Add shared memory based buffer metadata
This CLs reduces BufferHub CPU consumption by adding asynchronous
state transition so that out-of-process VR composition can run on 2016
pixel devices smoothly. In addition, this CL addresses a couple corner
cases in the existing bufferhub logic, which fixes various blackscreen
issues.
1/ Tracks buffer transition states (gained, posted, acquired, released)
from the client side via atomic shared memory and adds
PostAsync/AcquireAsync/ReleaseAsync/GainAsync with metadata and
fence support.
2/ Adds dequeue order guarantee for buffers enqueued with
dvrWriteBufferQueuePostBuffer.
3/ Synchronous BuffeHub operations are still supported.
4/ Bump up the bufferhubd's soft limit of open file descriptor.
5/ Handle orphaned consumer in acquired state. This is a corner case
that consumer process goes aways (most likely due to a crash) leaving
buffer stuck in acquired state with inconsistent buffer state.
6/ Fixes a race condition for released buffer to be Gain'ed and
Acquire'd when a new consumer is created in released state.
7/ Improve silent consumer queue efficiency: Silent queues no longer
import buffers or receive signals about new buffers and they are
limited to only spawning other consumers and notifications about
producers hanging up.
8/ Modify PDX/UDS channel event signaling to work around epoll
behavior. PDX UDS uses a combination of an eventfd and an epoll set
to simulate the original PDX transport channel events. An odd
behavior discovered in the kernel implementation of epoll was found
that causes the epoll fd to "unsignal" itself whenever epoll_wait()
is called on it, regardless of whether it should still be
pending. This breaks the edge triggerd behavior in nested epoll sets
that channel events depend on. Since this is unlikely to ever be
fixed in the kernel we work around the behavior by using the epoll
set only as a logical OR of two eventfds and never calling
epoll_wait() on it. When polling is required we use regluar poll()
with the eventfds and data fd to avoid the bad behavior in
epoll_wait().
9/ Keep reading data after PDX hangup signal. UDS will signal hangup
when the other end of the socket closes. However, data could still be
in the kerenl buffer and should be consumed. Fix an issue where the
service misses an impulse sent right before the socket is closed.
Bug: 65455724
Bug: 65458354
Bug: 65458312
Bug: 64027135
Bug: 67424527
Test: libpdx_uds_tests
bufferhub_tests
buffer_hub_queue-test
buffer_hub_queue_producer-test
dvr_api-test
Change-Id: Id07db1f206ccf4e06f7ee3c671193334408971ca
diff --git a/libs/vr/libpdx/Android.bp b/libs/vr/libpdx/Android.bp
index 8fce140..10c0b31 100644
--- a/libs/vr/libpdx/Android.bp
+++ b/libs/vr/libpdx/Android.bp
@@ -36,6 +36,7 @@
"variant_tests.cpp",
],
static_libs: [
+ "libcutils",
"libgmock",
"libpdx",
"liblog",
diff --git a/libs/vr/libpdx/private/pdx/client_channel.h b/libs/vr/libpdx/private/pdx/client_channel.h
index dbfd626..10a49bb 100644
--- a/libs/vr/libpdx/private/pdx/client_channel.h
+++ b/libs/vr/libpdx/private/pdx/client_channel.h
@@ -1,6 +1,8 @@
#ifndef ANDROID_PDX_CLIENT_CHANNEL_H_
#define ANDROID_PDX_CLIENT_CHANNEL_H_
+#include <vector>
+
#include <pdx/channel_handle.h>
#include <pdx/file_handle.h>
#include <pdx/status.h>
@@ -20,6 +22,15 @@
virtual int event_fd() const = 0;
virtual Status<int> GetEventMask(int events) = 0;
+ struct EventSource {
+ int event_fd;
+ int event_mask;
+ };
+
+ // Returns a set of event-generating fds with and event mask for each. These
+ // fds are owned by the ClientChannel and must never be closed by the caller.
