Line data    Source code

       1             : /* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
       2             : /* vim: set ts=8 sts=2 et sw=2 tw=80: */
       3             : /* This Source Code Form is subject to the terms of the Mozilla Public
       4             :  * License, v. 2.0. If a copy of the MPL was not distributed with this
       5             :  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
       6             : 
       7             : #include <math.h>
       8             : 
       9             : #include "nsString.h"
      10             : #include "nsIMemoryReporter.h"
      11             : #include "mozilla/ipc/SharedMemory.h"
      12             : #include "mozilla/Atomics.h"
      13             : 
      14             : namespace mozilla {
      15             : namespace ipc {
      16             : 
      17             : static Atomic<size_t> gShmemAllocated;
      18             : static Atomic<size_t> gShmemMapped;
      19             : 
      20           3 : class ShmemReporter final : public nsIMemoryReporter
      21             : {
      22           3 :   ~ShmemReporter() {}
      23             : 
      24             : public:
      25             :   NS_DECL_THREADSAFE_ISUPPORTS
      26             : 
      27             :   NS_IMETHOD
      28           0 :   CollectReports(nsIHandleReportCallback* aHandleReport, nsISupports* aData,
      29             :                  bool aAnonymize) override
      30             :   {
      31           0 :     MOZ_COLLECT_REPORT(
      32             :       "shmem-allocated", KIND_OTHER, UNITS_BYTES, gShmemAllocated,
      33             :       "Memory shared with other processes that is accessible (but not "
      34           0 :       "necessarily mapped).");
      35             : 
      36           0 :     MOZ_COLLECT_REPORT(
      37             :       "shmem-mapped", KIND_OTHER, UNITS_BYTES, gShmemMapped,
      38             :       "Memory shared with other processes that is mapped into the address "
      39           0 :       "space.");
      40             : 
      41           0 :     return NS_OK;
      42             :   }
      43             : };
      44             : 
      45          18 : NS_IMPL_ISUPPORTS(ShmemReporter, nsIMemoryReporter)
      46             : 
      47          50 : SharedMemory::SharedMemory()
      48             :   : mAllocSize(0)
      49          50 :   , mMappedSize(0)
      50             : {
      51             :   static Atomic<bool> registered;
      52          50 :   if (registered.compareExchange(false, true)) {
      53           3 :     RegisterStrongMemoryReporter(new ShmemReporter());
      54             :   }
      55          50 : }
      56             : 
      57             : /*static*/ size_t
      58           9 : SharedMemory::PageAlignedSize(size_t aSize)
      59             : {
      60           9 :   size_t pageSize = SystemPageSize();
      61           9 :   size_t nPagesNeeded = size_t(ceil(double(aSize) / double(pageSize)));
      62           9 :   return pageSize * nPagesNeeded;
      63             : }
      64             : 
      65             : void
      66          13 : SharedMemory::Created(size_t aNBytes)
      67             : {
      68          13 :   mAllocSize = aNBytes;
      69          13 :   gShmemAllocated += mAllocSize;
      70          13 : }
      71             : 
      72             : void
      73          50 : SharedMemory::Mapped(size_t aNBytes)
      74             : {
      75          50 :   mMappedSize = aNBytes;
      76          50 :   gShmemMapped += mMappedSize;
      77          50 : }
      78             : 
      79             : void
      80          37 : SharedMemory::Unmapped()
      81             : {
      82          37 :   MOZ_ASSERT(gShmemMapped >= mMappedSize,
      83             :              "Can't unmap more than mapped");
      84          37 :   gShmemMapped -= mMappedSize;
      85          37 :   mMappedSize = 0;
      86          37 : }
      87             : 
      88             : /*static*/ void
      89          37 : SharedMemory::Destroyed()
      90             : {
      91          37 :   MOZ_ASSERT(gShmemAllocated >= mAllocSize,
      92             :              "Can't destroy more than allocated");
      93          37 :   gShmemAllocated -= mAllocSize;
      94          37 :   mAllocSize = 0;
      95          37 : }
      96             : 
      97             : } // namespace ipc
      98             : } // namespace mozilla