Merge "libbinder(_ndk): document getService" am: 36937323

    static const int DUMP_FLAG_PROTO = 1 << 4;

    /**

     * Retrieve an existing service, blocking for a few seconds

     * if it doesn't yet exist.

     * Retrieve an existing service, blocking for a few seconds if it doesn't yet exist. This

     * does polling. A more efficient way to make sure you unblock as soon as the service is

     * available is to use waitForService or to use service notifications.

     *

     * Warning: when using this API, typically, you should call it in a loop. It's dangerous to

     * assume that nullptr could mean that the service is not available. The service could just

     * be starting. Generally, whether a service exists, this information should be declared

     * externally (for instance, an Android feature might imply the existence of a service,

     * a system property, or in the case of services in the VINTF manifest, it can be checked

     * with isDeclared).

     */

    virtual sp<IBinder>         getService( const String16& name) const = 0;

/**

 * Gets a binder object with this specific instance name. Blocks for a couple of seconds waiting on

 * it. This also implicitly calls AIBinder_incStrong (so the caller of this function is responsible

 * for calling AIBinder_decStrong).

 * for calling AIBinder_decStrong). This does polling. A more efficient way to make sure you

 * unblock as soon as the service is available is to use AIBinder_waitForService.

 *

 * WARNING: when using this API across an APEX boundary, do not use with unstable

 * AIDL services. TODO(b/139325195)

 *

 * WARNING: when using this API, typically, you should call it in a loop. It's dangerous to

 * assume that nullptr could mean that the service is not available. The service could just

 * be starting. Generally, whether a service exists, this information should be declared

 * externally (for instance, an Android feature might imply the existence of a service,

 * a system property, or in the case of services in the VINTF manifest, it can be checked

 * with AServiceManager_isDeclared).

 *

 * \param instance identifier of the service used to lookup the service.

 */

__attribute__((warn_unused_result)) AIBinder* AServiceManager_getService(const char* instance)