gstreamer/ext/wpe/WPEThreadedView.cpp
Matthew Waters 3ed0ee95f2 wpesrc: fix possible small deadlock on shutdown
Problem is that unreffing the EGLImage/SHM Buffer while holding the
images_mutex lock may deadlock when a new buffer is advertised and
an attempt is made to lock the images_mutex there.

The advertisement of the new image/buffer is performed in the
WPEContextThread and the blocking dispatch when unreffing wants to run
something on the WPEContextThread however images_mutex has already been
locked by the destructor.

Delay unreffing images/buffers outside of images_mutex and instead just
clear the relevant fields within the lock.

Part-of: <https://gitlab.freedesktop.org/gstreamer/gst-plugins-bad/-/merge_requests/1843>
2021-01-25 09:15:28 +00:00

678 lines
21 KiB
C++

/* Copyright (C) <2018, 2019, 2020> Philippe Normand <philn@igalia.com>
* Copyright (C) <2018> Žan Doberšek <zdobersek@igalia.com>
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Library General Public
* License as published by the Free Software Foundation; either
* version 2 of the License, or (at your option) any later version.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Library General Public License for more details.
*
* You should have received a copy of the GNU Library General Public
* License along with this library; if not, write to the
* Free Software Foundation, Inc., 51 Franklin St, Fifth Floor,
* Boston, MA 02110-1301, USA.
*/
#ifdef HAVE_CONFIG_H
#include <config.h>
#endif
#include "WPEThreadedView.h"
#include <gst/gl/gl.h>
#include <gst/gl/egl/gsteglimage.h>
#include <gst/gl/egl/gstgldisplay_egl.h>
#include <wayland-server.h>
#include <cstdio>
#include <mutex>
#if ENABLE_SHM_BUFFER_SUPPORT
#include <wpe/unstable/fdo-shm.h>
#endif
GST_DEBUG_CATEGORY_EXTERN (wpe_src_debug);
#define GST_CAT_DEFAULT wpe_src_debug
#if defined(WPE_FDO_CHECK_VERSION) && WPE_FDO_CHECK_VERSION(1, 3, 0)
#define USE_DEPRECATED_FDO_EGL_IMAGE 0
#define WPE_GLIB_SOURCE_PRIORITY G_PRIORITY_DEFAULT
#else
#define USE_DEPRECATED_FDO_EGL_IMAGE 1
#define WPE_GLIB_SOURCE_PRIORITY -70
#endif
class GMutexHolder {
public:
GMutexHolder(GMutex& mutex)
: m(mutex)
{
g_mutex_lock(&m);
}
~GMutexHolder()
{
g_mutex_unlock(&m);
}
private:
GMutex& m;
};
static WPEContextThread *s_view = NULL;
WPEContextThread& WPEContextThread::singleton()
{
if (!s_view)
s_view = new WPEContextThread;
return *s_view;
}
WPEContextThread::WPEContextThread()
{
g_mutex_init(&threading.mutex);
g_cond_init(&threading.cond);
{
GMutexHolder lock(threading.mutex);
threading.thread = g_thread_new("WPEContextThread", s_viewThread, this);
g_cond_wait(&threading.cond, &threading.mutex);
GST_DEBUG("thread spawned");
}
}
WPEContextThread::~WPEContextThread()
{
if (threading.thread) {
g_thread_unref(threading.thread);
threading.thread = nullptr;
}
g_mutex_clear(&threading.mutex);
g_cond_clear(&threading.cond);
}
template<typename Function>
void WPEContextThread::dispatch(Function func)
{
struct Payload {
Function& func;
};
struct Payload payload { func };
