Try to increase file descriptor rlimit if necessary

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

1 files changed, 23 insertions, 0 deletions

diff --git a/src/util.cpp b/src/util.cpp
index 3fd624c42c..8b6d8b32c8 100644
--- a/src/util.cpp
+++ b/src/util.cpp
@@ -10,6 +10,7 @@
 #endif
 #include <fcntl.h>
 #include <sys/stat.h>
+#include <sys/resource.h>
 #endif
 
 #include "util.h"
@@ -1167,6 +1168,28 @@ bool TruncateFile(FILE *file, unsigned int length) {
 #endif
 }
 
+
+// this function tries to raise the file descriptor limit to the requested number.
+// It returns the actual file descriptor limit (which may be more or less than nMinFD)
+int RaiseFileDescriptorLimit(int nMinFD) {
+#if defined(WIN32)
+    return 2048;
+#else
+    struct rlimit limitFD;
+    if (getrlimit(RLIMIT_NOFILE, &limitFD) != -1) {
+        if (limitFD.rlim_cur < (rlim_t)nMinFD) {
+            limitFD.rlim_cur = nMinFD;
+            if (limitFD.rlim_cur > limitFD.rlim_max)
+                limitFD.rlim_cur = limitFD.rlim_max;
+            setrlimit(RLIMIT_NOFILE, &limitFD);
+            getrlimit(RLIMIT_NOFILE, &limitFD);
+        }
+        return limitFD.rlim_cur;
+    }
+    return nMinFD; // getrlimit failed, assume it's fine
+#endif
+}
+
 // this function tries to make a particular range of a file allocated (corresponding to disk space)
 // it is advisory, and the range specified in the arguments will never contain live data
 void AllocateFileRange(FILE *file, unsigned int offset, unsigned int length) {