1 files changed, 307 insertions, 0 deletions
diff --git a/gfx/layers/client/TextureClientPool.cpp b/gfx/layers/client/TextureClientPool.cpp
new file mode 100644
index 0000000000..1dbef5fb84
--- /dev/null
+++ b/gfx/layers/client/TextureClientPool.cpp
@@ -0,0 +1,307 @@
+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim: set ts=8 sts=2 et sw=2 tw=80: */
+/* 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 "TextureClientPool.h"
+#include "CompositableClient.h"
+#include "mozilla/layers/CompositableForwarder.h"
+#include "mozilla/layers/TextureForwarder.h"
+#include "mozilla/StaticPrefs_layers.h"
+
+#include "nsComponentManagerUtils.h"
+
+#define TCP_LOG(...)
+// #define TCP_LOG(...) printf_stderr(__VA_ARGS__);
+
+namespace mozilla {
+namespace layers {
+
+// We want to shrink to our maximum size of N unused tiles
+// after a timeout to allow for short-term budget requirements
+static void ShrinkCallback(nsITimer* aTimer, void* aClosure) {
+  static_cast<TextureClientPool*>(aClosure)->ShrinkToMaximumSize();
+}
+
+// After a certain amount of inactivity, let's clear the pool so that
+// we don't hold onto tiles needlessly. In general, allocations are
+// cheap enough that re-allocating isn't an issue unless we're allocating
+// at an inopportune time (e.g. mid-animation).
+static void ClearCallback(nsITimer* aTimer, void* aClosure) {
+  static_cast<TextureClientPool*>(aClosure)->Clear();
+}
+
+TextureClientPool::TextureClientPool(
+    KnowsCompositor* aKnowsCompositor, gfx::SurfaceFormat aFormat,
+    gfx::IntSize aSize, TextureFlags aFlags, uint32_t aShrinkTimeoutMsec,
+    uint32_t aClearTimeoutMsec, uint32_t aInitialPoolSize,
+    uint32_t aPoolUnusedSize, TextureForwarder* aAllocator)
+    : mKnowsCompositor(aKnowsCompositor),
+      mFormat(aFormat),
+      mSize(aSize),
+      mFlags(aFlags),
+      mShrinkTimeoutMsec(aShrinkTimeoutMsec),
+      mClearTimeoutMsec(aClearTimeoutMsec),
+      mInitialPoolSize(aInitialPoolSize),
+      mPoolUnusedSize(aPoolUnusedSize),
+      mOutstandingClients(0),
+      mSurfaceAllocator(aAllocator),
+      mDestroyed(false) {
+  TCP_LOG("TexturePool %p created with maximum unused texture clients %u\n",
+          this, mInitialPoolSize);
+  mShrinkTimer = NS_NewTimer();
+  mClearTimer = NS_NewTimer();
+  if (aFormat == gfx::SurfaceFormat::UNKNOWN) {
+    gfxWarning() << "Creating texture pool for SurfaceFormat::UNKNOWN format";
+  }
+}
+
+TextureClientPool::~TextureClientPool() {
+  mShrinkTimer->Cancel();
+  mClearTimer->Cancel();
+}
+
+#ifdef GFX_DEBUG_TRACK_CLIENTS_IN_POOL
+static bool TestClientPool(const char* what, TextureClient* aClient,
+                           TextureClientPool* aPool) {
+  if (!aClient || !aPool) {
+    return false;
+  }
+
+  TextureClientPool* actual = aClient->mPoolTracker;
+  bool ok = (actual == aPool);
+  if (ok) {
+    ok = (aClient->GetFormat() == aPool->GetFormat());
+  }
+
+  if (!ok) {
+    if (actual) {
+      gfxCriticalError() << "Pool error(" << what << "): " << aPool << "-"
+                         << aPool->GetFormat() << ", " << actual << "-"
+                         << actual->GetFormat() << ", " << aClient->GetFormat();
+      MOZ_CRASH("GFX: Crashing with actual");
+    } else {
+      gfxCriticalError() << "Pool error(" << what << "): " << aPool << "-"
+                         << aPool->GetFormat() << ", nullptr, "
+                         << aClient->GetFormat();
+      MOZ_CRASH("GFX: Crashing without actual");
+    }
+  }
+  return ok;
+}
+#endif
+
+already_AddRefed<TextureClient> TextureClientPool::GetTextureClient() {
+  // Try to fetch a client from the pool
+  RefPtr<TextureClient> textureClient;
+
+  // We initially allocate mInitialPoolSize for our pool. If we run
