Try to increase file descriptor rlimit if necessary

As the default can be too low, especially on OSX.

1 files changed, 20 insertions, 0 deletions

diff --git a/src/init.cpp b/src/init.cpp
index 7024f3f785..8efe6dfdcf 100644
--- a/src/init.cpp
+++ b/src/init.cpp
@@ -28,6 +28,15 @@ using namespace boost;
 CWallet* pwalletMain;
 CClientUIInterface uiInterface;
 
+#ifdef WIN32
+// Win32 LevelDB doesn't use filedescriptors, and the ones used for
+// accessing block files, don't count towards to fd_set size limit
+// anyway.
+#define MIN_CORE_FILEDESCRIPTORS 0
+#else
+#define MIN_CORE_FILEDESCRIPTORS 150
+#endif
+
 // Used to pass flags to the Bind() function
 enum BindFlags {
     BF_NONE         = 0,
@@ -518,6 +527,16 @@ bool AppInit2(boost::thread_group& threadGroup)
         SoftSetBoolArg("-rescan", true);
     }
 
+    // Make sure enough file descriptors are available
+    int nBind = std::max((int)mapArgs.count("-bind"), 1);
+    nMaxConnections = GetArg("-maxconnections", 125);
+    nMaxConnections = std::max(std::min(nMaxConnections, FD_SETSIZE - nBind - MIN_CORE_FILEDESCRIPTORS), 0);
+    int nFD = RaiseFileDescriptorLimit(nMaxConnections + MIN_CORE_FILEDESCRIPTORS);
+    if (nFD < MIN_CORE_FILEDESCRIPTORS)
+        return InitError(_("Not enough file descriptors available."));
+    if (nFD - MIN_CORE_FILEDESCRIPTORS < nMaxConnections)
+        nMaxConnections = nFD - MIN_CORE_FILEDESCRIPTORS;
+
     // ********************************************************* Step 3: parameter-to-internal-flags
 
     fDebug = GetBoolArg("-debug");
@@ -594,6 +613,7 @@ bool AppInit2(boost::thread_group& threadGroup)
         printf("Startup time: %s\n", DateTimeStrFormat("%Y-%m-%d %H:%M:%S", GetTime()).c_str());
     printf("Default data directory %s\n", GetDefaultDataDir().string().c_str());
     printf("Used data directory %s\n", strDataDir.c_str());
+    printf("Using at most %i connections (%i file descriptors available)\n", nMaxConnections, nFD);
     std::ostringstream strErrors;
 
     if (fDaemon)