Bug 1518639: Move startup locking to the remote service. r=jimm

Makes nsRemoteService responsible for the shared lock for the time between
attempting to contact a remote server and starting up our own server.

Differential Revision: https://phabricator.services.mozilla.com/D19070

--HG--
extra : rebase_source : d2191966989c1b6db0dfb0db91f1b27d85046835
extra : intermediate-source : 405ea32162ba129b0c3e9ed75c9de13259d2d759
extra : source : 4da03e7a957c180d5997e3d8f6903b22f9a800c4

toolkit/components/remote/moz.build

@@ -27,4 +27,7 @@ if 'gtk' in CONFIG['MOZ_WIDGET_TOOLKIT']:
         CXXFLAGS += CONFIG['MOZ_DBUS_GLIB_CFLAGS']
     CXXFLAGS += CONFIG['TK_CFLAGS']
 
+LOCAL_INCLUDES += [
+    '../../profile',
+]
 FINAL_LIBRARY = 'xul'

toolkit/components/remote/nsRemoteService.cpp

@@ -18,6 +18,11 @@
 #include "nsString.h"
 #include "nsServiceManagerUtils.h"
 #include "mozilla/ModuleUtils.h"
+#include "SpecialSystemDirectory.h"
+
+// Time to wait for the remoting service to start
+#define START_TIMEOUT_SEC 5
+#define START_SLEEP_MSEC 100
 
 using namespace mozilla;
 
@@ -26,6 +31,47 @@ extern char** gArgv;
 
 NS_IMPL_ISUPPORTS(nsRemoteService, nsIObserver)
 
+void nsRemoteService::LockStartup(nsCString& aProgram, const char* aProfile) {
+  nsCOMPtr<nsIFile> mutexDir;
+  nsresult rv = GetSpecialSystemDirectory(OS_TemporaryDirectory,
+                                          getter_AddRefs(mutexDir));
+  if (NS_SUCCEEDED(rv)) {
+    nsAutoCString mutexPath(aProgram);
+    if (aProfile) {
+      mutexPath.Append(NS_LITERAL_CSTRING("_") + nsDependentCString(aProfile));
+    }
+    mutexDir->AppendNative(mutexPath);
+
+    rv = mutexDir->Create(nsIFile::DIRECTORY_TYPE, 0700);
+    if (NS_SUCCEEDED(rv) || rv == NS_ERROR_FILE_ALREADY_EXISTS) {
+      mRemoteLockDir = mutexDir;
+    }
+  }
+
+  if (mRemoteLockDir) {
+    const mozilla::TimeStamp epoch = mozilla::TimeStamp::Now();
+    do {
+      rv = mRemoteLock.Lock(mRemoteLockDir, nullptr);
+      if (NS_SUCCEEDED(rv)) break;
+      PR_Sleep(START_SLEEP_MSEC);
+    } while ((mozilla::TimeStamp::Now() - epoch) <
+             mozilla::TimeDuration::FromSeconds(START_TIMEOUT_SEC));
+    if (NS_FAILED(rv)) {
+      NS_WARNING("Cannot lock remote start mutex");
+    }
+  }
+}
+
+void nsRemoteService::UnlockStartup() {
+  mRemoteLock.Unlock();
+  mRemoteLock.Cleanup();
+
+  if (mRemoteLockDir) {
+    mRemoteLockDir->Remove(false);
+    mRemoteLockDir = nullptr;
+  }
+}
+
 RemoteResult nsRemoteService::StartClient(const char* aDesktopStartupID,
                                           nsCString& program,
                                           const char* profile) {

toolkit/components/remote/nsRemoteService.h

@@ -13,6 +13,8 @@
 #include "nsIObserver.h"
 #include "nsPIDOMWindow.h"
 #include "mozilla/UniquePtr.h"
+#include "nsIFile.h"
+#include "nsProfileLock.h"
 
 enum RemoteResult {
   REMOTE_NOT_FOUND = 0,
@@ -28,6 +30,9 @@ class nsRemoteService final : public nsIObserver {
 
   nsRemoteService() = default;
 
