resource.h (2220B)
1 /* 2 * Copyright 2019 The WebRTC Project Authors. All rights reserved. 3 * 4 * Use of this source code is governed by a BSD-style license 5 * that can be found in the LICENSE file in the root of the source 6 * tree. An additional intellectual property rights grant can be found 7 * in the file PATENTS. All contributing project authors may 8 * be found in the AUTHORS file in the root of the source tree. 9 */ 10 11 #ifndef API_ADAPTATION_RESOURCE_H_ 12 #define API_ADAPTATION_RESOURCE_H_ 13 14 #include <string> 15 16 #include "api/ref_count.h" 17 #include "api/scoped_refptr.h" 18 #include "rtc_base/system/rtc_export.h" 19 20 namespace webrtc { 21 22 class Resource; 23 24 enum class ResourceUsageState { 25 // Action is needed to minimze the load on this resource. 26 kOveruse, 27 // Increasing the load on this resource is desired, if possible. 28 kUnderuse, 29 }; 30 31 RTC_EXPORT const char* ResourceUsageStateToString( 32 ResourceUsageState usage_state); 33 34 class RTC_EXPORT ResourceListener { 35 public: 36 virtual ~ResourceListener(); 37 38 virtual void OnResourceUsageStateMeasured(scoped_refptr<Resource> resource, 39 ResourceUsageState usage_state) = 0; 40 }; 41 42 // A Resource monitors an implementation-specific resource. It may report 43 // kOveruse or kUnderuse when resource usage is high or low enough that we 44 // should perform some sort of mitigation to fulfil the resource's constraints. 45 // 46 // The methods on this interface are invoked on the adaptation task queue. 47 // Resource usage measurements may be performed on an any task queue. 48 // 49 // The Resource is reference counted to prevent use-after-free when posting 50 // between task queues. As such, the implementation MUST NOT make any 51 // assumptions about which task queue Resource is destructed on. 52 class RTC_EXPORT Resource : public RefCountInterface { 53 public: 54 Resource(); 55 // Destruction may happen on any task queue. 56 ~Resource() override; 57 58 virtual std::string Name() const = 0; 59 // The `listener` may be informed of resource usage measurements on any task 60 // queue, but not after this method is invoked with the null argument. 61 virtual void SetResourceListener(ResourceListener* listener) = 0; 62 }; 63 64 } // namespace webrtc 65 66 #endif // API_ADAPTATION_RESOURCE_H_