+  // out of TextureClients, we allocate additional TextureClients to try and
+  // keep around mPoolUnusedSize
+  if (mTextureClients.empty()) {
+    AllocateTextureClient();
+  }
+
+  if (mTextureClients.empty()) {
+    // All our allocations failed, return nullptr
+    return nullptr;
+  }
+
+  mOutstandingClients++;
+  textureClient = mTextureClients.top();
+  mTextureClients.pop();
+#ifdef GFX_DEBUG_TRACK_CLIENTS_IN_POOL
+  if (textureClient) {
+    textureClient->mPoolTracker = this;
+  }
+  DebugOnly<bool> ok = TestClientPool("fetch", textureClient, this);
+  MOZ_ASSERT(ok);
+#endif
+  TCP_LOG("TexturePool %p giving %p from pool; size %u outstanding %u\n", this,
+          textureClient.get(), mTextureClients.size(), mOutstandingClients);
+
+  return textureClient.forget();
+}
+
+void TextureClientPool::AllocateTextureClient() {
+  TCP_LOG("TexturePool %p allocating TextureClient, outstanding %u\n", this,
+          mOutstandingClients);
+
+  TextureAllocationFlags allocFlags = ALLOC_DEFAULT;
+
+  RefPtr<TextureClient> newClient;
+  if (StaticPrefs::layers_force_shmem_tiles_AtStartup()) {
+    // gfx::BackendType::NONE means use the content backend
+    newClient = TextureClient::CreateForRawBufferAccess(
+        mSurfaceAllocator, mFormat, mSize, gfx::BackendType::NONE, GetBackend(),
+        mFlags, allocFlags);
+  } else {
+    newClient = TextureClient::CreateForDrawing(
+        mSurfaceAllocator, mFormat, mSize, mKnowsCompositor,
+        BackendSelector::Content, mFlags, allocFlags);
+  }
+
+  if (newClient) {
+    mTextureClients.push(newClient);
+  }
+}
+
+void TextureClientPool::ResetTimers() {
+  // Shrink down if we're beyond our maximum size
+  if (mShrinkTimeoutMsec &&
+      mTextureClients.size() + mTextureClientsDeferred.size() >
+          mPoolUnusedSize) {
+    TCP_LOG("TexturePool %p scheduling a shrink-to-max-size\n", this);
+    mShrinkTimer->InitWithNamedFuncCallback(
+        ShrinkCallback, this, mShrinkTimeoutMsec, nsITimer::TYPE_ONE_SHOT,
+        "layers::TextureClientPool::ResetTimers");
+  }
+
+  // Clear pool after a period of inactivity to reduce memory consumption
+  if (mClearTimeoutMsec) {
+    TCP_LOG("TexturePool %p scheduling a clear\n", this);
+    mClearTimer->InitWithNamedFuncCallback(
+        ClearCallback, this, mClearTimeoutMsec, nsITimer::TYPE_ONE_SHOT,
+        "layers::TextureClientPool::ResetTimers");
+  }
+}
+
+void TextureClientPool::ReturnTextureClient(TextureClient* aClient) {
+  if (!aClient || mDestroyed) {
+    return;
+  }
+#ifdef GFX_DEBUG_TRACK_CLIENTS_IN_POOL
+  DebugOnly<bool> ok = TestClientPool("return", aClient, this);
+  MOZ_ASSERT(ok);
+#endif
+  // Add the client to the pool:
+  MOZ_ASSERT(mOutstandingClients > mTextureClientsDeferred.size());
+  mOutstandingClients--;
+  mTextureClients.push(aClient);
+  TCP_LOG("TexturePool %p had client %p returned; size %u outstanding %u\n",
+          this, aClient, mTextureClients.size(), mOutstandingClients);
+
+  ResetTimers();
+}
+
+void TextureClientPool::ReturnTextureClientDeferred(TextureClient* aClient) {
+  if (!aClient || mDestroyed) {
+    return;
+  }
+  MOZ_ASSERT(aClient->GetReadLock());
+#ifdef GFX_DEBUG_TRACK_CLIENTS_IN_POOL
+  DebugOnly<bool> ok = TestClientPool("defer", aClient, this);
+  MOZ_ASSERT(ok);
+#endif
+  mTextureClientsDeferred.push_back(aClient);
+  TCP_LOG(
+      "TexturePool %p had client %p defer-returned, size %u outstanding %u\n",
+      this, aClient, mTextureClientsDeferred.size(), mOutstandingClients);
+
+  ResetTimers();
+}
+
+void TextureClientPool::ShrinkToMaximumSize() {
+  // We're over our desired maximum size, immediately shrink down to the
+  // maximum.
