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/* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
* file, You can obtain one at http://mozilla.org/MPL/2.0/. */
#include "CanvasRenderThread.h"
#include "mozilla/BackgroundHangMonitor.h"
#include "mozilla/SharedThreadPool.h"
#include "mozilla/StaticPrefs_gfx.h"
#include "mozilla/gfx/CanvasManagerParent.h"
#include "mozilla/gfx/gfxVars.h"
#include "mozilla/layers/CanvasTranslator.h"
#include "mozilla/layers/CompositorThread.h"
#include "mozilla/webrender/RenderThread.h"
#include "nsThread.h"
#include "prsystem.h"
#include "transport/runnable_utils.h"
bool NS_IsInCanvasThreadOrWorker() {
return mozilla::gfx::CanvasRenderThread::IsInCanvasRenderOrWorkerThread();
}
namespace mozilla::gfx {
static StaticRefPtr<CanvasRenderThread> sCanvasRenderThread;
static mozilla::BackgroundHangMonitor* sBackgroundHangMonitor;
#ifdef DEBUG
static bool sCanvasRenderThreadEverStarted = false;
#endif
CanvasRenderThread::CanvasRenderThread(nsCOMPtr<nsIThread>&& aThread,
bool aCreatedThread)
: mMutex("CanvasRenderThread::mMutex"),
mThread(std::move(aThread)),
mCreatedThread(aCreatedThread) {}
CanvasRenderThread::~CanvasRenderThread() = default;
// static
void CanvasRenderThread::Start() {
MOZ_ASSERT(NS_IsMainThread());
MOZ_ASSERT(!sCanvasRenderThread);
#ifdef DEBUG
// Check to ensure nobody will try to ever start us more than once during
// the process' lifetime (in particular after Stop).
MOZ_ASSERT(!sCanvasRenderThreadEverStarted);
sCanvasRenderThreadEverStarted = true;
#endif
nsCOMPtr<nsIThread> thread;
if (!gfxVars::SupportsThreadsafeGL()) {
thread = wr::RenderThread::GetRenderThread();
MOZ_ASSERT(thread);
} else if (!gfxVars::UseCanvasRenderThread()) {
thread = layers::CompositorThread();
MOZ_ASSERT(thread);
}
if (thread) {
sCanvasRenderThread =
new CanvasRenderThread(std::move(thread), /* aCreatedThread */ false);
return;
}
// This is 4M, which is higher than the default 256K.
// Increased with bug 1753349 to accommodate the `chromium/5359` branch of
// ANGLE, which has large peak stack usage for some pathological shader
// compilations.
//
// Previously increased to 512K to accommodate Mesa in bug 1753340.
//
// Previously increased to 320K to avoid a stack overflow in the
// Intel Vulkan driver initialization in bug 1716120.
//
// Note: we only override it if it's limited already.
const uint32_t stackSize =
nsIThreadManager::DEFAULT_STACK_SIZE ? 4096 << 10 : 0;
nsresult rv = NS_NewNamedThread(
"CanvasRenderer", getter_AddRefs(thread),
NS_NewRunnableFunction(
"CanvasRender::BackgroundHangSetup",
[]() {
sBackgroundHangMonitor = new mozilla::BackgroundHangMonitor(
"CanvasRendererBHM",
/* Timeout values are powers-of-two to enable us get better
data. 128ms is chosen for transient hangs because 8Hz should
be the minimally acceptable goal for Compositor
responsiveness (normal goal is 60Hz). */
128,
/* 2048ms is chosen for permanent hangs because it's longer than
* most Compositor hangs seen in the wild, but is short enough
* to not miss getting native hang stacks. */
2048);
nsCOMPtr<nsIThread> thread = NS_GetCurrentThread();
nsThread* nsthread = static_cast<nsThread*>(thread.get());
nsthread->SetUseHangMonitor(true);
nsthread->SetPriority(nsISupportsPriority::PRIORITY_HIGH);
}),
{.stackSize = stackSize});
if (NS_WARN_IF(NS_FAILED(rv))) {
return;
}
sCanvasRenderThread =
new CanvasRenderThread(std::move(thread), /* aCreatedThread */ true);
}
// static
void CanvasRenderThread::Shutdown() {
MOZ_ASSERT(NS_IsMainThread());
// It is possible we never initialized this thread in the parent process,
// because we used the GPU process instead.
if (!sCanvasRenderThread) {
MOZ_ASSERT(XRE_IsParentProcess());
return;
}
// This closes all of the IPDL actors with possibly active task queues.
CanvasManagerParent::Shutdown();
// Queue any remaining global cleanup for CanvasTranslator
layers::CanvasTranslator::Shutdown();
bool createdThread = sCanvasRenderThread->mCreatedThread;
nsCOMPtr<nsIThread> oldThread = sCanvasRenderThread->GetCanvasRenderThread();
// Ensure that we flush the CanvasRenderThread event queue before clearing our
// singleton.
NS_DispatchAndSpinEventLoopUntilComplete(
"CanvasRenderThread::Shutdown"_ns, oldThread,
NS_NewRunnableFunction("CanvasRenderThread::Shutdown", []() -> void {}));
// Null out sCanvasRenderThread before we enter synchronous Shutdown,
// from here on we are to be considered shut down for our consumers.
sCanvasRenderThread = nullptr;
// We do a synchronous shutdown here while spinning the MT event loop, but
// only if we created a dedicated CanvasRender thread.
if (createdThread) {
oldThread->Shutdown();
}
}
// static
bool CanvasRenderThread::IsInCanvasRenderThread() {
return sCanvasRenderThread &&
sCanvasRenderThread->mThread == NS_GetCurrentThread();
}
/* static */ bool CanvasRenderThread::IsInCanvasWorkerThread() {
// It is possible there are no worker threads, and the worker is the same as
// the CanvasRenderThread itself.
return sCanvasRenderThread &&
sCanvasRenderThread->mThread == NS_GetCurrentThread();
}
/* static */ bool CanvasRenderThread::IsInCanvasRenderOrWorkerThread() {
// It is possible there are no worker threads, and the worker is the same as
// the CanvasRenderThread itself.
return sCanvasRenderThread &&
sCanvasRenderThread->mThread == NS_GetCurrentThread();
}
// static
already_AddRefed<nsIThread> CanvasRenderThread::GetCanvasRenderThread() {
nsCOMPtr<nsIThread> thread;
if (sCanvasRenderThread) {
thread = sCanvasRenderThread->mThread;
}
return thread.forget();
}
/* static */ void CanvasRenderThread::Dispatch(
already_AddRefed<nsIRunnable> aRunnable) {
if (!sCanvasRenderThread) {
MOZ_DIAGNOSTIC_CRASH("Dispatching after CanvasRenderThread shutdown!");
return;
}
sCanvasRenderThread->mThread->Dispatch(std::move(aRunnable));
}
} // namespace mozilla::gfx