This package contains an implementation of a remote_mutex to be used by many different nodes. There are some rare cases when a common resource needs to be shared but used with mutual exclusion. Each mutex has a unique name through-out the system.

Mutex Guard

The mutex guard is a single node and guards a single mutex. To start a mutex guard run

rosrun remote_mutex mutex nameOfMutex

Use the mutex in your node

To use the mutex, you have to first add to manifest.xml a dependency to this package and to the CMakeLists.txt to link the executable with the RemoteMutex library.

In the code you should include

#include "remote_mutex/RemoteMutex.h"

and then create an RemoteMutex object

RemoteMutex mutex("nameOfMutex");

the new object can now be used to lock, unlock or get the status of the remote mutex using the object's methods.

For example by calling

mutex.lock();

The call blocks until it can locked. Note that you can set a maximum amount of time to wait. For example,

bool locked = mutex.lock(ros::Duration(2));

will try to lock for 2 minutes. If it fails, then it will return false.

For the full documentation see API.

Technical Information

The remote mutex implementation is based on a single service that the mutex guard serves. The mutex clients lock and unlock the mutex by calling a service (this is done by the RemoteMutex implementation).