Base: WritePlatformFile now retries the operation if

base/platform_file.h

Index: base/platform_file.h
===================================================================
--- base/platform_file.h	(revision 97736)
+++ base/platform_file.h	(working copy)
@@ -123,7 +123,8 @@
 
 // Writes the given buffer into the file at the given offset, overwritting any
 // data that was previously there. Returns the number of bytes written, or -1
-// on error.
+// on error. Note that this function automatically retries writing if it is

[darin (slow to review), 2011/08/25 23:54:24]

Is this to match the behavior of Windows?  If so, does that mean that this
change is about ensuring that, on all platforms, all of the given data will be
written unless there is an error?

[rvargas (doing something else), 2011/08/26 00:09:36]

Something like that. I have another code review where I'm using
WritePlatformFile, and this issue came afloat. I don't think it makes sense to
ask all users of Write() to have loops to make sure that the operation succeeds,
even if all OSes were behaving the same way regarding signals (actually, if all
OSes were doing it, maybe that would be the familiar thing to do, dunno).

I was just thinking that maybe we should add something like ReadUntilComplete()
to this file to be more symmetric. Maybe in a follow-up cl?

+// expected for the underlying platform to write less data than |size|.
 BASE_EXPORT int WritePlatformFile(PlatformFile file, int64 offset,
                                   const char* data, int size);