Bug 580790 - Connection::initialize can access preferences off of the main thread

Makes things go boom when preferences are accessed off of the main thread.
r=dwitte
sr=bsmedberg
a=blocking2.0

modules/libpref/src/nsPrefBranch.cpp

@@ -44,6 +44,7 @@
 #endif
 
 #include "nsPrefBranch.h"
+#include "nsPrefService.h"
 #include "nsILocalFile.h"
 #include "nsIObserverService.h"
 #include "nsXPCOM.h"
@@ -52,6 +53,7 @@
 #include "nsString.h"
 #include "nsReadableUtils.h"
 #include "nsXPIDLString.h"
+#include "nsThreadUtils.h"
 #include "nsIStringBundle.h"
 #include "prefapi.h"
 #include "prmem.h"
@@ -153,6 +155,9 @@ NS_INTERFACE_MAP_END
 NS_IMETHODIMP nsPrefBranch::GetRoot(char **aRoot)
 {
   NS_ENSURE_ARG_POINTER(aRoot);
+  if (NS_UNLIKELY(!nsPrefService::CheckAndLogBackgroundThreadUse())) {
+    return NS_ERROR_UNEXPECTED;
+  }
 
   mPrefRoot.Truncate(mPrefRootLength);
   *aRoot = ToNewCString(mPrefRoot);
@@ -161,6 +166,10 @@ NS_IMETHODIMP nsPrefBranch::GetRoot(char **aRoot)
 
 NS_IMETHODIMP nsPrefBranch::GetPrefType(const char *aPrefName, PRInt32 *_retval)
 {
+  if (NS_UNLIKELY(!nsPrefService::CheckAndLogBackgroundThreadUse())) {
+    return NS_ERROR_UNEXPECTED;
+  }
+
 #ifdef MOZ_IPC
   if (ContentChild* cpc = GetContentChild()) {
     nsresult rv = NS_ERROR_NOT_AVAILABLE;
@@ -179,6 +188,10 @@ NS_IMETHODIMP nsPrefBranch::GetPrefType(const char *aPrefName, PRInt32 *_retval)
 
 NS_IMETHODIMP nsPrefBranch::GetBoolPref(const char *aPrefName, PRBool *_retval)
 {
+  if (NS_UNLIKELY(!nsPrefService::CheckAndLogBackgroundThreadUse())) {
+    return NS_ERROR_UNEXPECTED;
+  }
+
 #ifdef MOZ_IPC
   if (ContentChild* cpc = GetContentChild()) {
     nsresult rv = NS_ERROR_NOT_AVAILABLE;
@@ -196,6 +209,10 @@ NS_IMETHODIMP nsPrefBranch::GetBoolPref(const char *aPrefName, PRBool *_retval)
 
 NS_IMETHODIMP nsPrefBranch::SetBoolPref(const char *aPrefName, PRInt32 aValue)
 {
+  if (NS_UNLIKELY(!nsPrefService::CheckAndLogBackgroundThreadUse())) {
+    return NS_ERROR_UNEXPECTED;
+  }
+
 #ifdef MOZ_IPC
   if (GetContentChild()) {
     NS_ERROR("cannot set pref from content process");
@@ -209,6 +226,10 @@ NS_IMETHODIMP nsPrefBranch::SetBoolPref(const char *aPrefName, PRInt32 aValue)
 
 NS_IMETHODIMP nsPrefBranch::GetCharPref(const char *aPrefName, char **_retval)
 {
+  if (NS_UNLIKELY(!nsPrefService::CheckAndLogBackgroundThreadUse())) {
+    return NS_ERROR_UNEXPECTED;
+  }
+
 #ifdef MOZ_IPC
   if (ContentChild* cpc = GetContentChild()) {
     nsresult rv = NS_ERROR_NOT_AVAILABLE;
@@ -228,6 +249,10 @@ NS_IMETHODIMP nsPrefBranch::GetCharPref(const char *aPrefName, char **_retval)
 
 NS_IMETHODIMP nsPrefBranch::SetCharPref(const char *aPrefName, const char *aValue)
 {
+  if (NS_UNLIKELY(!nsPrefService::CheckAndLogBackgroundThreadUse())) {
+    return NS_ERROR_UNEXPECTED;
+  }
+
 #ifdef MOZ_IPC
   if (GetContentChild()) {
     NS_ERROR("cannot set pref from content process");
@@ -241,6 +266,10 @@ NS_IMETHODIMP nsPrefBranch::SetCharPref(const char *aPrefName, const char *aValu
 
