/// <summary>
/// Method to force the refresh of a cached secret state.
/// Returns true if the refresh completed without error.
/// </summary>
public async Task <bool> RefreshNowAsync()
{
refreshNeeded = true;
// When forcing a refresh, always sleep with a random jitter
// to prevent coding errors that could be calling refreshNow
// in a loop.
long sleep = FORCE_REFRESH_JITTERED_DELAY.GetRetryDelay(1).Milliseconds;
// Make sure we are not waiting for the next refresh after an
// exception. If we are, sleep based on the retry delay of
// the refresh to prevent a hard loop in attempting to refresh a
// secret that continues to throw an exception such as AccessDenied.
if (null != exception)
{
long wait = nextRetryTime - Environment.TickCount;
sleep = Math.Max(wait, sleep);
}
Thread.Sleep((int)sleep);
// Perform the requested refresh.
bool success = false;
await Lock.WaitAsync();
try
{
success = await RefreshAsync();
}
finally
{
Lock.Release();
}
return(null == exception && success);
}
/// <summary>
/// Refresh the cached secret state only when needed.
/// </summary>
private async Task <bool> RefreshAsync()
{
if (!IsRefreshNeeded())
{
return(false);
}
refreshNeeded = false;
try
{
SetResult(await ExecuteRefreshAsync());
exception = null;
exceptionCount = 0;
return(true);
}
catch (Exception ex) when(ex is AmazonServiceException || ex is AmazonClientException)
{
exception = ex;
// Determine the amount of growth in exception backoff time based on the growth
// factor and default backoff duration.
nextRetryTime = Environment.TickCount + EXCEPTION_JITTERED_DELAY.GetRetryDelay((int)exceptionCount).Milliseconds;
}
return(false);
}