Patch for allowing several V8 instances in process:...

src/flags.cc

 // Copyright 2006-2008 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 320 matching lines @@
 
 
 static Flag* FindFlag(const char* name) {
   for (size_t i = 0; i < num_flags; ++i) {
     if (EqualNames(name, flags[i].name()))
       return &flags[i];
   }
   return NULL;
 }
 
+static MutexLockAdapter flag_list_lock(OS::CreateMutex());
 
 // static
 int FlagList::SetFlagsFromCommandLine(int* argc,
                                       char** argv,
                                       bool remove_flags) {
+  V8SharedStateLocker flags_list_locker(&flag_list_lock);
   // parse arguments
   for (int i = 1; i < *argc;) {
     int j = i;  // j > 0
     const char* arg = argv[i++];
 
     // split arg into flag components
     char buffer[1*KB];
     const char* name;
     const char* value;
     bool is_bool;
@@ skipping 106 matching lines @@
 
 
 static char* SkipBlackSpace(char* p) {
   while (*p != '\0' && isspace(*p) == 0) p++;
   return p;
 }
 
 
 // static
 int FlagList::SetFlagsFromString(const char* str, int len) {
+  V8SharedStateLocker flags_list_locker(&flag_list_lock);
   // make a 0-terminated copy of str
   char* copy0 = NewArray<char>(len + 1);
   memcpy(copy0, str, len);
   copy0[len] = '\0';
 
   // strip leading white space
   char* copy = SkipWhiteSpace(copy0);
 
   // count the number of 'arguments'
   int argc = 1;  // be compatible with SetFlagsFromCommandLine()
@@ skipping 64 matching lines @@
 const char** JSArguments::argv() { return argv_; }
 const char*& JSArguments::operator[](int idx) { return argv_[idx]; }
 JSArguments& JSArguments::operator=(JSArguments args) {
     argc_ = args.argc_;
     argv_ = args.argv_;
     return *this;
 }
 
 
 } }  // namespace v8::internal