implement alternative native build, we're kind of at a turning point here, see roadmap for ideas

13 files changed, 1134 insertions, 0 deletions

diff --git a/flow-native/Makefile b/flow-native/Makefile
new file mode 100644
index 0000000..fb973f3
--- /dev/null
+++ b/flow-native/Makefile
@@ -0,0 +1,56 @@
+# Build native binaries for flow.
+# ===============================
+
+# name of the library to produce
+NAME=flow
+MAJOR=3
+MINOR=0
+MICRO=0
+
+SONAME=lib$(NAME).so.$(MAJOR)
+TARGET=$(SONAME).$(MINOR).$(MICRO)
+
+JAVA_HOME=/usr/lib/jvm/java-7-oracle
+
+# where the library should be installed
+PREFIX?=usr/lib
+
+# compiler and linker settings
+CC=$(CROSS_COMPILE)gcc
+LD=$(CROSS_COMPILE)ld
+CFLAGS= -O2 -fPIC -Wall
+
+# since java connot easily load a library with a specific
+# major version, the vesion is included in the library's name
+
+LDFLAGS+=-shared -Wl,-soname,$(SONAME)
+INCLUDES=./include/ $(JAVA_HOME)/include/ $(JAVA_HOME)/include/linux/
+
+OBJECTS=flow_jni.o posix/flow.o
+
+# rules
+all: $(TARGET) $(SONAME)
+
+$(TARGET): $(OBJECTS)
+	$(CC) $(LDFLAGS) -o $@ $^
+	
+$(SONAME): $(TARGET)
+	ln -s $(TARGET) $(SONAME)
+
+%.o: %.c
+	$(CC) $(CFLAGS) $(addprefix -I, $(INCLUDES)) -o $@ -c $<
+
+install:
+	cp -P -t $(DESTDIR)/$(PREFIX)/ $(TARGET) $(SONAME)
+
+uninstall:
+	rm $(DESTDIR)/$(PREFIX)/$(TARGET)
+	rm $(DESTDIR)/$(PREFIX)/$(SONAME)
+	
+clean:
+	rm -f posix/*.o
+	rm -f posix/*.so
+	rm -f $(TARGET)
+	rm -f $(SONAME)
+
+.PHONY: clean install
diff --git a/flow-native/debian/changelog b/flow-native/debian/changelog
new file mode 100644
index 0000000..7dac466
--- /dev/null
+++ b/flow-native/debian/changelog
@@ -0,0 +1,5 @@
+flow (0.1) UNRELEASED; urgency=low
+
+  * Initial release.
+
+ -- Jakob Odersky <jodersky@gmail.com>  Thu, 27 Mar 2014 22:55:53 +0100
diff --git a/flow-native/debian/compat b/flow-native/debian/compat
new file mode 100644
index 0000000..45a4fb7
--- /dev/null
+++ b/flow-native/debian/compat
@@ -0,0 +1 @@
+8
diff --git a/flow-native/debian/control b/flow-native/debian/control
new file mode 100644
index 0000000..5fc8b77
--- /dev/null
+++ b/flow-native/debian/control
@@ -0,0 +1,16 @@
+Source: flow
+Priority: extra
+Maintainer: Jakob Odersky <jodersky@gmail.com>
+Build-Depends: debhelper (>= 8.0.0)
+Standards-Version: 3.9.3
+Section: libs
+Homepage: https://github.com/jodersky/flow
+Vcs-Git: git://github.com/jodersky/flow.git
+
+Package: libflow3
+Section: libs
+Architecture: any
+Depends: ${shlibs:Depends}, ${misc:Depends}
+Description: Provides the native backend and JNI bindings for flow.
+ This package contains a native library to fully enable flow, a
+ serial communication library for Scala.
\ No newline at end of file
diff --git a/flow-native/debian/copyright b/flow-native/debian/copyright
new file mode 100644
index 0000000..d26a00a
--- /dev/null
+++ b/flow-native/debian/copyright
@@ -0,0 +1,36 @@
+Format: http://dep.debian.net/deps/dep5
+Upstream-Name: flow
+Source: https://github.com/jodersky/flow
+
+Files: *
+Copyright: 2014 Jakob Odersky <jodersky@gmail.com>
+License: BSD-3-Clause
+
+Files: debian/*
+Copyright: 2014 Jakob Odersky <jodersky@gmail.com>
+License: BSD-3-Clause
+
+License: BSD-3-Clause
+ Redistribution and use in source and binary forms, with or without
+ modification, are permitted provided that the following conditions
+ are met:
+ 1. Redistributions of source code must retain the above copyright
+    notice, this list of conditions and the following disclaimer.
+ 2. Redistributions in binary form must reproduce the above copyright
+    notice, this list of conditions and the following disclaimer in the
+    documentation and/or other materials provided with the distribution.
+ 3. Neither the name of the University nor the names of its contributors
+    may be used to endorse or promote products derived from this software
+    without specific prior written permission.
+ .
+ THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
+ ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
+ FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ SUCH DAMAGE.
diff --git a/flow-native/debian/libflow3.dirs b/flow-native/debian/libflow3.dirs
new file mode 100644
index 0000000..6845771
--- /dev/null
+++ b/flow-native/debian/libflow3.dirs
@@ -0,0 +1 @@
+usr/lib
diff --git a/flow-native/debian/rules b/flow-native/debian/rules
new file mode 100755
index 0000000..b760bee
--- /dev/null
+++ b/flow-native/debian/rules
@@ -0,0 +1,13 @@
+#!/usr/bin/make -f
+# -*- makefile -*-
+# Sample debian/rules that uses debhelper.
