Helper types and functions to report unrecoverable errors. More...

Typedefs
using	google::cloud::TerminateHandler = std::function< void(char const *msg)>
	Terminate handler. More...

Functions
TerminateHandler	google::cloud::SetTerminateHandler (TerminateHandler f)
	Install terminate handler and get the old one atomically. More...

TerminateHandler	google::cloud::GetTerminateHandler ()
	Get the currently installed handler. More...

void	google::cloud::Terminate (char const *msg)
	Invoke the currently installed handler. More...

Detailed Description

Helper types and functions to report unrecoverable errors.

In some rare cases, the client libraries may need to terminate the application because it encounters an unrecoverable error. For example:

If the application calls StatusOr<T>::value(), and the library was compiled with exceptions disabled, and the StatusOr<T> contains an error, then the function throws an exception to report the error as the function cannot return a valid value. Applications that disable exceptions should query the StatusOr<T> status (using .ok() or .status()) and avoid calling .value() if the StatusOr<T> is holding an error.
If the application calls future<T>::get(), the library was compiled with exceptions disabled, and (somehow) the future is satisfied with an exception. Note that the library APIs typically return future<StatusOr<T>> to avoid this problem, but the application may have created future<T> and promise<T> pairs in their own code.

In these cases there is no mechanism to return the error. The library cannot continue working correctly and must terminate the program. The application may want to intercept these errors, before the application crashes, and log or otherwise capture additional information to help with debugging or troubleshooting. The functions in this module can be used to do so.

By their nature, there is no mechanism to "handle" and "recover" from unrecoverable errors. All the application can do is log additional information before the program terminates.

Note that the libraries do not use functions that can trigger unrecoverable errors (if they do we consider that a library bug).

The default behavior in the client library is to call std::abort() when an unrecoverable error occurs.

Typedef Documentation

◆ TerminateHandler

using google::cloud::TerminateHandler = typedef std::function<void(char const* msg)>

Terminate handler.

It should handle the error, whose description are given in msg and should never return.

Function Documentation

◆ GetTerminateHandler()

TerminateHandler google::cloud::GetTerminateHandler ( )

Get the currently installed handler.

Returns: The currently installed handler.

◆ SetTerminateHandler()

TerminateHandler google::cloud::SetTerminateHandler ( TerminateHandler f )

Install terminate handler and get the old one atomically.

Parameters

f	the handler. It should never return, behaviour is undefined otherwise.

Returns: Previously set handler.

◆ Terminate()

void google::cloud::Terminate ( char const * msg )

Invoke the currently installed handler.