Updated readme again

README.md

@@ -48,11 +48,12 @@ Traps are used in the main loop to break on signals
         // ...
     }
 
-## Timers
+### Timers
 
 Timers fire asynchronously at fixed 1 second intervals. It requires signals to be
 processed; see above.
 
+    // Once every second...
     $timer = new Timer(function () {
         echo ".";
     });
@@ -72,11 +73,53 @@ if (!$lock->acquire()) {
 
 ## SysV wrappers
 
+All these wrappers depend on a `KeyInterface` being passed to the constructor.
+This is usually an instance of a `FileKey`, created as such:
+
+    $key = new FileKey(__FILE__);
+
+The key has a project identifier that starts at `chr(0)`, or `"\0"`. To increase
+this identifier, and thus point to another segment, just clone it.
+
+    $key2 = clone $key1;
+
 ### Semaphores
 
 ### Mutexes
 
-### Messagae Queues
+### Message Queues
+
+    $key = new FileKey(__FILE__);
+    $msgq = new Queue($key);
+
+    $msgq->send(1, [ "Some data", [ "format"=>"foo" ]]);
+
+    $data = $msgq->receive(1, $type);
+
+    $msgq->destroy();
+
+### Shared Memory
+
+Shared memory using `SharedData` supports integrity checking when setting, using
+the third parameter to `set()`.
+
+    $key = new FileKey(__FILE__);
+    $shm = new SharedData($key);
+
+    do {
+        $counter = $shm->get("counter") + 1;
+    } while (!$shm->set("counter", $counter, true));
+
+    $shm->destroy();
+
+The `SharedMemory` class is a simple integer-indexed array
+
+    $key = new FileKey(__FILE__);
+    $shm = new SharedMemory($key);
+
+    $shm[0] = 42;    
+
+    $shm->destroy();
 
 ## Communication