Add active services count callback to lazy services.
Additionally, expose methods to tryUnregister/reRegister
services.
Bug: 176239128
Test: test aidl_lazy_test
Change-Id: I9aa3c9b681bd340ca340fe7ed818ba3533678af2
diff --git a/libs/binder/LazyServiceRegistrar.cpp b/libs/binder/LazyServiceRegistrar.cpp
index 2e15e50..1173138 100644
--- a/libs/binder/LazyServiceRegistrar.cpp
+++ b/libs/binder/LazyServiceRegistrar.cpp
@@ -14,6 +14,7 @@
* limitations under the License.
*/
+#include "log/log_main.h"
#define LOG_TAG "AidlLazyServiceRegistrar"
#include <binder/LazyServiceRegistrar.h>
@@ -37,6 +38,13 @@
bool allowIsolated, int dumpFlags);
void forcePersist(bool persist);
+ void setActiveServicesCountCallback(const std::function<bool(int)>&
+ activeServicesCountCallback);
+
+ bool tryUnregister();
+
+ void reRegister();
+
protected:
Status onClients(const sp<IBinder>& service, bool clients) override;
@@ -49,6 +57,7 @@
// whether, based on onClients calls, we know we have a client for this
// service or not
bool clients = false;
+ bool registered = true;
};
/**
@@ -62,6 +71,14 @@
*/
void tryShutdown();
+ /**
+ * Try to shutdown the process, unless:
+ * - 'forcePersist' is 'true', or
+ * - The active services count callback returns 'true', or
+ * - Some services have clients.
+ */
+ void maybeTryShutdown();
+
// count of services with clients
size_t mNumConnectedServices;
@@ -69,6 +86,9 @@
std::map<std::string, Service> mRegisteredServices;
bool mForcePersist;
+
+ // Callback used to report the number of services with clients
+ std::function<bool(int)> mActiveServicesCountCallback;
};
class ClientCounterCallback {
@@ -83,6 +103,13 @@
*/
void forcePersist(bool persist);
+ void setActiveServicesCountCallback(const std::function<bool(int)>&
+ activeServicesCountCallback);
+
+ bool tryUnregister();
+
+ void reRegister();
+
private:
sp<ClientCounterCallbackImpl> mImpl;
};
@@ -131,8 +158,60 @@
void ClientCounterCallbackImpl::forcePersist(bool persist) {
mForcePersist = persist;
- if(!mForcePersist) {
+ if (!mForcePersist && mNumConnectedServices == 0) {
// Attempt a shutdown in case the number of clients hit 0 while the flag was on
+ maybeTryShutdown();
+ }
+}
+
+bool ClientCounterCallbackImpl::tryUnregister() {
+ auto manager = interface_cast<AidlServiceManager>(asBinder(defaultServiceManager()));
+
+ for (auto& [name, entry] : mRegisteredServices) {
+ bool success = manager->tryUnregisterService(name, entry.service).isOk();
+
+ if (!success) {
+ ALOGI("Failed to unregister service %s", name.c_str());
+ return false;
+ }
+ entry.registered = false;
+ }
+
+ return true;
+}
+
+void ClientCounterCallbackImpl::reRegister() {
+ for (auto& [name, entry] : mRegisteredServices) {
+ // re-register entry if not already registered
+ if (entry.registered) {
+ continue;
+ }
+
+ if (!registerService(entry.service, name, entry.allowIsolated,
+ entry.dumpFlags)) {
+ // Must restart. Otherwise, clients will never be able to get a hold of this service.
+ LOG_ALWAYS_FATAL("Bad state: could not re-register services");
+ }
+
+ entry.registered = true;
+ }
+}
+
+void ClientCounterCallbackImpl::maybeTryShutdown() {
+ if (mForcePersist) {
+ ALOGI("Shutdown prevented by forcePersist override flag.");
+ return;
+ }
+
+ bool handledInCallback = false;
+ if (mActiveServicesCountCallback != nullptr) {
+ handledInCallback = mActiveServicesCountCallback(mNumConnectedServices);
+ }
+
+ // If there is no callback defined or the callback did not handle this
+ // client count change event, try to shutdown the process if its services
+ // have no clients.
