The Tor Browser: ipc/glue/SharedMemory.cpp@6474c204b198

Cloned upstream origin tor-browser at tor-browser-31.3.0esr-4.5-1-build1
revision ID fc1c9ff7c1b2defdbc039f12214767608f46423f for hacking purpose.

     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/. */

     7 #include <math.h>

     9 #include "nsString.h"

    10 #include "nsIMemoryReporter.h"

    11 #include "mozilla/ipc/SharedMemory.h"

    12 #include "mozilla/Atomics.h"

    14 namespace mozilla {

    15 namespace ipc {

    17 static Atomic<size_t> gShmemAllocated;

    18 static Atomic<size_t> gShmemMapped;

    20 class ShmemReporter MOZ_FINAL : public nsIMemoryReporter

    21 {

    22 public:

    23   NS_DECL_THREADSAFE_ISUPPORTS

    25   NS_IMETHOD

    26   CollectReports(nsIHandleReportCallback* aHandleReport, nsISupports* aData)

    27   {

    28     nsresult rv;

    29     rv = MOZ_COLLECT_REPORT(

    30       "shmem-allocated", KIND_OTHER, UNITS_BYTES, gShmemAllocated,

    31       "Memory shared with other processes that is accessible (but not "

    32       "necessarily mapped).");

    33     NS_ENSURE_SUCCESS(rv, rv);

    35     rv = MOZ_COLLECT_REPORT(

    36       "shmem-mapped", KIND_OTHER, UNITS_BYTES, gShmemMapped,

    37       "Memory shared with other processes that is mapped into the address "

    38       "space.");

    39     NS_ENSURE_SUCCESS(rv, rv);

    41     return NS_OK;

    42   }

    43 };

    45 NS_IMPL_ISUPPORTS(ShmemReporter, nsIMemoryReporter)

    47 SharedMemory::SharedMemory()

    48   : mAllocSize(0)

    49   , mMappedSize(0)

    50 {

    51   MOZ_COUNT_CTOR(SharedMemory);

    52   static Atomic<bool> registered;

    53   if (registered.compareExchange(false, true)) {

    54     RegisterStrongMemoryReporter(new ShmemReporter());

    55   }

    56 }

    58 /*static*/ size_t

    59 SharedMemory::PageAlignedSize(size_t aSize)

    60 {

    61   size_t pageSize = SystemPageSize();

    62   size_t nPagesNeeded = size_t(ceil(double(aSize) / double(pageSize)));

    63   return pageSize * nPagesNeeded;

    64 }

    66 void

    67 SharedMemory::Created(size_t aNBytes)

    68 {

    69   mAllocSize = aNBytes;

    70   gShmemAllocated += mAllocSize;

    71 }

    73 void

    74 SharedMemory::Mapped(size_t aNBytes)

    75 {

    76   mMappedSize = aNBytes;

    77   gShmemMapped += mMappedSize;

    78 }

    80 void

    81 SharedMemory::Unmapped()

    82 {

    83   NS_ABORT_IF_FALSE(gShmemMapped >= mMappedSize,

    84                     "Can't unmap more than mapped");

    85   gShmemMapped -= mMappedSize;

    86   mMappedSize = 0;

    87 }

    89 /*static*/ void

    90 SharedMemory::Destroyed()

    91 {

    92   NS_ABORT_IF_FALSE(gShmemAllocated >= mAllocSize,

    93                     "Can't destroy more than allocated");

    94   gShmemAllocated -= mAllocSize;

    95   mAllocSize = 0;

    96 }

    98 } // namespace ipc

    99 } // namespace mozilla

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