gecko-dev/xpcom/base/nsMemoryReporterManager.cpp

/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
/* vim: set ts=8 sts=4 et sw=4 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/. */

#include "nsAtomTable.h"
#include "nsAutoPtr.h"
#include "nsCOMPtr.h"
#include "nsCOMArray.h"
#include "nsServiceManagerUtils.h"
#include "nsMemoryReporterManager.h"
#include "nsISimpleEnumerator.h"
#include "nsITimer.h"
#include "nsThreadUtils.h"
#include "nsIDOMWindow.h"
#include "nsPIDOMWindow.h"
#include "nsIObserverService.h"
#include "nsIGlobalObject.h"
#include "nsIXPConnect.h"
#if defined(XP_LINUX) || defined(__FreeBSD__)
#include "nsMemoryInfoDumper.h"
#endif
#include "mozilla/Attributes.h"
#include "mozilla/PodOperations.h"
#include "mozilla/Services.h"
#include "mozilla/Telemetry.h"
#include "mozilla/dom/PMemoryReportRequestParent.h" // for dom::MemoryReport

#ifndef XP_WIN
#include <unistd.h>
#endif

using namespace mozilla;

#if defined(MOZ_MEMORY)
#  define HAVE_JEMALLOC_STATS 1
#  include "mozmemory.h"
#endif  // MOZ_MEMORY

#if defined(XP_LINUX)

static nsresult GetProcSelfStatmField(int aField, int64_t* aN)
{
    // There are more than two fields, but we're only interested in the first
    // two.
    static const int MAX_FIELD = 2;
    size_t fields[MAX_FIELD];
    MOZ_ASSERT(aField < MAX_FIELD, "bad field number");
    FILE* f = fopen("/proc/self/statm", "r");
    if (f) {
        int nread = fscanf(f, "%zu %zu", &fields[0], &fields[1]);
        fclose(f);
        if (nread == MAX_FIELD) {
            *aN = fields[aField] * getpagesize();
            return NS_OK;
        }
    }
    return NS_ERROR_FAILURE;
}

#define HAVE_VSIZE_AND_RESIDENT_REPORTERS 1
static nsresult
VsizeDistinguishedAmount(int64_t* aN)
{
    return GetProcSelfStatmField(0, aN);
}

static nsresult
ResidentDistinguishedAmount(int64_t* aN)
{
    return GetProcSelfStatmField(1, aN);
}

static nsresult
ResidentFastDistinguishedAmount(int64_t* aN)
{
    return ResidentDistinguishedAmount(aN);
}

#define HAVE_RESIDENT_UNIQUE_REPORTER
class ResidentUniqueReporter MOZ_FINAL : public nsIMemoryReporter
{
public:
    NS_DECL_ISUPPORTS

    NS_METHOD CollectReports(nsIHandleReportCallback* aHandleReport,
                             nsISupports* aData)
    {
        // You might be tempted to calculate USS by subtracting the "shared"
        // value from the "resident" value in /proc/<pid>/statm. But at least
        // on Linux, statm's "shared" value actually counts pages backed by
        // files, which has little to do with whether the pages are actually
        // shared. /proc/self/smaps on the other hand appears to give us the
        // correct information.

        FILE *f = fopen("/proc/self/smaps", "r");
        if (NS_WARN_IF(!f))
            return NS_ERROR_UNEXPECTED;

        int64_t amount = 0;
        char line[256];
        while (fgets(line, sizeof(line), f)) {
            long long val = 0;
            if (sscanf(line, "Private_Dirty: %lld kB", &val) == 1 ||
                sscanf(line, "Private_Clean: %lld kB", &val) == 1) {
                amount += val * 1024; // convert from kB to bytes
            }
        }

        fclose(f);

        return MOZ_COLLECT_REPORT(
            "resident-unique", KIND_OTHER, UNITS_BYTES, amount,
"Memory mapped by the process that is present in physical memory and not "
"shared with any other processes.  This is also known as the process's unique "
"set size (USS).  This is the amount of RAM we'd expect to be freed if we "
"closed this process.");
    }
};
NS_IMPL_ISUPPORTS1(ResidentUniqueReporter, nsIMemoryReporter)

#elif defined(__DragonFly__) || defined(__FreeBSD__) \
    || defined(__NetBSD__) || defined(__OpenBSD__)

