Hi,
see audit trail for details. I tested on x86_64-linux (with/without
_GLIBCXX_X86_RDRAND artificially undefined) the below straightforward
patch and checked by hand the strace. I'm going to apply it soon.
Thanks,
Paolo.
///////////////////
2013-07-22 Paolo Carlini <paolo.carl...@oracle.com>
PR c++/57920
* src/c++11/random.cc (random_device::_M_getval): If possible, use
read instead of std::fread.
* include/std/random: Do not include <cstdio> unnecessarily.
Index: include/std/random
===================================================================
--- include/std/random (revision 201122)
+++ include/std/random (working copy)
@@ -36,7 +36,6 @@
#else
#include <cmath>
-#include <cstdio>
#include <cstdlib>
#include <string>
#include <iosfwd>
Index: src/c++11/random.cc
===================================================================
--- src/c++11/random.cc (revision 201122)
+++ src/c++11/random.cc (working copy)
@@ -30,7 +30,12 @@
# include <cpuid.h>
#endif
+#include <cstdio>
+#ifdef _GLIBCXX_HAVE_UNISTD_H
+# include <unistd.h>
+#endif
+
namespace std _GLIBCXX_VISIBILITY(default)
{
@@ -126,8 +131,12 @@
#endif
result_type __ret;
+#ifdef _GLIBCXX_HAVE_UNISTD_H
+ read(fileno(_M_file), reinterpret_cast<void*>(&__ret),
sizeof(result_type));
+#else
std::fread(reinterpret_cast<void*>(&__ret), sizeof(result_type),
1, _M_file);
+#endif
return __ret;
}