+# This file was originally written by Joey Hess and Craig Small.
+# As a special exception, when this file is copied by dh-make into a
+# dh-make output file, you may use that output file without restriction.
+# This special exception was added by Craig Small in version 0.37 of dh-make.
+
+# Uncomment this to turn on verbose mode.
+#export DH_VERBOSE=1
+
+%:
+	dh $@ 
diff --git a/flow-native/flow_jni.c b/flow-native/flow_jni.c
new file mode 100644
index 0000000..8ec2aed
--- /dev/null
+++ b/flow-native/flow_jni.c
@@ -0,0 +1,169 @@
+#include "flow.h"
+#include "com_github_jodersky_flow_internal_NativeSerial.h"
+
+
+static inline void throwException(JNIEnv* env, const char* const exception, const char * const message) {
+  (*env)->ThrowNew(env, (*env)->FindClass(env, exception), message); 
+}
+
+static inline void check(JNIEnv* env, int id) {
+  switch (id) {
+    case E_IO: throwException(env, "java/io/IOException", ""); break;
+    case E_BUSY: throwException(env, "com/github/jodersky/flow/PortInUseException", ""); break;
+    case E_ACCESS_DENIED: throwException(env, "com/github/jodersky/flow/AccessDeniedException", ""); break;
+    case E_INVALID_SETTINGS: throwException(env, "com/github/jodersky/flow/InvalidSettingsException", ""); break;
+    case E_INTERRUPT: throwException(env, "com/github/jodersky/flow/PortInterruptedException", ""); break;
+    case E_NO_PORT: throwException(env, "com/github/jodersky/flow/NoSuchPortException", ""); break;
+    default: return;
+  }
+}
+ 
+
+/*
+ * Class:     com_github_jodersky_flow_internal_NativeSerial
+ * Method:    open
+ * Signature: (Ljava/lang/String;IIZI)J
+ */
+JNIEXPORT jlong JNICALL Java_com_github_jodersky_flow_internal_NativeSerial_open
+  (JNIEnv *env, jclass clazz, jstring port_name, jint baud, jint char_size, jboolean two_stop_bits, jint parity) { 
+
+    const char *dev = (*env)->GetStringUTFChars(env, port_name, 0);
+    struct serial_config* config;
+    int r = serial_open(dev, baud, char_size, two_stop_bits, parity, &config);
+    (*env)->ReleaseStringUTFChars(env, port_name, dev);
+
+  
+    if (r < 0) {
+      check(env, r);
+      return 0;
+    }
+  
+    long jpointer = (long) config;
+    return jpointer;
+
+}
+
+/*
+ * Class:     com_github_jodersky_flow_internal_NativeSerial
+ * Method:    readDirect
+ * Signature: (JLjava/nio/ByteBuffer;)I
+ */
+JNIEXPORT jint JNICALL Java_com_github_jodersky_flow_internal_NativeSerial_readDirect
+  (JNIEnv *env, jclass clazz, jlong config, jobject buffer) {
+
+    char* local_buffer = (char*) (*env)->GetDirectBufferAddress(env, buffer);
+    if (local_buffer == NULL) {
+        throwException(env, "java/lang/IllegalArgumentException", "ByteBuffer not direct");
+        return -1;
+    }
+    jlong size = (*env)->GetDirectBufferCapacity(env, buffer);
+
+    int r = serial_read((struct serial_config*) config, local_buffer, (size_t) size);
+    if (r < 0) {
+      check(env, r);
+      return -1;
+    }
+    return r;
+
+}
+
+/*
+ * Class:     com_github_jodersky_flow_internal_NativeSerial
+ * Method:    read
+ * Signature: (J[B)I
+ */
+JNIEXPORT jint JNICALL Java_com_github_jodersky_flow_internal_NativeSerial_read
+  (JNIEnv *env, jclass clazz, jlong config, jbyteArray buffer) {
+
+    jsize size = (*env)->GetArrayLength(env, buffer);
+    char local_buffer[size];
+    int r = serial_read((struct serial_config*) config, local_buffer, size);
+    if (r < 0) {
+      check(env, r);
+      return -1;
+    }
+
+    (*env)->SetByteArrayRegion(env, buffer, 0, r, (signed char *) local_buffer);
+    return r;
+
+}
+
+/*
+ * Class:     com_github_jodersky_flow_internal_NativeSerial
+ * Method:    cancelRead
+ * Signature: (J)V
+ */
+JNIEXPORT void JNICALL Java_com_github_jodersky_flow_internal_NativeSerial_cancelRead
+  (JNIEnv *env, jclass clazz, jlong config) {
+
+  int r = serial_cancel_read((struct serial_config*) config);
+  if (r < 0) {
+    check(env, r);
+  }
+    
+}
+
+/*
+ * Class:     com_github_jodersky_flow_internal_NativeSerial
+ * Method:    writeDirect
+ * Signature: (JLjava/nio/ByteBuffer;I)I
+ */
+JNIEXPORT jint JNICALL Java_com_github_jodersky_flow_internal_NativeSerial_writeDirect