#include <sys/param.h>
#include <sys/sysctl.h>
#if defined(__DragonFly__) || defined(__FreeBSD__)
#include <sys/user.h>
#endif

#include <unistd.h>

#if defined(__NetBSD__)
#undef KERN_PROC
#define KERN_PROC KERN_PROC2
#define KINFO_PROC struct kinfo_proc2
#else
#define KINFO_PROC struct kinfo_proc
#endif

#if defined(__DragonFly__)
#define KP_SIZE(kp) (kp.kp_vm_map_size)
#define KP_RSS(kp) (kp.kp_vm_rssize * getpagesize())
#elif defined(__FreeBSD__)
#define KP_SIZE(kp) (kp.ki_size)
#define KP_RSS(kp) (kp.ki_rssize * getpagesize())
#elif defined(__NetBSD__)
#define KP_SIZE(kp) (kp.p_vm_msize * getpagesize())
#define KP_RSS(kp) (kp.p_vm_rssize * getpagesize())
#elif defined(__OpenBSD__)
#define KP_SIZE(kp) ((kp.p_vm_dsize + kp.p_vm_ssize                     \
                      + kp.p_vm_tsize) * getpagesize())
#define KP_RSS(kp) (kp.p_vm_rssize * getpagesize())
#endif

static nsresult GetKinfoProcSelf(KINFO_PROC* aProc)
{
    int mib[] = {
        CTL_KERN,
        KERN_PROC,
        KERN_PROC_PID,
        getpid(),
#if defined(__NetBSD__) || defined(__OpenBSD__)
        sizeof(KINFO_PROC),
        1,
#endif
    };
    u_int miblen = sizeof(mib) / sizeof(mib[0]);
    size_t size = sizeof(KINFO_PROC);
    if (sysctl(mib, miblen, aProc, &size, nullptr, 0))
        return NS_ERROR_FAILURE;

    return NS_OK;
}

#define HAVE_VSIZE_AND_RESIDENT_REPORTERS 1
static nsresult
VsizeDistinguishedAmount(int64_t* aN)
{
    KINFO_PROC proc;
    nsresult rv = GetKinfoProcSelf(&proc);
    if (NS_SUCCEEDED(rv))
        *aN = KP_SIZE(proc);

    return rv;
}

static nsresult
ResidentDistinguishedAmount(int64_t* aN)
{
    KINFO_PROC proc;
    nsresult rv = GetKinfoProcSelf(&proc);
    if (NS_SUCCEEDED(rv))
        *aN = KP_RSS(proc);

    return rv;
}

static nsresult
ResidentFastDistinguishedAmount(int64_t* aN)
{
    return ResidentDistinguishedAmount(aN);
}

#ifdef __FreeBSD__
#include <libutil.h>
#include <algorithm>

static nsresult
GetKinfoVmentrySelf(int64_t* prss, uint64_t* maxreg)
{
    int cnt;
    struct kinfo_vmentry *vmmap, *kve;
    if ((vmmap = kinfo_getvmmap(getpid(), &cnt)) == nullptr)
        return NS_ERROR_FAILURE;

    if (prss)
        *prss = 0;
    if (maxreg)
        *maxreg = 0;

    for (int i = 0; i < cnt; i++) {
        kve = &vmmap[i];
        if (prss)
            *prss += kve->kve_private_resident;
        if (maxreg)
            *maxreg = std::max(*maxreg,
                               kve->kve_end - kve->kve_start);
    }

    free(vmmap);
    return NS_OK;
}

#define HAVE_PRIVATE_REPORTER
static nsresult
PrivateDistinguishedAmount(int64_t* aN)
{
    int64_t priv;
    nsresult rv = GetKinfoVmentrySelf(&priv, nullptr);
    NS_ENSURE_SUCCESS(rv, rv);
    *aN = priv * getpagesize();
    return NS_OK;
}

#define HAVE_VSIZE_MAX_CONTIGUOUS_REPORTER 1
static nsresult
VsizeMaxContiguousDistinguishedAmount(int64_t* aN)
{
    uint64_t biggestRegion;
    nsresult rv = GetKinfoVmentrySelf(nullptr, &biggestRegion);
    if (NS_SUCCEEDED(rv))
        *aN = biggestRegion;

    return NS_OK;
}
#endif // FreeBSD

#elif defined(SOLARIS)

