From cf8769dcf4733e7d3b58f8f1d3a97dbfd32a5929 Mon Sep 17 00:00:00 2001
From: Guillaume Roguez <guillaume.roguez@savoirfairelinux.com>
Date: Thu, 9 Apr 2015 12:42:29 -0400
Subject: [PATCH] video: shared memory renderer refactoring
Direct rendering done by client
Refs #70057
---
CMakeLists.txt | 1 +
src/private/shmrenderer.cpp | 359 ++++++++++++++++------------------
src/private/shmrenderer.h | 8 +-
src/private/videorenderer_p.h | 7 +-
src/video/renderer.cpp | 27 +--
src/video/renderer.h | 6 +-
6 files changed, 187 insertions(+), 221 deletions(-)
diff --git a/CMakeLists.txt b/CMakeLists.txt
index 0a6cb115..3b073fbb 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -28,6 +28,7 @@ ADD_DEFINITIONS("-std=c++1y")
ADD_DEFINITIONS(
${QT_DEFINITIONS}
-fexceptions
+ -O2
)
PROJECT(ringclient)
diff --git a/src/private/shmrenderer.cpp b/src/private/shmrenderer.cpp
index 622f2133..d386fbd3 100644
--- a/src/private/shmrenderer.cpp
+++ b/src/private/shmrenderer.cpp
@@ -21,7 +21,6 @@
#include <QtCore/QDebug>
#include <QtCore/QMutex>
#include <QtCore/QThread>
-#include <QtCore/QTime>
#include <sys/ipc.h>
#include <sys/sem.h>
@@ -37,33 +36,35 @@
#endif
#include <QtCore/QTimer>
+#include <chrono>
+
#include "private/videorenderermanager.h"
#include "video/resolution.h"
#include "private/videorenderer_p.h"
+// Uncomment following line to output in console the FPS value
//#define DEBUG_FPS
-#ifdef DEBUG_FPS
-#include <chrono>
-#endif
-///Shared memory object
-// Implementation note: double-buffering
-// Shared memory is divided in two regions, each representing one frame.
-// First byte of each frame is warranted to by aligned on 16 bytes.
-// One region is marked readable: this region can be safely read.
-// The other region is writeable: only the producer can use it.
+/* Shared memory object
+ * Implementation note: double-buffering
+ * Shared memory is divided in two regions, each representing one frame.
+ * First byte of each frame is warranted to by aligned on 16 bytes.
+ * One region is marked readable: this region can be safely read.
+ * The other region is writeable: only the producer can use it.
+ */
struct SHMHeader {
- sem_t mutex; // Lock it before any operations on following fields.
- sem_t frameGenMutex; // unlocked by producer when frameGen modified
- unsigned frameGen; // monotonically incremented when a producer changes readOffset
- unsigned frameSize; // size in bytes of 1 frame
- unsigned readOffset; // offset of readable frame in data
- unsigned writeOffset; // offset of writable frame in data
+ sem_t mutex; // Lock it before any operations on following fields.
+ sem_t frameGenMutex; // unlocked by producer when frameGen modified
+ unsigned frameGen; // monotonically incremented when a producer changes readOffset
+ unsigned frameSize; // size in bytes of 1 frame
+ unsigned mapSize; // size to map if you need to see all data
+ unsigned readOffset; // offset of readable frame in data
+ unsigned writeOffset; // offset of writable frame in data
#pragma GCC diagnostic push
#pragma GCC diagnostic ignored "-pedantic"
- char data[]; // the whole shared memory
+ char data[]; // the whole shared memory
#pragma GCC diagnostic pop
};
@@ -71,85 +72,83 @@ namespace Video {
class ShmRendererPrivate : public QObject
{
- Q_OBJECT
