libbinder_ndk: APIs for polling
Useful for constructing single-threaded servers, and requested for use
by an APEX, so adding here. These correspond exactly to libbinder APIs.
Bug: 161498137
Test: atest libbinder_ndk_unit_test
Change-Id: I3bffd2bc65a7a637c626ef084f617a6f19c20208
diff --git a/libs/binder/ndk/include_platform/android/binder_process.h b/libs/binder/ndk/include_platform/android/binder_process.h
index fdefbb4..f408fad 100644
--- a/libs/binder/ndk/include_platform/android/binder_process.h
+++ b/libs/binder/ndk/include_platform/android/binder_process.h
@@ -19,10 +19,15 @@
#include <stdint.h>
#include <sys/cdefs.h>
+#include <android/binder_status.h>
+
__BEGIN_DECLS
/**
* This creates a threadpool for incoming binder transactions if it has not already been created.
+ *
+ * When using this, it is expected that ABinderProcess_setupPolling and
+ * ABinderProcess_handlePolledCommands are not used.
*/
void ABinderProcess_startThreadPool();
/**
@@ -37,4 +42,27 @@
*/
void ABinderProcess_joinThreadPool();
+/**
+ * This gives you an fd to wait on. Whenever data is available on the fd,
+ * ABinderProcess_handlePolledCommands can be called to handle binder queries.
+ * This is expected to be used in a single threaded process which waits on
+ * events from multiple different fds.
+ *
+ * When using this, it is expected ABinderProcess_startThreadPool and
+ * ABinderProcess_joinThreadPool are not used.
+ *
+ * \param fd out param corresponding to the binder domain opened in this
+ * process.
+ * \return STATUS_OK on success
+ */
+__attribute__((weak)) binder_status_t ABinderProcess_setupPolling(int* fd) __INTRODUCED_IN(31);
+
+/**
+ * This will handle all queued binder commands in this process and then return.
+ * It is expected to be called whenever there is data on the fd.
+ *
+ * \return STATUS_OK on success
+ */
+__attribute__((weak)) binder_status_t ABinderProcess_handlePolledCommands() __INTRODUCED_IN(31);
+
__END_DECLS
diff --git a/libs/binder/ndk/libbinder_ndk.map.txt b/libs/binder/ndk/libbinder_ndk.map.txt
index 9b5fa26..d435382 100644
--- a/libs/binder/ndk/libbinder_ndk.map.txt
+++ b/libs/binder/ndk/libbinder_ndk.map.txt
@@ -113,6 +113,8 @@
LIBBINDER_NDK31 { # introduced=31
global:
+ ABinderProcess_handlePolledCommands; # apex
+ ABinderProcess_setupPolling; # apex
AIBinder_getCallingSid; # apex
AIBinder_setRequestingSid; # apex
};
diff --git a/libs/binder/ndk/process.cpp b/libs/binder/ndk/process.cpp
index c89caaf..ac582a4 100644
--- a/libs/binder/ndk/process.cpp
+++ b/libs/binder/ndk/process.cpp
@@ -34,3 +34,11 @@
void ABinderProcess_joinThreadPool() {
IPCThreadState::self()->joinThreadPool();
}
+
+binder_status_t ABinderProcess_setupPolling(int* fd) {
+ return IPCThreadState::self()->setupPolling(fd);
+}
+
+binder_status_t ABinderProcess_handlePolledCommands() {
+ return IPCThreadState::self()->handlePolledCommands();
+}
diff --git a/libs/binder/ndk/tests/libbinder_ndk_unit_test.cpp b/libs/binder/ndk/tests/libbinder_ndk_unit_test.cpp
index e3fdb4b..9b2fcf0 100644
--- a/libs/binder/ndk/tests/libbinder_ndk_unit_test.cpp
+++ b/libs/binder/ndk/tests/libbinder_ndk_unit_test.cpp
@@ -24,6 +24,7 @@
#include <android/binder_process.h>
#include <gtest/gtest.h>
#include <iface/iface.h>
+#include <utils/Looper.h>
// warning: this is assuming that libbinder_ndk is using the same copy
// of libbinder that we are.
@@ -107,19 +108,39 @@
}
};
-int manualService(const char* instance) {
- ABinderProcess_setThreadPoolMaxThreadCount(0);
-
+void manualService(const char* instance) {
// Strong reference to MyFoo kept by service manager.
binder_status_t status = (new MyFoo)->addService(instance);
if (status != STATUS_OK) {
LOG(FATAL) << "Could not register: " << status << " " << instance;
}
+}
+int manualPollingService(const char* instance) {
+ int fd;
+ CHECK(STATUS_OK == ABinderProcess_setupPolling(&fd));
+ manualService(instance);
+ class Handler : public LooperCallback {
+ int handleEvent(int /*fd*/, int /*events*/, void* /*data*/) override {
+ ABinderProcess_handlePolledCommands();
+ return 1; // Continue receiving callbacks.
+ }
+ };
+
+ sp<Looper> looper = Looper::prepare(0 /* opts */);
+ looper->addFd(fd, Looper::POLL_CALLBACK, Looper::EVENT_INPUT, new Handler(), nullptr /*data*/);
+ // normally, would add additional fds
+ while (true) {
+ looper->pollAll(-1 /* timeoutMillis */);
+ }
+ return 1; // should not reach
+}
+int manualThreadPoolService(const char* instance) {
+ ABinderProcess_setThreadPoolMaxThreadCount(0);
+ manualService(instance);
ABinderProcess_joinThreadPool();
-
- return 1; // should not return
+ return 1;
}
// This is too slow
@@ -448,11 +469,11 @@
if (fork() == 0) {
prctl(PR_SET_PDEATHSIG, SIGHUP);
- return manualService(IFoo::kInstanceNameToDieFor);
+ return manualThreadPoolService(IFoo::kInstanceNameToDieFor);
}
if (fork() == 0) {
prctl(PR_SET_PDEATHSIG, SIGHUP);
- return manualService(IFoo::kSomeInstanceName);
+ return manualPollingService(IFoo::kSomeInstanceName);
}
if (fork() == 0) {
prctl(PR_SET_PDEATHSIG, SIGHUP);
