displayconfig: Restrict the scope of death_service_mutex_
Multiple display config calls is causing deadlock when one
of them is waiting for commit and there are no free binder
threads.
- Allow perform calls to run concurrently.
- Execute service death callback exclusively.
Change-Id: I804e72d4961315c6fac13f5f967788b5bbc0febe
diff --git a/services/config/src/device_impl.cpp b/services/config/src/device_impl.cpp
index 4541368..c8f64dc 100644
--- a/services/config/src/device_impl.cpp
+++ b/services/config/src/device_impl.cpp
@@ -146,6 +146,7 @@
void DeviceImpl::serviceDied(uint64_t client_handle,
const android::wp<::android::hidl::base::V1_0::IBase>& callback) {
+ std::lock_guard<std::shared_mutex> exclusive_lock(shared_mutex_);
std::lock_guard<std::recursive_mutex> lock(death_service_mutex_);
auto itr = display_config_map_.find(client_handle);
std::shared_ptr<DeviceClientContext> client = itr->second;
@@ -989,16 +990,21 @@
Return<void> DeviceImpl::perform(uint64_t client_handle, uint32_t op_code,
const ByteStream &input_params, const HandleStream &input_handles,
perform_cb _hidl_cb) {
+ std::shared_lock<std::shared_mutex> shared_lock(shared_mutex_);
int32_t error = 0;
- std::lock_guard<std::recursive_mutex> lock(death_service_mutex_);
- auto itr = display_config_map_.find(client_handle);
- if (itr == display_config_map_.end()) {
- error = -EINVAL;
- _hidl_cb(error, {}, {});
- return Void();
+ std::shared_ptr<DeviceClientContext> client = nullptr;
+
+ {
+ std::lock_guard<std::recursive_mutex> lock(death_service_mutex_);
+ auto itr = display_config_map_.find(client_handle);
+ if (itr == display_config_map_.end()) {
+ error = -EINVAL;
+ _hidl_cb(error, {}, {});
+ return Void();
+ }
+ client = itr->second;
}
- std::shared_ptr<DeviceClientContext> client = itr->second;
if (!client) {
error = -EINVAL;
_hidl_cb(error, {}, {});
diff --git a/services/config/src/device_impl.h b/services/config/src/device_impl.h
index cf60366..3433d05 100644
--- a/services/config/src/device_impl.h
+++ b/services/config/src/device_impl.h
@@ -74,6 +74,7 @@
#include <utility>
#include <string>
#include <vector>
+#include <shared_mutex>
#include "opcode_types.h"
@@ -187,6 +188,7 @@
std::map<uint64_t, std::shared_ptr<DeviceClientContext>> display_config_map_;
uint64_t client_id_ = 0;
std::recursive_mutex death_service_mutex_;
+ std::shared_mutex shared_mutex_;
static DeviceImpl *device_obj_;
static std::mutex device_lock_;
};