path: root/mail/thunderbird/files/patch-bug1438678

commit 68124009fc5a
Author: Nicholas Nethercote <nnethercote@mozilla.com>
Date:   Fri Feb 16 17:54:16 2018 +1100

    Bug 1438678 - Pass early prefs via shared memory instead of the command line. r=bobowen,jld,glandium.
    
    This patch replaces the large -intPrefs/-boolPrefs/-stringPrefs flags with
    a short-lived, anonymous, shared memory segment that is used to pass the early
    prefs.
    
    Removing the bloat from the command line is nice, but more important is the
    fact that this will let us pass more prefs at content process start-up, which
    will allow us to remove the early/late prefs split (bug 1436911).
    
    Although this mechanism is only used for prefs, it's conceivable that it could
    be used for other data that must be received very early by children, and for
    which the command line isn't ideal.
    
    Notable details:
    
    - Much of the patch deals with the various platform-specific ways of passing
      handles/fds to children.
    
      - Linux and Mac: we use a fixed fd (8) in combination with the new
        GeckoChildProcessHost::AddFdToRemap() function (which ensures the child
        won't close the fd).
    
      - Android: like Linux and Mac, but the handles get passed via "parcels" and
        we use the new SetPrefsFd() function instead of the fixed fd.
    
      - Windows: there is no need to duplicate the handle because Windows handles
        are system-wide. But we do use the new
        GeckoChildProcessHost::AddHandleToShare() function to add it to the list of
        inheritable handles. We also ensure that list is processed on all paths
        (MOZ_SANDBOX with sandbox, MOZ_SANDBOX without sandbox, non-MOZ_SANDBOX) so
        that the handles are marked as inheritable. The handle is passed via the
        -prefsHandle flag.
    
      The -prefsLen flag is used on all platforms to indicate the size of the
      shared memory segment.
    
    - The patch also moves the serialization/deserialization of the prefs in/out of
      the shared memory into libpref, which is a better spot for it. (This means
      Preferences::MustSendToContentProcesses() can be removed.)
    
    MozReview-Commit-ID: 8fREEBiYFvc
    
    --HG--
    extra : rebase_source : 7e4c8ebdbcd7d74d6bd2ab3c9e75a6a17dbd8dfe
---
 dom/ipc/ContentParent.cpp                          |  91 +++++++-------
 dom/ipc/ContentProcess.cpp                         | 121 ++++++++++---------
 dom/ipc/ContentProcess.h                           |   5 +
 ipc/chromium/src/base/process_util_win.cc          |   4 +
 ipc/glue/GeckoChildProcessHost.cpp                 |  36 +++---
 ipc/glue/GeckoChildProcessHost.h                   |  10 ++
 .../org/mozilla/gecko/process/IChildProcess.aidl   |   3 +-
 .../main/java/org/mozilla/gecko/GeckoThread.java   |  13 +-
 .../org/mozilla/gecko/mozglue/GeckoLoader.java     |   2 +-
 .../mozilla/gecko/process/GeckoProcessManager.java |  19 +--
 .../gecko/process/GeckoServiceChildProcess.java    |   4 +-
 modules/libpref/Preferences.cpp                    | 134 +++++++++++++++++++--
 modules/libpref/Preferences.h                      |  17 +--
 mozglue/android/APKOpen.cpp                        |   4 +-
 toolkit/xre/Bootstrap.cpp                          |   4 +-
 toolkit/xre/Bootstrap.h                            |   2 +-
 toolkit/xre/nsEmbedFunctions.cpp                   |   3 +-
 widget/android/GeneratedJNIWrappers.cpp            |   4 +-
 widget/android/GeneratedJNIWrappers.h              |   5 +-
 xpcom/build/nsXULAppAPI.h                          |   2 +-
 20 files changed, 318 insertions(+), 165 deletions(-)

diff --git dom/ipc/ContentParent.cpp dom/ipc/ContentParent.cpp
index e27f3eedc1b1..60be7005354b 100644
--- dom/ipc/ContentParent.cpp
+++ dom/ipc/ContentParent.cpp
@@ -7,6 +7,7 @@
 #include "mozilla/DebugOnly.h"
 
 #include "base/basictypes.h"
+#include "base/shared_memory.h"
 
 #include "ContentParent.h"
 #include "TabParent.h"
@@ -1998,61 +1999,56 @@ ContentParent::LaunchSubprocess(ProcessPriority aInitialPriority /* = PROCESS_PR
   extraArgs.push_back(idStr);
   extraArgs.push_back(IsForBrowser() ? "-isForBrowser" : "-notForBrowser");
 
-  nsAutoCStringN<1024> boolPrefs;
-  nsAutoCStringN<1024> intPrefs;
-  nsAutoCStringN<1024> stringPrefs;
+  // Prefs information is passed via anonymous shared memory to avoid bloating
+  // the command line.
 
-  size_t prefsLen;
-  ContentPrefs::GetEarlyPrefs(&prefsLen);
+  // Serialize the early prefs.
+  nsAutoCStringN<1024> prefs;
+  Preferences::SerializeEarlyPreferences(prefs);
 
-  for (unsigned int i = 0; i < prefsLen; i++) {
-    const char* prefName = ContentPrefs::GetEarlyPref(i);
-    MOZ_ASSERT(i == 0 || strcmp(prefName, ContentPrefs::GetEarlyPref(i - 1)) > 0,
-               "Content process preferences should be sorted alphabetically.");
-
-    if (!Preferences::MustSendToContentProcesses(prefName)) {
-      continue;
-    }
-
-    switch (Preferences::GetType(prefName)) {
-    case nsIPrefBranch::PREF_INT:
-      intPrefs.Append(nsPrintfCString("%u:%d|", i, Preferences::GetInt(prefName)));
-      break;
-    case nsIPrefBranch::PREF_BOOL:
-      boolPrefs.Append(nsPrintfCString("%u:%d|", i, Preferences::GetBool(prefName)));
-      break;
-    case nsIPrefBranch::PREF_STRING: {
-      nsAutoCString value;
-      Preferences::GetCString(prefName, value);
-      stringPrefs.Append(nsPrintfCString("%u:%d;%s|", i, value.Length(), value.get()));
-      }
-      break;
-    case nsIPrefBranch::PREF_INVALID:
-      break;
-    default:
-      printf("preference type: %x\n", Preferences::GetType(prefName));
-      MOZ_CRASH();
-    }
+  // Set up the shared memory.
+  base::SharedMemory shm;
+  if (!shm.Create("", /* read_only */ false, /* open_existing */ false,
+                  prefs.Length())) {
+    NS_ERROR("failed to create shared memory in the parent");
+    MarkAsDead();
+    return false;
+  }
+  if (!shm.Map(prefs.Length())) {
+    NS_ERROR("failed to map shared memory in the parent");
+    MarkAsDead();
+    return false;
   }
 
