Set up NaClChromeMainArgs number_of_cores member so apps can size threadpools appropriately

The outer sandbox on Linux and OSX was preventing
sysconf(_SC_NPROCESSORS_ONLN) from succeeding, so that NaCl
applications that need the number of threads were getting a
bogus value (-1 when using newlib, and 1 when using glibc).

TEST= run_sysconf_nprocessors_onln_test
BUG= 176522

Review URL: https://chromiumcodereview.appspot.com/14238013

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@195190 0039d316-1c4b-4281-b951-d872f2087c98

4 files changed, 40 insertions, 4 deletions

diff --git a/chrome/nacl/nacl_helper_linux.cc b/chrome/nacl/nacl_helper_linux.cc
index 53c2fb30..a066db7 100644
--- a/chrome/nacl/nacl_helper_linux.cc
+++ b/chrome/nacl/nacl_helper_linux.cc
@@ -40,7 +40,8 @@ namespace {
 //   if (!child) {
 // Note: this code doesn't attempt to support SELINUX or the SECCOMP sandbox.
 void BecomeNaClLoader(const std::vector<int>& child_fds,
-                      size_t prereserved_sandbox_size) {
+                      size_t prereserved_sandbox_size,
+                      int number_of_cores) {
   VLOG(1) << "NaCl loader: setting up IPC descriptor";
   // don't need zygote FD any more
   if (HANDLE_EINTR(close(kNaClZygoteDescriptor)) != 0)
@@ -51,6 +52,7 @@ void BecomeNaClLoader(const std::vector<int>& child_fds,
   MessageLoopForIO main_message_loop;
   NaClListener listener;
   listener.set_prereserved_sandbox_size(prereserved_sandbox_size);
+  listener.set_number_of_cores(number_of_cores);
   listener.Listen();
   _exit(0);
 }
@@ -58,7 +60,8 @@ void BecomeNaClLoader(const std::vector<int>& child_fds,
 // Some of this code was lifted from
 // content/browser/zygote_main_linux.cc:ForkWithRealPid()
 void HandleForkRequest(const std::vector<int>& child_fds,
-                       size_t prereserved_sandbox_size) {
+                       size_t prereserved_sandbox_size,
+                       int number_of_cores) {
   VLOG(1) << "nacl_helper: forking";
   pid_t childpid = fork();
   if (childpid < 0) {
@@ -96,7 +99,7 @@ void HandleForkRequest(const std::vector<int>& child_fds,
     if (HANDLE_EINTR(close(child_fds[kNaClParentFDIndex])) != 0)
       LOG(ERROR) << "close(child_fds[kNaClParentFDIndex]) failed";
     if (validack) {
-      BecomeNaClLoader(child_fds, prereserved_sandbox_size);
+      BecomeNaClLoader(child_fds, prereserved_sandbox_size, number_of_cores);
     } else {
       LOG(ERROR) << "Failed to synch with zygote";
     }
@@ -236,6 +239,7 @@ int main(int argc, char* argv[]) {
 #endif
   std::vector<int> empty; // for SendMsg() calls
   size_t prereserved_sandbox_size = CheckReservedAtZero();
+  int number_of_cores = sysconf(_SC_NPROCESSORS_ONLN);
 
   CheckRDebug(argv[0]);
 
@@ -272,7 +276,7 @@ int main(int argc, char* argv[]) {
     } else if (msglen == sizeof(kNaClForkRequest) - 1 &&
                memcmp(buf, kNaClForkRequest, msglen) == 0) {
       if (kNaClParentFDIndex + 1 == fds.size()) {
-        HandleForkRequest(fds, prereserved_sandbox_size);
+        HandleForkRequest(fds, prereserved_sandbox_size, number_of_cores);
         continue;  // fork succeeded. Note: child does not return
       } else {
         LOG(ERROR) << "nacl_helper: unexpected number of fds, got "
diff --git a/chrome/nacl/nacl_listener.cc b/chrome/nacl/nacl_listener.cc
index 5f3ced4..477be0e 100644
--- a/chrome/nacl/nacl_listener.cc
+++ b/chrome/nacl/nacl_listener.cc
@@ -7,6 +7,10 @@
 #include <errno.h>
 #include <stdlib.h>
 