GSource* source = g_idle_source_new();
g_source_set_callback(source, [](gpointer data) -> gboolean {
auto& view = WPEContextThread::singleton();
GMutexHolder lock(view.threading.mutex);
auto* payload = static_cast<struct Payload*>(data);
payload->func();
g_cond_signal(&view.threading.cond);
return G_SOURCE_REMOVE;
}, &payload, nullptr);
g_source_set_priority(source, WPE_GLIB_SOURCE_PRIORITY);
{
GMutexHolder lock(threading.mutex);
g_source_attach(source, glib.context);
g_cond_wait(&threading.cond, &threading.mutex);
}
g_source_unref(source);
}
gpointer WPEContextThread::s_viewThread(gpointer data)
{
auto& view = *static_cast<WPEContextThread*>(data);
view.glib.context = g_main_context_new();
view.glib.loop = g_main_loop_new(view.glib.context, FALSE);
g_main_context_push_thread_default(view.glib.context);
{
GSource* source = g_idle_source_new();
g_source_set_callback(source,
[](gpointer data) -> gboolean {
auto& view = *static_cast<WPEContextThread*>(data);
GMutexHolder lock(view.threading.mutex);
g_cond_signal(&view.threading.cond);
return G_SOURCE_REMOVE;
},
&view, nullptr);
g_source_attach(source, view.glib.context);
g_source_unref(source);
}
g_main_loop_run(view.glib.loop);
g_main_loop_unref(view.glib.loop);
view.glib.loop = nullptr;
g_main_context_pop_thread_default(view.glib.context);
g_main_context_unref(view.glib.context);
view.glib.context = nullptr;
return nullptr;
}
WPEView* WPEContextThread::createWPEView(GstWpeSrc* src, GstGLContext* context, GstGLDisplay* display, int width, int height)
{
GST_DEBUG("context %p display %p, size (%d,%d)", context, display, width, height);
static std::once_flag s_loaderFlag;
std::call_once(s_loaderFlag,
[] {
#if defined(WPE_BACKEND_CHECK_VERSION) && WPE_BACKEND_CHECK_VERSION(1, 2, 0)
wpe_loader_init("libWPEBackend-fdo-1.0.so");
#endif
});
WPEView* view = nullptr;
dispatch([&]() mutable {
if (!glib.web_context) {
auto* manager = webkit_website_data_manager_new_ephemeral();
glib.web_context = webkit_web_context_new_with_website_data_manager(manager);
g_object_unref(manager);
}
view = new WPEView(glib.web_context, src, context, display, width, height);
});
if (view && view->hasUri()) {
GST_DEBUG("waiting load to finish");
view->waitLoadCompletion();
GST_DEBUG("done");
}
return view;
}
static gboolean s_loadFailed(WebKitWebView*, WebKitLoadEvent, gchar* failing_uri, GError* error, gpointer data)
{
GstWpeSrc* src = GST_WPE_SRC(data);
GST_ELEMENT_ERROR (GST_ELEMENT_CAST(src), RESOURCE, FAILED, (NULL), ("Failed to load %s (%s)", failing_uri, error->message));
return FALSE;
}
static gboolean s_loadFailedWithTLSErrors(WebKitWebView*, gchar* failing_uri, GTlsCertificate*, GTlsCertificateFlags, gpointer data)
{
// Defer to load-failed.
return FALSE;
}
static void s_loadProgressChaned(GObject* object, GParamSpec*, gpointer data)
{
GstElement* src = GST_ELEMENT_CAST (data);
// The src element is locked already so we can't call
// gst_element_post_message(). Instead retrieve the bus manually and use it
// directly.