-  nsCString schedulerPrefs = Scheduler::GetPrefs();
+  // Copy the serialized prefs into the shared memory.
+  memcpy(static_cast<char*>(shm.memory()), prefs.get(), prefs.Length());
 
-  // Only do these ones if they're non-empty.
-  if (!intPrefs.IsEmpty()) {
-    extraArgs.push_back("-intPrefs");
-    extraArgs.push_back(intPrefs.get());
-  }
-  if (!boolPrefs.IsEmpty()) {
-    extraArgs.push_back("-boolPrefs");
-    extraArgs.push_back(boolPrefs.get());
-  }
-  if (!stringPrefs.IsEmpty()) {
-    extraArgs.push_back("-stringPrefs");
-    extraArgs.push_back(stringPrefs.get());
-  }
+#if defined(XP_WIN)
+  // Record the handle as to-be-shared, and pass it via a command flag. This
+  // works because Windows handles are system-wide.
+  HANDLE prefsHandle = shm.handle();
+  mSubprocess->AddHandleToShare(prefsHandle);
+  extraArgs.push_back("-prefsHandle");
+  extraArgs.push_back(
+    nsPrintfCString("%zu", reinterpret_cast<uintptr_t>(prefsHandle)).get());
+#else
+  // In contrast, Unix fds are per-process. So remap the fd to a fixed one that
+  // will be used in the child.
+  // XXX: bug 1440207 is about improving how fixed fds are used.
+  //
+  // Note: on Android, AddFdToRemap() sets up the fd to be passed via a Parcel,
+  // and the fixed fd isn't used. However, we still need to mark it for
+  // remapping so it doesn't get closed in the child.
+  mSubprocess->AddFdToRemap(shm.handle().fd, kPrefsFileDescriptor);
+#endif
+
+  // Pass the length via a command flag.
+  extraArgs.push_back("-prefsLen");
+  extraArgs.push_back(nsPrintfCString("%zu", uintptr_t(prefs.Length())).get());
 
   // Scheduler prefs need to be handled differently because the scheduler needs
   // to start up in the content process before the normal preferences service.
+  nsCString schedulerPrefs = Scheduler::GetPrefs();
   extraArgs.push_back("-schedulerPrefs");
   extraArgs.push_back(schedulerPrefs.get());
 
@@ -2061,6 +2057,7 @@ ContentParent::LaunchSubprocess(ProcessPriority aInitialPriority /* = PROCESS_PR
   }
 
   if (!mSubprocess->LaunchAndWaitForProcessHandle(extraArgs)) {
+    NS_ERROR("failed to launch child in the parent");
     MarkAsDead();
     return false;
   }
diff --git dom/ipc/ContentProcess.cpp dom/ipc/ContentProcess.cpp
index e3c1f16910c6..2441c8cb9224 100644
--- dom/ipc/ContentProcess.cpp
+++ dom/ipc/ContentProcess.cpp
@@ -8,6 +8,8 @@
 
 #include "ContentProcess.h"
 #include "ContentPrefs.h"
+#include "base/shared_memory.h"
+#include "mozilla/Preferences.h"
 #include "mozilla/Scheduler.h"
 
 #if defined(XP_MACOSX) && defined(MOZ_CONTENT_SANDBOX)
@@ -15,7 +17,6 @@
 #endif
 
 #if (defined(XP_WIN) || defined(XP_MACOSX)) && defined(MOZ_CONTENT_SANDBOX)
-#include "mozilla/Preferences.h"
 #include "mozilla/SandboxSettings.h"
 #include "nsAppDirectoryServiceDefs.h"
 #include "nsDirectoryService.h"
@@ -81,6 +82,16 @@ SetUpSandboxEnvironment()
 }
 #endif
 
+#ifdef ANDROID
+static int gPrefsFd = -1;
+
+void
+SetPrefsFd(int aFd)
+{
+  gPrefsFd = aFd;
+}
+#endif
+
 bool
 ContentProcess::Init(int aArgc, char* aArgv[])
 {
@@ -88,9 +99,10 @@ ContentProcess::Init(int aArgc, char* aArgv[])
   bool foundAppdir = false;
   bool foundChildID = false;
   bool foundIsForBrowser = false;
-  bool foundIntPrefs = false;
-  bool foundBoolPrefs = false;
-  bool foundStringPrefs = false;
+#ifdef XP_WIN
+  bool foundPrefsHandle = false;
+#endif
+  bool foundPrefsLen = false;
   bool foundSchedulerPrefs = false;
 
   uint64_t childID;
@@ -103,7 +115,8 @@ ContentProcess::Init(int aArgc, char* aArgv[])
 #endif
 