#include <procfs.h>
#include <fcntl.h>
#include <unistd.h>

static void XMappingIter(int64_t& vsize, int64_t& resident)
{
    vsize = -1;
    resident = -1;
    int mapfd = open("/proc/self/xmap", O_RDONLY);
    struct stat st;
    prxmap_t* prmapp = nullptr;
    if (mapfd >= 0) {
        if (!fstat(mapfd, &st)) {
            int nmap = st.st_size / sizeof(prxmap_t);
            while (1) {
                // stat(2) on /proc/<pid>/xmap returns an incorrect value,
                // prior to the release of Solaris 11.
                // Here is a workaround for it.
                nmap *= 2;
                prmapp = (prxmap_t*)malloc((nmap + 1) * sizeof(prxmap_t));
                if (!prmapp) {
                    // out of memory
                    break;
                }
                int n = pread(mapfd, prmapp, (nmap + 1) * sizeof(prxmap_t), 0);
                if (n < 0) {
                    break;
                }
                if (nmap >= n / sizeof (prxmap_t)) {
                    vsize = 0;
                    resident = 0;
                    for (int i = 0; i < n / sizeof (prxmap_t); i++) {
                        vsize += prmapp[i].pr_size;
                        resident += prmapp[i].pr_rss * prmapp[i].pr_pagesize;
                    }
                    break;
                }
                free(prmapp);
            }
            free(prmapp);
        }
        close(mapfd);
    }
}

#define HAVE_VSIZE_AND_RESIDENT_REPORTERS 1
static nsresult
VsizeDistinguishedAmount(int64_t* aN)
{
    int64_t vsize, resident;
    XMappingIter(vsize, resident);
    if (vsize == -1) {
        return NS_ERROR_FAILURE;
    }
    *aN = vsize;
    return NS_OK;
}

static nsresult
ResidentDistinguishedAmount(int64_t* aN)
{
    int64_t vsize, resident;
    XMappingIter(vsize, resident);
    if (resident == -1) {
        return NS_ERROR_FAILURE;
    }
    *aN = resident;
    return NS_OK;
}

static nsresult
ResidentFastDistinguishedAmount(int64_t* aN)
{
    return ResidentDistinguishedAmount(aN);
}

#elif defined(XP_MACOSX)

#include <mach/mach_init.h>
#include <mach/task.h>

static bool GetTaskBasicInfo(struct task_basic_info* aTi)
{
    mach_msg_type_number_t count = TASK_BASIC_INFO_COUNT;
    kern_return_t kr = task_info(mach_task_self(), TASK_BASIC_INFO,
                                 (task_info_t)aTi, &count);
    return kr == KERN_SUCCESS;
}

// The VSIZE figure on Mac includes huge amounts of shared memory and is always
// absurdly high, eg. 2GB+ even at start-up.  But both 'top' and 'ps' report
// it, so we might as well too.
#define HAVE_VSIZE_AND_RESIDENT_REPORTERS 1
static nsresult
VsizeDistinguishedAmount(int64_t* aN)
{
    task_basic_info ti;
    if (!GetTaskBasicInfo(&ti))
        return NS_ERROR_FAILURE;

    *aN = ti.virtual_size;
    return NS_OK;
}

// If we're using jemalloc on Mac, we need to instruct jemalloc to purge the
// pages it has madvise(MADV_FREE)'d before we read our RSS in order to get
// an accurate result.  The OS will take away MADV_FREE'd pages when there's
// memory pressure, so ideally, they shouldn't count against our RSS.
//
// Purging these pages can take a long time for some users (see bug 789975),
// so we provide the option to get the RSS without purging first.
static nsresult ResidentDistinguishedAmountHelper(int64_t* aN, bool aDoPurge)
{
#ifdef HAVE_JEMALLOC_STATS
    if (aDoPurge) {
      Telemetry::AutoTimer<Telemetry::MEMORY_FREE_PURGED_PAGES_MS> timer;
      jemalloc_purge_freed_pages();
    }
#endif

    task_basic_info ti;
    if (!GetTaskBasicInfo(&ti))
        return NS_ERROR_FAILURE;

    *aN = ti.resident_size;
    return NS_OK;
}

static nsresult
ResidentFastDistinguishedAmount(int64_t* aN)
{
    return ResidentDistinguishedAmountHelper(aN, /* doPurge = */ false);
}

static nsresult
ResidentDistinguishedAmount(int64_t* aN)
{
    return ResidentDistinguishedAmountHelper(aN, /* doPurge = */ true);
}

