[PATCH] Add timeout to _poll_loop function to avoid infinite looping

[Jiri Prochazka]

When Slave is using NetworkManager, polling is used to activate DBus connection.
This may result in infinite loop (eg. when device is not in LOWER_UP state, but is in UP state).
This patch adds timeout control in _poll_loop method, timeout value is set to 10s.

Signed-off-by: Jiri Prochazka 
---
 lnst/Slave/NmConfigDevice.py | 8 ++++++--
 1 file changed, 6 insertions(+), 2 deletions(-)

diff --git a/lnst/Slave/NmConfigDevice.py b/lnst/Slave/NmConfigDevice.py
index 8e2f1dd..3da54f1 100644
--- a/lnst/Slave/NmConfigDevice.py
+++ b/lnst/Slave/NmConfigDevice.py
@@ -153,10 +153,14 @@ class NmConfigDeviceGeneric(object):
             self._loop.quit()

def _poll_loop(self, func, expected_val, *args):
-        while True:
+        timer = 0
+        while timer < 10:
             if func(*args) == expected_val:
-                break
+                return
             time.sleep(1)
+            timer += 1
+        msg = "Timed out during NetworkManager polling."
+        raise Exception(msg)

def _convert_hwaddr(self, dev_config):
         if "hwaddr" in dev_config:

[Ondrej Lichtner]

On Mon, Jun 29, 2015 at 04:06:40PM +0200, Jiri Prochazka wrote:
> When Slave is using NetworkManager, polling is used to activate DBus connection.
> This may result in infinite loop (eg. when device is not in LOWER_UP state, but is in UP state).
> This patch adds timeout control in _poll_loop method, timeout value is set to 10s.
> Signed-off-by: Jiri Prochazka
>
> lnst/Slave/NmConfigDevice.py | 8 ++++++--
>  1 file changed, 6 insertions(+), 2 deletions(-)
>
> diff --git a/lnst/Slave/NmConfigDevice.py b/lnst/Slave/NmConfigDevice.py
> index 8e2f1dd..3da54f1 100644
> --- a/lnst/Slave/NmConfigDevice.py
> +++ b/lnst/Slave/NmConfigDevice.py
> @@ -153,10 +153,14 @@ class NmConfigDeviceGeneric(object):
>              self._loop.quit()
>  def _poll_loop(self, func, expected_val, *args):
>    while True:
>    timer = 0
>    while timer < 10:

^^^^
This should be a parameter of the function not just a random constant...
And there should be a defult value constant at the start of the file
where other NM related constants are defined.
>          if func(*args) == expected_val:
>            break
>            return
>        time.sleep(1)
>        timer += 1
>    msg = "Timed out during NetworkManager polling."
>    raise Exception(msg)
>
> def _convert_hwaddr(self, dev_config):
>        if "hwaddr" in dev_config:
>
> -- 
> 2.4.3
>
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