+  (JNIEnv *env, jclass clazz, jlong config, jobject buffer, jint size) {
+
+    char* local_buffer = (char *) (*env)->GetDirectBufferAddress(env, buffer);
+    if (local_buffer == NULL) {
+        throwException(env, "java/lang/IllegalArgumentException", "ByteBuffer not direct");
+        return -1;
+    }
+
+    int r = serial_write((struct serial_config*) config, local_buffer, (size_t) size);
+    if (r < 0) {
+      check(env, r);
+      return -1;
+    }
+    return r;
+    
+}
+
+/*
+ * Class:     com_github_jodersky_flow_internal_NativeSerial
+ * Method:    write
+ * Signature: (J[BI)I
+ */
+JNIEXPORT jint JNICALL Java_com_github_jodersky_flow_internal_NativeSerial_write
+  (JNIEnv *env, jclass clazz, jlong config, jbyteArray buffer, jint size) {
+    
+    char* local_buffer = (char*) (*env)->GetByteArrayElements(env, buffer, NULL);
+    int r = serial_write((struct serial_config*) config, local_buffer, size);
+    (*env)->ReleaseByteArrayElements(env, buffer, (signed char*) local_buffer, JNI_ABORT);
+    if (r < 0) {
+      check(env, r);
+      return -1;
+    }
+    return r;
+
+}
+
+/*
+ * Class:     com_github_jodersky_flow_internal_NativeSerial
+ * Method:    close
+ * Signature: (J)V
+ */
+JNIEXPORT void JNICALL Java_com_github_jodersky_flow_internal_NativeSerial_close
+  (JNIEnv *env, jclass clazz, jlong config) {
+    int r = serial_close((struct serial_config*) config);
+    if (r < 0) {
+      check(env, r);
+    }
+}
+
+/*
+ * Class:     com_github_jodersky_flow_internal_NativeSerial
+ * Method:    debug
+ * Signature: (Z)V
+ */
+JNIEXPORT void JNICALL Java_com_github_jodersky_flow_internal_NativeSerial_debug
+  (JNIEnv *env, jclass clazz, jboolean value) {
+    serial_debug((bool) value);
+}
\ No newline at end of file
diff --git a/flow-native/include/com_github_jodersky_flow_internal_NativeSerial.h b/flow-native/include/com_github_jodersky_flow_internal_NativeSerial.h
new file mode 100644
index 0000000..04364fb
--- /dev/null
+++ b/flow-native/include/com_github_jodersky_flow_internal_NativeSerial.h
@@ -0,0 +1,83 @@
+/* DO NOT EDIT THIS FILE - it is machine generated */
+#include <jni.h>
+/* Header for class com_github_jodersky_flow_internal_NativeSerial */
+
+#ifndef _Included_com_github_jodersky_flow_internal_NativeSerial
+#define _Included_com_github_jodersky_flow_internal_NativeSerial
+#ifdef __cplusplus
+extern "C" {
+#endif
+#undef com_github_jodersky_flow_internal_NativeSerial_PARITY_NONE
+#define com_github_jodersky_flow_internal_NativeSerial_PARITY_NONE 0L
+#undef com_github_jodersky_flow_internal_NativeSerial_PARITY_ODD
+#define com_github_jodersky_flow_internal_NativeSerial_PARITY_ODD 1L
+#undef com_github_jodersky_flow_internal_NativeSerial_PARITY_EVEN
+#define com_github_jodersky_flow_internal_NativeSerial_PARITY_EVEN 2L
+/*
+ * Class:     com_github_jodersky_flow_internal_NativeSerial
+ * Method:    open
+ * Signature: (Ljava/lang/String;IIZI)J
+ */
+JNIEXPORT jlong JNICALL Java_com_github_jodersky_flow_internal_NativeSerial_open
+  (JNIEnv *, jclass, jstring, jint, jint, jboolean, jint);
+
+/*
+ * Class:     com_github_jodersky_flow_internal_NativeSerial
+ * Method:    readDirect
+ * Signature: (JLjava/nio/ByteBuffer;)I
+ */
+JNIEXPORT jint JNICALL Java_com_github_jodersky_flow_internal_NativeSerial_readDirect
+  (JNIEnv *, jclass, jlong, jobject);
+
+/*
+ * Class:     com_github_jodersky_flow_internal_NativeSerial
+ * Method:    read
+ * Signature: (J[B)I
+ */
+JNIEXPORT jint JNICALL Java_com_github_jodersky_flow_internal_NativeSerial_read
+  (JNIEnv *, jclass, jlong, jbyteArray);
+
+/*
+ * Class:     com_github_jodersky_flow_internal_NativeSerial
+ * Method:    cancelRead
+ * Signature: (J)V
+ */
+JNIEXPORT void JNICALL Java_com_github_jodersky_flow_internal_NativeSerial_cancelRead
+  (JNIEnv *, jclass, jlong);
+
+/*
+ * Class:     com_github_jodersky_flow_internal_NativeSerial
+ * Method:    writeDirect
+ * Signature: (JLjava/nio/ByteBuffer;I)I
+ */
+JNIEXPORT jint JNICALL Java_com_github_jodersky_flow_internal_NativeSerial_writeDirect
+  (JNIEnv *, jclass, jlong, jobject, jint);
+
+/*
