Add methods to enable configuration of ResourceConstraints based on limits derived at runtime.

src/platform-freebsd.cc

 // Copyright 2012 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 181 matching lines @@
     LOG(isolate SharedLibraryEvent(start_of_path, start, end));
   }
   close(fd);
 }
 
 
 void OS::SignalCodeMovingGC() {
 }
 
 
+uintptr_t OS::TotalPhysicalMemory() {
+  int pages, page_size;
+  size_t size = sizeof(pages);
+  sysctlbyname("vm.stats.vm.v_page_count", &pages, &size, NULL, 0);
+  sysctlbyname("vm.stats.vm.v_page_size", &page_size, &size, NULL, 0);
+  if (pages == -1 || page_size == -1) {
+    UNREACHABLE();
+    return 0;
+  }
+  return static_cast<uintptr_t>(pages) * page_size;
+}
+
 
 // Constants used for mmap.
 static const int kMmapFd = -1;
 static const int kMmapFdOffset = 0;
 
 
 VirtualMemory::VirtualMemory() : address_(NULL), size_(0) { }
 
 
 VirtualMemory::VirtualMemory(size_t size)
@@ skipping 118 matching lines @@
   return munmap(base, size) == 0;
 }
 
 
 bool VirtualMemory::HasLazyCommits() {
   // TODO(alph): implement for the platform.
   return false;
 }
 
 } }  // namespace v8::internal