   char* schedulerPrefs = nullptr;
-  InfallibleTArray<Pref> prefsArray;
+  base::SharedMemoryHandle prefsHandle = base::SharedMemory::NULLHandle();
+  size_t prefsLen = 0;
   for (int idx = aArgc; idx > 0; idx--) {
     if (!aArgv[idx]) {
       continue;
@@ -134,54 +147,24 @@ ContentProcess::Init(int aArgc, char* aArgv[])
       }
       isForBrowser = strcmp(aArgv[idx], "-notForBrowser");
       foundIsForBrowser = true;
-    } else if (!strcmp(aArgv[idx], "-intPrefs")) {
-      char* str = aArgv[idx + 1];
-      while (*str) {
-        int32_t index = strtol(str, &str, 10);
-        MOZ_ASSERT(str[0] == ':');
-        str++;
-        MaybePrefValue value(PrefValue(static_cast<int32_t>(strtol(str, &str, 10))));
-        MOZ_ASSERT(str[0] == '|');
-        str++;
-        // XXX: we assume these values as default values, which may not be
-        // true. We also assume they are unlocked. Fortunately, these prefs
-        // get reset properly by the first IPC message.
-        Pref pref(nsCString(ContentPrefs::GetEarlyPref(index)),
-                  /* isLocked */ false, value, MaybePrefValue());
-        prefsArray.AppendElement(pref);
-      }
-      foundIntPrefs = true;
-    } else if (!strcmp(aArgv[idx], "-boolPrefs")) {
+#ifdef XP_WIN
+    } else if (!strcmp(aArgv[idx], "-prefsHandle")) {
       char* str = aArgv[idx + 1];
-      while (*str) {
-        int32_t index = strtol(str, &str, 10);
-        MOZ_ASSERT(str[0] == ':');
-        str++;
-        MaybePrefValue value(PrefValue(!!strtol(str, &str, 10)));
-        MOZ_ASSERT(str[0] == '|');
-        str++;
-        Pref pref(nsCString(ContentPrefs::GetEarlyPref(index)),
-                  /* isLocked */ false, value, MaybePrefValue());
-        prefsArray.AppendElement(pref);
-      }
-      foundBoolPrefs = true;
-    } else if (!strcmp(aArgv[idx], "-stringPrefs")) {
+      MOZ_ASSERT(str[0] != '\0');
+      // ContentParent uses %zu to print a word-sized unsigned integer. So even
+      // though strtoull() returns a long long int, it will fit in a uintptr_t.
+      prefsHandle = reinterpret_cast<HANDLE>(strtoull(str, &str, 10));
+      MOZ_ASSERT(str[0] == '\0');
+      foundPrefsHandle = true;
+#endif
+    } else if (!strcmp(aArgv[idx], "-prefsLen")) {
       char* str = aArgv[idx + 1];
-      while (*str) {
-        int32_t index = strtol(str, &str, 10);
-        MOZ_ASSERT(str[0] == ':');
-        str++;
-        int32_t length = strtol(str, &str, 10);
-        MOZ_ASSERT(str[0] == ';');
-        str++;
-        MaybePrefValue value(PrefValue(nsCString(str, length)));
-        Pref pref(nsCString(ContentPrefs::GetEarlyPref(index)),
-                  /* isLocked */ false, value, MaybePrefValue());
-        prefsArray.AppendElement(pref);
-        str += length + 1;
-        MOZ_ASSERT(*(str - 1) == '|');
-      }
-      foundStringPrefs = true;
+      MOZ_ASSERT(str[0] != '\0');
+      // ContentParent uses %zu to print a word-sized unsigned integer. So even
+      // though strtoull() returns a long long int, it will fit in a uintptr_t.
+      prefsLen = strtoull(str, &str, 10);
+      MOZ_ASSERT(str[0] == '\0');
+      foundPrefsLen = true;
     } else if (!strcmp(aArgv[idx], "-schedulerPrefs")) {
       schedulerPrefs = aArgv[idx + 1];
       foundSchedulerPrefs = true;
@@ -209,21 +192,43 @@ ContentProcess::Init(int aArgc, char* aArgv[])
     bool allFound = foundAppdir
                  && foundChildID
                  && foundIsForBrowser
-                 && foundIntPrefs
-                 && foundBoolPrefs
-                 && foundStringPrefs
-                 && foundSchedulerPrefs;
-
+                 && foundPrefsLen
+                 && foundSchedulerPrefs
+#ifdef XP_WIN
+                 && foundPrefsHandle
+#endif
 #if defined(XP_MACOSX) && defined(MOZ_CONTENT_SANDBOX)
-    allFound &= foundProfile;
+                 && foundProfile
 #endif
+                 && true;
 
     if (allFound) {
       break;
     }
   }
 
-  Preferences::SetEarlyPreferences(&prefsArray);
+#ifdef ANDROID
+  // Android is different; get the FD via gPrefsFd instead of a fixed fd.
+  MOZ_RELEASE_ASSERT(gPrefsFd != -1);
+  prefsHandle = base::FileDescriptor(gPrefsFd, /* auto_close */ true);
+#elif XP_UNIX
+  prefsHandle = base::FileDescriptor(kPrefsFileDescriptor,
+                                     /* auto_close */ true);
+#endif
+
+  // Set up early prefs from the shared memory.
+  base::SharedMemory shm;
+  if (!shm.SetHandle(prefsHandle, /* read_only */ true)) {
+    NS_ERROR("failed to open shared memory in the child");
+    return false;
+  }
+  if (!shm.Map(prefsLen)) {
+    NS_ERROR("failed to map shared memory in the child");
+    return false;
+  }
+  Preferences::DeserializeEarlyPreferences(static_cast<char*>(shm.memory()),
+                                           prefsLen);
+
   Scheduler::SetPrefs(schedulerPrefs);
   mContent.Init(IOThreadChild::message_loop(),
                 ParentPid(),
diff --git dom/ipc/ContentProcess.h dom/ipc/ContentProcess.h
index a3854c761e10..6582c94da496 100644
--- dom/ipc/ContentProcess.h
+++ dom/ipc/ContentProcess.h
@@ -49,6 +49,11 @@ private:
   DISALLOW_EVIL_CONSTRUCTORS(ContentProcess);
 };
 
+#ifdef ANDROID
+// Android doesn't use -prefsHandle, it gets that FD another way.
+void SetPrefsFd(int aFd);
+#endif
+
 } // namespace dom
 } // namespace mozilla
 
diff --git ipc/chromium/src/base/process_util_win.cc ipc/chromium/src/base/process_util_win.cc
index 3ed54cd744ac..46667985cd71 100644
--- ipc/chromium/src/base/process_util_win.cc
+++ ipc/chromium/src/base/process_util_win.cc
@@ -354,6 +354,10 @@ bool LaunchApp(const std::wstring& cmdline,
   LPPROC_THREAD_ATTRIBUTE_LIST lpAttributeList = NULL;
   std::vector<HANDLE> handlesToInherit;
   for (HANDLE h : options.handles_to_inherit) {
+    if (SetHandleInformation(h, HANDLE_FLAG_INHERIT, HANDLE_FLAG_INHERIT) == 0) {
+      MOZ_DIAGNOSTIC_ASSERT(false, "SetHandleInformation failed");
+      return false;
+    }
     handlesToInherit.push_back(h);
   }
 
diff --git ipc/glue/GeckoChildProcessHost.cpp ipc/glue/GeckoChildProcessHost.cpp
index d18ed9edd4ca..3be1c51d10bb 100644
--- ipc/glue/GeckoChildProcessHost.cpp
+++ ipc/glue/GeckoChildProcessHost.cpp
@@ -1030,9 +1030,6 @@ GeckoChildProcessHost::PerformAsyncLaunchInternal(std::vector<std::string>& aExt
 
   if (!CrashReporter::IsDummy()) {
     PROsfd h = PR_FileDesc2NativeHandle(crashAnnotationWritePipe);
-# if defined(MOZ_SANDBOX)
-    mSandboxBroker.AddHandleToShare(reinterpret_cast<HANDLE>(h));
-# endif // defined(MOZ_SANDBOX)
     mLaunchOptions->handles_to_inherit.push_back(reinterpret_cast<HANDLE>(h));
     std::string hStr = std::to_string(h);
     cmdLine.AppendLooseValue(UTF8ToWide(hStr));
@@ -1043,6 +1040,11 @@ GeckoChildProcessHost::PerformAsyncLaunchInternal(std::vector<std::string>& aExt
 
