pdx: Rework error reporting when transfering file and channel handles
There is a lot of confusion about reporting errors when passing file
and channel handles over PDX transport between client and service.
Methods like Message::PushFileHandle return an integer which means
both a file handle reference value (if positive) and a possible error
code (if negative). But file handles could contain negative values too
(when they are empty). This is used frequently when passing buffer
fences around (when a fence is not being used, its fd is set to -1).
This results in a special case of when PushFileHandle is called with
a file handle with value of -1, the return value is actually "-errno"
which becomes dependent on a global state (errno is not set by
PushFileHandle itself in case file handle value is negative) and results
in unpredicted behavior (sometimes errno is 0, sometimes its >0).
Cleaned this all up by using Status<T> everywhere we used an int to
pass value payload along with possible error code.
Now the semantics of the calls are more clear.
Bug: 36866492
Test: `m -j32` for sailfish-eng succeeds
Ran unit tests on device (pdx_tests, libpdx_uds_tests, bufferhub_tests,
buffer_hub_queue-test, buffer_hub_queue_producer-test), all pass
Ran CubeSea, NativeTreasureHunt and Ithaca on Sailfish with vrflinger
enabled, was able to use controller and screen rendered correctly.
Change-Id: I0f40c3f356fcba8bc217d5219a0ddf9685e57fd7
diff --git a/services/vr/bufferhubd/buffer_hub.cpp b/services/vr/bufferhubd/buffer_hub.cpp
index 80efcf8..de4950e 100644
--- a/services/vr/bufferhubd/buffer_hub.cpp
+++ b/services/vr/bufferhubd/buffer_hub.cpp
@@ -189,7 +189,7 @@
channel->HandleImpulse(message);
}
-int BufferHubService::HandleMessage(Message& message) {
+pdx::Status<void> BufferHubService::HandleMessage(Message& message) {
ATRACE_NAME("BufferHubService::HandleMessage");
auto channel = message.GetChannel<BufferHubChannel>();
@@ -207,22 +207,22 @@
case BufferHubRPC::CreateBuffer::Opcode:
DispatchRemoteMethod<BufferHubRPC::CreateBuffer>(
*this, &BufferHubService::OnCreateBuffer, message);
- return 0;
+ return {};
case BufferHubRPC::CreatePersistentBuffer::Opcode:
DispatchRemoteMethod<BufferHubRPC::CreatePersistentBuffer>(
*this, &BufferHubService::OnCreatePersistentBuffer, message);
- return 0;
+ return {};
case BufferHubRPC::GetPersistentBuffer::Opcode:
DispatchRemoteMethod<BufferHubRPC::GetPersistentBuffer>(
*this, &BufferHubService::OnGetPersistentBuffer, message);
- return 0;
+ return {};
case BufferHubRPC::CreateProducerQueue::Opcode:
DispatchRemoteMethod<BufferHubRPC::CreateProducerQueue>(
*this, &BufferHubService::OnCreateProducerQueue, message);
- return 0;
+ return {};
default:
return DefaultHandleMessage(message);
@@ -438,11 +438,11 @@
"BufferHubChannel::SignalAvailable: channel_id=%d buffer_id=%d",
channel_id(), buffer_id());
if (!IsDetached()) {
- const int ret = service_->ModifyChannelEvents(channel_id_, 0, POLLIN);
- ALOGE_IF(ret < 0,
+ const auto status = service_->ModifyChannelEvents(channel_id_, 0, POLLIN);
+ ALOGE_IF(!status,
"BufferHubChannel::SignalAvailable: failed to signal availability "
"channel_id=%d: %s",
- channel_id_, strerror(-ret));
+ channel_id_, status.GetErrorMessage().c_str());
} else {
ALOGD_IF(TRACE, "BufferHubChannel::SignalAvailable: detached buffer.");
}
@@ -454,11 +454,11 @@
"BufferHubChannel::ClearAvailable: channel_id=%d buffer_id=%d",
channel_id(), buffer_id());
if (!IsDetached()) {
- const int ret = service_->ModifyChannelEvents(channel_id_, POLLIN, 0);
- ALOGE_IF(ret < 0,
+ const auto status = service_->ModifyChannelEvents(channel_id_, POLLIN, 0);
+ ALOGE_IF(!status,
"BufferHubChannel::ClearAvailable: failed to clear availability "
"channel_id=%d: %s",
- channel_id_, strerror(-ret));
