Control the Cloud C++ client library behavior with respect to polling on long running operations.
Some operations in Cloud services return a google.longrunning.Operation object. As their name implies, these objects represent requests that may take a long time to complete, in some cases operations may take tens of seconds or even 30 minutes to complete.
The Cloud C++ client libraries models these long running operations as a google::cloud::future<StatusOr<T>>, where T represents the final result of the operation. In the background, the library polls the service until the operation completes (or fails) and then satisfies the future.
This class defines the interface for policies that control the behavior of this polling loop.
This function is called at the beginning of the polling loop. Policies that are based on relative time should restart their timers when this function is called.
Returns
Type
Description
std::unique_ptr< PollingPolicy >
OnFailure(Status const &)
A callback to indicate that a polling attempt failed.
This is called when a polling request fails. Note that this callback is not invoked when the polling request succeeds with "operation not done".
Parameter
Name
Description
status
Status const &
Returns
Type
Description
bool
true if the failure should be treated as transient and the polling loop should continue.
WaitPeriod()
How long should the polling loop wait before trying again.
[[["Easy to understand","easyToUnderstand","thumb-up"],["Solved my problem","solvedMyProblem","thumb-up"],["Other","otherUp","thumb-up"]],[["Hard to understand","hardToUnderstand","thumb-down"],["Incorrect information or sample code","incorrectInformationOrSampleCode","thumb-down"],["Missing the information/samples I need","missingTheInformationSamplesINeed","thumb-down"],["Other","otherDown","thumb-down"]],["Last updated 2025-03-05 UTC."],[[["The content provides documentation for the `PollingPolicy` class in the Google Cloud C++ client library, which is used to manage the behavior of polling loops for long-running operations."],["The latest release candidate for the library is version 2.37.0-rc, and a comprehensive list of previous versions, down to version 2.10.1, is provided for the `PollingPolicy` class."],["The `PollingPolicy` class is designed to handle `google.longrunning.Operation` objects, which represent requests that might take a considerable time to complete, and controls the polling loop for them."],["The class includes functions such as `clone()`, `OnFailure(Status const &)`, and `WaitPeriod()`, which allow for customization of the polling behavior, such as restarting timers, handling failures, and setting the wait time between polls."],["The `PollingPolicy` class uses a `google::cloud::future` to model the long-running operations as they become completed, along with a callback system to indicate the failure of a polling attempt."]]],[]]
