Bug 977026 - Part 2: B2G loader. r=khuey, r=cyu

--HG--
rename : ipc/app/MozillaRuntimeMain.cpp => ipc/contentproc/plugin-container.cpp

b2g/app/B2GLoader.cpp

@@ -0,0 +1,167 @@
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim: set sw=2 ts=2 autoindent cindent expandtab: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this file,
+ * You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "nsXULAppAPI.h"
+#include "nsXPCOMGlue.h"
+#include "nsStringGlue.h"
+#include "nsCOMPtr.h"
+#include "nsIFile.h"
+#include "BinaryPath.h"
+#include "nsAutoPtr.h"
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <unistd.h>
+#include <fcntl.h>
+#include <sys/types.h>
+#include <sys/socket.h>
+
+#include <dlfcn.h>
+
+#include "nsXPCOMPrivate.h" // for MAXPATHLEN and XPCOM_DLL
+
+#define ASSERT(x) if (!(x)) { MOZ_CRASH(); }
+
+
+// Functions being loaded by XPCOMGlue
+XRE_ProcLoaderServiceRunType XRE_ProcLoaderServiceRun;
+XRE_ProcLoaderClientInitType XRE_ProcLoaderClientInit;
+
+static const nsDynamicFunctionLoad kXULFuncs[] = {
+  { "XRE_ProcLoaderServiceRun", (NSFuncPtr*) &XRE_ProcLoaderServiceRun },
+  { "XRE_ProcLoaderClientInit", (NSFuncPtr*) &XRE_ProcLoaderClientInit },
+  { nullptr, nullptr }
+};
+
+static int
+GetDirnameSlash(const char *aPath, char *aOutDir, int aMaxLen)
+{
+  char *lastSlash = strrchr(aPath, XPCOM_FILE_PATH_SEPARATOR[0]);
+  if (lastSlash == nullptr) {
+    return 0;
+  }
+  int cpsz = lastSlash - aPath + 1; // include slash
+  if (aMaxLen <= cpsz) {
+    return 0;
+  }
+  strncpy(aOutDir, aPath, cpsz);
+  aOutDir[cpsz] = 0;
+  return cpsz;
+}
+
+static bool
+GetXPCOMPath(const char *aProgram, char *aOutPath, int aMaxLen)
+{
+  nsAutoArrayPtr<char> progBuf(new char[aMaxLen]);
+  nsresult rv = mozilla::BinaryPath::Get(aProgram, progBuf);
+  NS_ENSURE_SUCCESS(rv, false);
+
+  int len = GetDirnameSlash(progBuf, aOutPath, aMaxLen);
+  NS_ENSURE_TRUE(!!len, false);
+
+  NS_ENSURE_TRUE((len + sizeof(XPCOM_DLL)) < aMaxLen, false);
+  char *afterSlash = aOutPath + len;
+  strcpy(afterSlash, XPCOM_DLL);
+  return true;
+}
+
+static bool
+LoadLibxul(const char *aXPCOMPath)
+{
+  nsresult rv;
+
+  XPCOMGlueEnablePreload();
+  rv = XPCOMGlueStartup(aXPCOMPath);
+  NS_ENSURE_SUCCESS(rv, false);
+
+  rv = XPCOMGlueLoadXULFunctions(kXULFuncs);
+  NS_ENSURE_SUCCESS(rv, false);
+
+  return true;
+}
+
+static bool
+LoadStaticData(const char *aProgram)
+{
+  char xpcomPath[MAXPATHLEN];
+  bool ok = GetXPCOMPath(aProgram, xpcomPath, MAXPATHLEN);
+  NS_ENSURE_TRUE(ok, false);
+
+  ok = LoadLibxul(xpcomPath);
+  return ok;
+}
+
+/**
+ * Fork and run parent and child process.
+ *
+ * The parent is the b2g process and child for Nuwa.
+ */
+static int
+RunProcesses(int argc, const char *argv[])
+{
+  /*
+   * The original main() of the b2g process.  It is renamed to
+   * b2g_main() for the b2g loader.
+   */
+  int b2g_main(int argc, const char *argv[]);
+
+  int ipcSockets[2] = {-1, -1};
+  int r = socketpair(AF_LOCAL, SOCK_STREAM, 0, ipcSockets);
+  ASSERT(r == 0);
+  int parentSock = ipcSockets[0];
+  int childSock = ipcSockets[1];
+
+  r = fcntl(parentSock, F_SETFL, O_NONBLOCK);
+  ASSERT(r != -1);
+  r = fcntl(childSock, F_SETFL, O_NONBLOCK);
+  ASSERT(r != -1);
+
+  pid_t pid = fork();
+  ASSERT(pid >= 0);
+  bool isChildProcess = pid == 0;
+
+  close(isChildProcess ? parentSock : childSock);
+
+  if (isChildProcess) {
+    /* The Nuwa process */
+    /* This provides the IPC service of loading Nuwa at the process.
+     * The b2g process would send a IPC message of loading Nuwa
+     * as the replacement of forking and executing plugin-container.
+     */
+    return XRE_ProcLoaderServiceRun(getppid(), childSock, argc, argv);
+  }
+
+  // The b2g process
+  int childPid = pid;
+  XRE_ProcLoaderClientInit(childPid, parentSock);
+  return b2g_main(argc, argv);
+}
+
+/**
+ * B2G Loader is responsible for loading the b2g process and the
+ * Nuwa process.  It forks into the parent process, for the b2g
+ * process, and the child process, for the Nuwa process.
+ *
+ * The loader loads libxul and performs initialization of static data
+ * before forking, so relocation of libxul and static data can be
+ * shared between the b2g process, the Nuwa process, and the content
+ * processes.
+ */
+int
+main(int argc, const char* argv[])
+{
+  const char *program = argv[0];
+  /*
+   * Before fork(), libxul and static data of Gecko are loaded for
+   * sharing.
+   */
+  bool ok = LoadStaticData(program);
+  if (!ok) {
+    return 255;
+  }
+
+  return RunProcesses(argc, argv);
+}