#elif defined(XP_WIN)

#include <windows.h>
#include <psapi.h>
#include <algorithm>

#define HAVE_VSIZE_AND_RESIDENT_REPORTERS 1
static nsresult
VsizeDistinguishedAmount(int64_t* aN)
{
    MEMORYSTATUSEX s;
    s.dwLength = sizeof(s);

    if (!GlobalMemoryStatusEx(&s)) {
        return NS_ERROR_FAILURE;
    }

    *aN = s.ullTotalVirtual - s.ullAvailVirtual;
    return NS_OK;
}

static nsresult
ResidentDistinguishedAmount(int64_t* aN)
{
    PROCESS_MEMORY_COUNTERS pmc;
    pmc.cb = sizeof(PROCESS_MEMORY_COUNTERS);

    if (!GetProcessMemoryInfo(GetCurrentProcess(), &pmc, sizeof(pmc))) {
        return NS_ERROR_FAILURE;
    }

    *aN = pmc.WorkingSetSize;
    return NS_OK;
}

static nsresult
ResidentFastDistinguishedAmount(int64_t* aN)
{
    return ResidentDistinguishedAmount(aN);
}

#define HAVE_VSIZE_MAX_CONTIGUOUS_REPORTER 1
static nsresult
VsizeMaxContiguousDistinguishedAmount(int64_t* aN)
{
    SIZE_T biggestRegion = 0;
    MEMORY_BASIC_INFORMATION vmemInfo = {0};
    for (size_t currentAddress = 0; ; ) {
        if (!VirtualQuery((LPCVOID)currentAddress, &vmemInfo, sizeof(vmemInfo))) {
            // Something went wrong, just return whatever we've got already.
            break;
        }

        if (vmemInfo.State == MEM_FREE) {
            biggestRegion = std::max(biggestRegion, vmemInfo.RegionSize);
        }

        SIZE_T lastAddress = currentAddress;
        currentAddress += vmemInfo.RegionSize;

        // If we overflow, we've examined all of the address space.
        if (currentAddress < lastAddress) {
            break;
        }
    }

    *aN = biggestRegion;
    return NS_OK;
}

#define HAVE_PRIVATE_REPORTER
static nsresult
PrivateDistinguishedAmount(int64_t* aN)
{
    PROCESS_MEMORY_COUNTERS_EX pmcex;
    pmcex.cb = sizeof(PROCESS_MEMORY_COUNTERS_EX);

    if (!GetProcessMemoryInfo(
            GetCurrentProcess(),
            (PPROCESS_MEMORY_COUNTERS) &pmcex, sizeof(pmcex))) {
        return NS_ERROR_FAILURE;
    }

    *aN = pmcex.PrivateUsage;
    return NS_OK;
}
#endif  // XP_<PLATFORM>

#ifdef HAVE_VSIZE_MAX_CONTIGUOUS_REPORTER
class VsizeMaxContiguousReporter MOZ_FINAL : public nsIMemoryReporter
{
public:
    NS_DECL_ISUPPORTS

    NS_METHOD CollectReports(nsIHandleReportCallback* aHandleReport,
                             nsISupports* aData)
    {
        int64_t amount;
        nsresult rv = VsizeMaxContiguousDistinguishedAmount(&amount);
        NS_ENSURE_SUCCESS(rv, rv);
        return MOZ_COLLECT_REPORT(
            "vsize-max-contiguous", KIND_OTHER, UNITS_BYTES, amount,
            "Size of the maximum contiguous block of available virtual "
            "memory.");
    }
};
NS_IMPL_ISUPPORTS1(VsizeMaxContiguousReporter, nsIMemoryReporter)
#endif

#ifdef HAVE_PRIVATE_REPORTER
class PrivateReporter MOZ_FINAL : public nsIMemoryReporter
{
public:
    NS_DECL_ISUPPORTS

    NS_METHOD CollectReports(nsIHandleReportCallback* aHandleReport,
                             nsISupports* aData)
    {
        int64_t amount;
        nsresult rv = PrivateDistinguishedAmount(&amount);
        NS_ENSURE_SUCCESS(rv, rv);
        return MOZ_COLLECT_REPORT(
            "private", KIND_OTHER, UNITS_BYTES, amount,
"Memory that cannot be shared with other processes, including memory that is "
"committed and marked MEM_PRIVATE, data that is not mapped, and executable "
"pages that have been written to.");
    }
};
NS_IMPL_ISUPPORTS1(PrivateReporter, nsIMemoryReporter)
#endif