+ * Class:     com_github_jodersky_flow_internal_NativeSerial
+ * Method:    write
+ * Signature: (J[BI)I
+ */
+JNIEXPORT jint JNICALL Java_com_github_jodersky_flow_internal_NativeSerial_write
+  (JNIEnv *, jclass, jlong, jbyteArray, jint);
+
+/*
+ * Class:     com_github_jodersky_flow_internal_NativeSerial
+ * Method:    close
+ * Signature: (J)V
+ */
+JNIEXPORT void JNICALL Java_com_github_jodersky_flow_internal_NativeSerial_close
+  (JNIEnv *, jclass, jlong);
+
+/*
+ * Class:     com_github_jodersky_flow_internal_NativeSerial
+ * Method:    debug
+ * Signature: (Z)V
+ */
+JNIEXPORT void JNICALL Java_com_github_jodersky_flow_internal_NativeSerial_debug
+  (JNIEnv *, jclass, jboolean);
+
+#ifdef __cplusplus
+}
+#endif
+#endif
diff --git a/flow-native/include/flow.h b/flow-native/include/flow.h
new file mode 100644
index 0000000..ff80259
--- /dev/null
+++ b/flow-native/include/flow.h
@@ -0,0 +1,90 @@
+#ifndef FLOW_H
+#define FLOW_H
+
+#include <stdbool.h>
+#include <stddef.h>
+
+#ifdef _cplusplus
+extern "C" {
+#endif
+
+//general error codes that are returned by functions
+#define E_IO -1 //IO error
+#define E_ACCESS_DENIED -2 //access denied
+#define E_BUSY -3 // port is busy
+#define E_INVALID_SETTINGS -4 // some port settings are invalid
+#define E_INTERRUPT -5 // not really an error, function call aborted because port is closed
+#define E_NO_PORT -6 //requested port does not exist
+
+#define PARITY_NONE 0
+#define PARITY_ODD 1
+#define PARITY_EVEN 2
+
+/** Contains internal configuration of an open serial port. */
+struct serial_config;
+
+/**Opens a serial port and allocates memory for storing configuration. Note: if this function fails,
+ * any internally allocated resources will be freed.
+ * @param port_name name of port
+ * @param baud baud rate
+ * @param char_size character size of data transmitted through serial device
+ * @param two_stop_bits set to use two stop bits instead of one
+ * @param parity kind of parity checking to use
+ * @param serial pointer to memory that will be allocated with a serial structure
+ * @return 0 on success
+ * @return E_NO_PORT if the given port does not exist
+ * @return E_ACCESS_DENIED if permissions are not sufficient to open port
+ * @return E_BUSY if port is already in use
+ * @return E_INVALID_SETTINGS if any of the specified settings are invalid
+ * @return E_IO on other error */
+int serial_open(
+    const char* port_name,
+    int baud,
+    int char_size,
+    bool two_stop_bits,
+    int parity,
+    struct serial_config** const serial);
+
+/**Closes a previously opened serial port and frees memory containing the configuration. Note: after a call to
+ * this function, the 'serial' pointer will become invalid, make sure you only call it once. This function is NOT
+ * thread safe, make sure no read or write is in prgress when this function is called (the reason is that per 
+ * close manual page, close should not be called on a file descriptor that is in use by another thread). 
+ * @param serial pointer to serial configuration that is to be closed (and freed)
+ * @return 0 on success
+ * @return E_IO on error */
+int serial_close(struct serial_config* const serial);
+
+/**Starts a read from a previously opened serial port. The read is blocking, however it may be
+ * interrupted by calling 'serial_cancel_read' on the given serial port.
+ * @param serial pointer to serial configuration from which to read
+ * @param buffer buffer into which data is read
+ * @param size maximum buffer size
+ * @return n>0 the number of bytes read into buffer
+ * @return E_INTERRUPT if the call to this function was interrupted
+ * @return E_IO on IO error */
+int serial_read(struct serial_config* const serial, char* const buffer, size_t size);
+
+/**Cancels a blocked read call. This function is thread safe, i.e. it may be called from a thread even
+ * while another thread is blocked in a read call.
+ * @param serial_config the serial port to interrupt
+ * @return 0 on success
+ * @return E_IO on error */
+int serial_cancel_read(struct serial_config* const serial);
+
+/**Writes data to a previously opened serial port. Non bocking.