 # if defined(MOZ_SANDBOX)
   if (shouldSandboxCurrentProcess) {
+    // Mark the handles to inherit as inheritable.
+    for (HANDLE h : mLaunchOptions->handles_to_inherit) {
+      mSandboxBroker.AddHandleToShare(h);
+    }
+
     if (mSandboxBroker.LaunchApp(cmdLine.program().c_str(),
                                  cmdLine.command_line_string().c_str(),
                                  mLaunchOptions->env_map,
@@ -1180,7 +1182,7 @@ GeckoChildProcessHost::LaunchAndroidService(const char* type,
                                             const base::file_handle_mapping_vector& fds_to_remap,
                                             ProcessHandle* process_handle)
 {
-  MOZ_ASSERT((fds_to_remap.size() > 0) && (fds_to_remap.size() <= 3));
+  MOZ_RELEASE_ASSERT((2 <= fds_to_remap.size()) && (fds_to_remap.size() <= 4));
   JNIEnv* const env = mozilla::jni::GetEnvForThread();
   MOZ_ASSERT(env);
 
@@ -1189,21 +1191,25 @@ GeckoChildProcessHost::LaunchAndroidService(const char* type,
   for (int ix = 0; ix < argvSize; ix++) {
     jargs->SetElement(ix, jni::StringParam(argv[ix].c_str(), env));
   }
-  base::file_handle_mapping_vector::const_iterator it = fds_to_remap.begin();
-  int32_t ipcFd = it->first;
-  it++;
-  // If the Crash Reporter is disabled, there will not be a second file descriptor.
+
+  // XXX: this processing depends entirely on the internals of
+  // ContentParent::LaunchSubprocess()
+  // GeckoChildProcessHost::PerformAsyncLaunchInternal(), and the order in
+  // which they append to fds_to_remap. There must be a better way to do it.
+  // See bug 1440207.
+  int32_t prefsFd = fds_to_remap[0].first;
+  int32_t ipcFd = fds_to_remap[1].first;
   int32_t crashFd = -1;
   int32_t crashAnnotationFd = -1;
-  if (it != fds_to_remap.end() && !CrashReporter::IsDummy()) {
-    crashFd = it->first;
-    it++;
+  if (fds_to_remap.size() == 3) {
+    crashAnnotationFd = fds_to_remap[2].first;
   }
-  if (it != fds_to_remap.end()) {
-    crashAnnotationFd = it->first;
-    it++;
+  if (fds_to_remap.size() == 4) {
+    crashFd = fds_to_remap[2].first;
+    crashAnnotationFd = fds_to_remap[3].first;
   }
-  int32_t handle = java::GeckoProcessManager::Start(type, jargs, ipcFd, crashFd, crashAnnotationFd);
+
+  int32_t handle = java::GeckoProcessManager::Start(type, jargs, prefsFd, ipcFd, crashFd, crashAnnotationFd);
 
   if (process_handle) {
     *process_handle = handle;
diff --git ipc/glue/GeckoChildProcessHost.h ipc/glue/GeckoChildProcessHost.h
index 631c42066bc7..0345e221abcc 100644
--- ipc/glue/GeckoChildProcessHost.h
+++ ipc/glue/GeckoChildProcessHost.h
@@ -103,6 +103,16 @@ public:
   }
 #endif
 
+#ifdef XP_WIN
+  void AddHandleToShare(HANDLE aHandle) {
+    mLaunchOptions->handles_to_inherit.push_back(aHandle);
+  }
+#else
+  void AddFdToRemap(int aSrcFd, int aDstFd) {
+    mLaunchOptions->fds_to_remap.push_back(std::make_pair(aSrcFd, aDstFd));
+  }
+#endif
+
   /**
    * Must run on the IO thread.  Cause the OS process to exit and
    * ensure its OS resources are cleaned up.
diff --git mobile/android/geckoview/src/main/aidl/org/mozilla/gecko/process/IChildProcess.aidl mobile/android/geckoview/src/main/aidl/org/mozilla/gecko/process/IChildProcess.aidl
index ba26ae1ba06b..a2535f44c72b 100644
--- mobile/android/geckoview/src/main/aidl/org/mozilla/gecko/process/IChildProcess.aidl
+++ mobile/android/geckoview/src/main/aidl/org/mozilla/gecko/process/IChildProcess.aidl
@@ -12,6 +12,7 @@ import android.os.ParcelFileDescriptor;
 interface IChildProcess {
     int getPid();
     boolean start(in IProcessManager procMan, in String[] args, in Bundle extras,
-                  in ParcelFileDescriptor ipcPfd, in ParcelFileDescriptor crashReporterPfd,
+                  in ParcelFileDescriptor prefsPfd, in ParcelFileDescriptor ipcPfd,
+                  in ParcelFileDescriptor crashReporterPfd,
                   in ParcelFileDescriptor crashAnnotationPfd);
 }
diff --git mobile/android/geckoview/src/main/java/org/mozilla/gecko/GeckoThread.java mobile/android/geckoview/src/main/java/org/mozilla/gecko/GeckoThread.java
index dfabfd05daf0..8311920afeec 100644
--- mobile/android/geckoview/src/main/java/org/mozilla/gecko/GeckoThread.java
+++ mobile/android/geckoview/src/main/java/org/mozilla/gecko/GeckoThread.java
@@ -128,6 +128,7 @@ public class GeckoThread extends Thread {
     public static final int FLAG_PRELOAD_CHILD = 2; // Preload child during main thread start.
 
