src: do platform-specific initialization earlier

Execute the per-platform initialization logic as early as possible,
for two reasons:

1. It opens the way for an upcoming commit to simplify early SIGUSR1
   handling.

2. It should make life easier for embedders because io.js no longer
   mucks around with the file descriptor limit or signal disposition
   of the process.

PR-URL: #615
Reviewed-By: Sam Roberts <sam@strongloop.com>

src/node.cc

@@ -3322,6 +3322,36 @@ static void DebugEnd(const FunctionCallbackInfo<Value>& args) {
 }
 
 
+inline void PlatformInit() {
+#ifdef __POSIX__
+  // Raise the open file descriptor limit.
+  struct rlimit lim;
+  if (getrlimit(RLIMIT_NOFILE, &lim) == 0 && lim.rlim_cur != lim.rlim_max) {
+    // Do a binary search for the limit.
+    rlim_t min = lim.rlim_cur;
+    rlim_t max = 1 << 20;
+    // But if there's a defined upper bound, don't search, just set it.
+    if (lim.rlim_max != RLIM_INFINITY) {
+      min = lim.rlim_max;
+      max = lim.rlim_max;
+    }
+    do {
+      lim.rlim_cur = min + (max - min) / 2;
+      if (setrlimit(RLIMIT_NOFILE, &lim)) {
+        max = lim.rlim_cur;
+      } else {
+        min = lim.rlim_cur;
+      }
+    } while (min + 1 < max);
+  }
+  // Ignore SIGPIPE
+  RegisterSignalHandler(SIGPIPE, SIG_IGN);
+  RegisterSignalHandler(SIGINT, SignalExit, true);
+  RegisterSignalHandler(SIGTERM, SignalExit, true);
+#endif  // __POSIX__
+}
+
+
 void Init(int* argc,
           const char** argv,
           int* exec_argc,
@@ -3396,35 +3426,6 @@ void Init(int* argc,
 
   V8::SetArrayBufferAllocator(&ArrayBufferAllocator::the_singleton);
 
-#ifdef __POSIX__
-  // Raise the open file descriptor limit.
-  {  // NOLINT (whitespace/braces)
-    struct rlimit lim;
-    if (getrlimit(RLIMIT_NOFILE, &lim) == 0 && lim.rlim_cur != lim.rlim_max) {
-      // Do a binary search for the limit.
-      rlim_t min = lim.rlim_cur;
-      rlim_t max = 1 << 20;
-      // But if there's a defined upper bound, don't search, just set it.
-      if (lim.rlim_max != RLIM_INFINITY) {
-        min = lim.rlim_max;
-        max = lim.rlim_max;
-      }
-      do {
-        lim.rlim_cur = min + (max - min) / 2;
-        if (setrlimit(RLIMIT_NOFILE, &lim)) {
-          max = lim.rlim_cur;
-        } else {
-          min = lim.rlim_cur;
-        }
-      } while (min + 1 < max);
-    }
-  }
-  // Ignore SIGPIPE
-  RegisterSignalHandler(SIGPIPE, SIG_IGN);
-  RegisterSignalHandler(SIGINT, SignalExit, true);
-  RegisterSignalHandler(SIGTERM, SignalExit, true);
-#endif  // __POSIX__
-
   if (!use_debug_agent) {
     RegisterDebugSignalHandler();
   }
@@ -3610,6 +3611,8 @@ Environment* CreateEnvironment(Isolate* isolate,
 
 
 int Start(int argc, char** argv) {
+  PlatformInit();
+
   const char* replaceInvalid = secure_getenv("NODE_INVALID_UTF8");
 
   if (replaceInvalid == nullptr)