,7 @@ bool CSerialSocket::Open(uint64_t iTimeoutMs /* = 0 */)
     return false;
   }
 
-  if (!SetTimeouts(m_socket, &m_iError, false))
+  if (!SetTimeouts(m_socket, &m_iError, MAXDWORD))
   {
     m_strError = "unable to set timeouts";
     FormatWindowsError(GetLastError(), m_strError);
-- 
2.34.1