9ebf727f56
- Guards against duplicate activations by checking wether the backend of the prior scope is the same as the current ones - Makes sure that only the most outer backend scope deactivates by tracking activation state
67 lines
1.6 KiB
C++
67 lines
1.6 KiB
C++
#include <mbgl/renderer/backend_scope.hpp>
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#include <mbgl/renderer/renderer_backend.hpp>
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#include <mbgl/util/thread_local.hpp>
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#include <cassert>
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namespace mbgl {
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static util::ThreadLocal<BackendScope> currentScope;
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BackendScope::BackendScope(RendererBackend& backend_, ScopeType scopeType_)
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: priorScope(currentScope.get()),
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nextScope(nullptr),
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backend(backend_),
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scopeType(scopeType_) {
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if (priorScope) {
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assert(priorScope->nextScope == nullptr);
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priorScope->nextScope = this;
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priorScope->deactivate();
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}
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activate();
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currentScope.set(this);
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}
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BackendScope::~BackendScope() {
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assert(nextScope == nullptr);
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deactivate();
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if (priorScope) {
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priorScope->activate();
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currentScope.set(priorScope);
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assert(priorScope->nextScope == this);
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priorScope->nextScope = nullptr;
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} else {
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currentScope.set(nullptr);
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}
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}
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void BackendScope::activate() {
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if (scopeType == ScopeType::Explicit &&
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!(priorScope && this->backend == priorScope->backend) &&
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!(nextScope && this->backend == nextScope->backend)) {
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// Only activate when set to Explicit and
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// only once per RenderBackend
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backend.activate();
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activated = true;
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}
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}
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void BackendScope::deactivate() {
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if (activated &&
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!(nextScope && this->backend == nextScope->backend)) {
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// Only deactivate when set to Explicit and
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// only once per RenderBackend
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backend.deactivate();
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activated = false;
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}
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}
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bool BackendScope::exists() {
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return currentScope.get();
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}
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} // namespace mbgl
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