GstBus* bus = GST_ELEMENT_BUS (src);
double estimatedProgress;
g_object_get(object, "estimated-load-progress", &estimatedProgress, nullptr);
gst_object_ref (bus);
gst_bus_post (bus, gst_message_new_element(GST_OBJECT_CAST(src), gst_structure_new("wpe-stats", "estimated-load-progress", G_TYPE_DOUBLE, estimatedProgress * 100, nullptr)));
gst_object_unref (bus);
}
WPEView::WPEView(WebKitWebContext* web_context, GstWpeSrc* src, GstGLContext* context, GstGLDisplay* display, int width, int height)
{
g_mutex_init(&threading.ready_mutex);
g_cond_init(&threading.ready_cond);
threading.ready = FALSE;
g_mutex_init(&images_mutex);
if (context)
gst.context = GST_GL_CONTEXT(gst_object_ref(context));
if (display) {
gst.display = GST_GL_DISPLAY(gst_object_ref(display));
}
wpe.width = width;
wpe.height = height;
if (context && display) {
if (gst_gl_context_get_gl_platform(context) == GST_GL_PLATFORM_EGL) {
gst.display_egl = gst_gl_display_egl_from_gl_display (gst.display);
} else {
GST_DEBUG ("Available GStreamer GL Context is not EGL - not creating an EGL display from it");
}
}
if (gst.display_egl) {
EGLDisplay eglDisplay = (EGLDisplay)gst_gl_display_get_handle (GST_GL_DISPLAY(gst.display_egl));
GST_DEBUG("eglDisplay %p", eglDisplay);
m_isValid = wpe_fdo_initialize_for_egl_display(eglDisplay);
GST_DEBUG("FDO EGL display initialisation result: %d", m_isValid);
} else {
#if ENABLE_SHM_BUFFER_SUPPORT
m_isValid = wpe_fdo_initialize_shm();
GST_DEBUG("FDO SHM initialisation result: %d", m_isValid);
#else
GST_WARNING("FDO SHM support is available only in WPEBackend-FDO 1.7.0");
#endif
}
if (!m_isValid)
return;
if (gst.display_egl) {
wpe.exportable = wpe_view_backend_exportable_fdo_egl_create(&s_exportableEGLClient, this, wpe.width, wpe.height);
} else {
#if ENABLE_SHM_BUFFER_SUPPORT
wpe.exportable = wpe_view_backend_exportable_fdo_create(&s_exportableClient, this, wpe.width, wpe.height);
#endif
}
auto* wpeViewBackend = wpe_view_backend_exportable_fdo_get_view_backend(wpe.exportable);
auto* viewBackend = webkit_web_view_backend_new(wpeViewBackend, (GDestroyNotify) wpe_view_backend_exportable_fdo_destroy, wpe.exportable);
#if defined(WPE_BACKEND_CHECK_VERSION) && WPE_BACKEND_CHECK_VERSION(1, 1, 0)
wpe_view_backend_add_activity_state(wpeViewBackend, wpe_view_activity_state_visible | wpe_view_activity_state_focused | wpe_view_activity_state_in_window);
#endif
webkit.view = WEBKIT_WEB_VIEW(g_object_new(WEBKIT_TYPE_WEB_VIEW, "web-context", web_context, "backend", viewBackend, nullptr));
g_signal_connect(webkit.view, "load-failed", G_CALLBACK(s_loadFailed), src);
g_signal_connect(webkit.view, "load-failed-with-tls-errors", G_CALLBACK(s_loadFailedWithTLSErrors), src);
g_signal_connect(webkit.view, "notify::estimated-load-progress", G_CALLBACK(s_loadProgressChaned), src);
gst_wpe_src_configure_web_view(src, webkit.view);
const gchar* location;
gboolean drawBackground = TRUE;
g_object_get(src, "location", &location, "draw-background", &drawBackground, nullptr);
setDrawBackground(drawBackground);
if (location)
loadUriUnlocked(location);
}
WPEView::~WPEView()
{
GstEGLImage *egl_pending = NULL;
GstEGLImage *egl_committed = NULL;
GstBuffer *shm_pending = NULL;
GstBuffer *shm_committed = NULL;