 NS_IMETHODIMP nsPrefBranch::GetIntPref(const char *aPrefName, PRInt32 *_retval)
 {
+  if (NS_UNLIKELY(!nsPrefService::CheckAndLogBackgroundThreadUse())) {
+    return NS_ERROR_UNEXPECTED;
+  }
+
 #ifdef MOZ_IPC
   if (ContentChild* cpc = GetContentChild()) {
     nsresult rv = NS_ERROR_NOT_AVAILABLE;
@@ -258,6 +287,10 @@ NS_IMETHODIMP nsPrefBranch::GetIntPref(const char *aPrefName, PRInt32 *_retval)
 
 NS_IMETHODIMP nsPrefBranch::SetIntPref(const char *aPrefName, PRInt32 aValue)
 {
+  if (NS_UNLIKELY(!nsPrefService::CheckAndLogBackgroundThreadUse())) {
+    return NS_ERROR_UNEXPECTED;
+  }
+
 #ifdef MOZ_IPC
   if (GetContentChild()) {
     NS_ERROR("cannot set pref from content process");
@@ -271,6 +304,10 @@ NS_IMETHODIMP nsPrefBranch::SetIntPref(const char *aPrefName, PRInt32 aValue)
 
 NS_IMETHODIMP nsPrefBranch::GetComplexValue(const char *aPrefName, const nsIID & aType, void **_retval)
 {
+  if (NS_UNLIKELY(!nsPrefService::CheckAndLogBackgroundThreadUse())) {
+    return NS_ERROR_UNEXPECTED;
+  }
+
   nsresult       rv;
   nsXPIDLCString utf8String;
 
@@ -445,6 +482,10 @@ NS_IMETHODIMP nsPrefBranch::GetComplexValue(const char *aPrefName, const nsIID &
 
 NS_IMETHODIMP nsPrefBranch::SetComplexValue(const char *aPrefName, const nsIID & aType, nsISupports *aValue)
 {
+  if (NS_UNLIKELY(!nsPrefService::CheckAndLogBackgroundThreadUse())) {
+    return NS_ERROR_UNEXPECTED;
+  }
+
 #ifdef MOZ_IPC
   if (GetContentChild()) {
     NS_ERROR("cannot set pref from content process");
@@ -534,6 +575,10 @@ NS_IMETHODIMP nsPrefBranch::SetComplexValue(const char *aPrefName, const nsIID &
 
 NS_IMETHODIMP nsPrefBranch::ClearUserPref(const char *aPrefName)
 {
+  if (NS_UNLIKELY(!nsPrefService::CheckAndLogBackgroundThreadUse())) {
+    return NS_ERROR_UNEXPECTED;
+  }
+
 #ifdef MOZ_IPC
   if (GetContentChild()) {
     NS_ERROR("cannot set pref from content process");
@@ -548,6 +593,9 @@ NS_IMETHODIMP nsPrefBranch::ClearUserPref(const char *aPrefName)
 NS_IMETHODIMP nsPrefBranch::PrefHasUserValue(const char *aPrefName, PRBool *_retval)
 {
   NS_ENSURE_ARG_POINTER(_retval);
+  if (NS_UNLIKELY(!nsPrefService::CheckAndLogBackgroundThreadUse())) {
+    return NS_ERROR_UNEXPECTED;
+  }
 
 #ifdef MOZ_IPC
   if (ContentChild* cpc = GetContentChild()) {
@@ -567,6 +615,10 @@ NS_IMETHODIMP nsPrefBranch::PrefHasUserValue(const char *aPrefName, PRBool *_ret
 
 NS_IMETHODIMP nsPrefBranch::LockPref(const char *aPrefName)
 {
+  if (NS_UNLIKELY(!nsPrefService::CheckAndLogBackgroundThreadUse())) {
+    return NS_ERROR_UNEXPECTED;
+  }
+
 #ifdef MOZ_IPC
   if (GetContentChild()) {
     NS_ERROR("cannot lock pref from content process");
@@ -581,6 +633,9 @@ NS_IMETHODIMP nsPrefBranch::LockPref(const char *aPrefName)
 NS_IMETHODIMP nsPrefBranch::PrefIsLocked(const char *aPrefName, PRBool *_retval)
 {
   NS_ENSURE_ARG_POINTER(_retval);
+  if (NS_UNLIKELY(!nsPrefService::CheckAndLogBackgroundThreadUse())) {
+    return NS_ERROR_UNEXPECTED;
+  }
 