+ channel_id_, status.GetErrorMessage().c_str());
} else {
ALOGD_IF(TRACE, "BufferHubChannel::ClearAvailable: detached buffer.");
}
@@ -469,11 +469,11 @@
ALOGD_IF(TRACE, "BufferHubChannel::Hangup: channel_id=%d buffer_id=%d",
channel_id(), buffer_id());
if (!IsDetached()) {
- const int ret = service_->ModifyChannelEvents(channel_id_, 0, POLLHUP);
+ const auto status = service_->ModifyChannelEvents(channel_id_, 0, POLLHUP);
ALOGE_IF(
- ret < 0,
+ !status,
"BufferHubChannel::Hangup: failed to signal hangup channel_id=%d: %s",
- channel_id_, strerror(-ret));
+ channel_id_, status.GetErrorMessage().c_str());
} else {
ALOGD_IF(TRACE, "BufferHubChannel::Hangup: detached buffer.");
}
diff --git a/services/vr/bufferhubd/buffer_hub.h b/services/vr/bufferhubd/buffer_hub.h
index 28cb468..8a7dca8 100644
--- a/services/vr/bufferhubd/buffer_hub.h
+++ b/services/vr/bufferhubd/buffer_hub.h
@@ -141,7 +141,7 @@
BufferHubService();
~BufferHubService() override;
- int HandleMessage(pdx::Message& message) override;
+ pdx::Status<void> HandleMessage(pdx::Message& message) override;
void HandleImpulse(pdx::Message& message) override;
void OnChannelClose(pdx::Message& message,
diff --git a/services/vr/bufferhubd/producer_channel.cpp b/services/vr/bufferhubd/producer_channel.cpp
index 43010b0..903d174 100644
--- a/services/vr/bufferhubd/producer_channel.cpp
+++ b/services/vr/bufferhubd/producer_channel.cpp
@@ -161,12 +161,12 @@
auto consumer = std::make_shared<ConsumerChannel>(
service(), buffer_id(), channel_id, shared_from_this());
- const int ret = service()->SetChannel(channel_id, consumer);
- if (ret < 0) {
+ const auto channel_status = service()->SetChannel(channel_id, consumer);
+ if (!channel_status) {
ALOGE(
"ProducerChannel::CreateConsumer: failed to set new consumer channel: "
"%s",
- strerror(-ret));
+ channel_status.GetErrorMessage().c_str());
return RemoteChannelHandle();
}
diff --git a/services/vr/bufferhubd/producer_queue_channel.cpp b/services/vr/bufferhubd/producer_queue_channel.cpp
index 08f1e9d..7952642 100644
--- a/services/vr/bufferhubd/producer_queue_channel.cpp
+++ b/services/vr/bufferhubd/producer_queue_channel.cpp
@@ -97,18 +97,18 @@
"ProducerQueueChannel::OnCreateConsumerQueue: failed to push consumer "
"channel: %s",
status.GetErrorMessage().c_str());
- REPLY_ERROR_RETURN(message, ENOMEM, {});
+ REPLY_ERROR_RETURN(message, status.error(), {});
}
- const int ret = service()->SetChannel(
+ const auto channel_status = service()->SetChannel(
channel_id, std::make_shared<ConsumerQueueChannel>(
service(), buffer_id(), channel_id, shared_from_this()));
- if (ret < 0) {
+ if (!channel_status) {
ALOGE(
"ProducerQueueChannel::OnCreateConsumerQueue: failed to set new "
"consumer channel: %s",
- strerror(-ret));
- REPLY_ERROR_RETURN(message, ENOMEM, {});
+ channel_status.GetErrorMessage().c_str());
+ REPLY_ERROR_RETURN(message, channel_status.error(), {});
}
return std::make_pair(status.take(), meta_size_bytes_);
@@ -214,12 +214,13 @@
"ProducerQueueChannel::AllocateBuffer: buffer_id=%d, buffer_handle=%d",
buffer_id, buffer_handle.value());
- const int ret = service()->SetChannel(buffer_id, producer_channel);
- if (ret < 0) {
+ const auto channel_status =
+ service()->SetChannel(buffer_id, producer_channel);
+ if (!channel_status) {
ALOGE(
- "ProducerQueueChannel::AllocateBuffer: failed to set prodcuer channel "
+ "ProducerQueueChannel::AllocateBuffer: failed to set producer channel "
"for new BufferHubBuffer: %s",
- strerror(-ret));
+ channel_status.GetErrorMessage().c_str());
return {};
}
@@ -252,7 +253,7 @@
return {std::move(buffer_handle), slot};
}
-int ProducerQueueChannel::OnProducerQueueDetachBuffer(Message& message,
+int ProducerQueueChannel::OnProducerQueueDetachBuffer(Message& /*message*/,
size_t slot) {
if (buffers_[slot].expired()) {
ALOGE(