GST_TRACE ("%p destroying", this);
g_mutex_clear(&threading.ready_mutex);
g_cond_clear(&threading.ready_cond);
{
GMutexHolder lock(images_mutex);
if (egl.pending) {
egl_pending = egl.pending;
egl.pending = nullptr;
}
if (egl.committed) {
egl_committed = egl.committed;
egl.committed = nullptr;
}
if (shm.pending) {
GST_TRACE ("%p freeing shm pending %" GST_PTR_FORMAT, this, shm.pending);
shm_pending = shm.pending;
shm.pending = nullptr;
}
if (shm.committed) {
GST_TRACE ("%p freeing shm commited %" GST_PTR_FORMAT, this, shm.committed);
shm_committed = shm.committed;
shm.committed = nullptr;
}
}
if (egl_pending)
gst_egl_image_unref (egl_pending);
if (egl_committed)
gst_egl_image_unref (egl_committed);
if (shm_pending)
gst_buffer_unref (shm_pending);
if (shm_committed)
gst_buffer_unref (shm_committed);
WPEContextThread::singleton().dispatch([&]() {
if (webkit.view) {
g_object_unref(webkit.view);
webkit.view = nullptr;
}
});
if (gst.display_egl) {
gst_object_unref(gst.display_egl);
gst.display_egl = nullptr;
}
if (gst.display) {
gst_object_unref(gst.display);
gst.display = nullptr;
}
if (gst.context) {
gst_object_unref(gst.context);
gst.context = nullptr;
}
if (webkit.uri) {
g_free(webkit.uri);
webkit.uri = nullptr;
}
g_mutex_clear(&images_mutex);
GST_TRACE ("%p destroyed", this);
}
void WPEView::notifyLoadFinished()
{
GMutexHolder lock(threading.ready_mutex);
if (!threading.ready) {
threading.ready = TRUE;
g_cond_signal(&threading.ready_cond);
}
}
void WPEView::waitLoadCompletion()
{
GMutexHolder lock(threading.ready_mutex);
while (!threading.ready)
g_cond_wait(&threading.ready_cond, &threading.ready_mutex);
}
GstEGLImage* WPEView::image()
{
GstEGLImage* ret = nullptr;
bool dispatchFrameComplete = false;
GstEGLImage *prev_image = NULL;
{
GMutexHolder lock(images_mutex);
GST_TRACE("pending %" GST_PTR_FORMAT " (%d) committed %" GST_PTR_FORMAT " (%d)", egl.pending,
GST_IS_EGL_IMAGE(egl.pending) ? GST_MINI_OBJECT_REFCOUNT_VALUE(GST_MINI_OBJECT_CAST(egl.pending)) : 0,
egl.committed,
GST_IS_EGL_IMAGE(egl.committed) ? GST_MINI_OBJECT_REFCOUNT_VALUE(GST_MINI_OBJECT_CAST(egl.committed)) : 0);
if (egl.pending) {
prev_image = egl.committed;
egl.committed = egl.pending;
egl.pending = nullptr;
dispatchFrameComplete = true;
}
if (egl.committed)
ret = egl.committed;
}
if (prev_image)
gst_egl_image_unref(prev_image);
if (dispatchFrameComplete)
frameComplete();
return ret;
}
GstBuffer* WPEView::buffer()
{
GstBuffer* ret = nullptr;
bool dispatchFrameComplete = false;
GstBuffer *prev_image = NULL;
{
GMutexHolder lock(images_mutex);
GST_TRACE("pending %" GST_PTR_FORMAT " (%d) committed %" GST_PTR_FORMAT " (%d)", shm.pending,
GST_IS_BUFFER(shm.pending) ? GST_MINI_OBJECT_REFCOUNT_VALUE(GST_MINI_OBJECT_CAST(shm.pending)) : 0,
shm.committed,
GST_IS_BUFFER(shm.committed) ? GST_MINI_OBJECT_REFCOUNT_VALUE(GST_MINI_OBJECT_CAST(shm.committed)) : 0);
if (shm.pending) {
prev_image = shm.committed;
shm.committed = shm.pending;
shm.pending = nullptr;
dispatchFrameComplete = true;
}
if (shm.committed)
ret = shm.committed;
}
if (prev_image)
gst_buffer_unref(prev_image);
if (dispatchFrameComplete)
frameComplete();
return ret;
}
void WPEView::resize(int width, int height)
{
GST_DEBUG("resize to %dx%d", width, height);
