use sbt-native and jni plugin

1 files changed, 294 insertions, 0 deletions

diff --git a/flow-native/src/flow.c b/flow-native/src/flow.c
new file mode 100644
index 0000000..09ffca6
--- /dev/null
+++ b/flow-native/src/flow.c
@@ -0,0 +1,294 @@
+/*
+ * Copyright (C) 2013 Jakob Odersky
+ * 
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are
+ * met:
+ * 
+ * * Redistributions of source code must retain the above copyright
+ *   notice, this list of conditions and the following disclaimer.
+ * * 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.
+ * * Neither the name of the  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 COPYRIGHT HOLDERS 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 COPYRIGHT
+ * OWNER 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.
+ * 
+ */
+ 
+#include <stdlib.h>
+#include <stdio.h>
+#include <stdbool.h>
+#include <unistd.h>
+#include <errno.h>
+#include <termios.h>
+#include <fcntl.h>
+#include <poll.h>
+#include "com_github_jodersky_flow_low_NativeSerial.h"
+
+#define E_PERMISSION -1
+#define E_OPEN -2
+#define E_BUSY -3
+#define E_BAUD -4
+#define E_PIPE -5
+#define E_MALLOC -6
+#define E_POINTER -7
+#define E_POLL -8
+#define E_IO -9
+#define E_CLOSE -10
+
+
+static bool debug = false;
+#define DEBUG(f) if (debug) {f;}
+
+//contains file descriptors used in managing a serial port
+struct serial_config {
+  
+  int fd; //serial port
+  int pipe_read; //event
+  int pipe_write; //event
+  
+};
+
+/* return values:
+ * 0 ok
+ * E_PERMISSION don't have permission to open
+ * E_OPEN can't get file descriptor
+ * E_BUSY device busy
+ * E_BAUD invalid baudrate
+ * E_PIPE can't open pipe for graceful closing
+ * E_MALLOC malloc error
+ */
+int serial_open(const char* device, int baud, struct serial_config** serial) {
+  
+  int fd = open(device, O_RDWR | O_NOCTTY | O_NONBLOCK);
+  
+  if (fd < 0) {
+    DEBUG(perror(device));
+    if (errno == EACCES) return E_PERMISSION;
+    else return E_OPEN;
+  }
+  
+  if (flock(fd, LOCK_EX | LOCK_NB) < 0) {
+    DEBUG(perror(device));
+    return E_BUSY;
+  }
+  
+  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: return E_BAUD; break;
+  }
+
+  /* configure new port settings */
+  struct termios newtio;
+  newtio.c_cflag &= ~(PARENB | CSTOPB | CSIZE | CRTSCTS); // 8N1
+  newtio.c_cflag |= CS8 | CREAD | CLOCAL;
+  newtio.c_iflag &= ~(IXON | IXOFF | IXANY); // turn off s/w flow ctrl
+  newtio.c_lflag &= ~(ICANON | ECHO | ECHOE | ISIG); // make raw
+  newtio.c_oflag &= ~OPOST; // make raw
+
+  // see: http://unixwiz.net/techtips/termios-vmin-vtime.html
+  //newtio.c_cc[VMIN] = 1;
+  //newtio.c_cc[VTIME] = 2*10/baud;
+  cfsetspeed(&newtio, bd);
+  
+  /* load new settings to port */
+  tcflush(fd, TCIOFLUSH);
+  tcsetattr(fd,TCSANOW,&newtio);
+  
+  int pipe_fd[2];
+  if (pipe2(pipe_fd, O_NONBLOCK) < 0) {
+    DEBUG(perror(device));
+    return E_PIPE;
+  }
+  
+  struct serial_config* s = malloc(sizeof(s));
+  if (s == NULL) {
+    return E_MALLOC;
+  }
+  
+  s->fd = fd;
+  s->pipe_read = pipe_fd[0];
+  s->pipe_write = pipe_fd[1];
+  (*serial) = s;
+  
+  return 0;
+}
+
+void serial_close(struct serial_config* serial) {
+  
+  if (serial == NULL) return;
+  
+  int data = 0xffffffff;
+  
+  //write to pipe to wake up any blocked read thread (self-pipe trick)
+  if (write(serial->pipe_write, &data, 1) <= 0) {