+  //
+  // We cull from the deferred TextureClients first, as we can't reuse those
+  // until they get returned.
+  uint32_t totalUnusedTextureClients =
+      mTextureClients.size() + mTextureClientsDeferred.size();
+
+  // If we have > mInitialPoolSize outstanding, then we want to keep around
+  // mPoolUnusedSize at a maximum. If we have fewer than mInitialPoolSize
+  // outstanding, then keep around the entire initial pool size.
+  uint32_t targetUnusedClients;
+  if (mOutstandingClients > mInitialPoolSize) {
+    targetUnusedClients = mPoolUnusedSize;
+  } else {
+    targetUnusedClients = mInitialPoolSize;
+  }
+
+  TCP_LOG(
+      "TexturePool %p shrinking to maximum unused size %u; current pool size "
+      "%u; total outstanding %u\n",
+      this, targetUnusedClients, totalUnusedTextureClients,
+      mOutstandingClients);
+
+  while (totalUnusedTextureClients > targetUnusedClients) {
+    if (!mTextureClientsDeferred.empty()) {
+      mOutstandingClients--;
+      TCP_LOG("TexturePool %p dropped deferred client %p; %u remaining\n", this,
+              mTextureClientsDeferred.front().get(),
+              mTextureClientsDeferred.size() - 1);
+      mTextureClientsDeferred.pop_front();
+    } else {
+      TCP_LOG("TexturePool %p dropped non-deferred client %p; %u remaining\n",
+              this, mTextureClients.top().get(), mTextureClients.size() - 1);
+      mTextureClients.pop();
+    }
+    totalUnusedTextureClients--;
+  }
+}
+
+void TextureClientPool::ReturnDeferredClients() {
+  if (mTextureClientsDeferred.empty()) {
+    return;
+  }
+
+  TCP_LOG("TexturePool %p returning %u deferred clients to pool\n", this,
+          mTextureClientsDeferred.size());
+
+  ReturnUnlockedClients();
+  ShrinkToMaximumSize();
+}
+
+void TextureClientPool::ReturnUnlockedClients() {
+  for (auto it = mTextureClientsDeferred.begin();
+       it != mTextureClientsDeferred.end();) {
+    MOZ_ASSERT((*it)->GetReadLock()->AsNonBlockingLock()->GetReadCount() >= 1);
+    // Last count is held by the lock itself.
+    if (!(*it)->IsReadLocked()) {
+      mTextureClients.push(*it);
+      it = mTextureClientsDeferred.erase(it);
+
+      MOZ_ASSERT(mOutstandingClients > 0);
+      mOutstandingClients--;
+    } else {
+      it++;
+    }
+  }
+}
+
+void TextureClientPool::ReportClientLost() {
+  MOZ_ASSERT(mOutstandingClients > mTextureClientsDeferred.size());
+  mOutstandingClients--;
+  TCP_LOG("TexturePool %p getting report client lost; down to %u outstanding\n",
+          this, mOutstandingClients);
+}
+
+void TextureClientPool::Clear() {
+  TCP_LOG("TexturePool %p getting cleared\n", this);
+  while (!mTextureClients.empty()) {
+    TCP_LOG("TexturePool %p releasing client %p\n", this,
+            mTextureClients.top().get());
+    mTextureClients.pop();
+  }
+  while (!mTextureClientsDeferred.empty()) {
+    MOZ_ASSERT(mOutstandingClients > 0);
+    mOutstandingClients--;
+    TCP_LOG("TexturePool %p releasing deferred client %p\n", this,
+            mTextureClientsDeferred.front().get());
+    mTextureClientsDeferred.pop_front();
+  }
+}
+
+void TextureClientPool::Destroy() {
+  Clear();
+  mDestroyed = true;
+  mInitialPoolSize = 0;
+  mPoolUnusedSize = 0;
+  mKnowsCompositor = nullptr;
+}
+
+}  // namespace layers
+}  // namespace mozilla