+#if defined(OS_POSIX)
+#include <unistd.h>
+#endif
+
 #include "base/command_line.h"
 #include "base/logging.h"
 #include "base/memory/scoped_ptr.h"
@@ -141,6 +145,9 @@ NaClListener::NaClListener() : shutdown_event_(true, false),
 #if defined(OS_LINUX)
                                prereserved_sandbox_size_(0),
 #endif
+#if defined(OS_POSIX)
+                               number_of_cores_(-1),  // unknown/error
+#endif
                                main_loop_(NULL) {
   io_thread_.StartWithOptions(base::Thread::Options(MessageLoop::TYPE_IO, 0));
 #if defined(OS_WIN)
@@ -226,6 +233,7 @@ void NaClListener::OnStart(const nacl::NaClStartParams& params) {
     LOG(ERROR) << "Failed to dup() the urandom FD";
     return;
   }
+  args->number_of_cores = number_of_cores_;
   args->create_memory_object_func = CreateMemoryObject;
 # if defined(OS_MACOSX)
   CHECK(handles.size() >= 1);
diff --git a/chrome/nacl/nacl_listener.h b/chrome/nacl/nacl_listener.h
index 20e3e78..66627c0 100644
--- a/chrome/nacl/nacl_listener.h
+++ b/chrome/nacl/nacl_listener.h
@@ -34,6 +34,11 @@ class NaClListener : public IPC::Listener {
     prereserved_sandbox_size_ = prereserved_sandbox_size;
   }
 #endif
+#if defined(OS_POSIX)
+  void set_number_of_cores(int number_of_cores) {
+    number_of_cores_ = number_of_cores;
+  }
+#endif
 
  private:
   void OnStart(const nacl::NaClStartParams& params);
@@ -51,6 +56,16 @@ class NaClListener : public IPC::Listener {
 #if defined(OS_LINUX)
   size_t prereserved_sandbox_size_;
 #endif
+#if defined(OS_POSIX)
+  /*
+   * The outer sandbox on Linux and OSX prevents
+   * sysconf(_SC_NPROCESSORS) from working; in Windows, there are no
+   * problems with invoking GetSystemInfo.  Therefore, only in
+   * OS_POSIX do we need to supply the number of cores into
+   * NaClChromeMainArgs object.
+   */
+  int number_of_cores_;
+#endif
 
   // Used to identify what thread we're on.
   MessageLoop* main_loop_;
diff --git a/chrome/nacl/nacl_main.cc b/chrome/nacl/nacl_main.cc
index 9b7a8c6..a7c1124 100644
--- a/chrome/nacl/nacl_main.cc
+++ b/chrome/nacl/nacl_main.cc
@@ -33,6 +33,12 @@ int NaClMain(const content::MainFunctionParams& parameters) {
   bool no_sandbox = parsed_command_line.HasSwitch(switches::kNoSandbox);
   platform.InitSandboxTests(no_sandbox);
 
+#if defined(OS_POSIX)
+  // The number of cores must be obtained before the invocation of
+  // platform.EnableSandbox(), so cannot simply be inlined below.
+  int number_of_cores = sysconf(_SC_NPROCESSORS_ONLN);
+#endif
+
   if (!no_sandbox) {
     platform.EnableSandbox();
   }
@@ -40,6 +46,9 @@ int NaClMain(const content::MainFunctionParams& parameters) {
 
   if (sandbox_test_result) {
     NaClListener listener;
+#if defined(OS_POSIX)
+    listener.set_number_of_cores(number_of_cores);
+#endif
     listener.Listen();
   } else {
     // This indirectly prevents the test-harness-success-cookie from being set,