wpe.width = width;
wpe.height = height;
s_view->dispatch([&]() {
if (wpe.exportable && wpe_view_backend_exportable_fdo_get_view_backend(wpe.exportable))
wpe_view_backend_dispatch_set_size(wpe_view_backend_exportable_fdo_get_view_backend(wpe.exportable), wpe.width, wpe.height);
});
}
void WPEView::frameComplete()
{
GST_TRACE("frame complete");
s_view->dispatch([&]() {
GST_TRACE("dispatching");
wpe_view_backend_exportable_fdo_dispatch_frame_complete(wpe.exportable);
});
}
void WPEView::loadUriUnlocked(const gchar* uri)
{
if (webkit.uri)
g_free(webkit.uri);
GST_DEBUG("loading %s", uri);
webkit.uri = g_strdup(uri);
webkit_web_view_load_uri(webkit.view, webkit.uri);
}
void WPEView::loadUri(const gchar* uri)
{
s_view->dispatch([&]() {
loadUriUnlocked(uri);
});
}
void WPEView::loadData(GBytes* bytes)
{
s_view->dispatch([this, bytes = g_bytes_ref(bytes)]() {
webkit_web_view_load_bytes(webkit.view, bytes, nullptr, nullptr, nullptr);
g_bytes_unref(bytes);
});
}
void WPEView::setDrawBackground(gboolean drawsBackground)
{
#if WEBKIT_CHECK_VERSION(2, 24, 0)
GST_DEBUG("%s background rendering", drawsBackground ? "Enabling" : "Disabling");
WebKitColor color;
webkit_color_parse(&color, drawsBackground ? "white" : "transparent");
webkit_web_view_set_background_color(webkit.view, &color);
#else
GST_FIXME("webkit_web_view_set_background_color is not implemented in WPE %u.%u. Please upgrade to 2.24", webkit_get_major_version(), webkit_get_minor_version());
#endif
}
void WPEView::releaseImage(gpointer imagePointer)
{
s_view->dispatch([&]() {
GST_TRACE("Dispatch release exported image %p", imagePointer);
#if USE_DEPRECATED_FDO_EGL_IMAGE
wpe_view_backend_exportable_fdo_egl_dispatch_release_image(wpe.exportable,
static_cast<EGLImageKHR>(imagePointer));
#else
wpe_view_backend_exportable_fdo_egl_dispatch_release_exported_image(wpe.exportable,
static_cast<struct wpe_fdo_egl_exported_image*>(imagePointer));
#endif
});
}
struct ImageContext {
WPEView* view;
gpointer image;
};
void WPEView::handleExportedImage(gpointer image)
{
ImageContext* imageContext = g_slice_new(ImageContext);
imageContext->view = this;
imageContext->image = static_cast<gpointer>(image);
EGLImageKHR eglImage;
#if USE_DEPRECATED_FDO_EGL_IMAGE
eglImage = static_cast<EGLImageKHR>(image);
#else
eglImage = wpe_fdo_egl_exported_image_get_egl_image(static_cast<struct wpe_fdo_egl_exported_image*>(image));
#endif
auto* gstImage = gst_egl_image_new_wrapped(gst.context, eglImage, GST_GL_RGBA, imageContext, s_releaseImage);
{
GMutexHolder lock(images_mutex);
GST_TRACE("EGLImage %p wrapped in GstEGLImage %" GST_PTR_FORMAT, eglImage, gstImage);
gst_clear_mini_object ((GstMiniObject **) &egl.pending);
egl.pending = gstImage;
notifyLoadFinished();
}
}
#if ENABLE_SHM_BUFFER_SUPPORT
struct SHMBufferContext {
WPEView* view;
struct wpe_fdo_shm_exported_buffer* buffer;
};
void WPEView::releaseSHMBuffer(gpointer data)
{
SHMBufferContext* context = static_cast<SHMBufferContext*>(data);
s_view->dispatch([&]() {
auto* buffer = static_cast<struct wpe_fdo_shm_exported_buffer*>(context->buffer);
GST_TRACE("Dispatch release exported buffer %p", buffer);
wpe_view_backend_exportable_fdo_dispatch_release_shm_exported_buffer(wpe.exportable, buffer);
});
}