#ifdef HAVE_VSIZE_AND_RESIDENT_REPORTERS
class VsizeReporter MOZ_FINAL : public nsIMemoryReporter
{
public:
    NS_DECL_ISUPPORTS

    NS_METHOD CollectReports(nsIHandleReportCallback* aHandleReport,
                             nsISupports* aData)
    {
        int64_t amount;
        nsresult rv = VsizeDistinguishedAmount(&amount);
        NS_ENSURE_SUCCESS(rv, rv);

        return MOZ_COLLECT_REPORT(
            "vsize", KIND_OTHER, UNITS_BYTES, amount,
"Memory mapped by the process, including code and data segments, the heap, "
"thread stacks, memory explicitly mapped by the process via mmap and similar "
"operations, and memory shared with other processes. This is the vsize figure "
"as reported by 'top' and 'ps'.  This figure is of limited use on Mac, where "
"processes share huge amounts of memory with one another.  But even on other "
"operating systems, 'resident' is a much better measure of the memory "
"resources used by the process.");
    }
};
NS_IMPL_ISUPPORTS1(VsizeReporter, nsIMemoryReporter)

class ResidentReporter MOZ_FINAL : public nsIMemoryReporter
{
public:
    NS_DECL_ISUPPORTS

    NS_METHOD CollectReports(nsIHandleReportCallback* aHandleReport,
                             nsISupports* aData)
    {
        int64_t amount;
        nsresult rv = ResidentDistinguishedAmount(&amount);
        NS_ENSURE_SUCCESS(rv, rv);

        return MOZ_COLLECT_REPORT(
            "resident", KIND_OTHER, UNITS_BYTES, amount,
"Memory mapped by the process that is present in physical memory, also known "
"as the resident set size (RSS).  This is the best single figure to use when "
"considering the memory resources used by the process, but it depends both on "
"other processes being run and details of the OS kernel and so is best used "
"for comparing the memory usage of a single process at different points in "
"time.");
    }
};
NS_IMPL_ISUPPORTS1(ResidentReporter, nsIMemoryReporter)

#endif  // HAVE_VSIZE_AND_RESIDENT_REPORTERS

#ifdef XP_UNIX

#include <sys/resource.h>

#define HAVE_PAGE_FAULT_REPORTERS 1

class PageFaultsSoftReporter MOZ_FINAL : public nsIMemoryReporter
{
public:
    NS_DECL_ISUPPORTS

    NS_METHOD CollectReports(nsIHandleReportCallback* aHandleReport,
                             nsISupports* aData)
    {
        struct rusage usage;
        int err = getrusage(RUSAGE_SELF, &usage);
        if (err != 0) {
            return NS_ERROR_FAILURE;
        }
        int64_t amount = usage.ru_minflt;

        return MOZ_COLLECT_REPORT(
            "page-faults-soft", KIND_OTHER, UNITS_COUNT_CUMULATIVE, amount,
"The number of soft page faults (also known as 'minor page faults') that "
"have occurred since the process started.  A soft page fault occurs when the "
"process tries to access a page which is present in physical memory but is "
"not mapped into the process's address space.  For instance, a process might "
"observe soft page faults when it loads a shared library which is already "
"present in physical memory. A process may experience many thousands of soft "
"page faults even when the machine has plenty of available physical memory, "
"and because the OS services a soft page fault without accessing the disk, "
"they impact performance much less than hard page faults.");
    }
};
NS_IMPL_ISUPPORTS1(PageFaultsSoftReporter, nsIMemoryReporter)

static nsresult
PageFaultsHardDistinguishedAmount(int64_t* aAmount)
{
    struct rusage usage;
    int err = getrusage(RUSAGE_SELF, &usage);
    if (err != 0) {
        return NS_ERROR_FAILURE;
    }
    *aAmount = usage.ru_majflt;
    return NS_OK;
}

class PageFaultsHardReporter MOZ_FINAL : public nsIMemoryReporter
{
public:
    NS_DECL_ISUPPORTS

