From f3a9dcf7776104a982aa2a2c2376b312f8b00681 Mon Sep 17 00:00:00 2001
From: Stephen Birarda <commit@birarda.com>
Date: Mon, 6 May 2013 13:08:45 -0700
Subject: [PATCH] if we fail to open SerialInterface twice then don't keep
 trying

---
 interface/src/SerialInterface.cpp | 40 +++++++++++++++++++------------
 interface/src/SerialInterface.h   |  5 ++--
 2 files changed, 28 insertions(+), 17 deletions(-)

diff --git a/interface/src/SerialInterface.cpp b/interface/src/SerialInterface.cpp
index 5878ab672e..2efe487304 100644
--- a/interface/src/SerialInterface.cpp
+++ b/interface/src/SerialInterface.cpp
@@ -34,6 +34,11 @@ const int GRAVITY_SAMPLES = 200;                    //  Use the first samples to
 
 const bool USING_INVENSENSE_MPU9150 = 1;
 
+SerialInterface::SerialInterface() :
+    active(false),
+    _failedOpenAttempts(0) {
+}
+
 void SerialInterface::pair() {
     
 #ifdef __APPLE__
@@ -43,25 +48,29 @@ void SerialInterface::pair() {
     int matchStatus;
     regex_t regex;
     
-    // for now this only works on OS X, where the usb serial shows up as /dev/tty.usb*
-    if((devDir = opendir("/dev"))) {
-        while((entry = readdir(devDir))) {
-            regcomp(&regex, "tty\\.usb", REG_EXTENDED|REG_NOSUB);
-            matchStatus = regexec(&regex, entry->d_name, (size_t) 0, NULL, 0);
-            if (matchStatus == 0) {
-                char *serialPortname = new char[100];
-                sprintf(serialPortname, "/dev/%s", entry->d_name);
-                
-                initializePort(serialPortname, 115200);
-                
-                delete [] serialPortname;
+    if (_failedOpenAttempts < 2) {
+        // if we've already failed to open the detected interface twice then don't try again
+        
+        // for now this only works on OS X, where the usb serial shows up as /dev/tty.usb*
+        if((devDir = opendir("/dev"))) {
+            while((entry = readdir(devDir))) {
+                regcomp(&regex, "tty\\.usb", REG_EXTENDED|REG_NOSUB);
+                matchStatus = regexec(&regex, entry->d_name, (size_t) 0, NULL, 0);
+                if (matchStatus == 0) {
+                    char *serialPortname = new char[100];
+                    sprintf(serialPortname, "/dev/%s", entry->d_name);
+                    
+                    initializePort(serialPortname, 115200);
+                    
+                    delete [] serialPortname;
+                }
+                regfree(&regex);
             }
-            regfree(&regex);
+            closedir(devDir);
         }
-        closedir(devDir);
     }
-#endif
     
+#endif
 }
 
 //  connect to the serial port
@@ -73,6 +82,7 @@ int SerialInterface::initializePort(char* portname, int baud) {
     
     if (serialFd == -1) {
         printLog("Failed.\n");
+        _failedOpenAttempts++;
         return -1;     //  Failed to open port
     }    
     struct termios options;
diff --git a/interface/src/SerialInterface.h b/interface/src/SerialInterface.h
index 9558a1601f..917c968c3f 100644
--- a/interface/src/SerialInterface.h
+++ b/interface/src/SerialInterface.h
@@ -36,7 +36,7 @@ extern const bool USING_INVENSENSE_MPU9150;
 
 class SerialInterface {
 public:
-    SerialInterface() { active = false; };
+    SerialInterface();
     void pair();
     void readData();
     
@@ -56,7 +56,7 @@ public:
     glm::vec3 getGravity() {return gravity;};
     
 private:
-    int initializePort(char * portname, int baud);
+    int initializePort(char* portname, int baud);
     void resetSerial();
     int lastMeasured[NUM_CHANNELS];
     float trailingAverage[NUM_CHANNELS];
@@ -68,6 +68,7 @@ private:
     int _lastYaw;
     int _lastPitch;
     int _lastRoll;
+    int _failedOpenAttempts;
 };
 
 #endif