-public:
- ShmRendererPrivate(Video::ShmRenderer* parent);
-
- //Attributes
- QString m_ShmPath ;
- int m_fd ;
- SHMHeader* m_pShmArea ;
- unsigned m_ShmAreaLen ;
- uint m_BufferGen ;
- QTimer* m_pTimer ;
- int m_fpsC ;
- int m_Fps ;
- QTime m_CurrentTime;
-
-#ifdef DEBUG_FPS
- unsigned m_frameCount;
- std::chrono::time_point<std::chrono::system_clock> m_lastFrameDebug;
-#endif
-
- //Constants
- static const int TIMEOUT_SEC = 1; // 1 second
-
- //Helpers
- timespec createTimeout();
- bool shmLock ();
- void shmUnlock ();
- bool renderToBitmap();
- bool resizeShm();
-
-private:
- Video::ShmRenderer* q_ptr;
-
-private Q_SLOTS:
- void timedEvents();
+ Q_OBJECT
+
+ public:
+ ShmRendererPrivate(ShmRenderer* parent);
+
+ // Attributes
+ QString m_ShmPath ;
+ int m_fd ;
+ SHMHeader* m_pShmArea ;
+ unsigned m_ShmAreaLen ;
+ uint m_FrameGen ;
+ QTimer* m_pTimer ;
+ int m_fpsC ;
+ int m_Fps ;
+ std::chrono::time_point<std::chrono::system_clock> m_lastFrameDebug;
+
+ // Constants
+ static const int FPS_RATE_SEC = 1;
+ static const int FRAME_CHECK_RATE_HZ = 120;
+
+ // Helpers
+ timespec createTimeout();
+ bool shmLock();
+ void shmUnlock();
+ bool getNewFrame(bool wait);
+ bool remapShm();
+
+ private:
+ Video::ShmRenderer* q_ptr;
};
-}
-
-Video::ShmRendererPrivate::ShmRendererPrivate(Video::ShmRenderer* parent) : QObject(parent), q_ptr(parent),
- m_fd(-1),m_fpsC(0),m_Fps(0),
- m_pShmArea((SHMHeader*)MAP_FAILED), m_ShmAreaLen(0), m_BufferGen(0),
- m_pTimer(nullptr)
+ShmRendererPrivate::ShmRendererPrivate(ShmRenderer* parent)
+ : QObject(parent)
+ , q_ptr(parent)
+ , m_fd(-1)
+ , m_fpsC(0)
+ , m_Fps(0)
+ , m_pShmArea((SHMHeader*)MAP_FAILED)
+ , m_ShmAreaLen(0)
+ , m_FrameGen(0)
+ , m_pTimer(nullptr)
#ifdef DEBUG_FPS
- , m_frameCount(0)
- , m_lastFrameDebug(std::chrono::system_clock::now())
+ , m_frameCount(0)
+ , m_lastFrameDebug(std::chrono::system_clock::now())
#endif
{
}
-///Constructor
-Video::ShmRenderer::ShmRenderer(const QByteArray& id, const QString& shmPath, const QSize& res): Renderer(id, res), d_ptr(new ShmRendererPrivate(this))
+/// Constructor
+ShmRenderer::ShmRenderer(const QByteArray& id, const QString& shmPath,
+ const QSize& res)
+ : Renderer(id, res)
+ , d_ptr(new ShmRendererPrivate(this))
{
d_ptr->m_ShmPath = shmPath;
setObjectName("Video::Renderer:"+id);
}
-///Destructor
-Video::ShmRenderer::~ShmRenderer()
+/// Destructor
+ShmRenderer::~ShmRenderer()
{
stopShm();
}
-///Get the data from shared memory and transform it into a QByteArray
+/// Wait new frame data from shared memory and save pointer
bool
-Video::ShmRendererPrivate::renderToBitmap()
+ShmRendererPrivate::getNewFrame(bool wait)
{
- QMutexLocker locker {q_ptr->mutex()};
-
-#ifdef Q_OS_LINUX
- if (!q_ptr->isRendering())
- return false;
-
if (!shmLock())
return false;
- if (m_BufferGen == m_pShmArea->frameGen) {
+ if (m_FrameGen == m_pShmArea->frameGen) {
shmUnlock();
+ if (not wait)
+ return false;
+
// wait for a new frame, max 33ms
static const struct timespec timeout = {0, 33000000};
if (::sem_timedwait(&m_pShmArea->frameGenMutex, &timeout) < 0)
@@ -159,69 +158,76 @@ Video::ShmRendererPrivate::renderToBitmap()
return false;
}
- // valid frame to render?
- if (not m_pShmArea->frameSize)
+ // valid frame to render (daemon may have stopped)?