     private static final String EXTRA_ARGS = "args";
+    private static final String EXTRA_PREFS_FD = "prefsFd";
     private static final String EXTRA_IPC_FD = "ipcFd";
     private static final String EXTRA_CRASH_FD = "crashFd";
     private static final String EXTRA_CRASH_ANNOTATION_FD = "crashAnnotationFd";
@@ -149,7 +150,8 @@ public class GeckoThread extends Thread {
 
     private synchronized boolean init(final GeckoProfile profile, final String[] args,
                                       final Bundle extras, final int flags,
-                                      final int ipcFd, final int crashFd,
+                                      final int prefsFd, final int ipcFd,
+                                      final int crashFd,
                                       final int crashAnnotationFd) {
         ThreadUtils.assertOnUiThread();
         uiThreadId = android.os.Process.myTid();
@@ -163,6 +165,7 @@ public class GeckoThread extends Thread {
         mFlags = flags;
 
         mExtras = (extras != null) ? new Bundle(extras) : new Bundle(3);
+        mExtras.putInt(EXTRA_PREFS_FD, prefsFd);
         mExtras.putInt(EXTRA_IPC_FD, ipcFd);
         mExtras.putInt(EXTRA_CRASH_FD, crashFd);
         mExtras.putInt(EXTRA_CRASH_ANNOTATION_FD, crashAnnotationFd);
@@ -174,15 +177,16 @@ public class GeckoThread extends Thread {
 
     public static boolean initMainProcess(final GeckoProfile profile, final String[] args,
                                           final Bundle extras, final int flags) {
-        return INSTANCE.init(profile, args, extras, flags,
+        return INSTANCE.init(profile, args, extras, flags, /* fd */ -1,
                              /* fd */ -1, /* fd */ -1, /* fd */ -1);
     }
 
     public static boolean initChildProcess(final String[] args, final Bundle extras,
-                                           final int ipcFd, final int crashFd,
+                                           final int prefsFd, final int ipcFd,
+                                           final int crashFd,
                                            final int crashAnnotationFd) {
         return INSTANCE.init(/* profile */ null, args, extras, /* flags */ 0,
-                             ipcFd, crashFd, crashAnnotationFd);
+                             prefsFd, ipcFd, crashFd, crashAnnotationFd);
     }
 
     private static boolean canUseProfile(final Context context, final GeckoProfile profile,
@@ -442,6 +446,7 @@ public class GeckoThread extends Thread {
 
         // And go.
         GeckoLoader.nativeRun(args,
+                              mExtras.getInt(EXTRA_PREFS_FD, -1),
                               mExtras.getInt(EXTRA_IPC_FD, -1),
                               mExtras.getInt(EXTRA_CRASH_FD, -1),
                               mExtras.getInt(EXTRA_CRASH_ANNOTATION_FD, -1));
diff --git mobile/android/geckoview/src/main/java/org/mozilla/gecko/mozglue/GeckoLoader.java mobile/android/geckoview/src/main/java/org/mozilla/gecko/mozglue/GeckoLoader.java
index b1830fd86945..ac128b651e7b 100644
--- mobile/android/geckoview/src/main/java/org/mozilla/gecko/mozglue/GeckoLoader.java
+++ mobile/android/geckoview/src/main/java/org/mozilla/gecko/mozglue/GeckoLoader.java
@@ -463,7 +463,7 @@ public final class GeckoLoader {
     public static native boolean verifyCRCs(String apkName);
 
     // These methods are implemented in mozglue/android/APKOpen.cpp
-    public static native void nativeRun(String[] args, int ipcFd, int crashFd, int crashAnnotationFd);
+    public static native void nativeRun(String[] args, int prefsFd, int ipcFd, int crashFd, int crashAnnotationFd);
     private static native void loadGeckoLibsNative(String apkName);
     private static native void loadSQLiteLibsNative(String apkName);
     private static native void loadNSSLibsNative(String apkName);
diff --git mobile/android/geckoview/src/main/java/org/mozilla/gecko/process/GeckoProcessManager.java mobile/android/geckoview/src/main/java/org/mozilla/gecko/process/GeckoProcessManager.java
index b762e1c9a3eb..dba329ba8f92 100644
--- mobile/android/geckoview/src/main/java/org/mozilla/gecko/process/GeckoProcessManager.java
+++ mobile/android/geckoview/src/main/java/org/mozilla/gecko/process/GeckoProcessManager.java
@@ -169,14 +169,14 @@ public final class GeckoProcessManager extends IProcessManager.Stub {
 
     @WrapForJNI
     private static int start(final String type, final String[] args,
-                             final int ipcFd, final int crashFd,
-                             final int crashAnnotationFd) {
-        return INSTANCE.start(type, args, ipcFd, crashFd, crashAnnotationFd, /* retry */ false);
+                             final int prefsFd, final int ipcFd,
+                             final int crashFd, final int crashAnnotationFd) {
+        return INSTANCE.start(type, args, prefsFd, ipcFd, crashFd, crashAnnotationFd, /* retry */ false);
     }
 
-    private int start(final String type, final String[] args, final int ipcFd,
-                      final int crashFd, final int crashAnnotationFd,
-                      final boolean retry) {
+    private int start(final String type, final String[] args, final int prefsFd,
+                      final int ipcFd, final int crashFd,
+                      final int crashAnnotationFd, final boolean retry) {
         final ChildConnection connection = getConnection(type);
         final IChildProcess child = connection.bind();
         if (child == null) {
@@ -184,10 +184,12 @@ public final class GeckoProcessManager extends IProcessManager.Stub {
         }
 
         final Bundle extras = GeckoThread.getActiveExtras();
+        final ParcelFileDescriptor prefsPfd;
         final ParcelFileDescriptor ipcPfd;
         final ParcelFileDescriptor crashPfd;
         final ParcelFileDescriptor crashAnnotationPfd;
         try {
+            prefsPfd = ParcelFileDescriptor.fromFd(prefsFd);
             ipcPfd = ParcelFileDescriptor.fromFd(ipcFd);
             crashPfd = (crashFd >= 0) ? ParcelFileDescriptor.fromFd(crashFd) : null;
             crashAnnotationPfd = (crashAnnotationFd >= 0) ? ParcelFileDescriptor.fromFd(crashAnnotationFd) : null;
@@ -198,7 +200,8 @@ public final class GeckoProcessManager extends IProcessManager.Stub {
 
         boolean started = false;
         try {
-            started = child.start(this, args, extras, ipcPfd, crashPfd, crashAnnotationPfd);
+            started = child.start(this, args, extras, prefsPfd, ipcPfd, crashPfd,
+                                  crashAnnotationPfd);
         } catch (final RemoteException e) {
         }
 
