Add m-esr52 at 52.6.0

1 files changed, 288 insertions, 0 deletions

diff --git a/xpcom/base/nsMemoryReporterManager.h b/xpcom/base/nsMemoryReporterManager.h
new file mode 100644
index 000000000..8240cbe34
--- /dev/null
+++ b/xpcom/base/nsMemoryReporterManager.h
@@ -0,0 +1,288 @@
+/* -*- 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/. */
+
+#ifndef nsMemoryReporterManager_h__
+#define nsMemoryReporterManager_h__
+
+#include "mozilla/Mutex.h"
+#include "nsHashKeys.h"
+#include "nsIMemoryReporter.h"
+#include "nsITimer.h"
+#include "nsServiceManagerUtils.h"
+#include "nsTHashtable.h"
+
+namespace mozilla {
+namespace dom {
+class ContentParent;
+class MemoryReport;
+} // namespace dom
+} // namespace mozilla
+
+class nsITimer;
+
+class nsMemoryReporterManager final : public nsIMemoryReporterManager
+{
+  virtual ~nsMemoryReporterManager();
+
+public:
+  NS_DECL_THREADSAFE_ISUPPORTS
+  NS_DECL_NSIMEMORYREPORTERMANAGER
+
+  nsMemoryReporterManager();
+
+  // Gets the memory reporter manager service.
+  static nsMemoryReporterManager* GetOrCreate()
+  {
+    nsCOMPtr<nsIMemoryReporterManager> imgr =
+      do_GetService("@mozilla.org/memory-reporter-manager;1");
+    return static_cast<nsMemoryReporterManager*>(imgr.get());
+  }
+
+  typedef nsDataHashtable<nsRefPtrHashKey<nsIMemoryReporter>, bool> StrongReportersTable;
+  typedef nsDataHashtable<nsPtrHashKey<nsIMemoryReporter>, bool> WeakReportersTable;
+
+  // Inter-process memory reporting proceeds as follows.
+  //
+  // - GetReports() (declared within NS_DECL_NSIMEMORYREPORTERMANAGER)
+  //   synchronously gets memory reports for the current process, sets up some
+  //   state (mPendingProcessesState) for when child processes report back --
+  //   including a timer -- and starts telling child processes to get memory
+  //   reports.  Control then returns to the main event loop.
+  //
+  //   The number of concurrent child process reports is limited by the pref
+  //   "memory.report_concurrency" in order to prevent the memory overhead of
+  //   memory reporting from causing problems, especially on B2G when swapping
+  //   to compressed RAM; see bug 1154053.
+  //
+  // - HandleChildReport() is called (asynchronously) once per child process
+  //   reporter callback.
+  //
+  // - EndProcessReport() is called (asynchronously) once per process that
+  //   finishes reporting back, including the parent.  If all processes do so
+  //   before time-out, the timer is cancelled.  If there are child processes
+  //   whose requests have not yet been sent, they will be started until the
+  //   concurrency limit is (again) reached.
+  //
+  // - TimeoutCallback() is called (asynchronously) if all the child processes
+  //   don't respond within the time threshold.
+  //
+  // - FinishReporting() finishes things off.  It is *always* called -- either
+  //   from EndChildReport() (if all child processes have reported back) or
+  //   from TimeoutCallback() (if time-out occurs).
+  //
+  // All operations occur on the main thread.
+  //
+  // The above sequence of steps is a "request".  A partially-completed request
+  // is described as "in flight".
+  //
+  // Each request has a "generation", a unique number that identifies it.  This
+  // is used to ensure that each reports from a child process corresponds to
+  // the appropriate request from the parent process.  (It's easier to
+  // implement a generation system than to implement a child report request
+  // cancellation mechanism.)
+  //
+  // Failures are mostly ignored, because it's (a) typically the most sensible
+  // thing to do, and (b) often hard to do anything else.  The following are
+  // the failure cases of note.
+  //
+  // - If a request is made while the previous request is in flight, the new
+  //   request is ignored, as per getReports()'s specification.  No error is
+  //   reported, because the previous request will complete soon enough.