    NS_METHOD CollectReports(nsIHandleReportCallback* aHandleReport,
                             nsISupports* aData)
    {
        int64_t amount = 0;
        nsresult rv = PageFaultsHardDistinguishedAmount(&amount);
        NS_ENSURE_SUCCESS(rv, rv);

        return MOZ_COLLECT_REPORT(
            "page-faults-hard", KIND_OTHER, UNITS_COUNT_CUMULATIVE, amount,
"The number of hard page faults (also known as 'major page faults') that have "
"occurred since the process started.  A hard page fault occurs when a process "
"tries to access a page which is not present in physical memory. The "
"operating system must access the disk in order to fulfill a hard page fault. "
"When memory is plentiful, you should see very few hard page faults. But if "
"the process tries to use more memory than your machine has available, you "
"may see many thousands of hard page faults. Because accessing the disk is up "
"to a million times slower than accessing RAM, the program may run very "
"slowly when it is experiencing more than 100 or so hard page faults a "
"second.");
    }
};
NS_IMPL_ISUPPORTS1(PageFaultsHardReporter, nsIMemoryReporter)

#endif  // HAVE_PAGE_FAULT_REPORTERS

/**
 ** memory reporter implementation for jemalloc and OSX malloc,
 ** to obtain info on total memory in use (that we know about,
 ** at least -- on OSX, there are sometimes other zones in use).
 **/

#ifdef HAVE_JEMALLOC_STATS

// This has UNITS_PERCENTAGE, so it is multiplied by 100.
static int64_t
HeapOverheadRatio(jemalloc_stats_t* aStats)
{
    return (int64_t) 10000 *
      (aStats->waste + aStats->bookkeeping + aStats->page_cache) /
      ((double)aStats->allocated);
}

class JemallocHeapReporter MOZ_FINAL : public nsIMemoryReporter
{
public:
    NS_DECL_ISUPPORTS

    NS_METHOD CollectReports(nsIHandleReportCallback* aHandleReport,
                             nsISupports* aData)
    {
        jemalloc_stats_t stats;
        jemalloc_stats(&stats);

        nsresult rv;

        rv = MOZ_COLLECT_REPORT(
            "heap-allocated", KIND_OTHER, UNITS_BYTES, stats.allocated,
"Memory mapped by the heap allocator that is currently allocated to the "
"application.  This may exceed the amount of memory requested by the "
"application because the allocator regularly rounds up request sizes. (The "
"exact amount requested is not recorded.)");
        NS_ENSURE_SUCCESS(rv, rv);

        // We mark this and the other heap-overhead reporters as KIND_NONHEAP
        // because KIND_HEAP memory means "counted in heap-allocated", which
        // this is not.
        rv = MOZ_COLLECT_REPORT(
            "explicit/heap-overhead/waste", KIND_NONHEAP, UNITS_BYTES,
            stats.waste,
"Committed bytes which do not correspond to an active allocation and which the "
"allocator is not intentionally keeping alive (i.e., not 'heap-bookkeeping' or "
"'heap-page-cache').  Although the allocator will waste some space under any "
"circumstances, a large value here may indicate that the heap is highly "
"fragmented, or that allocator is performing poorly for some other reason.");
        NS_ENSURE_SUCCESS(rv, rv);

        rv = MOZ_COLLECT_REPORT(
            "explicit/heap-overhead/bookkeeping", KIND_NONHEAP, UNITS_BYTES,
            stats.bookkeeping,
            "Committed bytes which the heap allocator uses for internal data "
            "structures.");
        NS_ENSURE_SUCCESS(rv, rv);

        rv = MOZ_COLLECT_REPORT(
            "explicit/heap-overhead/page-cache", KIND_NONHEAP, UNITS_BYTES,
            stats.page_cache,
"Memory which the allocator could return to the operating system, but hasn't. "
"The allocator keeps this memory around as an optimization, so it doesn't "
"have to ask the OS the next time it needs to fulfill a request. This value "
"is typically not larger than a few megabytes.");
        NS_ENSURE_SUCCESS(rv, rv);

        rv = MOZ_COLLECT_REPORT(
            "heap-committed", KIND_OTHER, UNITS_BYTES,
            stats.allocated + stats.waste + stats.bookkeeping + stats.page_cache,
"Memory mapped by the heap allocator that is committed, i.e. in physical "
"memory or paged to disk.  This value corresponds to 'heap-allocated' + "
"'heap-waste' + 'heap-bookkeeping' + 'heap-page-cache', but because "
"these values are read at different times, the result probably won't match "
"exactly.");
        NS_ENSURE_SUCCESS(rv, rv);

