Have exception name end in Error; Update the docs.

Update the docstrings and changelog, have the new exception name
end in Error rather than Exception.

ChangeLog.md

diff --git a/ChangeLog.md b/ChangeLog.md
index 84f2483..6adc8d4 100644
--- a/ChangeLog.md
+++ b/ChangeLog.md
@@ -2,8 +2,10 @@
 
 * Adds an optional `portserver_address` parameter to `pick_unused_port()` so
   that callers can specify their own regardless of `os.environ`.
-* Fall back to `AF_INET` when `AF_UNIX` is not available to communicate with
-  a portserver.
+* `pick_unused_port()` now raises `NoFreePortFoundError` when no available port
+  could be found rather than spinning in a loop trying forever.
+* Fall back to `socket.AF_INET` when `socket.AF_UNIX` support is not available
+  to communicate with a portserver.
 
 ## 1.2.0
 

src/portpicker.py

diff --git a/src/portpicker.py b/src/portpicker.py
index cd92952..7636733 100644
--- a/src/portpicker.py
+++ b/src/portpicker.py
@@ -61,7 +61,7 @@
 _random_ports = set()
 
 
-class NoFreePortFoundException(Exception):
+class NoFreePortFoundError(Exception):
     """Exception indicating that no free port could be found."""
     pass
 
@@ -145,17 +145,18 @@
       pid: PID to tell the portserver to associate the reservation with. If
         None, the current process's PID is used.
       portserver_address: The address (path) of a unix domain socket
-        with which to connect to a portserver.  A leading '@'
-        character indicates an address in the "abstract namespace." If
-        None, or no port is returned by the portserver at the provided
+        with which to connect to a portserver, a leading '@'
+        character indicates an address in the "abstract namespace".  OR
+        On systems without socket.AF_UNIX, this is an AF_INET address.
+        If None, or no port is returned by the portserver at the provided
         address, the environment will be checked for a PORTSERVER_ADDRESS
-        variable. If that's not set, no port server will be used.
+        variable.  If that is not set, no port server will be used.
 
     Returns:
       A port number that is unused on both TCP and UDP.
 
     Raises:
-      NoFreePortFoundException: No free port could be found.
+      NoFreePortFoundError: No free port could be found.
     """
     if _free_ports:
         port = _free_ports.pop()
@@ -188,7 +189,7 @@
       A port number that is unused on both TCP and UDP.
 
     Raises:
-      NoFreePortFoundException: No free port could be found.
+      NoFreePortFoundError: No free port could be found.
     """
     # Try random ports first.
     rng = random.Random()
@@ -210,7 +211,7 @@
             return port
 
     # Give up.
-    raise NoFreePortFoundException()
+    raise NoFreePortFoundError()
 
 
 def get_port_from_port_server(portserver_address, pid=None):
@@ -227,6 +228,7 @@
       portserver_address: The address (path) of a unix domain socket
         with which to connect to the portserver.  A leading '@'
         character indicates an address in the "abstract namespace."
+        On systems without socket.AF_UNIX, this is an AF_INET address.
       pid: The PID to tell the portserver to associate the reservation with.
         If None, the current process's PID is used.
 

src/tests/portpicker_test.py

diff --git a/src/tests/portpicker_test.py b/src/tests/portpicker_test.py
index 8220ca0..ccc5500 100644
--- a/src/tests/portpicker_test.py
+++ b/src/tests/portpicker_test.py
@@ -205,7 +205,7 @@
             for _ in range(100):
                 try:
                     port = portpicker._pick_unused_port_without_server()
-                except portpicker.NoFreePortFoundException:
+                except portpicker.NoFreePortFoundError:
                     continue
                 else:
                     got_at_least_one_port = True