diff --git a/libserialport.h.in b/libserialport.h.in index 3d38a0d..e1f670d 100644 --- a/libserialport.h.in +++ b/libserialport.h.in @@ -756,7 +756,17 @@ enum sp_return sp_set_flowcontrol(struct sp_port *port, enum sp_flowcontrol flow */ /** - * Read bytes from the specified serial port, blocking until available. + * Read bytes from the specified serial port, blocking until complete. + * + * @warning If your program runs on Unix and makes use of signal handlers, + * note that this function will repeat blocking system calls that + * are interrupted by a signal and return with EINTR. If your program + * needs to abort blocking reads when a signal is handled, you will + * need to implement your own loop using sp_nonblocking_read() + * together with a blocking method that makes sense for your program. + * E.g. you can obtain the file descriptor for an open port using + * sp_get_port_handle() and use this to call select() or pselect(), + * with appropriate arrangements to return if a signal is received. * * @param port Pointer to port structure. * @param buf Buffer in which to store the bytes read. @@ -793,6 +803,16 @@ enum sp_return sp_nonblocking_read(struct sp_port *port, void *buf, size_t count * been transmitted, use the sp_output_waiting() function. To wait until all * written bytes have actually been transmitted, use the sp_drain() function. * + * @warning If your program runs on Unix and makes use of signal handlers, + * note that this function will repeat blocking system calls that + * are interrupted by a signal and return with EINTR. If your program + * needs to abort blocking reads when a signal is handled, you will + * need to implement your own loop using sp_nonblocking_read() + * together with a blocking method that makes sense for your program. + * E.g. you can obtain the file descriptor for an open port using + * sp_get_port_handle() and use this to call select() or pselect(), + * with appropriate arrangements to return if a signal is received. + * * @param port Pointer to port structure. * @param buf Buffer containing the bytes to write. * @param count Requested number of bytes to write.