Binder API for freeze state change notification.
Bug: 338097747
Change-Id: Iac340abc7a1a0700148cded9adb0451b8a4eae73
Test: atest BinderLibTest
diff --git a/libs/binder/ProcessState.cpp b/libs/binder/ProcessState.cpp
index a42ede2..47fd38f 100644
--- a/libs/binder/ProcessState.cpp
+++ b/libs/binder/ProcessState.cpp
@@ -57,6 +57,25 @@
// -------------------------------------------------------------------------
+namespace {
+bool readDriverFeatureFile(const char* filename) {
+ int fd = open(filename, O_RDONLY | O_CLOEXEC);
+ char on;
+ if (fd == -1) {
+ ALOGE_IF(errno != ENOENT, "%s: cannot open %s: %s", __func__, filename, strerror(errno));
+ return false;
+ }
+ if (read(fd, &on, sizeof(on)) == -1) {
+ ALOGE("%s: error reading to %s: %s", __func__, filename, strerror(errno));
+ close(fd);
+ return false;
+ }
+ close(fd);
+ return on == '1';
+}
+
+} // namespace
+
namespace android {
using namespace android::binder::impl;
@@ -472,27 +491,20 @@
#define DRIVER_FEATURES_PATH "/dev/binderfs/features/"
bool ProcessState::isDriverFeatureEnabled(const DriverFeature feature) {
- static const char* const names[] = {
- [static_cast<int>(DriverFeature::ONEWAY_SPAM_DETECTION)] =
- DRIVER_FEATURES_PATH "oneway_spam_detection",
- [static_cast<int>(DriverFeature::EXTENDED_ERROR)] =
- DRIVER_FEATURES_PATH "extended_error",
- };
- int fd = open(names[static_cast<int>(feature)], O_RDONLY | O_CLOEXEC);
- char on;
- if (fd == -1) {
- ALOGE_IF(errno != ENOENT, "%s: cannot open %s: %s", __func__,
- names[static_cast<int>(feature)], strerror(errno));
- return false;
+ // Use static variable to cache the results.
+ if (feature == DriverFeature::ONEWAY_SPAM_DETECTION) {
+ static bool enabled = readDriverFeatureFile(DRIVER_FEATURES_PATH "oneway_spam_detection");
+ return enabled;
}
- if (read(fd, &on, sizeof(on)) == -1) {
- ALOGE("%s: error reading to %s: %s", __func__,
- names[static_cast<int>(feature)], strerror(errno));
- close(fd);
- return false;
+ if (feature == DriverFeature::EXTENDED_ERROR) {
+ static bool enabled = readDriverFeatureFile(DRIVER_FEATURES_PATH "extended_error");
+ return enabled;
}
- close(fd);
- return on == '1';
+ if (feature == DriverFeature::FREEZE_NOTIFICATION) {
+ static bool enabled = readDriverFeatureFile(DRIVER_FEATURES_PATH "freeze_notification");
+ return enabled;
+ }
+ return false;
}
status_t ProcessState::enableOnewaySpamDetection(bool enable) {