+ * @param serial pointer to serial configuration to which to write
+ * @param data data to write
+ * @param size number of bytes to write from data
+ * @return n>0 the number of bytes written
+ * @return E_IO on IO error */
+int serial_write(struct serial_config* const serial, char* const data, size_t size);
+
+/**Sets debugging option. If debugging is enabled, detailed error message are printed from method calls. */
+void serial_debug(bool value);
+
+#ifdef __cplusplus
+}
+#endif
+
+
+#endif /* FLOW_H */
diff --git a/flow-native/posix/flow.c b/flow-native/posix/flow.c
new file mode 100644
index 0000000..7f7d54b
--- /dev/null
+++ b/flow-native/posix/flow.c
@@ -0,0 +1,247 @@
+#include <stdlib.h>
+#include <stdio.h>
+#include <unistd.h>
+#include <errno.h>
+#include <termios.h>
+#include <fcntl.h>
+#include <sys/file.h>
+#include "flow.h"
+
+
+#define DATA_CANCEL 0xffffffff
+
+static bool debug = false;
+#define DEBUG(f) if (debug) {f}
+
+void serial_debug(bool value) {
+    debug = value;
+}
+
+//contains file descriptors used in managing a serial port
+struct serial_config {
+    int port_fd; // file descriptor of serial port
+
+    /* a pipe is used to abort a serial read by writing something into the
+     * write end of the pipe */
+    int pipe_read_fd; // file descriptor, read end of pipe
+    int pipe_write_fd; // file descriptor, write end of pipe
+};
+
+int serial_open(
+    const char* const port_name,
+    int baud,
+    int char_size,
+    bool two_stop_bits,
+    int parity,
+    struct serial_config** serial) {
+
+    int fd = open(port_name, O_RDWR | O_NOCTTY | O_NONBLOCK);
+  
+    if (fd < 0) {
+        int en = errno;
+        DEBUG(perror("error obtaining port file descriptor"););
+        if (en == EACCES) return E_ACCESS_DENIED;
+        if (en == ENOENT) return E_NO_PORT;
+        return E_IO;
+    }
+  
+    if (flock(fd, LOCK_EX | LOCK_NB) < 0) {
+        DEBUG(perror("error acquiring lock on port"););
+        close(fd);
+        return E_BUSY;
+    }
+  
+    /* configure new port settings */
+    struct termios newtio;
+  
+    /* following calls correspond to makeraw() */
+    newtio.c_iflag &= ~(IGNBRK | BRKINT | PARMRK | ISTRIP | INLCR | IGNCR | ICRNL | IXON);
+    newtio.c_oflag &= ~OPOST;
+    newtio.c_lflag &= ~(ECHO | ECHONL | ICANON | ISIG | IEXTEN);
+    newtio.c_cflag &= ~(CSIZE | PARENB);
+  
+    /* set speed */
+    speed_t bd;
+    switch (baud) {
+        case 50: bd = B50; break;
+        case 75: bd = B75; break;
+        case 110: bd = B110; break;
+        case 134: bd = B134; break;
+        case 150: bd = B150; break;
+        case 200: bd = B200; break;
+        case 300: bd = B300; break;
+        case 600: bd = B600; break;
+        case 1200: bd = B1200; break;
+        case 1800: bd = B1800; break;
+        case 2400: bd = B2400; break;
+        case 4800: bd = B4800; break;
+        case 9600: bd = B9600; break;
+        case 19200: bd = B19200; break;
+        case 38400: bd = B38400; break;
+        case 57600: bd = B57600; break;
+        case 115200: bd = B115200; break;
+        case 230400: bd = B230400; break;
+        default:
+            close(fd);
+            DEBUG(fprintf(stderr, "invalid baud rate %d\n", baud););
+            return E_INVALID_SETTINGS;
+    }
+  
+    if (cfsetspeed(&newtio, bd) < 0) {
+        DEBUG(perror("error setting baud rate"););
+        close(fd);
+        return E_IO;
+    }
+
+    /* set char size*/
+    switch (char_size) {
+        case 5: newtio.c_cflag |= CS5; break;
+        case 6: newtio.c_cflag |= CS6; break;
+        case 7: newtio.c_cflag |= CS7; break;
+        case 8: newtio.c_cflag |= CS8; break;
+        default:
+            close(fd);
+            DEBUG(fprintf(stderr, "invalid character size %d\n", char_size););
+            return E_INVALID_SETTINGS;
+    }
+  
+    /* use two stop bits */
+    if (two_stop_bits){
+        newtio.c_cflag |= CSTOPB;
+    }
+  
+    /* set parity */
+    switch (parity) {
+        case PARITY_NONE: break;
+        case PARITY_ODD: newtio.c_cflag |= (PARENB | PARODD); break;
+        case PARITY_EVEN: newtio.c_cflag |= PARENB; break;
+        default:
+            close(fd);
+            DEBUG(fprintf(stderr, "invalid parity %d\n", parity););
+            return E_INVALID_SETTINGS;
+    }
+  
+    if (tcflush(fd, TCIOFLUSH) < 0) {
+        DEBUG(perror("error flushing serial settings"););
+        close(fd);
+        return E_IO;
+    }
+  
+    if (tcsetattr(fd, TCSANOW, &newtio) < 0) {
+        DEBUG(perror("error applying serial settings"););
+        close(fd);
+        return E_IO;
+    }
+  
+    int pipe_fd[2];
+    if (pipe(pipe_fd) < 0) {
+        DEBUG(perror("error opening pipe"););
+        close(fd);
+        return E_IO;
+    }
+  
+    if (fcntl(pipe_fd[0], F_SETFL, O_NONBLOCK) < 0 || fcntl(pipe_fd[1], F_SETFL, O_NONBLOCK) < 0) {
+        DEBUG(perror("error setting pipe to non-blocking"););
+        close(fd);
+        close(pipe_fd[0]);
+        close(pipe_fd[1]);
+        return E_IO;
+    }
+  
+    struct serial_config* s = malloc(sizeof(s));
+    if (s == NULL) {
+        DEBUG(perror("error allocating memory for serial configuration"););
+        close(fd);
+        close(pipe_fd[0]);
+        close(pipe_fd[1]);
+        return E_IO;
+    }
+  
+    s->port_fd = fd;
+    s->pipe_read_fd = pipe_fd[0];
+    s->pipe_write_fd = pipe_fd[1];
+    (*serial) = s;
+  
+    return 0;
