Merge branch '1.14' into 1.15

Conflicts:
	sites/www/changelog.rst

2 files changed, 17 insertions, 7 deletions

diff --git a/paramiko/proxy.py b/paramiko/proxy.py
index 0664ac6e..ca602c4c 100644
--- a/paramiko/proxy.py
+++ b/paramiko/proxy.py
@@ -24,6 +24,7 @@ import signal
 from subprocess import Popen, PIPE
 from select import select
 import socket
+import time
 
 from paramiko.ssh_exception import ProxyCommandFailure
 from paramiko.util import ClosingContextManager
@@ -79,20 +80,24 @@ class ProxyCommand(ClosingContextManager):
         :return: the length of the read content, as an `int`
         """
         try:
-            start = datetime.now()
+            start = time.time()
             while len(self.buffer) < size:
+                select_timeout = None
                 if self.timeout is not None:
-                    elapsed = (datetime.now() - start).microseconds
-                    timeout = self.timeout * 1000 * 1000  # to microseconds
-                    if elapsed >= timeout:
+                    elapsed = (time.time() - start)
+                    if elapsed >= self.timeout:
                         raise socket.timeout()
-                r, w, x = select([self.process.stdout], [], [], 0.0)
+                    select_timeout = self.timeout - elapsed
+
+                r, w, x = select(
+                    [self.process.stdout], [], [], select_timeout)
                 if r and r[0] == self.process.stdout:
-                    b = os.read(self.process.stdout.fileno(), 1)
+                    b = os.read(
+                        self.process.stdout.fileno(), size - len(self.buffer))
                     # Store in class-level buffer for persistence across
                     # timeouts; this makes us act more like a real socket
                     # (where timeouts don't actually drop data.)
-                    self.buffer.append(b)
+                    self.buffer.extend(b)
             result = ''.join(self.buffer)
             self.buffer = []
             return result
diff --git a/sites/www/changelog.rst b/sites/www/changelog.rst
index 4e56ad1f..bf76d984 100644
--- a/sites/www/changelog.rst
+++ b/sites/www/changelog.rst
@@ -2,6 +2,11 @@
 Changelog
 =========
 
+* :bug:`413` (also :issue:`414`, :issue:`420`, :issue:`454`) Be significantly
+  smarter about polling & timing behavior when running proxy commands, to avoid
+  unnecessary (often 100%!) CPU usage. Major thanks to Jason Dunsmore for
+  report & initial patchset and to Chris Adams & John Morrissey for followup
+  improvements.
 * :bug:`455` Tweak packet size handling to conform better to the OpenSSH RFCs;
   this helps address issues with interactive program cursors. Courtesy of Jeff
   Quast.