 #ifdef MOZ_IPC
   if (ContentChild* cpc = GetContentChild()) {
@@ -600,6 +655,10 @@ NS_IMETHODIMP nsPrefBranch::PrefIsLocked(const char *aPrefName, PRBool *_retval)
 
 NS_IMETHODIMP nsPrefBranch::UnlockPref(const char *aPrefName)
 {
+  if (NS_UNLIKELY(!nsPrefService::CheckAndLogBackgroundThreadUse())) {
+    return NS_ERROR_UNEXPECTED;
+  }
+
 #ifdef MOZ_IPC
   if (GetContentChild()) {
     NS_ERROR("cannot unlock pref from content process");
@@ -619,6 +678,10 @@ NS_IMETHODIMP nsPrefBranch::ResetBranch(const char *aStartingAt)
 
 NS_IMETHODIMP nsPrefBranch::DeleteBranch(const char *aStartingAt)
 {
+  if (NS_UNLIKELY(!nsPrefService::CheckAndLogBackgroundThreadUse())) {
+    return NS_ERROR_UNEXPECTED;
+  }
+
 #ifdef MOZ_IPC
   if (GetContentChild()) {
     NS_ERROR("cannot set pref from content process");
@@ -632,6 +695,10 @@ NS_IMETHODIMP nsPrefBranch::DeleteBranch(const char *aStartingAt)
 
 NS_IMETHODIMP nsPrefBranch::GetChildList(const char *aStartingAt, PRUint32 *aCount, char ***aChildArray)
 {
+  if (NS_UNLIKELY(!nsPrefService::CheckAndLogBackgroundThreadUse())) {
+    return NS_ERROR_UNEXPECTED;
+  }
+
   char            **outArray;
   PRInt32         numPrefs;
   PRInt32         dwIndex;
@@ -702,6 +769,10 @@ NS_IMETHODIMP nsPrefBranch::GetChildList(const char *aStartingAt, PRUint32 *aCou
 
 NS_IMETHODIMP nsPrefBranch::AddObserver(const char *aDomain, nsIObserver *aObserver, PRBool aHoldWeak)
 {
+  if (NS_UNLIKELY(!nsPrefService::CheckAndLogBackgroundThreadUse())) {
+    return NS_ERROR_UNEXPECTED;
+  }
+
   PrefCallbackData *pCallback;
   const char *pref;
 
@@ -767,6 +838,9 @@ NS_IMETHODIMP nsPrefBranch::RemoveObserver(const char *aDomain, nsIObserver *aOb
 {
   NS_ENSURE_ARG_POINTER(aDomain);
   NS_ENSURE_ARG_POINTER(aObserver);
+  if (NS_UNLIKELY(!nsPrefService::CheckAndLogBackgroundThreadUse())) {
+    return NS_ERROR_UNEXPECTED;
+  }
 
 #ifdef MOZ_IPC
   if (XRE_GetProcessType() == GeckoProcessType_Content) {

modules/libpref/src/nsPrefService.cpp

@@ -45,6 +45,7 @@
 #include "nsAppDirectoryServiceDefs.h"
 #include "nsDirectoryServiceDefs.h"
 #include "nsICategoryManager.h"
+#include "nsIConsoleService.h"
 #include "nsCategoryManagerUtils.h"
 #include "nsNetUtil.h"
 #include "nsIFile.h"
@@ -56,6 +57,7 @@
 #include "nsCOMArray.h"
 #include "nsXPCOMCID.h"
 #include "nsAutoPtr.h"
+#include "nsThreadUtils.h"
 
 #include "nsQuickSort.h"
 #include "prmem.h"
@@ -199,6 +201,10 @@ NS_IMETHODIMP nsPrefService::Observe(nsISupports *aSubject, const char *aTopic,
 