b2g/app/moz.build

@@ -9,6 +9,11 @@ if not CONFIG['LIBXUL_SDK']:
         PROGRAM = CONFIG['MOZ_APP_NAME'] + "-bin"
     else:
         PROGRAM = CONFIG['MOZ_APP_NAME']
+    if CONFIG['MOZ_B2G_LOADER']:
+        SOURCES += [
+            'B2GLoader.cpp',
+        ]
+
     SOURCES += [
         'nsBrowserApp.cpp',
     ]

b2g/app/nsBrowserApp.cpp

@@ -17,6 +17,7 @@
 
 #include <stdio.h>
 #include <stdarg.h>
+#include <string.h>
 
 #include "nsCOMPtr.h"
 #include "nsIFile.h"
@@ -163,9 +164,22 @@ static int do_main(int argc, char* argv[])
   return XRE_main(argc, argv, &sAppData, 0);
 }
 
-int main(int argc, char* argv[])
+#ifdef MOZ_B2G_LOADER
+/*
+ * The main() in B2GLoader.cpp is the new main function instead of the
+ * main() here if it is enabled.  So, rename it to b2g_man().
+ */
+#define main b2g_main
+#define _CONST const
+#else
+#define _CONST
+#endif
+
+int main(int argc, _CONST char* argv[])
 {
+#ifndef MOZ_B2G_LOADER
   char exePath[MAXPATHLEN];
+#endif
 
 #ifdef MOZ_WIDGET_GONK
   // This creates a ThreadPool for binder ipc. A ThreadPool is necessary to
@@ -175,7 +189,9 @@ int main(int argc, char* argv[])
   android::ProcessState::self()->startThreadPool();
 #endif
 
