Re: Review Request 35395: Improvements to the synchronized macro.

[Michael Park <mc...@gmail.com>]

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This is an automatically generated e-mail. To reply, visit:
https://reviews.apache.org/r/35395/
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(Updated June 14, 2015, 2:20 a.m.)


Review request for mesos, Benjamin Hindman and Joris Van Remoortere.


Summary (updated)
-----------------

Improvements to the synchronized macro.


Repository: mesos


Description
-------

(1) Simplify introducing new synchronization primitives.

Before:

```cpp
template <>
class Synchronized<bufferevent>
{
public:
  Synchronized(bufferevent* _bev) : bev(CHECK_NOTNULL(_bev))
  {
    bufferevent_lock(bev);
  }
  
  Synchronized(bufferevent** _bev) : Synchronized(*CHECK_NOTNULL(_bev)) {}
  
  ~Synchronized()
  {
    bufferevent_unlock(bev);
  }
  
  operator bool() const { return true; }

private:
  bufferevent* bev;
};
```

After:

```cpp
Synchronized<bufferevent> synchronize(bufferevent* bev) {
  return {
    bev,
    [](bufferevent* bev) { bufferevent_lock(bev); }
    [](bufferevent* bev) { bufferevent_unlock(bev); }
  };
}
```

(2) Enable `return` within `synchronized` and avoid the `control reaches end of non-void function` warning.

```cpp
int foo()
{
  int x = 42;
  std::mutex m;
  synchronized (m) {
    return x;
  }
}
```


Diffs
-----

  3rdparty/libprocess/3rdparty/stout/include/stout/synchronized.hpp 60eaf263f220b4990aefe4e5d6d2aa1296891e57 

Diff: https://reviews.apache.org/r/35395/diff/


Testing
-------

`make check`


Thanks,

Michael Park