Re: [Boost-bugs] [Boost C++ Libraries] #10980: boost::random::random_device bug with /dev/random

Subject: Re: [Boost-bugs] [Boost C++ Libraries] #10980: boost::random::random_device bug with /dev/random
From: Boost C++ Libraries (noreply_at_[hidden])
Date: 2015-01-29 08:11:08

#10980: boost::random::random_device bug with /dev/random
-------------------------------------------------+-------------------------
  Reporter:  Bastiaan Stougie                    |      Owner:  no-
  <bastiaan.stougie@…>                           |  maintainer
      Type:  Bugs                                |     Status:  new
 Milestone:  To Be Determined                    |  Component:  random
   Version:  Boost 1.56.0                        |   Severity:  Problem
Resolution:                                      |   Keywords:
                                                 |  random_device
-------------------------------------------------+-------------------------

Comment (by Bastiaan Stougie <bastiaan.stougie@…>):

 Here's a patch:

 {{{

 diff --git a/libs/random/src/random_device.cpp
 b/libs/random/src/random_device.cpp
 --- a/libs/random/src/random_device.cpp
 +++ b/libs/random/src/random_device.cpp
 @@ -168,13 +168,17 @@

    unsigned int next() {
          unsigned int result;
     -    long sz = read(fd, reinterpret_cast<char *>(&result),
 sizeof(result));
     -    if(sz == -1)
     -      error("error while reading");
     -    else if(sz != sizeof(result)) {
     -      errno = 0;
     -      error("EOF while reading");
     -    }
     +    size_t offset = 0;
     +    do {
     +      long sz = read(fd, reinterpret_cast<char *>(&result) + offset,
 sizeof(result) - offset);
     +      if(sz == -1)
     +        error("error while reading");
     +      else if(sz == 0) {
     +        errno = 0;
     +        error("EOF while reading");
     +      }
     +      offset += sz;
     +    } while (offset < sizeof(result));
          return result;
        }

 }}}

-- 
Ticket URL: <https://svn.boost.org/trac/boost/ticket/10980#comment:1>
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