+}
+
+
+int serial_close(struct serial_config* const serial) {
+    if (close(serial->pipe_write_fd) < 0) {
+        DEBUG(perror("error closing write end of pipe"););
+        return E_IO;
+    }
+    if (close(serial->pipe_read_fd) < 0) {
+        DEBUG(perror("error closing read end of pipe"););
+        return E_IO;
+    }
+  
+    if (flock(serial->port_fd, LOCK_UN) < 0){
+        DEBUG(perror("error releasing lock on port"););
+        return E_IO;
+    }
+    if (close(serial->port_fd) < 0) {
+        DEBUG(perror("error closing port"););
+        return E_IO;
+    }
+  
+    free(serial);
+    return 0;
+}
+
+int serial_read(struct serial_config* const serial, char* const buffer, size_t size) {
+    int port = serial->port_fd;
+    int pipe = serial->pipe_read_fd;
+
+    fd_set rfds;
+    FD_ZERO(&rfds);
+    FD_SET(port, &rfds);
+    FD_SET(pipe, &rfds);
+  
+    int nfds = pipe + 1;
+    if (pipe < port) nfds = port + 1;
+  
+    int n = select(nfds, &rfds, NULL, NULL, NULL);
+    if (n < 0) {
+        DEBUG(perror("error trying to call select on port and pipe"););
+        return E_IO;
+    }
+
+    if (FD_ISSET(pipe, &rfds)) {
+        return E_INTERRUPT;
+    } else if (FD_ISSET(port, &rfds)) {
+        int r = read(port, buffer, size);
+    
+        //treat 0 bytes read as an error to avoid problems on disconnect
+        //anyway, after a poll there should be more than 0 bytes available to read
+        if (r <= 0) {
+            DEBUG(perror("error data not available after select"););
+            return E_IO;
+        }
+        return r;
+    } else {
+        fprintf(stderr, "select returned unknown read sets\n");
+        return E_IO;
+    }
+}
+
+int serial_cancel_read(struct serial_config* const serial) {
+    int data = DATA_CANCEL;
+  
+    //write to pipe to wake up any blocked read thread (self-pipe trick)
+    if (write(serial->pipe_write_fd, &data, 1) < 0) {
+        DEBUG(perror("error writing to pipe during read cancel"););
+        return E_IO;
+    }
+  
+    return 0;
+}
+
+int serial_write(struct serial_config* const serial, char* const data, size_t size) {
+    int r = write(serial->port_fd, data, size);
+    if (r < 0) {
+        DEBUG(perror("error writing to port"););
+        return E_IO;
+    }
+    return r;
+}
\ No newline at end of file
diff --git a/flow-native/windows/README b/flow-native/windows/README
new file mode 100644
index 0000000..3d24410
--- /dev/null
+++ b/flow-native/windows/README
@@ -0,0 +1 @@
+The contents of the file flow.c were found in the avrdude project. They look like they may be a good starting point for serial communication on windows.
diff --git a/flow-native/windows/flow.c.disabled b/flow-native/windows/flow.c.disabled
new file mode 100644
index 0000000..86a267c
--- /dev/null
+++ b/flow-native/windows/flow.c.disabled
@@ -0,0 +1,416 @@
+/*
+ * avrdude - A Downloader/Uploader for AVR device programmers
+ * Copyright (C) 2003, 2004  Martin J. Thomas  <mthomas@rhrk.uni-kl.de>
+ * Copyright (C) 2006  Joerg Wunsch <j@uriah.heep.sax.de>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program. If not, see <http://www.gnu.org/licenses/>.
+ */
+
+/* $Id$ */
+
+/*
+ * Native Win32 serial interface for avrdude.
+ */
+
+#include "avrdude.h"
+
+#if defined(WIN32NATIVE)
+
+#include <windows.h>
+#include <stdio.h>
+#include <ctype.h>   /* for isprint */
+
+#include "serial.h"
+
+long serial_recv_timeout = 5000; /* ms */
+
+#define W32SERBUFSIZE 1024
+
+struct baud_mapping {
+  long baud;
+  DWORD speed;
+};
+
+/* HANDLE hComPort=INVALID_HANDLE_VALUE; */
+
+static struct baud_mapping baud_lookup_table [] = {
+  { 1200,   CBR_1200 },
+  { 2400,   CBR_2400 },
+  { 4800,   CBR_4800 },
+  { 9600,   CBR_9600 },
+  { 19200,  CBR_19200 },
+  { 38400,  CBR_38400 },
+  { 57600,  CBR_57600 },
+  { 115200, CBR_115200 },
+  { 0,      0 }                 /* Terminator. */
+};
+
+static DWORD serial_baud_lookup(long baud)
+{
+  struct baud_mapping *map = baud_lookup_table;
+
+  while (map->baud) {
+    if (map->baud == baud)
+      return map->speed;
+    map++;
+  }
+
+  /*
+   * If a non-standard BAUD rate is used, issue
+   * a warning (if we are verbose) and return the raw rate
+   */
+  if (verbose > 0)
+      fprintf(stderr, "%s: serial_baud_lookup(): Using non-standard baud rate: %ld",
+              progname, baud);
+
+  return baud;
+}
+
+
+static BOOL serial_w32SetTimeOut(HANDLE hComPort, DWORD timeout) // in ms
+{
+	COMMTIMEOUTS ctmo;
+	ZeroMemory (&ctmo, sizeof(COMMTIMEOUTS));
+	ctmo.ReadIntervalTimeout = timeout;
+	ctmo.ReadTotalTimeoutMultiplier = timeout;
+	ctmo.ReadTotalTimeoutConstant = timeout;
+
+	return SetCommTimeouts(hComPort, &ctmo);
+}
+
+static int ser_setspeed(union filedescriptor *fd, long baud)
+{
+	DCB dcb;
+	HANDLE hComPort = (HANDLE)fd->pfd;
+
+	ZeroMemory (&dcb, sizeof(DCB));
+	dcb.DCBlength = sizeof(DCB);
+	dcb.BaudRate = serial_baud_lookup (baud);
+	dcb.fBinary = 1;
+	dcb.fDtrControl = DTR_CONTROL_DISABLE;
+	dcb.fRtsControl = RTS_CONTROL_DISABLE;
+	dcb.ByteSize = 8;
+	dcb.Parity = NOPARITY;
+	dcb.StopBits = ONESTOPBIT;
+
+	if (!SetCommState(hComPort, &dcb))
+		return -1;
+
+	return 0;
+}
+
+
+static int ser_open(char * port, long baud, union filedescriptor *fdp)
+{
+	LPVOID lpMsgBuf;
+	HANDLE hComPort=INVALID_HANDLE_VALUE;
+	char *newname = 0;
+
+	/*
+	 * If the port is of the form "net:<host>:<port>", then
+	 * handle it as a TCP connection to a terminal server.
