Fix app.makeSingleInstance hanging on posix systems

Wait for the IO thread to be a thing before attempting to listen on the socket

Fixes #9880

atom/browser/api/atom_api_app.cc

@@ -577,6 +577,10 @@ void App::OnFinishLaunching(const base::DictionaryValue& launch_info) {
   media::AudioManager::SetGlobalAppName(Browser::Get()->GetName());
 #endif
   Emit("ready", launch_info);
+
+  if (process_singleton_) {
+    process_singleton_->OnBrowserReady();
+  }
 }
 
 void App::OnAccessibilitySupportChanged() {

chromium_src/chrome/browser/process_singleton.h

@@ -74,6 +74,8 @@ class ProcessSingleton : public base::NonThreadSafe {
   // TODO(brettw): Make the implementation of this method non-platform-specific
   // by making Linux re-use the Windows implementation.
   NotifyResult NotifyOtherProcessOrCreate();
+  void StartListeningOnSocket();
+  void OnBrowserReady();
 
   // Sets ourself up as the singleton instance.  Returns true on success.  If
   // false is returned, we are not the singleton instance and the caller must
@@ -173,6 +175,8 @@ class ProcessSingleton : public base::NonThreadSafe {
   // because it posts messages between threads.
   class LinuxWatcher;
   scoped_refptr<LinuxWatcher> watcher_;
+  int sock_;
+  bool listen_on_ready_ = false;
 #endif
 
   DISALLOW_COPY_AND_ASSIGN(ProcessSingleton);

chromium_src/chrome/browser/process_singleton_posix.cc

@@ -55,6 +55,7 @@
 
 #include <stddef.h>
 
+#include "atom/browser/browser.h"
 #include "atom/common/atom_command_line.h"
 
 #include "base/base_paths.h"
@@ -881,6 +882,22 @@ ProcessSingleton::NotifyResult ProcessSingleton::NotifyOtherProcessOrCreate() {
       base::TimeDelta::FromSeconds(kTimeoutInSeconds));
 }
 
+void ProcessSingleton::StartListeningOnSocket() {
+  BrowserThread::PostTask(
+      BrowserThread::IO,
+      FROM_HERE,
+      base::Bind(&ProcessSingleton::LinuxWatcher::StartListening,
+                 watcher_,
+                 sock_));
+}
+
+void ProcessSingleton::OnBrowserReady() {
+  if (listen_on_ready_) {
+    StartListeningOnSocket();
+    listen_on_ready_ = false;
+  }
+}
+
 ProcessSingleton::NotifyResult
 ProcessSingleton::NotifyOtherProcessWithTimeoutOrCreate(
     const base::CommandLine& command_line,
@@ -1032,12 +1049,13 @@ bool ProcessSingleton::Create() {
     NOTREACHED() << "listen failed: " << base::safe_strerror(errno);
 
   DCHECK(BrowserThread::IsMessageLoopValid(BrowserThread::IO));
-  BrowserThread::PostTask(
-      BrowserThread::IO,
-      FROM_HERE,
-      base::Bind(&ProcessSingleton::LinuxWatcher::StartListening,
-                 watcher_,
-                 sock));
+  sock_ = sock;
+
+  if (atom::Browser::Get()->is_ready()) {
+    StartListeningOnSocket();
+  } else {
+    listen_on_ready_ = true;
+  }
 
   return true;
 }

chromium_src/chrome/browser/process_singleton_win.cc

@@ -258,6 +258,9 @@ ProcessSingleton::NotifyOtherProcessOrCreate() {
   return result;
 }
 
+void ProcessSingleton::StartListeningOnSocket() {}
+void ProcessSingleton::OnBrowserReady() {}
+
 // Look for a Chrome instance that uses the same profile directory. If there
 // isn't one, create a message window with its title set to the profile
 // directory path.