+ if (not m_pShmArea->frameSize) {
+ shmUnlock();
return false;
+ }
- if (!resizeShm()) {
+ // map frame data
+ if (!remapShm()) {
qDebug() << "Could not resize shared memory";
return false;
}
- auto& renderer = static_cast<Video::Renderer*>(q_ptr)->d_ptr;
- auto& frame = renderer->otherFrame();
- if ((unsigned)frame.size() != m_pShmArea->frameSize)
- frame.resize(m_pShmArea->frameSize);
- std::copy_n(m_pShmArea->data + m_pShmArea->readOffset, m_pShmArea->frameSize, frame.data());
- m_BufferGen = m_pShmArea->frameGen;
- renderer->updateFrameIndex();
+ q_ptr->setFramePtr(m_pShmArea->data + m_pShmArea->readOffset);
+ m_FrameGen = m_pShmArea->frameGen;
+
shmUnlock();
-#ifdef DEBUG_FPS
+ ++m_fpsC;
+
+ // Compute the FPS shown to the client
auto currentTime = std::chrono::system_clock::now();
const std::chrono::duration<double> seconds = currentTime - m_lastFrameDebug;
- ++m_frameCount;
- if (seconds.count() > 1) {
- qDebug() << this << ": FPS " << (m_frameCount / seconds.count());
- m_frameCount = 0;
+ if (seconds.count() >= FPS_RATE_SEC) {
+ m_Fps = m_fpsC / seconds.count();
+ m_fpsC = 0;
m_lastFrameDebug = currentTime;
- }
+#ifdef DEBUG_FPS
+ qDebug() << this << ": FPS " << m_fps;
#endif
+ }
+ emit q_ptr->frameUpdated();
return true;
-#else
- return false;
-#endif
}
-///Resize the shared memory
+/// Remap the shared memory
+/// Shared memory in unlocked state if returns false (resize failed).
bool
-Video::ShmRendererPrivate::resizeShm()
+ShmRendererPrivate::remapShm()
{
- const auto areaSize = sizeof(SHMHeader) + 2 * m_pShmArea->frameSize + 15;
- if (m_ShmAreaLen == areaSize)
- return true;
+ // This loop handles case where deamon resize shared memory
+ // during time we unlock it for remapping.
+ while (m_ShmAreaLen != m_pShmArea->mapSize) {
+ auto mapSize = m_pShmArea->mapSize;
+ shmUnlock();
- shmUnlock();
- if (::munmap(m_pShmArea, m_ShmAreaLen)) {
- qDebug() << "Could not unmap shared area:" << strerror(errno);
- return false;
- }
+ if (::munmap(m_pShmArea, m_ShmAreaLen)) {
+ qDebug() << "Could not unmap shared area: " << strerror(errno);
+ return false;
+ }
- m_pShmArea = (SHMHeader*) ::mmap(nullptr, areaSize,
- PROT_READ | PROT_WRITE,
- MAP_SHARED, m_fd, 0);
- if (m_pShmArea == MAP_FAILED) {
- qDebug() << "Could not remap shared area";
- return false;
+ m_pShmArea = (SHMHeader*) ::mmap(nullptr, mapSize, PROT_READ | PROT_WRITE,
+ MAP_SHARED, m_fd, 0);
+ if (m_pShmArea == MAP_FAILED) {
+ qDebug() << "Could not remap shared area: " << strerror(errno);
+ return false;
+ }
+
+ if (!shmLock())
+ return false;
+
+ m_ShmAreaLen = mapSize;
}
- m_ShmAreaLen = areaSize;
- return shmLock();
+ return true;
}
-///Connect to the shared memory
-bool Video::ShmRenderer::startShm()
+/// Connect to the shared memory
+bool
+ShmRenderer::startShm()
{
if (d_ptr->m_fd != -1) {
qDebug() << "fd must be -1";
@@ -235,8 +241,9 @@ bool Video::ShmRenderer::startShm()
return false;
}
- const auto areaSize = sizeof(SHMHeader);
- d_ptr->m_pShmArea = (SHMHeader*) ::mmap(nullptr, areaSize,
+ // Map only header data
+ const auto mapSize = sizeof(SHMHeader);
+ d_ptr->m_pShmArea = (SHMHeader*) ::mmap(nullptr, mapSize,
PROT_READ | PROT_WRITE,
MAP_SHARED, d_ptr->m_fd, 0);
if (d_ptr->m_pShmArea == MAP_FAILED) {
@@ -244,14 +251,13 @@ bool Video::ShmRenderer::startShm()
return false;
}
- d_ptr->m_ShmAreaLen = areaSize;
-
- emit started();
+ d_ptr->m_ShmAreaLen = mapSize;
return true;
}
-///Disconnect from the shared memory
-void Video::ShmRenderer::stopShm()
+/// Disconnect from the shared memory