+  //
+  // - If one or more child processes fail to respond within the time limit,
+  //   things will proceed as if they don't exist.  No error is reported,
+  //   because partial information is better than nothing.
+  //
+  // - If a child process reports after the time-out occurs, it is ignored.
+  //   (Generation checking will ensure it is ignored even if a subsequent
+  //   request is in flight;  this is the main use of generations.)  No error
+  //   is reported, because there's nothing sensible to be done about it at
+  //   this late stage.
+  //
+  // - If the time-out occurs after a child process has sent some reports but
+  //   before it has signaled completion (see bug 1151597), then what it
+  //   successfully sent will be included, with no explicit indication that it
+  //   is incomplete.
+  //
+  // Now, what what happens if a child process is created/destroyed in the
+  // middle of a request?  Well, PendingProcessesState is initialized with an array
+  // of child process actors as of when the report started.  So...
+  //
+  // - If a process is created after reporting starts, it won't be sent a
+  //   request for reports.  So the reported data will reflect how things were
+  //   when the request began.
+  //
+  // - If a process is destroyed before it starts reporting back, the reported
+  //   data will reflect how things are when the request ends.
+  //
+  // - If a process is destroyed after it starts reporting back but before it
+  //   finishes, the reported data will contain a partial report for it.
+  //
+  // - If a process is destroyed after reporting back, but before all other
+  //   child processes have reported back, it will be included in the reported
+  //   data.  So the reported data will reflect how things were when the
+  //   request began.
+  //
+  // The inconsistencies between these cases are unfortunate but difficult to
+  // avoid.  It's enough of an edge case to not be worth doing more.
+  //
+  void HandleChildReport(uint32_t aGeneration,
+                         const mozilla::dom::MemoryReport& aChildReport);
+  void EndProcessReport(uint32_t aGeneration, bool aSuccess);
+
+  // Functions that (a) implement distinguished amounts, and (b) are outside of
+  // this module.
+  struct AmountFns
+  {
+    mozilla::InfallibleAmountFn mJSMainRuntimeGCHeap;
+    mozilla::InfallibleAmountFn mJSMainRuntimeTemporaryPeak;
+    mozilla::InfallibleAmountFn mJSMainRuntimeCompartmentsSystem;
+    mozilla::InfallibleAmountFn mJSMainRuntimeCompartmentsUser;
+
+    mozilla::InfallibleAmountFn mImagesContentUsedUncompressed;
+
+    mozilla::InfallibleAmountFn mStorageSQLite;
+
+    mozilla::InfallibleAmountFn mLowMemoryEventsVirtual;
+    mozilla::InfallibleAmountFn mLowMemoryEventsPhysical;
+
+    mozilla::InfallibleAmountFn mGhostWindows;
+
+    AmountFns()
+    {
+      mozilla::PodZero(this);
+    }
+  };
+  AmountFns mAmountFns;
+
+  // Convenience function to get RSS easily from other code.  This is useful
+  // when debugging transient memory spikes with printf instrumentation.
+  static int64_t ResidentFast();
+
+  // Convenience function to get peak RSS easily from other code.
+  static int64_t ResidentPeak();
+
+  // Convenience function to get USS easily from other code.  This is useful
+  // when debugging unshared memory pages for forked processes.
+  static int64_t ResidentUnique();
+
+  // Functions that measure per-tab memory consumption.
+  struct SizeOfTabFns
+  {
+    mozilla::JSSizeOfTabFn    mJS;
+    mozilla::NonJSSizeOfTabFn mNonJS;
+
+    SizeOfTabFns()
+    {
+      mozilla::PodZero(this);
+    }
+  };
+  SizeOfTabFns mSizeOfTabFns;
+
+private:
+  MOZ_MUST_USE nsresult
+  RegisterReporterHelper(nsIMemoryReporter* aReporter,
+                         bool aForce, bool aStrongRef, bool aIsAsync);
+
+  MOZ_MUST_USE nsresult StartGettingReports();
+  // No MOZ_MUST_USE here because ignoring the result is common and reasonable.
