camera: Fix client eviction/disconnect race.
- Add blocking wait in camera service connect call to
prevent race when client has called disconnect while
eviction of that client is taking place, resulting
in early call of device initialization before all
HAL resources are available.
Bug: 20038135
Change-Id: I7afc5bfa23612ba7f83293fa542ff983a5991230
diff --git a/services/camera/libcameraservice/CameraService.cpp b/services/camera/libcameraservice/CameraService.cpp
index dabfafa..414d563 100644
--- a/services/camera/libcameraservice/CameraService.cpp
+++ b/services/camera/libcameraservice/CameraService.cpp
@@ -866,7 +866,7 @@
std::shared_ptr<resource_policy::ClientDescriptor<String8, sp<BasicClient>>>* partial) {
status_t ret = NO_ERROR;
- std::vector<sp<BasicClient>> evictedClients;
+ std::vector<DescriptorPtr> evictedClients;
DescriptorPtr clientDescriptor;
{
if (effectiveApiLevel == API_1) {
@@ -974,7 +974,7 @@
ALOGE("CameraService::connect evicting conflicting client for camera ID %s",
i->getKey().string());
- evictedClients.push_back(clientSp);
+ evictedClients.push_back(i);
// Log the clients evicted
logEvent(String8::format("EVICT device %s client held by package %s (PID"
@@ -1001,12 +1001,31 @@
// Destroy evicted clients
for (auto& i : evictedClients) {
// Disconnect is blocking, and should only have returned when HAL has cleaned up
- i->disconnect(); // Clients will remove themselves from the active client list here
+ i->getValue()->disconnect(); // Clients will remove themselves from the active client list
}
- evictedClients.clear();
IPCThreadState::self()->restoreCallingIdentity(token);
+ for (const auto& i : evictedClients) {
+ ALOGV("%s: Waiting for disconnect to complete for client for device %s (PID %" PRId32 ")",
+ __FUNCTION__, i->getKey().string(), i->getOwnerId());
+ ret = mActiveClientManager.waitUntilRemoved(i, DEFAULT_DISCONNECT_TIMEOUT_NS);
+ if (ret == TIMED_OUT) {
+ ALOGE("%s: Timed out waiting for client for device %s to disconnect, "
+ "current clients:\n%s", __FUNCTION__, i->getKey().string(),
+ mActiveClientManager.toString().string());
+ return -EBUSY;
+ }
+ if (ret != NO_ERROR) {
+ ALOGE("%s: Received error waiting for client for device %s to disconnect: %s (%d), "
+ "current clients:\n%s", __FUNCTION__, i->getKey().string(), strerror(-ret),
+ ret, mActiveClientManager.toString().string());
+ return ret;
+ }
+ }
+
+ evictedClients.clear();
+
// Once clients have been disconnected, relock
mServiceLock.lock();