diff options
Diffstat (limited to 'src/main/c/flow-epoll.c')
| -rw-r--r-- | src/main/c/flow-epoll.c | 220 |
1 files changed, 220 insertions, 0 deletions
diff --git a/src/main/c/flow-epoll.c b/src/main/c/flow-epoll.c new file mode 100644 index 0000000..c9bb728 --- /dev/null +++ b/src/main/c/flow-epoll.c @@ -0,0 +1,220 @@ +#include <stdlib.h> +#include <stdio.h> +#include <unistd.h> +#include <errno.h> +#include <termios.h> +#include <fcntl.h> +//#include <sys/signal.h> +//#include <sys/types.h> +//#include <sys/file.h> +#include <sys/epoll.h> +#include <sys/eventfd.h> +#include "com_github_jodersky_flow_NativeSerial.h" + +//contains file descriptors used in managing a serial port +struct serial_config { + + int fd; //serial port + int efd; //event + int epfd; //file descriptor for epoll + +}; + +/* return values: + * >0 fd + * -1 can't get file descriptor + * -2 device busy + * -3 invalid baudrate + * -4 can't open pipe for graceful closing + * -5 can't create epoll + * -6 can't add event to epoll + * */ +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) { + perror(device); + return -1; + } + + if (flock(fd, LOCK_EX | LOCK_NB) < 0) { + perror(device); + return -2; + } + + 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: puts("invalid baudrate"); return -3; break; + } + + /* configure new port settings */ + struct termios newtio; + newtio.c_cflag &= ~PARENB; + newtio.c_cflag &= ~CSTOPB; + newtio.c_cflag &= ~CSIZE; + newtio.c_cflag |= CS8; + // no flow control + newtio.c_cflag &= ~CRTSCTS; + newtio.c_cflag &= ~HUPCL; // disable hang-up-on-close to avoid reset + newtio.c_cflag |= CREAD | CLOCAL; // turn on READ & ignore ctrl lines + 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, TCIFLUSH); + tcsetattr(fd,TCSANOW,&newtio); + + int efd = eventfd(0, EFD_NONBLOCK); + + int epfd = epoll_create(1); + if (epfd < 0) { + perror(device); + return -5; + } + + struct epoll_event serial_event; + serial_event.data.fd = fd; + serial_event.events = EPOLLIN; + + struct epoll_event efd_event = {0}; + efd_event.data.fd = efd; + efd_event.events = EPOLLIN | EPOLLET | EPOLLONESHOT; + + + if (epoll_ctl(epfd, EPOLL_CTL_ADD, fd, &serial_event) < 0 || epoll_ctl(epfd, EPOLL_CTL_ADD, efd, &efd_event) < 0) { + perror(device); + return -6; + } + + struct serial_config* s = malloc(sizeof(s)); + s->fd = fd; + s->efd = efd; + s->epfd = epfd; + (*serial) = s; + + return 0; +} +/* +int serial_pipe() { + int p = pipe(); + if (p < 0) { + perror("create pipe"); + } + return p; +} + +int serial_add_epoll(int fd, int pipe) { + int epfd = epoll_create(1); + + struct epoll_event event; + event.data.fd = fd; + event.events = EPOLLIN; + + if (epoll_ctl (epfd, EPOLL_CTL_ADD, fd, &event)) { + perror (device); + } + + return epfd; +} + +*/ +void serial_close(struct serial_config* serial) { + + if (serial == NULL) return; + + //write to pipe to wake up any blocked read thread (self-pipe trick) + eventfd_write(serial->efd, 1); + + close(serial->efd); + flock(serial->fd, LOCK_UN); + close(serial->fd); + close(serial->epfd); + + free(serial); +} + +int serial_read(struct serial_config* serial) { + struct epoll_event events[10];// = malloc (sizeof (struct epoll_event) * 10); + int nr_events = epoll_wait(serial->epfd, events, 10, -1); + if (nr_events < 0) { + perror("read"); + } + + int i; + for (i = 0; i < nr_events; i++) { + //printf ("event=%d on fd=%d\n", events[i].events, events[i].data.fd); + + if (events[i].data.fd == serial->fd) puts("from serial"); + else if (events[i].data.fd == serial->efd) puts("from pipe"); + else puts("from ???"); + } + /* + int buffer[256]; + int x = read(fd, buffer, 255); + if (x < 0) { + perror("read"); + }*/ + return nr_events; +} + + +// 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 jlong JNICALL Java_com_github_jodersky_flow_NativeSerial_open + (JNIEnv *env, jclass clazz, jstring device, jint baud) +{ + const char *dev = (*env)->GetStringUTFChars(env, device, 0); + + struct serial_config* serial; + serial_open(dev, baud, &serial); + + (*env)->ReleaseStringUTFChars(env, device, dev); + + return s2j(serial); +} + +JNIEXPORT void JNICALL Java_com_github_jodersky_flow_NativeSerial_close + (JNIEnv * env, jclass clazz, jlong serial) +{ + serial_close(j2s(serial)); +} + +JNIEXPORT jint JNICALL Java_com_github_jodersky_flow_NativeSerial_read + (JNIEnv * env, jclass clazz, jlong serial) +{ + return serial_read(j2s(serial)); +} |