+void
+ShmRenderer::stopShm()
{
if (d_ptr->m_fd < 0)
return;
@@ -267,103 +273,73 @@ void Video::ShmRenderer::stopShm()
d_ptr->m_pShmArea = (SHMHeader*) MAP_FAILED;
}
-///Lock the memory while the copy is being made
-bool Video::ShmRendererPrivate::shmLock()
+/// Lock the memory while the copy is being made
+bool
+ShmRendererPrivate::shmLock()
{
-#ifdef Q_OS_LINUX
- return sem_wait(&m_pShmArea->mutex) >= 0;
-#else
- return false;
-#endif
+ return ::sem_wait(&m_pShmArea->mutex) >= 0;
}
-///Remove the lock, allow a new frame to be drawn
-void Video::ShmRendererPrivate::shmUnlock()
+/// Remove the lock, allow a new frame to be drawn
+void
+ShmRendererPrivate::shmUnlock()
{
-#ifdef Q_OS_LINUX
- sem_post(&m_pShmArea->mutex);
-#endif
+ ::sem_post(&m_pShmArea->mutex);
}
-
/*****************************************************************************
* *
* Slots *
* *
****************************************************************************/
-///Update the buffer
-void Video::ShmRendererPrivate::timedEvents()
+/// Start the rendering loop
+void
+ShmRenderer::startRendering()
{
- if (renderToBitmap()) {
- //Compute the FPS shown to the client
- if (m_CurrentTime.second() != QTime::currentTime().second()) {
- m_Fps = m_fpsC;
- m_fpsC=0;
- m_CurrentTime = QTime::currentTime();
- }
- m_fpsC++;
-
- emit q_ptr->frameUpdated();
- }
- /*else {
- qDebug() << "Frame dropped";
- usleep(rand()%1000); //Be sure it can come back in sync
- }*/
-}
+ QMutexLocker locker {mutex()};
-///Start the rendering loop
-void Video::ShmRenderer::startRendering()
-{
- QMutexLocker locker {mutex()};
-
- if (!startShm()) {
- qDebug() << "Cannot start rendering on " << d_ptr->m_ShmPath;
- return;
- }
-
- if (!d_ptr->m_pTimer) {
- d_ptr->m_pTimer = new QTimer(nullptr);
-
-// m_pTimer->moveToThread(thread());
- connect(d_ptr->m_pTimer,SIGNAL(timeout()),d_ptr.data(),SLOT(timedEvents()));
- d_ptr->m_pTimer->setInterval(30);
- }
-
- if (!d_ptr->m_pTimer->isActive()) {
- qDebug() << "Is running" << thread()->isRunning();
- d_ptr->m_pTimer->start();
- }
- else
- qDebug() << "Timer already started!";
+ if (!startShm())
+ return;
- setRendering(true);
+ setRendering(true);
+ emit started();
}
-///Stop the rendering loop
-void Video::ShmRenderer::stopRendering()
+/// Stop the rendering loop
+void
+ShmRenderer::stopRendering()
{
- setRendering(false);
+ QMutexLocker locker {mutex()};
+ setRendering(false);
- QMutexLocker locker {mutex()};
- qDebug() << "Stopping rendering on" << this;
- if (d_ptr->m_pTimer)
- d_ptr->m_pTimer->stop();
- emit stopped();
- stopShm();
+ emit stopped();
+ stopShm();
}
-
/*****************************************************************************
* *
* Getters *
* *
****************************************************************************/
-///Get the current frame rate of this renderer
-int Video::ShmRenderer::fps() const
+/// Get the current frame rate of this renderer
+int
+ShmRenderer::fps() const
{
- return d_ptr->m_Fps;
+ return d_ptr->m_Fps;
+}
+
+/// Get frame data pointer from shared memory
+void*
+ShmRenderer::getFramePtr() const
+{
+ if (!isRendering())
+ return nullptr;
+
+ QMutexLocker lk {mutex()};
+ d_ptr->getNewFrame(false);
+ return Renderer::getFramePtr();
}
/*****************************************************************************
@@ -372,9 +348,12 @@ int Video::ShmRenderer::fps() const
* *
****************************************************************************/
-void Video::ShmRenderer::setShmPath(const QString& path)
+void
