1 // Copyright 2017 The Chromium Authors. All rights reserved. 2 // Use of this source code is governed by a BSD-style license that can be 3 // found in the LICENSE file. 4 5 #ifndef BASE_TRACE_EVENT_MEMORY_DUMP_PROVIDER_INFO_H_ 6 #define BASE_TRACE_EVENT_MEMORY_DUMP_PROVIDER_INFO_H_ 7 8 #include <memory> 9 #include <set> 10 11 #include "base/base_export.h" 12 #include "base/memory/ref_counted.h" 13 #include "base/trace_event/memory_dump_provider.h" 14 15 namespace base { 16 17 class SequencedTaskRunner; 18 19 namespace trace_event { 20 21 // Wraps a MemoryDumpProvider (MDP), which is registered via 22 // MemoryDumpManager(MDM)::RegisterDumpProvider(), holding the extra information 23 // required to deal with it (which task runner it should be invoked onto, 24 // whether it has been disabled, etc.) 25 // More importantly, having a refptr to this object guarantees that a MDP that 26 // is not thread-bound (hence which can only be unregistered via 27 // MDM::UnregisterAndDeleteDumpProviderSoon()) will stay alive as long as the 28 // refptr is held. 29 // 30 // Lifetime: 31 // At any time, there is at most one instance of this class for each instance 32 // of a given MemoryDumpProvider, but there might be several scoped_refptr 33 // holding onto each of this. Specifically: 34 // - In nominal conditions, there is a refptr for each registered MDP in the 35 // MDM's |dump_providers_| list. 36 // - In most cases, the only refptr (in the |dump_providers_| list) is destroyed 37 // by MDM::UnregisterDumpProvider(). 38 // - However, when MDM starts a dump, the list of refptrs is copied into the 39 // ProcessMemoryDumpAsyncState. That list is pruned as MDP(s) are invoked. 40 // - If UnregisterDumpProvider() is called on a non-thread-bound MDP while a 41 // dump is in progress, the extar extra of the handle is destroyed in 42 // MDM::SetupNextMemoryDump() or MDM::InvokeOnMemoryDump(), when the copy 43 // inside ProcessMemoryDumpAsyncState is erase()-d. 44 // - The PeakDetector can keep extra refptrs when enabled. 45 struct BASE_EXPORT MemoryDumpProviderInfo 46 : public RefCountedThreadSafe<MemoryDumpProviderInfo> { 47 public: 48 // Define a total order based on the |task_runner| affinity, so that MDPs 49 // belonging to the same SequencedTaskRunner are adjacent in the set. 50 struct Comparator { 51 bool operator()(const scoped_refptr<MemoryDumpProviderInfo>& a, 52 const scoped_refptr<MemoryDumpProviderInfo>& b) const; 53 }; 54 using OrderedSet = 55 std::set<scoped_refptr<MemoryDumpProviderInfo>, Comparator>; 56 57 MemoryDumpProviderInfo(MemoryDumpProvider* dump_provider, 58 const char* name, 59 scoped_refptr<SequencedTaskRunner> task_runner, 60 const MemoryDumpProvider::Options& options, 61 bool allowed_in_background_mode); 62 63 // It is safe to access the const fields below from any thread as they are 64 // never mutated. 65 66 MemoryDumpProvider* const dump_provider; 67 68 // The |options| arg passed to MDM::RegisterDumpProvider(). 69 const MemoryDumpProvider::Options options; 70 71 // Human readable name, not unique (distinct MDP instances might have the same 72 // name). Used for debugging, testing and whitelisting for BACKGROUND mode. 73 const char* const name; 74 75 // The task runner on which the MDP::OnMemoryDump call should be posted onto. 76 // Can be nullptr, in which case the MDP will be invoked on a background 77 // thread handled by MDM. 78 const scoped_refptr<SequencedTaskRunner> task_runner; 79 80 // True if the dump provider is whitelisted for background mode. 81 const bool allowed_in_background_mode; 82 83 // These fields below, instead, are not thread safe and can be mutated only: 84 // - On the |task_runner|, when not null (i.e. for thread-bound MDPS). 85 // - By the MDM's background thread (or in any other way that guarantees 86 // sequencing) for non-thread-bound MDPs. 87 88 // Used to transfer ownership for UnregisterAndDeleteDumpProviderSoon(). 89 // nullptr in all other cases. 90 std::unique_ptr<MemoryDumpProvider> owned_dump_provider; 91 92 // For fail-safe logic (auto-disable failing MDPs). 93 int consecutive_failures; 94 95 // Flagged either by the auto-disable logic or during unregistration. 96 bool disabled; 97 98 private: 99 friend class base::RefCountedThreadSafe<MemoryDumpProviderInfo>; 100 ~MemoryDumpProviderInfo(); 101 102 DISALLOW_COPY_AND_ASSIGN(MemoryDumpProviderInfo); 103 }; 104 105 } // namespace trace_event 106 } // namespace base 107 108 #endif // BASE_TRACE_EVENT_MEMORY_DUMP_PROVIDER_INFO_H_ 109