void WPEView::s_releaseSHMBuffer(gpointer data)
{
SHMBufferContext* context = static_cast<SHMBufferContext*>(data);
context->view->releaseSHMBuffer(data);
g_slice_free(SHMBufferContext, context);
}
void WPEView::handleExportedBuffer(struct wpe_fdo_shm_exported_buffer* buffer)
{
struct wl_shm_buffer* shmBuffer = wpe_fdo_shm_exported_buffer_get_shm_buffer(buffer);
auto format = wl_shm_buffer_get_format(shmBuffer);
if (format != WL_SHM_FORMAT_ARGB8888 && format != WL_SHM_FORMAT_XRGB8888) {
GST_ERROR("Unsupported pixel format: %d", format);
return;
}
int32_t width = wl_shm_buffer_get_width(shmBuffer);
int32_t height = wl_shm_buffer_get_height(shmBuffer);
gint stride = wl_shm_buffer_get_stride(shmBuffer);
gsize size = width * height * 4;
auto* data = static_cast<uint8_t*>(wl_shm_buffer_get_data(shmBuffer));
SHMBufferContext* bufferContext = g_slice_new(SHMBufferContext);
bufferContext->view = this;
bufferContext->buffer = buffer;
auto* gstBuffer = gst_buffer_new_wrapped_full(GST_MEMORY_FLAG_READONLY, data, size, 0, size, bufferContext, s_releaseSHMBuffer);
gsize offsets[1];
gint strides[1];
offsets[0] = 0;
strides[0] = stride;
gst_buffer_add_video_meta_full(gstBuffer, GST_VIDEO_FRAME_FLAG_NONE, GST_VIDEO_FORMAT_BGRA, width, height, 1, offsets, strides);
{
GMutexHolder lock(images_mutex);
GST_TRACE("SHM buffer %p wrapped in buffer %" GST_PTR_FORMAT, buffer, gstBuffer);
gst_clear_buffer (&shm.pending);
shm.pending = gstBuffer;
notifyLoadFinished();
}
}
#endif
struct wpe_view_backend_exportable_fdo_egl_client WPEView::s_exportableEGLClient = {
#if USE_DEPRECATED_FDO_EGL_IMAGE
// export_egl_image
[](void* data, EGLImageKHR image) {
auto& view = *static_cast<WPEView*>(data);
view.handleExportedImage(static_cast<gpointer>(image));
},
nullptr, nullptr,
#else
// export_egl_image
nullptr,
[](void* data, struct wpe_fdo_egl_exported_image* image) {
auto& view = *static_cast<WPEView*>(data);
view.handleExportedImage(static_cast<gpointer>(image));
},
nullptr,
#endif // USE_DEPRECATED_FDO_EGL_IMAGE
// padding
nullptr, nullptr
};
#if ENABLE_SHM_BUFFER_SUPPORT
struct wpe_view_backend_exportable_fdo_client WPEView::s_exportableClient = {
nullptr,
nullptr,
// export_shm_buffer
[](void* data, struct wpe_fdo_shm_exported_buffer* buffer) {
auto& view = *static_cast<WPEView*>(data);
view.handleExportedBuffer(buffer);
},
nullptr,
nullptr,
};
#endif
void WPEView::s_releaseImage(GstEGLImage* image, gpointer data)
{
ImageContext* context = static_cast<ImageContext*>(data);
context->view->releaseImage(context->image);
g_slice_free(ImageContext, context);
}
struct wpe_view_backend* WPEView::backend() const
{
return wpe.exportable ? wpe_view_backend_exportable_fdo_get_view_backend(wpe.exportable) : nullptr;
}
void WPEView::dispatchKeyboardEvent(struct wpe_input_keyboard_event& wpe_event)
{
s_view->dispatch([&]() {
wpe_view_backend_dispatch_keyboard_event(backend(), &wpe_event);
});
}
void WPEView::dispatchPointerEvent(struct wpe_input_pointer_event& wpe_event)
{
s_view->dispatch([&]() {
wpe_view_backend_dispatch_pointer_event(backend(), &wpe_event);
});
}
void WPEView::dispatchAxisEvent(struct wpe_input_axis_event& wpe_event)
{
s_view->dispatch([&]() {
wpe_view_backend_dispatch_axis_event(backend(), &wpe_event);
});
}