 NS_IMETHODIMP nsPrefService::ReadUserPrefs(nsIFile *aFile)
 {
+  if (NS_UNLIKELY(!CheckAndLogBackgroundThreadUse())) {
+    return NS_ERROR_UNEXPECTED;
+  }
+
 #ifdef MOZ_IPC
   if (XRE_GetProcessType() == GeckoProcessType_Content) {
     NS_ERROR("cannot load prefs from content process");
@@ -222,6 +228,10 @@ NS_IMETHODIMP nsPrefService::ReadUserPrefs(nsIFile *aFile)
 
 NS_IMETHODIMP nsPrefService::ResetPrefs()
 {
+  if (NS_UNLIKELY(!CheckAndLogBackgroundThreadUse())) {
+    return NS_ERROR_UNEXPECTED;
+  }
+
 #ifdef MOZ_IPC
   if (XRE_GetProcessType() == GeckoProcessType_Content) {
     NS_ERROR("cannot set prefs from content process");
@@ -240,6 +250,10 @@ NS_IMETHODIMP nsPrefService::ResetPrefs()
 
 NS_IMETHODIMP nsPrefService::ResetUserPrefs()
 {
+  if (NS_UNLIKELY(!CheckAndLogBackgroundThreadUse())) {
+    return NS_ERROR_UNEXPECTED;
+  }
+
 #ifdef MOZ_IPC
   if (XRE_GetProcessType() == GeckoProcessType_Content) {
     NS_ERROR("cannot set prefs from content process");
@@ -253,6 +267,10 @@ NS_IMETHODIMP nsPrefService::ResetUserPrefs()
 
 NS_IMETHODIMP nsPrefService::SavePrefFile(nsIFile *aFile)
 {
+  if (NS_UNLIKELY(!CheckAndLogBackgroundThreadUse())) {
+    return NS_ERROR_UNEXPECTED;
+  }
+
 #ifdef MOZ_IPC
   if (XRE_GetProcessType() == GeckoProcessType_Content) {
     NS_ERROR("cannot save prefs from content process");
@@ -265,6 +283,10 @@ NS_IMETHODIMP nsPrefService::SavePrefFile(nsIFile *aFile)
 
 NS_IMETHODIMP nsPrefService::GetBranch(const char *aPrefRoot, nsIPrefBranch **_retval)
 {
+  if (NS_UNLIKELY(!CheckAndLogBackgroundThreadUse())) {
+    return NS_ERROR_UNEXPECTED;
+  }
+
   nsresult rv;
 
   if ((nsnull != aPrefRoot) && (*aPrefRoot != '\0')) {
@@ -283,6 +305,10 @@ NS_IMETHODIMP nsPrefService::GetBranch(const char *aPrefRoot, nsIPrefBranch **_r
 
 NS_IMETHODIMP nsPrefService::GetDefaultBranch(const char *aPrefRoot, nsIPrefBranch **_retval)
 {
+  if (NS_UNLIKELY(!CheckAndLogBackgroundThreadUse())) {
+    return NS_ERROR_UNEXPECTED;
+  }
+
   nsresult rv;
 
   // TODO: - cache this stuff and allow consumers to share branches (hold weak references I think)
@@ -802,3 +828,22 @@ static nsresult pref_InitInitialObjects()
 
   return pref_LoadPrefsInDirList(NS_EXT_PREFS_DEFAULTS_DIR_LIST);
 }
+
+// static
+bool
+nsPrefService::CheckAndLogBackgroundThreadUse()
+{
+  if (NS_IsMainThread()) {
+    return true;
+  }
+
+  NS_ERROR("Cannot be used on a background thread!");
+  nsCOMPtr<nsIConsoleService> cs =
+    do_GetService("@mozilla.org/consoleservice;1");
+  if (cs) {
+    (void)cs->LogStringMessage(NS_LITERAL_STRING(
+      "Invalid use of the preferences on a background thread!"
+    ).get());
+  }
+  return false;
+}

modules/libpref/src/nsPrefService.h

@@ -65,7 +65,13 @@ public:
   virtual ~nsPrefService();
 
   nsresult Init();
-                           
+
+  /**
+   * Checks to make sure we are on the main thread and log if we are not.
+   *
+   * @returns true if on the main thread, and false otherwise.
+   */
+  static bool CheckAndLogBackgroundThreadUse();
 protected:
   nsresult NotifyServiceObservers(const char *aSubject);
   nsresult UseDefaultPrefFile();