Gavin Andresen: multiple instance check, -testnet use port 18333

git-svn-id: https://bitcoin.svn.sourceforge.net/svnroot/bitcoin/trunk@170 1a98c847-1fd6-4fd8-948a-caf3550aa51b

init.cpp

@@ -244,8 +244,7 @@ bool AppInit2(int argc, char* argv[])
     // Required to protect the database files if we're going to keep deleting log.*
     //
 #if defined(__WXMSW__) && defined(GUI)
-    // todo: wxSingleInstanceChecker wasn't working on Linux, never deleted its lock file
-    //  maybe should go by whether successfully bind port 8333 instead
+    // wxSingleInstanceChecker doesn't work on Linux
     wxString strMutexName = wxString("bitcoin_running.") + getenv("HOMEPATH");
     for (int i = 0; i < strMutexName.size(); i++)
         if (!isalnum(strMutexName[i]))
@@ -257,7 +256,6 @@ bool AppInit2(int argc, char* argv[])
         unsigned int nStart = GetTime();
         loop
         {
-            // TODO: find out how to do this in Linux, or replace with wxWidgets commands
             // Show the previous instance and exit
             HWND hwndPrev = FindWindowA("wxWindowClassNR", "Bitcoin");
             if (hwndPrev)
@@ -281,8 +279,18 @@ bool AppInit2(int argc, char* argv[])
     }
 #endif
 
+    // Make sure only a single bitcoin process is using the data directory.
+    string strLockFile = GetDataDir() + "/.lock";
+    FILE* file = fopen(strLockFile.c_str(), "a"); // empty lock file; created if it doesn't exist.
+    fclose(file);
+    static boost::interprocess::file_lock lock(strLockFile.c_str());
+    if (!lock.try_lock())
+    {
+        wxMessageBox(strprintf(_("Cannot obtain a lock on data directory %s.  Bitcoin is probably already running."), GetDataDir().c_str()), "Bitcoin");
+        return false;
+    }
+
     // Bind to the port early so we can tell if another instance is already running.
-    // This is a backup to wxSingleInstanceChecker, which doesn't work on Linux.
     string strErrors;
     if (!BindListenPort(strErrors))
     {