try to fix latency for cyton on macos (#551)

* try to fix latency for cyton on macos

Signed-off-by: Andrey Parfenov <a1994ndrey@gmail.com>

.github/workflows/cppcheck.yml

@@ -15,7 +15,7 @@ jobs:
       env:
         DEBIAN_FRONTEND: noninteractive
     - name: Run Cppcheck
-      run: cppcheck --std=c++11 -ithird_party/spdlog -ithird_party/libsvm -ithird_party/SimpleBLE -ithird_party/fmt -ithird_party/SimpleDBus -ithird_party/SimpleBluez --error-exitcode=1 --xml --xml-version=2 --force src cpp_package third_party 2>cppcheck_res.xml
+      run: cppcheck --std=c++11 -ithird_party/spdlog -ithird_party/libsvm -ithird_party/SimpleBLE -ithird_party/fmt -ithird_party/SimpleDBus -ithird_party/SimpleBluez -isrc/utils/os_serial_ioctl.cpp --error-exitcode=1 --xml --xml-version=2 --force src cpp_package third_party 2>cppcheck_res.xml
     - name: Generate Report
       if: ${{ failure() }}
       run: cppcheck-htmlreport --title=BrainFlow --file=cppcheck_res.xml --report-dir=report

src/board_controller/openbci/openbci_serial_board.cpp

@@ -127,6 +127,10 @@ int OpenBCISerialBoard::set_port_settings ()
         return (int)BrainFlowExitCodes::SET_PORT_ERROR;
     }
     safe_logger (spdlog::level::trace, "set port settings");
+#ifdef __APPLE__
+    int set_latency_res = serial->set_custom_latency (1);
+    safe_logger (spdlog::level::info, "set_latency_res is: {}", set_latency_res);
+#endif
     return send_to_board ("v");
 }
 

src/utils/inc/libftdi_serial.h

@@ -19,6 +19,7 @@ class LibFTDISerial : public Serial
     bool is_port_open ();
     int set_serial_port_settings (int ms_timeout = 1000, bool timeout_only = false);
     int set_custom_baudrate (int baudrate);
+    int set_custom_latency (int latency = 1);
     int flush_buffer ();
     int read_from_serial_port (void *bytes_to_read, int size);
     int send_to_serial_port (const void *message, int length);

src/utils/inc/os_serial.h

@@ -21,6 +21,7 @@ class OSSerial : public Serial
     bool is_port_open ();
     int set_serial_port_settings (int ms_timeout = 1000, bool timeout_only = false);
     int set_custom_baudrate (int baudrate);
+    int set_custom_latency (int latency = 1);
     int flush_buffer ();
     int read_from_serial_port (void *bytes_to_read, int size);
     int send_to_serial_port (const void *message, int length);

src/utils/inc/serial.h

@@ -29,6 +29,7 @@ class Serial
     // timeout_only indicates to configure only the timeout, not the baud and line properties
     virtual int set_serial_port_settings (int ms_timeout = 1000, bool timeout_only = false) = 0;
     virtual int set_custom_baudrate (int baudrate) = 0;
+    virtual int set_custom_latency (int latency = 1) = 0;
     virtual int flush_buffer () = 0;
     virtual int read_from_serial_port (void *bytes_to_read, int size) = 0;
     virtual int send_to_serial_port (const void *message, int length) = 0;

src/utils/libftdi_serial.cpp

@@ -141,6 +141,12 @@ int LibFTDISerial::set_custom_baudrate (int baudrate)
     }
 }
 
+int LibFTDISerial::set_custom_latency (int latency)
+{
+    log_error ("libftdi", "set_custom_latency is not supported for libftdi serial");
+    return (int)SerialExitCodes::SET_PORT_STATE_ERROR;
+}
+
 int LibFTDISerial::flush_buffer ()
 {
 #if FTDI_MAJOR_VERSION >= 2 || (FTDI_MAJOR_VERSION == 1 && FTDI_MINOR_VERSIOM >= 5)
@@ -317,6 +323,11 @@ int LibFTDISerial::set_custom_baudrate (int baudrate)
     return (int)SerialExitCodes::NO_LIBFTDI_ERROR;
 }
 
+int LibFTDISerial::set_custom_latency (int latency)
+{
+    return (int)SerialExitCodes::NO_LIBFTDI_ERROR;
+}
+
 int LibFTDISerial::flush_buffer ()
 {
     return (int)SerialExitCodes::NO_LIBFTDI_ERROR;

src/utils/os_serial_ioctl.cpp

@@ -28,6 +28,18 @@
 #include <termios.h>
 #include <unistd.h>
 
+#if defined __has_include
+#if __has_include(<sys/ioctl.h>) && __has_include(<IOKit/serial/ioss.h>)
+#include <sys/ioctl.h>
+
+#include <IOKit/serial/ioss.h>
+#else
+#define NO_IOCTL_HEADERS
+#endif
+#else
+#define NO_IOCTL_HEADERS
+#endif
+
 #endif
 
 
@@ -51,7 +63,20 @@ int OSSerial::set_custom_baudrate (int baudrate)
     return SerialExitCodes::OK;
 }
 
+int OSSerial::set_custom_latency (int latency)
+{
+    // there is a method to set latency in registry but it restarts the device, keep it separate and
+    // dont add here
+    return SerialExitCodes::SET_PORT_STATE_ERROR;
+}
+
 #elif defined(__linux__) && !defined(__ANDROID__)
+
+int OSSerial::set_custom_latency (int latency)
+{
+    return SerialExitCodes::SET_PORT_STATE_ERROR;
+}
+
 #ifdef NO_IOCTL_HEADERS
 int OSSerial::set_custom_baudrate (int baudrate)
 {
@@ -80,8 +105,17 @@ int OSSerial::set_custom_baudrate (int baudrate)
     }
 }
 #endif
-
 #elif defined(__APPLE__)
+int OSSerial::set_custom_latency (int latency)
+{
+#ifndef NO_IOCTL_HEADERS
+    unsigned long mics = latency;
+    ioctl (this->port_descriptor, IOSSDATALAT, &mics);
+    return SerialExitCodes::OK;
+#else
+    return SerialExitCodes::NO_SYSTEM_HEADERS_FOUND_ERROR;
+#endif
+}
 int OSSerial::set_custom_baudrate (int baudrate)
 {
     struct termios port_settings;
@@ -96,10 +130,14 @@ int OSSerial::set_custom_baudrate (int baudrate)
     tcflush (this->port_descriptor, TCIOFLUSH);
     return SerialExitCodes::OK;
 }
-
 #else
 int OSSerial::set_custom_baudrate (int baudrate)
 {
     return SerialExitCodes::SET_PORT_STATE_ERROR;
 }
+
+int OSSerial::set_custom_latency (int latency)
+{
+    return SerialExitCodes::SET_PORT_STATE_ERROR;
+}
 #endif