async Task <D2LSecurityToken> IPrivateKeyProvider.GetSigningCredentialsAsync()
{
// Hold a local reference so that we know we are talking about the same key
// after even if another thread changed m_privateKey (race condition when we
// are using a key very close to the rotation time.)
D2LSecurityToken privateKey = m_privateKey;
if (NeedFreshPrivateKey(privateKey))
{
// This Semaphore is used instead of lock(foo){}
// because await cannot be used within a lock
await m_privateKeyLock.WaitAsync().SafeAsync();
try {
privateKey = m_privateKey;
if (NeedFreshPrivateKey(privateKey))
{
m_privateKey = (await m_inner.GetSigningCredentialsAsync().SafeAsync()).Ref();
if (privateKey != null)
{
privateKey.Dispose();
}
privateKey = m_privateKey;
}
} finally {
m_privateKeyLock.Release();
}
}
return(privateKey.Ref());
}