Re: boost::recursive_mutex for thread-safe logging crashing

From: bill_kempf (williamkempf_at_[hidden])
Date: 2002-09-03 10:32:02

--- In Boost-Users_at_y..., "Ani Taggu" <yg-boost-users_at_m...> wrote:
> Hello:
> 
> I have a simple class to do simple thread-safe logging using 
recursive_mutex
> as shown below. The problem is, once in a while, it causes any 
thread to die
> while it tries to log. I haven't been able to isolate why this 
happens. Is
> recursive_mutex being used correctly?

I'm not sure I can answer why threads would "die".  I'm going to 
assume there's an exception being thrown in the thread, but that's 
just a guess.

I will comment on your logger, though.  It's flawed.  The stream 
library provided on your platform/compiler already provide the level 
of thread synchronization that your logger does.  The problem is 
that this level of thread synchronization granularity is not 
enough.  Consider your use case:

TheLog() << "Hello World" << endl;

The stream is synchronized when outputting "Hello World" and when 
outputting the "endl" manipulator, but not between these two 
seperate calls.  This means your output can be interleaved, and 
basically be unreadable because of this.  You really want to make 
the entire output sequence syncrhonized.

I'm also uncertain why you'd use a recursive_mutex in this case?

Bill Kempf