+ virtual std::vector<EventSource> GetEventSources() const = 0;
+
virtual LocalChannelHandle& GetChannelHandle() = 0;
virtual void* AllocateTransactionState() = 0;
virtual void FreeTransactionState(void* state) = 0;
diff --git a/libs/vr/libpdx/private/pdx/mock_client_channel.h b/libs/vr/libpdx/private/pdx/mock_client_channel.h
index 561c939..49e0682 100644
--- a/libs/vr/libpdx/private/pdx/mock_client_channel.h
+++ b/libs/vr/libpdx/private/pdx/mock_client_channel.h
@@ -11,6 +11,7 @@
public:
MOCK_CONST_METHOD0(GetIpcTag, uint32_t());
MOCK_CONST_METHOD0(event_fd, int());
+ MOCK_CONST_METHOD0(GetEventSources, std::vector<EventSource>());
MOCK_METHOD1(GetEventMask, Status<int>(int));
MOCK_METHOD0(GetChannelHandle, LocalChannelHandle&());
MOCK_METHOD0(AllocateTransactionState, void*());
diff --git a/libs/vr/libpdx/private/pdx/trace.h b/libs/vr/libpdx/private/pdx/trace.h
index ebe8491..c687fd6 100644
--- a/libs/vr/libpdx/private/pdx/trace.h
+++ b/libs/vr/libpdx/private/pdx/trace.h
@@ -1,35 +1,82 @@
#ifndef ANDROID_PDX_TRACE_H_
#define ANDROID_PDX_TRACE_H_
-// Tracing utilities for libpdx. Tracing in the service framework is enabled
-// under these conditions:
-// 1. ATRACE_TAG is defined, AND
-// 2. ATRACE_TAG does not equal ATRACE_TAG_NEVER, AND
-// 3. PDX_TRACE_ENABLED is defined, AND
-// 4. PDX_TRACE_ENABLED is equal to logical true.
-//
-// If any of these conditions are not met tracing is completely removed from the
-// library and headers.
+#include <array>
-// If ATRACE_TAG is not defined, default to never.
-#ifndef ATRACE_TAG
-#define ATRACE_TAG ATRACE_TAG_NEVER
-#endif
-
-// Include tracing functions after the trace tag is defined.
#include <utils/Trace.h>
-// If PDX_TRACE_ENABLED is not defined, default to off.
-#ifndef PDX_TRACE_ENABLED
-#define PDX_TRACE_ENABLED 0
+// Enables internal tracing in libpdx. This is disabled by default to avoid
+// spamming the trace buffers during normal trace activities. libpdx must be
+// built with this set to true to enable internal tracing.
+#ifndef PDX_LIB_TRACE_ENABLED
+#define PDX_LIB_TRACE_ENABLED false
#endif
-#if (ATRACE_TAG) != (ATRACE_TAG_NEVER) && (PDX_TRACE_ENABLED)
-#define PDX_TRACE_NAME ATRACE_NAME
-#else
-#define PDX_TRACE_NAME(name) \
- do { \
- } while (0)
-#endif
+namespace android {
+namespace pdx {
+
+// Utility to generate scoped tracers with arguments.
+class ScopedTraceArgs {
+ public:
+ template <typename... Args>
+ ScopedTraceArgs(uint64_t tag, const char* format, Args&&... args)
+ : tag_{tag} {
+ if (atrace_is_tag_enabled(tag_)) {
+ std::array<char, 1024> buffer;
+ snprintf(buffer.data(), buffer.size(), format,
+ std::forward<Args>(args)...);
+ atrace_begin(tag_, buffer.data());
+ }
+ }
+
+ ~ScopedTraceArgs() { atrace_end(tag_); }
+
+ private:
+ uint64_t tag_;
+
+ ScopedTraceArgs(const ScopedTraceArgs&) = delete;
+ void operator=(const ScopedTraceArgs&) = delete;
+};
+
+// Utility to generate scoped tracers.
+class ScopedTrace {
+ public:
+ template <typename... Args>
+ ScopedTrace(uint64_t tag, bool enabled, const char* name)
+ : tag_{tag}, enabled_{enabled} {
+ if (enabled_)
+ atrace_begin(tag_, name);
+ }
+
+ ~ScopedTrace() {
+ if (enabled_)
+ atrace_end(tag_);
+ }
+
+ private:
+ uint64_t tag_;
+ bool enabled_;
+
+ ScopedTrace(const ScopedTrace&) = delete;
+ void operator=(const ScopedTrace&) = delete;
+};
+
+} // namespace pdx
+} // namespace android
+
+// Macro to define a scoped tracer with arguments. Uses PASTE(x, y) macro
+// defined in utils/Trace.h.
+#define PDX_TRACE_FORMAT(format, ...) \
+ ::android::pdx::ScopedTraceArgs PASTE(__tracer, __LINE__) { \
+ ATRACE_TAG, format, ##__VA_ARGS__ \
+ }
+
+// TODO(eieio): Rename this to PDX_LIB_TRACE_NAME() for internal use by libpdx
+// and rename internal uses inside the library. This version is only enabled
+// when PDX_LIB_TRACE_ENABLED is true.
+#define PDX_TRACE_NAME(name) \
+ ::android::pdx::ScopedTrace PASTE(__tracer, __LINE__) { \
+ ATRACE_TAG, PDX_LIB_TRACE_ENABLED, name \
+ }
#endif // ANDROID_PDX_TRACE_H_