bind(0) before probing for random available ports. (#28)
When not using a portserver, assume that the OS knows best. This
should improve reliability.
Though the best thing to do is to use a portserver...
diff --git a/ChangeLog.md b/ChangeLog.md
index 8ca7f80..3cda728 100644
--- a/ChangeLog.md
+++ b/ChangeLog.md
@@ -1,3 +1,9 @@
+## 1.5.1
+
+* When not using a portserver *(you really should)*, try the `bind(0)`
+ approach before hunting for random unused ports. More reliable per
+ https://github.com/google/python_portpicker/issues/16.
+
## 1.5.0
* Add portserver support to Windows using named pipes. To create or connect to
diff --git a/setup.cfg b/setup.cfg
index 6a1e788..63c1ac4 100644
--- a/setup.cfg
+++ b/setup.cfg
@@ -1,7 +1,7 @@
# https://setuptools.readthedocs.io/en/latest/setuptools.html#configuring-setup-using-setup-cfg-files
[metadata]
name = portpicker
-version = 1.5.0
+version = 1.5.1b1
maintainer = Google LLC
maintainer_email = greg@krypto.org
license = Apache 2.0
diff --git a/src/portpicker.py b/src/portpicker.py
index 4717bbc..fc2825b 100644
--- a/src/portpicker.py
+++ b/src/portpicker.py
@@ -198,14 +198,6 @@
Raises:
NoFreePortFoundError: No free port could be found.
"""
- # Try random ports first.
- rng = random.Random()
- for _ in range(10):
- port = int(rng.randrange(15000, 25000))
- if is_port_free(port):
- _random_ports.add(port)
- return port
-
# Next, try a few times to get an OS-assigned port.
# Ambrose discovered that on the 2.6 kernel, calling Bind() on UDP socket
# returns the same port over and over. So always try TCP first.
@@ -217,6 +209,14 @@
_random_ports.add(port)
return port
+ # Try random ports as a last resort.
+ rng = random.Random()
+ for _ in range(10):
+ port = int(rng.randrange(15000, 25000))
+ if is_port_free(port):
+ _random_ports.add(port)
+ return port
+
# Give up.
raise NoFreePortFoundError()