+    DEBUG(perror("error writing to pipe during close"))
+  }
+  
+  close(serial->pipe_write);
+  close(serial->pipe_read);
+  
+  flock(serial->fd, LOCK_UN);
+  close(serial->fd);
+  
+  free(serial);
+}
+
+/* return
+ * >0 number of bytes read
+ * E_POINTER invalid serial pointer
+ * E_POLL poll error
+ * E_IO read error
+ * E_CLOSE close request
+ */
+int serial_read(struct serial_config* serial, unsigned char * buffer, size_t size) {
+  if (serial == NULL) {
+    return E_POINTER;
+  }
+  
+  struct pollfd sp; //serial poll
+  sp.fd = serial->fd;
+  sp.events = POLLIN;
+  
+  struct pollfd pp; //pipe poll
+  pp.fd = serial->pipe_read;
+  pp.events = POLLIN;
+  
+  struct pollfd poll_list[] = {sp, pp};
+  
+  int n = poll(poll_list,(unsigned long)3,-1);
+  if (n < 0) {
+    DEBUG(perror("read"));
+    return E_IO;
+  }
+  
+  if (sp.revents & POLLIN != 0) {
+    int r = read(sp.fd, 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) { 
+      if (r < 0) DEBUG(perror("read"));
+      return E_IO;
+    }
+    return r;
+  } else {
+    return E_CLOSE;
+  }
+}
+
+/*return
+ * >0 number of bytes written
+ * E_POINTER invalid serial config (null pointer)
+ * E_IO write error
+ */
+int serial_write(struct serial_config* serial, unsigned char* data, size_t size) {
+  if (serial == NULL) return E_POINTER;
+  
+  int r = write(serial->fd, data, size);
+  if (r < 0) {
+    DEBUG(perror("write"));
+    return E_IO;
+  }
+  return r;
+}
+
+
+
+// JNI bindings
+// ============
+
+inline struct serial_config* j2s(jlong pointer) {
+  return (struct serial_config*) pointer;
+}
+
+inline jlong s2j(struct serial_config* pointer) {
+  return (jlong) pointer;
+}
+
+JNIEXPORT jint JNICALL Java_com_github_jodersky_flow_low_NativeSerial_open
+  (JNIEnv *env, jclass clazz, jstring device, jint baud, jlongArray jserialp)
+{ 
+  const char *dev = (*env)->GetStringUTFChars(env, device, 0);
+  struct serial_config* serial;
+  int r = serial_open(dev, baud, &serial);
+  (*env)->ReleaseStringUTFChars(env, device, dev);
+  
+  long serialp = s2j(serial);
+  (*env)->SetLongArrayRegion(env, jserialp, 0, 1, &serialp);
+  
+  return r;
+}
+
+JNIEXPORT void JNICALL Java_com_github_jodersky_flow_low_NativeSerial_close
+  (JNIEnv * env, jclass clazz, jlong serial)
+{
+  serial_close(j2s(serial));
+}
+
+JNIEXPORT jint JNICALL Java_com_github_jodersky_flow_low_NativeSerial_read
+  (JNIEnv * env, jclass clazz, jlong serial, jbyteArray jbuffer)
+{
+  
+  jsize size = (*env)->GetArrayLength(env, jbuffer);
+  
+  unsigned char buffer[size];
+  int n = serial_read(j2s(serial), buffer, size);
+  if (n < 0) {
+    return n;
+  }
+  
+  (*env)->SetByteArrayRegion(env, jbuffer, 0, n, (signed char *) buffer);
+  return n;
+}
+
+JNIEXPORT jint JNICALL Java_com_github_jodersky_flow_low_NativeSerial_write
+  (JNIEnv * env, jclass clazz, jlong serial, jbyteArray jbuffer)
+{
+  unsigned char * buffer = (*env)->GetByteArrayElements(env, jbuffer, NULL);
+  int size = (*env)->GetArrayLength(env, jbuffer);
+  int r = serial_write(j2s(serial), buffer, size);
+  
+  (*env)->ReleaseByteArrayElements(env, jbuffer, buffer, JNI_ABORT);
+  
+  return r;
+}
+
+JNIEXPORT void JNICALL Java_com_github_jodersky_flow_low_NativeSerial_debug
+  (JNIEnv *env, jclass clazz, jboolean value)
+{
+  debug = (bool) value;
+}
+