+ShmRenderer::setShmPath(const QString& path)
{
- d_ptr->m_ShmPath = path;
+ d_ptr->m_ShmPath = path;
}
+} // namespace Video
+
#include <shmrenderer.moc>
diff --git a/src/private/shmrenderer.h b/src/private/shmrenderer.h
index 138134fd..e6074d27 100644
--- a/src/private/shmrenderer.h
+++ b/src/private/shmrenderer.h
@@ -52,10 +52,11 @@ class LIB_EXPORT ShmRenderer : public Renderer {
bool startShm ();
//Getters
- virtual int fps () const ;
+ virtual int fps() const;
+ virtual void* getFramePtr() const;
//Setters
- void setShmPath (const QString& path);
+ void setShmPath(const QString& path);
private:
QScopedPointer<ShmRendererPrivate> d_ptr;
@@ -64,9 +65,6 @@ class LIB_EXPORT ShmRenderer : public Renderer {
public Q_SLOTS:
void startRendering();
void stopRendering ();
-
-
-
};
}
diff --git a/src/private/videorenderer_p.h b/src/private/videorenderer_p.h
index 6770d5e5..dc88330b 100644
--- a/src/private/videorenderer_p.h
+++ b/src/private/videorenderer_p.h
@@ -38,15 +38,10 @@ public:
//Attributes
std::atomic_bool m_isRendering;
- QByteArray m_Frame[2] ;
- bool m_FrameIdx ;
QMutex* m_pMutex ;
QString m_Id ;
QSize m_pSize ;
-
- //Helpers
- QByteArray& otherFrame () ;
- void updateFrameIndex () ;
+ void* m_framePtr ;
private:
Video::Renderer* q_ptr;
diff --git a/src/video/renderer.cpp b/src/video/renderer.cpp
index d6ae913a..575caa87 100644
--- a/src/video/renderer.cpp
+++ b/src/video/renderer.cpp
@@ -23,8 +23,9 @@
//Qt
#include <QtCore/QMutex>
-Video::RendererPrivate::RendererPrivate(Video::Renderer* parent) : QObject(parent), q_ptr(parent),
-m_pMutex(new QMutex()), m_FrameIdx(false)
+Video::RendererPrivate::RendererPrivate(Video::Renderer* parent)
+ : QObject(parent), q_ptr(parent)
+ , m_pMutex(new QMutex())
{
}
@@ -49,19 +50,6 @@ bool Video::Renderer::isRendering() const
return d_ptr->m_isRendering;
}
-QByteArray& Video::RendererPrivate::otherFrame()
-{
- static QByteArray empty;
- return q_ptr->isRendering()?m_Frame[!m_FrameIdx]:empty;
-}
-
-///Return the current framerate
-const QByteArray& Video::Renderer::currentFrame() const
-{
- static QByteArray empty;
- return isRendering()?d_ptr->m_Frame[d_ptr->m_FrameIdx]:empty;
-}
-
///Get mutex, in case renderer and views are not in the same thread
QMutex* Video::Renderer::mutex() const
{
@@ -74,6 +62,11 @@ QSize Video::Renderer::size() const
return d_ptr->m_pSize;
}
+void* Video::Renderer::getFramePtr() const
+{
+ return d_ptr->m_framePtr;
+}
+
/*****************************************************************************
* *
* Setters *
@@ -91,9 +84,9 @@ void Video::Renderer::setSize(const QSize& size) const
d_ptr->m_pSize = size;
}
-void Video::RendererPrivate::updateFrameIndex()
+void Video::Renderer::setFramePtr(void* ptr) const
{
- m_FrameIdx = !m_FrameIdx;
+ d_ptr->m_framePtr = ptr;
}
#include <renderer.moc>
diff --git a/src/video/renderer.h b/src/video/renderer.h
index aa5f6548..cd38e0ab 100644
--- a/src/video/renderer.h
+++ b/src/video/renderer.h
@@ -60,17 +60,17 @@ public:
//Getters
virtual bool isRendering () const;
- virtual const QByteArray& currentFrame () const;
virtual QSize size () const;
virtual QMutex* mutex () const;
+ virtual void* getFramePtr () const;
//Setters
void setRendering(bool rendering) const;
void setSize(const QSize& size) const;
+ void setFramePtr(void* ptr) const;
Q_SIGNALS:
- ///Emitted when a new frame is ready
- void frameUpdated();
+ void frameUpdated(); // Emitted when a new frame is ready
void stopped ();
void started ();
--
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