FileDescriptor: passing fds over IPC

This patch introduces a FileDescriptor object which can be included in IPC messages and will perform the magic needed to pass file descriptors over IPC. After some consideration, Windows will continue to do the current DuplicateHandle tricks.

Review URL: http://codereview.chromium.org/20027


git-svn-id: svn://svn.chromium.org/chrome/trunk/src@9369 0039d316-1c4b-4281-b951-d872f2087c98

1 files changed, 32 insertions, 0 deletions

diff --git a/chrome/common/ipc_message_utils.h b/chrome/common/ipc_message_utils.h
index 64f5653..7887dcc 100644
--- a/chrome/common/ipc_message_utils.h
+++ b/chrome/common/ipc_message_utils.h
@@ -12,6 +12,9 @@
 #include "base/file_path.h"
 #include "base/string_util.h"
 #include "base/tuple.h"
+#if defined(OS_POSIX)
+#include "chrome/common/file_descriptor_posix.h"
+#endif
 #include "chrome/common/ipc_sync_message.h"
 #include "chrome/common/thumbnail_score.h"
 #include "webkit/glue/cache_manager.h"
@@ -662,6 +665,35 @@ struct ParamTraits<gfx::Size> {
   static void Log(const param_type& p, std::wstring* l);
 };
 
+#if defined(OS_POSIX)
+
+template<>
+struct ParamTraits<FileDescriptor> {
+  typedef FileDescriptor param_type;
+  static void Write(Message* m, const param_type& p) {
+    if (p.auto_close) {
+      m->descriptor_set()->AddAndAutoClose(p.fd);
+    } else {
+      m->descriptor_set()->Add(p.fd);
+    }
+  }
+  static bool Read(const Message* m, void** iter, param_type* r) {
+    r->auto_close = false;
+    r->fd = m->descriptor_set()->NextDescriptor();
+
+    return r->fd >= 0;
+  }
+  static void Log(const param_type& p, std::wstring* l) {
+    if (p.auto_close) {
+      l->append(StringPrintf(L"FD(%d auto-close)", p.fd));
+    } else {
+      l->append(StringPrintf(L"FD(%d)", p.fd));
+    }
+  }
+};
+
+#endif // defined(OS_POSIX)
+
 template<>
 struct ParamTraits<ThumbnailScore> {
   typedef ThumbnailScore param_type;