-  nsresult rv = mozilla::BinaryPath::Get(argv[0], exePath);
+  nsresult rv;
+#ifndef MOZ_B2G_LOADER
+  rv = mozilla::BinaryPath::Get(argv[0], exePath);
   if (NS_FAILED(rv)) {
     Output("Couldn't calculate the application directory.\n");
     return 255;
@@ -186,6 +202,7 @@ int main(int argc, char* argv[])
     return 255;
 
   strcpy(++lastSlash, XPCOM_DLL);
+#endif // MOZ_B2G_LOADER
 
 #if defined(XP_UNIX)
   // If the b2g app is launched from adb shell, then the shell will wind
@@ -209,6 +226,9 @@ int main(int argc, char* argv[])
   DllBlocklist_Initialize();
 #endif
 
+  // B2G loader has already initialized Gecko so we can't initialize
+  // it again here.
+#ifndef MOZ_B2G_LOADER
   // We do this because of data in bug 771745
   XPCOMGlueEnablePreload();
 
@@ -219,6 +239,7 @@ int main(int argc, char* argv[])
   }
   // Reset exePath so that it is the directory name and not the xpcom dll name
   *lastSlash = 0;
+#endif // MOZ_B2G_LOADER
 
   rv = XPCOMGlueLoadXULFunctions(kXULFuncs);
   if (NS_FAILED(rv)) {
@@ -253,7 +274,25 @@ int main(int argc, char* argv[])
   int result;
   {
     ScopedLogging log;
-    result = do_main(argc, argv);
+    char **_argv;
+
+    /*
+     * Duplicate argument vector to conform non-const argv of
+     * do_main() since XRE_main() is very stupid with non-const argv.
+     */
+    _argv = new char *[argc + 1];
+    for (int i = 0; i < argc; i++) {
+      _argv[i] = strdup(argv[i]);
+      MOZ_ASSERT(_argv[i] != nullptr);
+    }
+    _argv[argc] = nullptr;
+
+    result = do_main(argc, _argv);
+
+    for (int i = 0; i < argc; i++) {
+      free(_argv[i]);
+    }
+    delete[] _argv;
   }
 
   return result;

b2g/confvars.sh

@@ -59,6 +59,7 @@ MOZ_B2G=1
 
 if test "$OS_TARGET" = "Android"; then
 MOZ_NUWA_PROCESS=1
+MOZ_B2G_LOADER=1
 fi
 MOZ_FOLD_LIBS=1
 

configure.in

@@ -8614,6 +8614,14 @@ if test "$MOZ_WIDGET_TOOLKIT" = gonk -a -n "$MOZ_NUWA_PROCESS"; then
     AC_DEFINE(MOZ_NUWA_PROCESS)
 fi
 AC_SUBST(MOZ_NUWA_PROCESS)
+if test "$MOZ_WIDGET_TOOLKIT" = gonk -a -n "$MOZ_B2G_LOADER"; then
+    if test -z "$MOZ_NUWA_PROCESS"; then
+       AC_MSG_ERROR([B2G loader works with Nuwa]);
+    fi
+    export MOZ_B2G_LOADER
+    AC_DEFINE(MOZ_B2G_LOADER)
+fi
+AC_SUBST(MOZ_B2G_LOADER)
 
 AC_SUBST(NSPR_CFLAGS)
 AC_SUBST(NSPR_LIBS)

ipc/app/Makefile.in

@@ -37,6 +37,10 @@ include $(topsrcdir)/config/config.mk
 
 include $(topsrcdir)/config/rules.mk
 
+ifneq ($(MOZ_WIDGET_TOOLKIT),android)
+#LIBS += ../contentproc/$(LIB_PREFIX)plugin-container.$(LIB_SUFFIX)
+endif
+
 ifeq ($(OS_ARCH),WINNT) #{
 # Note the manifest file exists in the tree, so we use the explicit filename
 # here.