refactor build to a more generic structure

2 files changed, 371 insertions, 0 deletions

diff --git a/flow-native/include/flow.h b/flow-native/include/flow.h
new file mode 100644
index 0000000..3b6df24
--- /dev/null
+++ b/flow-native/include/flow.h
@@ -0,0 +1,76 @@
+#ifndef FLOW_H
+#define FLOW_H
+
+#include <stdbool.h>
+
+//general error codes that are meant to be communicated to user
+#define E_IO -1 //I/O error (port should be closed)
+#define E_ACCESS_DENIED -2 //access denied
+#define E_BUSY -3 // port is busy
+#define E_INVALID_BAUD -4 // baud rate is not valid
+#define E_INTERRUPT -5 // not really an error, function call aborted because port is closed
+#define E_NO_PORT -6
+
+//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
+  
+};
+
+/**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 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_BAUD if specified baudrate is non-standard
+ * @return E_IO on other error */
+int serial_open(const char* port_name, int baud, struct serial_config** 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* serial);
+
+/**Starts a read from a previously opened serial port. The read is blocking, however it may be
+ * interrupted by calling 'serial_interrupt' 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* serial, unsigned char* buffer, size_t size);
+
+/**Interrupts a blocked read call.
+ * @param serial_config the serial port to interrupt
+ * @return 0 on success
+ * @return E_IO on error */
+int serial_interrupt(struct serial_config* 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* serial, unsigned char* data, size_t size);
+
+/**Sets debugging option. If debugging is enabled, detailed error message are printed from method calls. */
+void serial_debug(bool value);
+
+
+#endif /* FLOW_H */
diff --git a/flow-native/unix/src/flow.c b/flow-native/unix/src/flow.c
new file mode 100644
index 0000000..174e9c0
--- /dev/null
+++ b/flow-native/unix/src/flow.c
@@ -0,0 +1,295 @@
+/*
+ * 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 <unistd.h>
+#include <errno.h>
+#include <termios.h>
+#include <fcntl.h>
+#include <poll.h>
+#include "com_github_jodersky_flow_internal_NativeSerial.h"
+#include "flow.h"
+
+static bool debug = false;
+#define DEBUG(f) if (debug) {f}
+
+void serial_debug(bool value) {
+  debug = value;
+}
+
+int serial_open(const char* port_name, int baud, struct serial_config** serial) {
+  
+  int fd = open(port_name, O_RDWR | O_NOCTTY | O_NONBLOCK);
+  
+  if (fd < 0) {
+    int en = errno;
+    DEBUG(perror("obtain 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("acquire lock on port"););
+    close(fd);
+    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:
+      close(fd);
+      return E_INVALID_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;
+  
+  if (cfsetspeed(&newtio, bd) < 0) {
+    DEBUG(perror("set baud rate"););
+    close(fd);
+    return E_IO;
+  }
+  
+  /* load new settings to port */
+  if (tcflush(fd, TCIOFLUSH) < 0) {
+    DEBUG(perror("flush serial settings"););
+    close(fd);
+    return E_IO;
+  }
+  
+  if (tcsetattr(fd, TCSANOW, &newtio) < 0) {
+    DEBUG(perror("apply serial settings"););
+    close(fd);
+    return E_IO;
+  }
+  
+  int pipe_fd[2];
+  if (pipe2(pipe_fd, O_NONBLOCK) < 0) {
+    DEBUG(perror("open pipe"););
+    close(fd);
+    return E_IO;
+  }
+  
+  struct serial_config* s = malloc(sizeof(s));
+  if (s == NULL) {
+    DEBUG(perror("allocate 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* serial) {
+  if (close(serial->pipe_write_fd) < 0) {
+    DEBUG(perror("close write end of pipe"););
+    return E_IO;
+  }
+  if (close(serial->pipe_read_fd) < 0) {
+    DEBUG(perror("close read end of pipe"););
+    return E_IO;
+  }
+  
+  if (flock(serial->port_fd, LOCK_UN) < 0){
+    DEBUG(perror("release lock on port"););
+    return E_IO;
+  }
+  if (close(serial->port_fd) < 0) {
+    DEBUG(perror("close port"););
+    return E_IO;
+  }
+  
+  free(serial);
+  return 0;
+}
+
+int serial_read(struct serial_config* serial, unsigned char* buffer, size_t size) {
+  
+  struct pollfd polls[2];
+  polls[0].fd = serial->port_fd; // serial poll
+  polls[0].events = POLLIN;
+  
+  polls[1].fd = serial->pipe_read_fd; // pipe poll
+  polls[1].events = POLLIN;
+  
+  int n = poll(polls,2,-1);
+  if (n < 0) {
+    DEBUG(perror("poll"););
+    return E_IO;
+  }
+  
+  if ((polls[0].revents & POLLIN) != 0) {
+    int r = read(polls[0].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) {
+      DEBUG(perror("read"););
+      return E_IO;
+    }
+    return r;
+  } else if ((polls[1].revents & POLLIN) != 0) {
+    return E_INTERRUPT;
+  } else {
+    fputs("poll revents: unknown revents\n", stderr);
+    return E_IO;
+  }
+}
+
+int serial_write(struct serial_config* serial, unsigned char* data, size_t size) {
+  int r = write(serial->port_fd, data, size);
+  if (r < 0) {
+    DEBUG(perror("write"););
+    return E_IO;
+  }
+  return r;
+}
+
+int serial_interrupt(struct serial_config* serial) {
+  int data = 0xffffffff;
+  
+  //write to pipe to wake up any blocked read thread (self-pipe trick)
+  if (write(serial->pipe_write_fd, &data, 1) < 0) {
+    DEBUG(perror("write to pipe for interrupt"););
+    return E_IO;
+  }
+  
+  return 0;
+}
+
+
+// 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_internal_NativeSerial_open
+  (JNIEnv *env, jclass clazz, jstring port_name, jint baud, jlongArray jserialp)
+{ 
+  const char *dev = (*env)->GetStringUTFChars(env, port_name, 0);
+  struct serial_config* serial;
+  int r = serial_open(dev, baud, &serial);
+  (*env)->ReleaseStringUTFChars(env, port_name, dev);
+  
+  long serialp = s2j(serial);
+  (*env)->SetLongArrayRegion(env, jserialp, 0, 1, &serialp);
+  
+  return r;
+}
+
+JNIEXPORT jint JNICALL Java_com_github_jodersky_flow_internal_NativeSerial_close
+  (JNIEnv * env, jclass clazz, jlong serial)
+{
+  serial_close(j2s(serial));
+}
+
+JNIEXPORT jint JNICALL Java_com_github_jodersky_flow_internal_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_internal_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 jint JNICALL Java_com_github_jodersky_flow_internal_NativeSerial_interrupt
+  (JNIEnv * env, jclass clazz, jlong serial)
+{
+  return serial_interrupt(j2s(serial));
+}
+
+JNIEXPORT void JNICALL Java_com_github_jodersky_flow_internal_NativeSerial_debug
+  (JNIEnv *env, jclass clazz, jboolean value)
+{
+  serial_debug((bool) value);
+}