        rv = MOZ_COLLECT_REPORT(
            "heap-overhead-ratio", KIND_OTHER, UNITS_PERCENTAGE,
            HeapOverheadRatio(&stats),
"Ratio of committed, unused bytes to allocated bytes; i.e., "
"'heap-overhead' / 'heap-allocated'.  This measures the overhead of "
"the heap allocator relative to amount of memory allocated.");
        NS_ENSURE_SUCCESS(rv, rv);

        return NS_OK;
    }
};
NS_IMPL_ISUPPORTS1(JemallocHeapReporter, nsIMemoryReporter)

#endif  // HAVE_JEMALLOC_STATS

// Why is this here?  At first glance, you'd think it could be defined and
// registered with nsMemoryReporterManager entirely within nsAtomTable.cpp.
// However, the obvious time to register it is when the table is initialized,
// and that happens before XPCOM components are initialized, which means the
// RegisterStrongMemoryReporter call fails.  So instead we do it here.
class AtomTablesReporter MOZ_FINAL : public nsIMemoryReporter
{
    MOZ_DEFINE_MALLOC_SIZE_OF(MallocSizeOf)

public:
    NS_DECL_ISUPPORTS

    NS_METHOD CollectReports(nsIHandleReportCallback* aHandleReport,
                             nsISupports* aData)
    {
        return MOZ_COLLECT_REPORT(
            "explicit/atom-tables", KIND_HEAP, UNITS_BYTES,
            NS_SizeOfAtomTablesIncludingThis(MallocSizeOf),
            "Memory used by the dynamic and static atoms tables.");
    }
};
NS_IMPL_ISUPPORTS1(AtomTablesReporter, nsIMemoryReporter)

#ifdef MOZ_DMD

namespace mozilla {
namespace dmd {

class DMDReporter MOZ_FINAL : public nsIMemoryReporter
{
public:
  NS_DECL_ISUPPORTS

  NS_IMETHOD CollectReports(nsIHandleReportCallback* aHandleReport,
                            nsISupports* aData)
  {
    dmd::Sizes sizes;
    dmd::SizeOf(&sizes);

#define REPORT(_path, _amount, _desc)                                         \
    do {                                                                      \
      nsresult rv;                                                            \
      rv = aHandleReport->Callback(EmptyCString(), NS_LITERAL_CSTRING(_path), \
                                   KIND_HEAP, UNITS_BYTES, _amount,           \
                                   NS_LITERAL_CSTRING(_desc), aData);         \
      if (NS_WARN_IF(NS_FAILED(rv)))                                          \
          return rv;                                                          \
    } while (0)

    REPORT("explicit/dmd/stack-traces/used",
           sizes.mStackTracesUsed,
           "Memory used by stack traces which correspond to at least "
           "one heap block DMD is tracking.");

    REPORT("explicit/dmd/stack-traces/unused",
           sizes.mStackTracesUnused,
           "Memory used by stack traces which don't correspond to any heap "
           "blocks DMD is currently tracking.");

    REPORT("explicit/dmd/stack-traces/table",
           sizes.mStackTraceTable,
           "Memory used by DMD's stack trace table.");

    REPORT("explicit/dmd/block-table",
           sizes.mBlockTable,
           "Memory used by DMD's live block table.");

#undef REPORT

    return NS_OK;
  }
};
NS_IMPL_ISUPPORTS1(DMDReporter, nsIMemoryReporter)

} // namespace dmd
} // namespace mozilla

#endif  // MOZ_DMD

/**
 ** nsMemoryReporterManager implementation
 **/

NS_IMPL_ISUPPORTS1(nsMemoryReporterManager, nsIMemoryReporterManager)

NS_IMETHODIMP
nsMemoryReporterManager::Init()
{
#if defined(HAVE_JEMALLOC_STATS) && defined(XP_LINUX)
    if (!jemalloc_stats)
        return NS_ERROR_FAILURE;
#endif

#ifdef HAVE_JEMALLOC_STATS
    RegisterStrongReporter(new JemallocHeapReporter());
#endif