@@ -209,7 +212,7 @@ public final class GeckoProcessManager extends IProcessManager.Stub {
             }
             Log.w(LOGTAG, "Attempting to kill running child " + type);
             connection.unbind();
-            return start(type, args, ipcFd, crashFd, crashAnnotationFd, /* retry */ true);
+            return start(type, args, prefsFd, ipcFd, crashFd, crashAnnotationFd, /* retry */ true);
         }
 
         try {
diff --git mobile/android/geckoview/src/main/java/org/mozilla/gecko/process/GeckoServiceChildProcess.java mobile/android/geckoview/src/main/java/org/mozilla/gecko/process/GeckoServiceChildProcess.java
index f1f6ce109fda..6dc19813fc10 100644
--- mobile/android/geckoview/src/main/java/org/mozilla/gecko/process/GeckoServiceChildProcess.java
+++ mobile/android/geckoview/src/main/java/org/mozilla/gecko/process/GeckoServiceChildProcess.java
@@ -63,6 +63,7 @@ public class GeckoServiceChildProcess extends Service {
         public boolean start(final IProcessManager procMan,
                              final String[] args,
                              final Bundle extras,
+                             final ParcelFileDescriptor prefsPfd,
                              final ParcelFileDescriptor ipcPfd,
                              final ParcelFileDescriptor crashReporterPfd,
                              final ParcelFileDescriptor crashAnnotationPfd) {
@@ -74,6 +75,7 @@ public class GeckoServiceChildProcess extends Service {
                 sProcessManager = procMan;
             }
 
+            final int prefsFd = prefsPfd.detachFd();
             final int ipcFd = ipcPfd.detachFd();
             final int crashReporterFd = crashReporterPfd != null ?
                                         crashReporterPfd.detachFd() : -1;
@@ -83,7 +85,7 @@ public class GeckoServiceChildProcess extends Service {
             ThreadUtils.postToUiThread(new Runnable() {
                 @Override
                 public void run() {
-                    if (GeckoThread.initChildProcess(args, extras, ipcFd, crashReporterFd,
+                    if (GeckoThread.initChildProcess(args, extras, prefsFd, ipcFd, crashReporterFd,
                                                      crashAnnotationFd)) {
                         GeckoThread.launch();
                     }
diff --git modules/libpref/Preferences.cpp modules/libpref/Preferences.cpp
index 330ed4a09b54..b884591c9271 100644
--- modules/libpref/Preferences.cpp
+++ modules/libpref/Preferences.cpp
@@ -2920,7 +2920,7 @@ public:
 
 } // namespace
 
-// A list of prefs sent early from the parent, via the command line.
+// A list of prefs sent early from the parent, via shared memory.
 static InfallibleTArray<dom::Pref>* gEarlyDomPrefs;
 
 /* static */ already_AddRefed<Preferences>
@@ -3081,11 +3081,130 @@ NS_IMPL_ISUPPORTS(Preferences,
                   nsISupportsWeakReference)
 
 /* static */ void
-Preferences::SetEarlyPreferences(const nsTArray<dom::Pref>* aDomPrefs)
+Preferences::SerializeEarlyPreferences(nsCString& aStr)
+{
+  MOZ_RELEASE_ASSERT(InitStaticMembers());
+
+  nsAutoCStringN<256> boolPrefs, intPrefs, stringPrefs;
+  size_t numEarlyPrefs;
+  dom::ContentPrefs::GetEarlyPrefs(&numEarlyPrefs);
+
+  for (unsigned int i = 0; i < numEarlyPrefs; i++) {
+    const char* prefName = dom::ContentPrefs::GetEarlyPref(i);
+    MOZ_ASSERT_IF(i > 0,
+                  strcmp(prefName, dom::ContentPrefs::GetEarlyPref(i - 1)) > 0);
+
+    Pref* pref = pref_HashTableLookup(prefName);
+    if (!pref || !pref->MustSendToContentProcesses()) {
+      continue;
+    }
+
+    switch (pref->Type()) {
+      case PrefType::Bool:
+        boolPrefs.Append(
+          nsPrintfCString("%u:%d|", i, Preferences::GetBool(prefName)));
+        break;
+      case PrefType::Int:
+        intPrefs.Append(
+          nsPrintfCString("%u:%d|", i, Preferences::GetInt(prefName)));
+        break;
+      case PrefType::String: {
+        nsAutoCString value;
+        Preferences::GetCString(prefName, value);
+        stringPrefs.Append(
+          nsPrintfCString("%u:%d;%s|", i, value.Length(), value.get()));
+      } break;
+      case PrefType::None:
+        break;
+      default:
+        printf_stderr("preference type: %d\n", int(pref->Type()));
+        MOZ_CRASH();
+    }
+  }
+
+  aStr.Truncate();
+  aStr.Append(boolPrefs);
+  aStr.Append('\n');
+  aStr.Append(intPrefs);
+  aStr.Append('\n');
+  aStr.Append(stringPrefs);
+  aStr.Append('\n');
+  aStr.Append('\0');
+}
+
+/* static */ void
+Preferences::DeserializeEarlyPreferences(char* aStr, size_t aStrLen)
 {
   MOZ_ASSERT(!XRE_IsParentProcess());
 
