mandoline sandbox: prewarm libraries before we raise the sandbox.

mandoline/services/core_services/main.cc

Index: mandoline/services/core_services/main.cc
diff --git a/mandoline/services/core_services/main.cc b/mandoline/services/core_services/main.cc
index ef8c8477a0e3a8494fbc3061219c48742719dd3b..91f81e5f5cb96325b5d8d4652d80da2b51f2db90 100644
--- a/mandoline/services/core_services/main.cc
+++ b/mandoline/services/core_services/main.cc
@@ -6,6 +6,30 @@
 #include "mojo/application/public/cpp/application_runner.h"
 #include "third_party/mojo/src/mojo/public/c/system/main.h"
 
+// TODO(erg): Much of this will be the same between mojo applications. Maybe we
+// could centralize this code?
+#if defined(OS_LINUX) && !defined(OS_ANDROID)
+#include "base/rand_util.h"
+#include "base/sys_info.h"
+
+// TODO(erg): Much of this was coppied from zygote_main_linux.cc
+extern "C" {
+void __attribute__((visibility("default"))) MojoSandboxWarm() {
+  base::RandUint64();

[jln (very slow on Chromium), 2015/07/29 20:28:04]

Do we still want to do that individually even though you already do it globally?

[Elliot Glaysher, 2015/07/29 21:08:32]

We don't do it globally. We do it in the copy of base that is in the shell,
which is different from the copy of base that's linked into the shared object
this function is in.

+  base::SysInfo::AmountOfPhysicalMemory();
+  base::SysInfo::MaxSharedMemorySize();
+  base::SysInfo::NumberOfProcessors();
+
+  // TODO(erg): icu does timezone initialization here.
+
+  // TODO(erg): Perform OpenSSL warmup; it wants access to /dev/urandom.
+
+  // TODO(erg): Initialize SkFontConfigInterface; it has its own odd IPC system
+  // which probably must be ported to mojo.
+}
+}
+#endif  // defined(OS_LINUX) && !defined(OS_ANDROID)
+
 MojoResult MojoMain(MojoHandle shell_handle) {
   mojo::ApplicationRunner runner(
       new core_services::CoreServicesApplicationDelegate);