+	 *
+	 * This is curently not implemented for Win32.
+	 */
+	if (strncmp(port, "net:", strlen("net:")) == 0) {
+		fprintf(stderr,
+			"%s: ser_open(): network connects are currently not"
+			"implemented for Win32 environments\n",
+			progname);
+		return -1;
+	}
+
+	if (strncasecmp(port, "com", strlen("com")) == 0) {
+
+	    // prepend "\\\\.\\" to name, required for port # >= 10
+	    newname = malloc(strlen("\\\\.\\") + strlen(port) + 1);
+
+	    if (newname == 0) {
+		fprintf(stderr,
+			"%s: ser_open(): out of memory\n",
+			progname);
+		exit(1);
+	    }
+	    strcpy(newname, "\\\\.\\");
+	    strcat(newname, port);
+
+	    port = newname;
+	}
+
+	hComPort = CreateFile(port, GENERIC_READ | GENERIC_WRITE, 0, NULL,
+		OPEN_EXISTING, FILE_ATTRIBUTE_NORMAL, NULL);
+
+	if (hComPort == INVALID_HANDLE_VALUE) {
+		FormatMessage( 
+			FORMAT_MESSAGE_ALLOCATE_BUFFER | 
+			FORMAT_MESSAGE_FROM_SYSTEM | 
+			FORMAT_MESSAGE_IGNORE_INSERTS,
+			NULL,
+			GetLastError(),
+			MAKELANGID(LANG_NEUTRAL, SUBLANG_DEFAULT), // Default language
+			(LPTSTR) &lpMsgBuf,
+			0,
+			NULL);
+		fprintf(stderr, "%s: ser_open(): can't open device \"%s\": %s\n",
+				progname, port, (char*)lpMsgBuf);
+		LocalFree( lpMsgBuf );
+		return -1;
+	}
+
+	if (!SetupComm(hComPort, W32SERBUFSIZE, W32SERBUFSIZE))
+	{
+		CloseHandle(hComPort);
+		fprintf(stderr, "%s: ser_open(): can't set buffers for \"%s\"\n",
+				progname, port);
+		return -1;
+	}
+
+        fdp->pfd = (void *)hComPort;
+	if (ser_setspeed(fdp, baud) != 0)
+	{
+		CloseHandle(hComPort);
+		fprintf(stderr, "%s: ser_open(): can't set com-state for \"%s\"\n",
+				progname, port);
+		return -1;
+	}
+
+	if (!serial_w32SetTimeOut(hComPort,0))
+	{
+		CloseHandle(hComPort);
+		fprintf(stderr, "%s: ser_open(): can't set initial timeout for \"%s\"\n",
+				progname, port);
+		return -1;
+	}
+
+	if (newname != 0) {
+	    free(newname);
+	}
+	return 0;
+}
+
+
+static void ser_close(union filedescriptor *fd)
+{
+	HANDLE hComPort=(HANDLE)fd->pfd;
+	if (hComPort != INVALID_HANDLE_VALUE)
+		CloseHandle (hComPort);
+
+	hComPort = INVALID_HANDLE_VALUE;
+}
+
+static int ser_set_dtr_rts(union filedescriptor *fd, int is_on)
+{
+	HANDLE hComPort=(HANDLE)fd->pfd;
+
+	if (is_on) {
+		EscapeCommFunction(hComPort, SETDTR);
+		EscapeCommFunction(hComPort, SETRTS);
+	} else {
+		EscapeCommFunction(hComPort, CLRDTR);
+		EscapeCommFunction(hComPort, CLRRTS);
+	}
+	return 0;
+}
+
+
+static int ser_send(union filedescriptor *fd, unsigned char * buf, size_t buflen)
+{
+	size_t len = buflen;
+	unsigned char c='\0';
+	DWORD written;
+        unsigned char * b = buf;
+
+	HANDLE hComPort=(HANDLE)fd->pfd;
+
+	if (hComPort == INVALID_HANDLE_VALUE) {
+		fprintf(stderr, "%s: ser_send(): port not open\n",
+              progname); 
+		exit(1);
+	}
+
+	if (!len)
+  return 0;
+
+	if (verbose > 3)
+	{
+		fprintf(stderr, "%s: Send: ", progname);
+
+		while (len) {
+			c = *b;
+			if (isprint(c)) {
+				fprintf(stderr, "%c ", c);
+			}
+			else {
+				fprintf(stderr, ". ");
+			}
+			fprintf(stderr, "[%02x] ", c);
+			b++;
+			len--;
+		}
+      fprintf(stderr, "\n");
+	}
+	
+	serial_w32SetTimeOut(hComPort,500);
+
