Thread IO safety: annotate file_util, and block IO thread from doing IO

- Mark functions in file_util_posix as requiring permission to perform
  disk actions.
- Mark the IO thread as disallowed from performing disk actions.
- Temporarily work around the protections in places where we currently
  have bugs.

BUG=59847,59849,60207,60211
TEST=no dchecks in debug builds

Review URL: http://codereview.chromium.org/3872002

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@63600 0039d316-1c4b-4281-b951-d872f2087c98

2 files changed, 15 insertions, 1 deletions

diff --git a/net/socket/ssl_client_socket_nss.cc b/net/socket/ssl_client_socket_nss.cc
index 136f138..324f50c 100644
--- a/net/socket/ssl_client_socket_nss.cc
+++ b/net/socket/ssl_client_socket_nss.cc
@@ -71,6 +71,7 @@
 #include "base/string_number_conversions.h"
 #include "base/string_util.h"
 #include "base/stringprintf.h"
+#include "base/thread_restrictions.h"
 #include "base/values.h"
 #include "net/base/address_list.h"
 #include "net/base/cert_status_flags.h"
@@ -176,6 +177,11 @@ class NSSSSLInitSingleton {
 // thread-safe, and the NSS SSL library will only ever be initialized once.
 // The NSS SSL library will be properly shut down on program exit.
 void EnsureNSSSSLInit() {
+  // Initializing SSL causes us to do blocking IO.
+  // Temporarily allow it until we fix
+  //   http://code.google.com/p/chromium/issues/detail?id=59847
+  base::ThreadRestrictions::ScopedAllowIO allow_io;
+
   Singleton<NSSSSLInitSingleton>::get();
 }
 
diff --git a/net/url_request/url_request_file_job.cc b/net/url_request/url_request_file_job.cc
index 8c282ff..f9c6559 100644
--- a/net/url_request/url_request_file_job.cc
+++ b/net/url_request/url_request_file_job.cc
@@ -23,6 +23,7 @@
 #include "base/message_loop.h"
 #include "base/platform_file.h"
 #include "base/string_util.h"
+#include "base/thread_restrictions.h"
 #include "build/build_config.h"
 #include "googleurl/src/gurl.h"
 #include "net/base/io_buffer.h"
@@ -128,8 +129,15 @@ void URLRequestFileJob::Start() {
     return;
   }
 #endif
+
+  // URL requests should not block on the disk!
+  //   http://code.google.com/p/chromium/issues/detail?id=59849
+  bool exists;
   base::PlatformFileInfo file_info;
-  bool exists = file_util::GetFileInfo(file_path_, &file_info);
+  {
+    base::ThreadRestrictions::ScopedAllowIO allow_io;
+    exists = file_util::GetFileInfo(file_path_, &file_info);
+  }
 
   // Continue asynchronously.
   MessageLoop::current()->PostTask(FROM_HERE, NewRunnableMethod(