+  nsresult FinishReporting();
+
+  void DispatchReporter(nsIMemoryReporter* aReporter, bool aIsAsync,
+                        nsIHandleReportCallback* aHandleReport,
+                        nsISupports* aHandleReportData,
+                        bool aAnonymize);
+
+  static void TimeoutCallback(nsITimer* aTimer, void* aData);
+  // Note: this timeout needs to be long enough to allow for the
+  // possibility of DMD reports and/or running on a low-end phone.
+  static const uint32_t kTimeoutLengthMS = 50000;
+
+  mozilla::Mutex mMutex;
+  bool mIsRegistrationBlocked;
+
+  StrongReportersTable* mStrongReporters;
+  WeakReportersTable* mWeakReporters;
+
+  // These two are only used for testing purposes.
+  StrongReportersTable* mSavedStrongReporters;
+  WeakReportersTable* mSavedWeakReporters;
+
+  uint32_t mNextGeneration;
+
+  // Used to keep track of state of which processes are currently running and
+  // waiting to run memory reports. Holds references to parameters needed when
+  // requesting a memory report and finishing reporting.
+  struct PendingProcessesState
+  {
+    uint32_t                             mGeneration;
+    bool                                 mAnonymize;
+    bool                                 mMinimize;
+    nsCOMPtr<nsITimer>                   mTimer;
+    nsTArray<RefPtr<mozilla::dom::ContentParent>> mChildrenPending;
+    uint32_t                             mNumProcessesRunning;
+    uint32_t                             mNumProcessesCompleted;
+    uint32_t                             mConcurrencyLimit;
+    nsCOMPtr<nsIHandleReportCallback>    mHandleReport;
+    nsCOMPtr<nsISupports>                mHandleReportData;
+    nsCOMPtr<nsIFinishReportingCallback> mFinishReporting;
+    nsCOMPtr<nsISupports>                mFinishReportingData;
+    nsString                             mDMDDumpIdent;
+
+    PendingProcessesState(uint32_t aGeneration, bool aAnonymize, bool aMinimize,
+                          uint32_t aConcurrencyLimit,
+                          nsIHandleReportCallback* aHandleReport,
+                          nsISupports* aHandleReportData,
+                          nsIFinishReportingCallback* aFinishReporting,
+                          nsISupports* aFinishReportingData,
+                          const nsAString& aDMDDumpIdent);
+  };
+
+  // Used to keep track of the state of the asynchronously run memory
+  // reporters. The callback and file handle used when all memory reporters
+  // have finished are also stored here.
+  struct PendingReportersState
+  {
+    // Number of memory reporters currently running.
+    uint32_t mReportsPending;
+
+    // Callback for when all memory reporters have completed.
+    nsCOMPtr<nsIFinishReportingCallback> mFinishReporting;
+    nsCOMPtr<nsISupports> mFinishReportingData;
+
+    // File handle to write a DMD report to if requested.
+    FILE* mDMDFile;
+
+    PendingReportersState(nsIFinishReportingCallback* aFinishReporting,
+                        nsISupports* aFinishReportingData,
+                        FILE* aDMDFile)
+      : mReportsPending(0)
+      , mFinishReporting(aFinishReporting)
+      , mFinishReportingData(aFinishReportingData)
+      , mDMDFile(aDMDFile)
+    {
+    }
+  };
+
+  // When this is non-null, a request is in flight.  Note: We use manual
+  // new/delete for this because its lifetime doesn't match block scope or
+  // anything like that.
+  PendingProcessesState* mPendingProcessesState;
+
+  // This is reinitialized each time a call to GetReports is initiated.
+  PendingReportersState* mPendingReportersState;
+
+  PendingProcessesState* GetStateForGeneration(uint32_t aGeneration);
+  static MOZ_MUST_USE bool
+  StartChildReport(mozilla::dom::ContentParent* aChild,
+                   const PendingProcessesState* aState);
+};
+
+#define NS_MEMORY_REPORTER_MANAGER_CID \
+{ 0xfb97e4f5, 0x32dd, 0x497a, \
+{ 0xba, 0xa2, 0x7d, 0x1e, 0x55, 0x7, 0x99, 0x10 } }
+
+#endif // nsMemoryReporterManager_h__