+	if (!WriteFile (hComPort, buf, buflen, &written, NULL)) {
+		fprintf(stderr, "%s: ser_send(): write error: %s\n",
+              progname, "sorry no info avail"); // TODO
+		exit(1);
+	}
+
+	if (written != buflen) {
+		fprintf(stderr, "%s: ser_send(): size/send mismatch\n",
+              progname); 
+		exit(1);
+	}
+
+	return 0;
+}
+
+
+static int ser_recv(union filedescriptor *fd, unsigned char * buf, size_t buflen)
+{
+	unsigned char c;
+	unsigned char * p = buf;
+	DWORD read;
+
+	HANDLE hComPort=(HANDLE)fd->pfd;
+	
+	if (hComPort == INVALID_HANDLE_VALUE) {
+		fprintf(stderr, "%s: ser_read(): port not open\n",
+              progname); 
+		exit(1);
+	}
+	
+	serial_w32SetTimeOut(hComPort, serial_recv_timeout);
+	
+	if (!ReadFile(hComPort, buf, buflen, &read, NULL)) {
+		LPVOID lpMsgBuf;
+		FormatMessage( 
+			FORMAT_MESSAGE_ALLOCATE_BUFFER | 
+			FORMAT_MESSAGE_FROM_SYSTEM | 
+			FORMAT_MESSAGE_IGNORE_INSERTS,
+			NULL,
+			GetLastError(),
+			MAKELANGID(LANG_NEUTRAL, SUBLANG_DEFAULT), // Default language
+			(LPTSTR) &lpMsgBuf,
+			0,
+			NULL 	);
+		fprintf(stderr, "%s: ser_recv(): read error: %s\n",
+			      progname, (char*)lpMsgBuf);
+		LocalFree( lpMsgBuf );
+		exit(1);
+	}
+
+	/* time out detected */
+	if (read == 0) {
+		if (verbose > 1)
+		fprintf(stderr,
+			"%s: ser_recv(): programmer is not responding\n",
+			progname);
+		return -1;
+	}
+
+	p = buf;
+
+	if (verbose > 3)
+	{
+		fprintf(stderr, "%s: Recv: ", progname);
+
+		while (read) {
+			c = *p;
+			if (isprint(c)) {
+				fprintf(stderr, "%c ", c);
+			}
+			else {
+				fprintf(stderr, ". ");
+			}
+			fprintf(stderr, "[%02x] ", c);
+
+			p++;
+			read--;
+		}
+		fprintf(stderr, "\n");
+	}
+  return 0;
+}
+
+
+static int ser_drain(union filedescriptor *fd, int display)
+{
+	// int rc;
+	unsigned char buf[10];
+	BOOL readres;
+	DWORD read;
+
+	HANDLE hComPort=(HANDLE)fd->pfd;
+
+  	if (hComPort == INVALID_HANDLE_VALUE) {
+		fprintf(stderr, "%s: ser_drain(): port not open\n",
+              progname); 
+		exit(1);
+	}
+
+	serial_w32SetTimeOut(hComPort,250);
+  
+	if (display) {
+		fprintf(stderr, "drain>");
+	}
+
+	while (1) {
+		readres=ReadFile(hComPort, buf, 1, &read, NULL);
+		if (!readres) {
+			LPVOID lpMsgBuf;
+			FormatMessage( 
+				FORMAT_MESSAGE_ALLOCATE_BUFFER | 
+				FORMAT_MESSAGE_FROM_SYSTEM | 
+				FORMAT_MESSAGE_IGNORE_INSERTS,
+				NULL,
+				GetLastError(),
+				MAKELANGID(LANG_NEUTRAL, SUBLANG_DEFAULT), // Default language
+				(LPTSTR) &lpMsgBuf,
+				0,
+				NULL 	);
+			fprintf(stderr, "%s: ser_drain(): read error: %s\n",
+					  progname, (char*)lpMsgBuf);
+			LocalFree( lpMsgBuf );
+			exit(1);
+		}
+
+		if (read) { // data avail
+			if (display) fprintf(stderr, "%02x ", buf[0]);
+		}
+		else { // no more data
+			if (display) fprintf(stderr, "<drain\n");
+			break;
+		}
+	} // while
+  return 0;
+}
+
+struct serial_device serial_serdev =
+{
+  .open = ser_open,
+  .setspeed = ser_setspeed,
+  .close = ser_close,
+  .send = ser_send,
+  .recv = ser_recv,
+  .drain = ser_drain,
+  .set_dtr_rts = ser_set_dtr_rts,
+  .flags = SERDEV_FL_CANSETSPEED,
+};
+
+struct serial_device *serdev = &serial_serdev;
+
+#endif /* WIN32NATIVE */