tree 683ff467472aaa99dcef409cde8e07c208525e42
parent 93b0e70870ceccb8bf439617848e99fe02ea08c8
author Patrick Williams <patrick@stwcx.xyz> 1492533510 -0500
committer Patrick Williams <patrick@stwcx.xyz> 1492533513 -0500

bus: change constructor semantics

Previously, the bus object had no semantics to recognize if
it was the primary-holder of a sd_bus or a secondary one.
On destruction, the object always called 'sd_bus_unref' and it
was assumed that the sd-bus library would properly close the
bus on last-unref.  This turns out not to be true and lead to
file-descriptor leaks.

Change the constructor to mimic what is done in 'message':
  - When the constructor is called with a sd_bus*, the class becomes
    a secondary-holder and calls 'sd_bus_unref' on destruction, which
    is the old behavior.  The class also calls 'sd_bus_ref' on
    construction, so this should no longer be done by callers.

  - When the constructor is called via the new_* functions (or by
    adding a std::false_type parameter), the class becomes a primary-
    holder and calls 'sd_bus_flush_close_unref' on destruction.

Note: Current callers that use syntax like 'bus(sd_bus_ref(b))' will
      need to be updated to avoid a file-descriptor leak.

Fixes openbmc/openbmc#1432.

Change-Id: Ic0c582f8fbfd44775bcdaffa6a21518a0cd056b1
Signed-off-by: Patrick Williams <patrick@stwcx.xyz>