-  gEarlyDomPrefs = new InfallibleTArray<dom::Pref>(mozilla::Move(*aDomPrefs));
+  MOZ_ASSERT(!gEarlyDomPrefs);
+  gEarlyDomPrefs = new InfallibleTArray<dom::Pref>();
+
+  char* p = aStr;
+
+  // XXX: we assume these pref values are default values, which may not be
+  // true. We also assume they are unlocked. Fortunately, these prefs get reset
+  // properly by the first IPC message.
+
+  // Get the bool prefs.
+  while (*p != '\n') {
+    int32_t index = strtol(p, &p, 10);
+    MOZ_ASSERT(p[0] == ':');
+    p++;
+    int v = strtol(p, &p, 10);
+    MOZ_ASSERT(v == 0 || v == 1);
+    dom::MaybePrefValue value(dom::PrefValue(!!v));
+    MOZ_ASSERT(p[0] == '|');
+    p++;
+    dom::Pref pref(nsCString(dom::ContentPrefs::GetEarlyPref(index)),
+                   /* isLocked */ false,
+                   value,
+                   dom::MaybePrefValue());
+    gEarlyDomPrefs->AppendElement(pref);
+  }
+  p++;
+
+  // Get the int prefs.
+  while (*p != '\n') {
+    int32_t index = strtol(p, &p, 10);
+    MOZ_ASSERT(p[0] == ':');
+    p++;
+    dom::MaybePrefValue value(
+      dom::PrefValue(static_cast<int32_t>(strtol(p, &p, 10))));
+    MOZ_ASSERT(p[0] == '|');
+    p++;
+    dom::Pref pref(nsCString(dom::ContentPrefs::GetEarlyPref(index)),
+                   /* isLocked */ false,
+                   value,
+                   dom::MaybePrefValue());
+    gEarlyDomPrefs->AppendElement(pref);
+  }
+  p++;
+
+  // Get the string prefs.
+  while (*p != '\n') {
+    int32_t index = strtol(p, &p, 10);
+    MOZ_ASSERT(p[0] == ':');
+    p++;
+    int32_t length = strtol(p, &p, 10);
+    MOZ_ASSERT(p[0] == ';');
+    p++;
+    dom::MaybePrefValue value(dom::PrefValue(nsCString(p, length)));
+    dom::Pref pref(nsCString(dom::ContentPrefs::GetEarlyPref(index)),
+                   /* isLocked */ false,
+                   value,
+                   dom::MaybePrefValue());
+    gEarlyDomPrefs->AppendElement(pref);
+    p += length + 1;
+    MOZ_ASSERT(*(p - 1) == '|');
+  }
+  p++;
+
+  MOZ_ASSERT(*p == '\0');
+
+  // We finished parsing on a '\0'. That should be the last char in the shared
+  // memory.
+  MOZ_ASSERT(aStr + aStrLen - 1 == p);
 
 #ifdef DEBUG
   MOZ_ASSERT(gPhase == ContentProcessPhase::eNoPrefsSet);
@@ -4298,15 +4417,6 @@ Preferences::HasUserValue(const char* aPrefName)
   return pref && pref->HasUserValue();
 }
 
-/* static */ bool
-Preferences::MustSendToContentProcesses(const char* aPrefName)
-{
-  NS_ENSURE_TRUE(InitStaticMembers(), false);
-
-  Pref* pref = pref_HashTableLookup(aPrefName);
-  return pref && pref->MustSendToContentProcesses();
-}
-
 /* static */ int32_t
 Preferences::GetType(const char* aPrefName)
 {
diff --git modules/libpref/Preferences.h modules/libpref/Preferences.h
index 1cb825ecbfe5..c149db62b525 100644
--- modules/libpref/Preferences.h
+++ modules/libpref/Preferences.h
@@ -41,6 +41,11 @@ class PrefValue;
 
 struct PrefsSizes;
 
+#ifdef XP_UNIX
+// XXX: bug 1440207 is about improving how fixed fds such as this are used.
+static const int kPrefsFileDescriptor = 8;
+#endif
+
 // Keep this in sync with PrefType in parser/src/lib.rs.
 enum class PrefValueKind : uint8_t
 {
@@ -230,9 +235,6 @@ public:
   // Whether the pref has a user value or not.
   static bool HasUserValue(const char* aPref);
 
-  // Must the pref be sent to content processes when they start?
-  static bool MustSendToContentProcesses(const char* aPref);
-
   // Adds/Removes the observer for the root pref branch. See nsIPrefBranch.idl
   // for details.
   static nsresult AddStrongObserver(nsIObserver* aObserver, const char* aPref);
@@ -328,11 +330,12 @@ public:
 
   // When a content process is created these methods are used to pass prefs in
   // bulk from the parent process. "Early" preferences are ones that are needed
-  // very early on in the content process's lifetime; they are passed via the
-  // command line. "Late" preferences are the remainder, which are passed via
-  // IPC message.
+  // very early on in the content process's lifetime; they are passed via a
+  // special shared memory segment. "Late" preferences are the remainder, which
+  // are passed via a standard IPC message.
+  static void SerializeEarlyPreferences(nsCString& aStr);
+  static void DeserializeEarlyPreferences(char* aStr, size_t aStrLen);
   static void GetPreferences(InfallibleTArray<dom::Pref>* aSettings);
-  static void SetEarlyPreferences(const nsTArray<dom::Pref>* aSettings);
   static void SetLatePreferences(const nsTArray<dom::Pref>* aSettings);
 
   // When a single pref is changed in the parent process, these methods are
diff --git mozglue/android/APKOpen.cpp mozglue/android/APKOpen.cpp
index 5f1ef55b605e..b57192488725 100644
--- mozglue/android/APKOpen.cpp
+++ mozglue/android/APKOpen.cpp
@@ -392,7 +392,7 @@ FreeArgv(char** argv, int argc)
 }
 
 extern "C" APKOPEN_EXPORT void MOZ_JNICALL
-Java_org_mozilla_gecko_mozglue_GeckoLoader_nativeRun(JNIEnv *jenv, jclass jc, jobjectArray jargs, int ipcFd, int crashFd, int crashAnnotationFd)
+Java_org_mozilla_gecko_mozglue_GeckoLoader_nativeRun(JNIEnv *jenv, jclass jc, jobjectArray jargs, int prefsFd, int ipcFd, int crashFd, int crashAnnotationFd)
 {
   int argc = 0;
   char** argv = CreateArgvFromObjectArray(jenv, jargs, &argc);
@@ -407,7 +407,7 @@ Java_org_mozilla_gecko_mozglue_GeckoLoader_nativeRun(JNIEnv *jenv, jclass jc, jo
     gBootstrap->GeckoStart(jenv, argv, argc, sAppData);
     ElfLoader::Singleton.ExpectShutdown(true);
   } else {
-    gBootstrap->XRE_SetAndroidChildFds(jenv, ipcFd, crashFd, crashAnnotationFd);
+    gBootstrap->XRE_SetAndroidChildFds(jenv, prefsFd, ipcFd, crashFd, crashAnnotationFd);
     gBootstrap->XRE_SetProcessType(argv[argc - 1]);
 
     XREChildData childData;
diff --git toolkit/xre/Bootstrap.cpp toolkit/xre/Bootstrap.cpp
index 5688519822a9..7e857969a4fb 100644
--- toolkit/xre/Bootstrap.cpp
+++ toolkit/xre/Bootstrap.cpp
@@ -78,8 +78,8 @@ public:
     ::GeckoStart(aEnv, argv, argc, aAppData);
   }
 