+  void LockStartup(nsCString& aProgram, const char* aProfile);
+  void UnlockStartup();
+
   RemoteResult StartClient(const char* aDesktopStartupID, nsCString& program,
                            const char* profile);
   void StartupServer(const char* aAppName, const char* aProfileName);
@@ -37,6 +42,8 @@ class nsRemoteService final : public nsIObserver {
   ~nsRemoteService();
 
   mozilla::UniquePtr<nsRemoteServer> mRemoteServer;
+  nsProfileLock mRemoteLock;
+  nsCOMPtr<nsIFile> mRemoteLockDir;
 };
 
 #endif  // __nsRemoteService_h__

toolkit/xre/nsAppRunner.cpp

@@ -196,8 +196,6 @@
 #  ifdef MOZ_ENABLE_DBUS
 #    include "nsDBusRemoteClient.h"
 #  endif
-// Time to wait for the remoting service to start
-#  define MOZ_XREMOTE_START_TIMEOUT_SEC 5
 #endif
 
 #if defined(DEBUG) && defined(XP_WIN32)
@@ -2882,8 +2880,6 @@ class XREMain {
   nsCOMPtr<nsIProfileLock> mProfileLock;
 #if defined(MOZ_WIDGET_GTK)
   RefPtr<nsRemoteService> mRemoteService;
-  nsProfileLock mRemoteLock;
-  nsCOMPtr<nsIFile> mRemoteLockDir;
 #endif
 
   UniquePtr<ScopedXPCOMStartup> mScopedXPCOM;
@@ -3919,35 +3915,7 @@ int XREMain::XRE_mainStartup(bool* aExitFlag) {
       // later.
       CheckArg("p", &profile, CheckArgFlag::None);
 
-      nsCOMPtr<nsIFile> mutexDir;
-      rv = GetSpecialSystemDirectory(OS_TemporaryDirectory,
-                                     getter_AddRefs(mutexDir));
-      if (NS_SUCCEEDED(rv)) {
-        nsAutoCString mutexPath = program;
-        if (profile) {
-          mutexPath.Append(NS_LITERAL_CSTRING("_") +
-                           nsDependentCString(profile));
-        }
-        mutexDir->AppendNative(mutexPath);
-
-        rv = mutexDir->Create(nsIFile::DIRECTORY_TYPE, 0700);
-        if (NS_SUCCEEDED(rv) || rv == NS_ERROR_FILE_ALREADY_EXISTS) {
-          mRemoteLockDir = mutexDir;
-        }
-      }
-
-      if (mRemoteLockDir) {
-        const TimeStamp epoch = mozilla::TimeStamp::Now();
-        do {
-          rv = mRemoteLock.Lock(mRemoteLockDir, nullptr);
-          if (NS_SUCCEEDED(rv)) break;
-          sched_yield();
-        } while ((TimeStamp::Now() - epoch) <
-                 TimeDuration::FromSeconds(MOZ_XREMOTE_START_TIMEOUT_SEC));
-        if (NS_FAILED(rv)) {
-          NS_WARNING("Cannot lock XRemote start mutex");
-        }
-      }
+      mRemoteService->LockStartup(program, profile);
 
       // Try to remote the entire command line. If this fails, start up
       // normally.
@@ -4592,11 +4560,7 @@ nsresult XREMain::XRE_mainRun() {
     // proxy window.
     if (mRemoteService) {
       mRemoteService->StartupServer(mAppData->remotingName, mProfileName.get());
-    }
-    if (mRemoteLockDir) {
-      mRemoteLock.Unlock();
-      mRemoteLock.Cleanup();
-      mRemoteLockDir->Remove(false);
+      mRemoteService->UnlockStartup();
     }
 #endif /* MOZ_WIDGET_GTK */