+ if (!handledInCallback && mNumConnectedServices == 0) {
tryShutdown();
}
}
@@ -162,53 +241,24 @@
ALOGI("Process has %zu (of %zu available) client(s) in use after notification %s has clients: %d",
mNumConnectedServices, mRegisteredServices.size(), name.c_str(), clients);
- tryShutdown();
+ maybeTryShutdown();
return Status::ok();
}
-void ClientCounterCallbackImpl::tryShutdown() {
- if(mNumConnectedServices > 0) {
- // Should only shut down if there are no clients
- return;
- }
+ void ClientCounterCallbackImpl::tryShutdown() {
+ ALOGI("Trying to shut down the service. No clients in use for any service in process.");
- if(mForcePersist) {
- ALOGI("Shutdown prevented by forcePersist override flag.");
- return;
- }
+ if (tryUnregister()) {
+ ALOGI("Unregistered all clients and exiting");
+ exit(EXIT_SUCCESS);
+ }
- ALOGI("Trying to shut down the service. No clients in use for any service in process.");
+ reRegister();
+}
- auto manager = interface_cast<AidlServiceManager>(asBinder(defaultServiceManager()));
-
- auto unRegisterIt = mRegisteredServices.begin();
- for (; unRegisterIt != mRegisteredServices.end(); ++unRegisterIt) {
- auto& entry = (*unRegisterIt);
-
- bool success = manager->tryUnregisterService(entry.first, entry.second.service).isOk();
-
- if (!success) {
- ALOGI("Failed to unregister service %s", entry.first.c_str());
- break;
- }
- }
-
- if (unRegisterIt == mRegisteredServices.end()) {
- ALOGI("Unregistered all clients and exiting");
- exit(EXIT_SUCCESS);
- }
-
- for (auto reRegisterIt = mRegisteredServices.begin(); reRegisterIt != unRegisterIt;
- reRegisterIt++) {
- auto& entry = (*reRegisterIt);
-
- // re-register entry
- if (!registerService(entry.second.service, entry.first, entry.second.allowIsolated,
- entry.second.dumpFlags)) {
- // Must restart. Otherwise, clients will never be able to get a hold of this service.
- ALOGE("Bad state: could not re-register services");
- }
- }
+void ClientCounterCallbackImpl::setActiveServicesCountCallback(const std::function<bool(int)>&
+ activeServicesCountCallback) {
+ mActiveServicesCountCallback = activeServicesCountCallback;
}
ClientCounterCallback::ClientCounterCallback() {
@@ -224,6 +274,19 @@
mImpl->forcePersist(persist);
}
+void ClientCounterCallback::setActiveServicesCountCallback(const std::function<bool(int)>&
+ activeServicesCountCallback) {
+ mImpl->setActiveServicesCountCallback(activeServicesCountCallback);
+}
+
+bool ClientCounterCallback::tryUnregister() {
+ return mImpl->tryUnregister();
+}
+
+void ClientCounterCallback::reRegister() {
+ mImpl->reRegister();
+}
+
} // namespace internal
LazyServiceRegistrar::LazyServiceRegistrar() {
@@ -247,5 +310,18 @@
mClientCC->forcePersist(persist);
}
+void LazyServiceRegistrar::setActiveServicesCountCallback(const std::function<bool(int)>&
+ activeServicesCountCallback) {
+ mClientCC->setActiveServicesCountCallback(activeServicesCountCallback);
+}
+
+bool LazyServiceRegistrar::tryUnregister() {
+ return mClientCC->tryUnregister();
+}
+
+void LazyServiceRegistrar::reRegister() {
+ mClientCC->reRegister();
+}
+
} // namespace hardware
} // namespace android
diff --git a/libs/binder/include/binder/LazyServiceRegistrar.h b/libs/binder/include/binder/LazyServiceRegistrar.h
index d18c88e..73893c7 100644
--- a/libs/binder/include/binder/LazyServiceRegistrar.h
+++ b/libs/binder/include/binder/LazyServiceRegistrar.h
@@ -16,6 +16,8 @@
#pragma once
+#include <functional>
+
#include <binder/IServiceManager.h>
#include <binder/Status.h>
#include <utils/StrongPointer.h>
@@ -53,6 +55,40 @@
*/
void forcePersist(bool persist);
+ /**
+ * Set a callback that is executed when the total number of services with
+ * clients changes.
+ * The callback takes an argument, which is the number of registered
+ * lazy services for this process which have clients.
+ *
+ * Callback return value:
+ * - false: Default behavior for lazy services (shut down the process if there
+ * are no clients).
+ * - true: Don't shut down the process even if there are no clients.
+ *
+ * This callback gives a chance to:
+ * 1 - Perform some additional operations before exiting;
+ * 2 - Prevent the process from exiting by returning "true" from the
+ * callback.
+ *
+ * This method should be called before 'registerService' to avoid races.
+ */
+ void setActiveServicesCountCallback(const std::function<bool(int)>&
+ activeServicesCountCallback);
+
+ /**
+ * Try to unregister all services previously registered with 'registerService'.
+ * Returns 'true' if successful.
+ */
+ bool tryUnregister();
+
+ /**
+ * Re-register services that were unregistered by 'tryUnregister'.
+ * This method should be called in the case 'tryUnregister' fails
+ * (and should be called on the same thread).
+ */
+ void reRegister();
+
private:
std::shared_ptr<internal::ClientCounterCallback> mClientCC;
LazyServiceRegistrar();