-  virtual void XRE_SetAndroidChildFds(JNIEnv* aEnv, int aIPCFd, int aCrashFd, int aCrashAnnotationFd) override {
-    ::XRE_SetAndroidChildFds(aEnv, aIPCFd, aCrashFd, aCrashAnnotationFd);
+  virtual void XRE_SetAndroidChildFds(JNIEnv* aEnv, int aPrefsFd, int aIPCFd, int aCrashFd, int aCrashAnnotationFd) override {
+    ::XRE_SetAndroidChildFds(aEnv, aPrefsFd, aIPCFd, aCrashFd, aCrashAnnotationFd);
   }
 #endif
 
diff --git toolkit/xre/Bootstrap.h toolkit/xre/Bootstrap.h
index 686d0a38e324..77adcef80e1f 100644
--- toolkit/xre/Bootstrap.h
+++ toolkit/xre/Bootstrap.h
@@ -113,7 +113,7 @@ public:
 #ifdef MOZ_WIDGET_ANDROID
   virtual void GeckoStart(JNIEnv* aEnv, char** argv, int argc, const StaticXREAppData& aAppData) = 0;
 
-  virtual void XRE_SetAndroidChildFds(JNIEnv* aEnv, int aIPCFd, int aCrashFd, int aCrashAnnotationFd) = 0;
+  virtual void XRE_SetAndroidChildFds(JNIEnv* aEnv, int aPrefsFd, int aIPCFd, int aCrashFd, int aCrashAnnotationFd) = 0;
 #endif
 
 #ifdef LIBFUZZER
diff --git toolkit/xre/nsEmbedFunctions.cpp toolkit/xre/nsEmbedFunctions.cpp
index 53bd2bc2eb47..83184e97ba92 100644
--- toolkit/xre/nsEmbedFunctions.cpp
+++ toolkit/xre/nsEmbedFunctions.cpp
@@ -243,9 +243,10 @@ GeckoProcessType sChildProcessType = GeckoProcessType_Default;
 
 #if defined(MOZ_WIDGET_ANDROID)
 void
-XRE_SetAndroidChildFds (JNIEnv* env, int ipcFd, int crashFd, int crashAnnotationFd)
+XRE_SetAndroidChildFds (JNIEnv* env, int prefsFd, int ipcFd, int crashFd, int crashAnnotationFd)
 {
   mozilla::jni::SetGeckoThreadEnv(env);
+  mozilla::dom::SetPrefsFd(prefsFd);
   IPC::Channel::SetClientChannelFd(ipcFd);
   CrashReporter::SetNotificationPipeForChild(crashFd);
   CrashReporter::SetCrashAnnotationPipeForChild(crashAnnotationFd);
diff --git widget/android/GeneratedJNIWrappers.cpp widget/android/GeneratedJNIWrappers.cpp
index e3f6af0cc575..4165df59f0e8 100644
--- widget/android/GeneratedJNIWrappers.cpp
+++ widget/android/GeneratedJNIWrappers.cpp
@@ -2355,9 +2355,9 @@ constexpr char GeckoProcessManager::GetEditableParent_t::signature[];
 constexpr char GeckoProcessManager::Start_t::name[];
 constexpr char GeckoProcessManager::Start_t::signature[];
 
-auto GeckoProcessManager::Start(mozilla::jni::String::Param a0, mozilla::jni::ObjectArray::Param a1, int32_t a2, int32_t a3, int32_t a4) -> int32_t
+auto GeckoProcessManager::Start(mozilla::jni::String::Param a0, mozilla::jni::ObjectArray::Param a1, int32_t a2, int32_t a3, int32_t a4, int32_t a5) -> int32_t
 {
-    return mozilla::jni::Method<Start_t>::Call(GeckoProcessManager::Context(), nullptr, a0, a1, a2, a3, a4);
+    return mozilla::jni::Method<Start_t>::Call(GeckoProcessManager::Context(), nullptr, a0, a1, a2, a3, a4, a5);
 }
 
 const char GeckoServiceChildProcess::name[] =
diff --git widget/android/GeneratedJNIWrappers.h widget/android/GeneratedJNIWrappers.h
index ece79ac94a71..228affa1e550 100644
--- widget/android/GeneratedJNIWrappers.h
+++ widget/android/GeneratedJNIWrappers.h
@@ -6696,10 +6696,11 @@ public:
                 mozilla::jni::ObjectArray::Param,
                 int32_t,
                 int32_t,
+                int32_t,
                 int32_t> Args;
         static constexpr char name[] = "start";
         static constexpr char signature[] =
-                "(Ljava/lang/String;[Ljava/lang/String;III)I";
+                "(Ljava/lang/String;[Ljava/lang/String;IIII)I";
         static const bool isStatic = true;
         static const mozilla::jni::ExceptionMode exceptionMode =
                 mozilla::jni::ExceptionMode::ABORT;
@@ -6709,7 +6710,7 @@ public:
                 mozilla::jni::DispatchTarget::CURRENT;
     };
 
-    static auto Start(mozilla::jni::String::Param, mozilla::jni::ObjectArray::Param, int32_t, int32_t, int32_t) -> int32_t;
+    static auto Start(mozilla::jni::String::Param, mozilla::jni::ObjectArray::Param, int32_t, int32_t, int32_t, int32_t) -> int32_t;
 
     static const mozilla::jni::CallingThread callingThread =
             mozilla::jni::CallingThread::ANY;
diff --git xpcom/build/nsXULAppAPI.h xpcom/build/nsXULAppAPI.h
index 94f6daf864c9..d6ac10d51d76 100644
--- xpcom/build/nsXULAppAPI.h
+++ xpcom/build/nsXULAppAPI.h
@@ -398,7 +398,7 @@ XRE_API(const char*,
 
 #if defined(MOZ_WIDGET_ANDROID)
 XRE_API(void,
-        XRE_SetAndroidChildFds, (JNIEnv* env, int ipcFd, int crashFd, int crashAnnotationFd))
+        XRE_SetAndroidChildFds, (JNIEnv* env, int prefsFd, int ipcFd, int crashFd, int crashAnnotationFd))
 #endif // defined(MOZ_WIDGET_ANDROID)
 
 XRE_API(void,