diff options
Diffstat (limited to 'src/main/native/flow.h')
-rw-r--r-- | src/main/native/flow.h | 72 |
1 files changed, 72 insertions, 0 deletions
diff --git a/src/main/native/flow.h b/src/main/native/flow.h new file mode 100644 index 0000000..97eae83 --- /dev/null +++ b/src/main/native/flow.h @@ -0,0 +1,72 @@ +#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 + +//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_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) */ +void serial_close(struct serial_config* serial); + +/**Starts a blocking 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 */ |