#ifdef HAVE_VSIZE_AND_RESIDENT_REPORTERS
    RegisterStrongReporter(new VsizeReporter());
    RegisterStrongReporter(new ResidentReporter());
#endif

#ifdef HAVE_VSIZE_MAX_CONTIGUOUS_REPORTER
    RegisterStrongReporter(new VsizeMaxContiguousReporter());
#endif

#ifdef HAVE_RESIDENT_UNIQUE_REPORTER
    RegisterStrongReporter(new ResidentUniqueReporter());
#endif

#ifdef HAVE_PAGE_FAULT_REPORTERS
    RegisterStrongReporter(new PageFaultsSoftReporter());
    RegisterStrongReporter(new PageFaultsHardReporter());
#endif

#ifdef HAVE_PRIVATE_REPORTER
    RegisterStrongReporter(new PrivateReporter());
#endif

    RegisterStrongReporter(new AtomTablesReporter());

#ifdef MOZ_DMD
    RegisterStrongReporter(new mozilla::dmd::DMDReporter());
#endif

#if defined(XP_LINUX) || defined(__FreeBSD__)
    nsMemoryInfoDumper::Initialize();
#endif

    return NS_OK;
}

namespace {

// ReporterEnumerator takes the two hashtables of reporters in its constructor
// and creates an nsISimpleEnumerator from its contents.
//
// The resultant enumerator works over a copy of the hashtable elements, so
// it's safe to mutate or destroy the hashtables after the enumerator is
// created.
//
class ReporterEnumerator MOZ_FINAL : public nsISimpleEnumerator
{
public:
    ReporterEnumerator(
        nsMemoryReporterManager::StrongReportersTable* aStrongReporters,
        nsMemoryReporterManager::WeakReportersTable* aWeakReporters)
      : mIndex(0)
    {
        aStrongReporters->EnumerateEntries(StrongEnumerator, this);
        aWeakReporters->EnumerateEntries(WeakEnumerator, this);
    }

    NS_DECL_ISUPPORTS
    NS_DECL_NSISIMPLEENUMERATOR

private:
    static PLDHashOperator
    StrongEnumerator(nsISupportsHashKey* aEntry, void* aData);

    static PLDHashOperator
    WeakEnumerator(nsPtrHashKey<nsISupports>* aEntry, void* aData);

    uint32_t mIndex;
    nsCOMArray<nsISupports> mArray;
};

NS_IMPL_ISUPPORTS1(ReporterEnumerator, nsISimpleEnumerator)

/* static */ PLDHashOperator
ReporterEnumerator::StrongEnumerator(nsISupportsHashKey* aElem, void* aData)
{
    ReporterEnumerator* enumerator = static_cast<ReporterEnumerator*>(aData);
    enumerator->mArray.AppendObject(aElem->GetKey());
    return PL_DHASH_NEXT;
}

/* static */ PLDHashOperator
ReporterEnumerator::WeakEnumerator(nsPtrHashKey<nsISupports>* aElem,
                                   void* aData)
{
    ReporterEnumerator* enumerator = static_cast<ReporterEnumerator*>(aData);
    enumerator->mArray.AppendObject(aElem->GetKey());
    return PL_DHASH_NEXT;
}

NS_IMETHODIMP
ReporterEnumerator::HasMoreElements(bool* aResult)
{
    *aResult = mIndex < mArray.Length();
    return NS_OK;
}

NS_IMETHODIMP
ReporterEnumerator::GetNext(nsISupports** aNext)
{
    if (mIndex < mArray.Length()) {
        nsCOMPtr<nsISupports> next = mArray.ObjectAt(mIndex);
        next.forget(aNext);
        mIndex++;
        return NS_OK;
    }

    *aNext = nullptr;
    return NS_ERROR_FAILURE;
}

} // anonymous namespace

nsMemoryReporterManager::nsMemoryReporterManager()
  : mMutex("nsMemoryReporterManager::mMutex"),
    mIsRegistrationBlocked(false),
    mStrongReporters(new StrongReportersTable()),
    mWeakReporters(new WeakReportersTable()),
    mSavedStrongReporters(nullptr),
    mSavedWeakReporters(nullptr),
    mNumChildProcesses(0),
    mNextGeneration(1),
    mGetReportsState(nullptr)
{
}

nsMemoryReporterManager::~nsMemoryReporterManager()
{
    delete mStrongReporters;
    delete mWeakReporters;
    NS_ASSERTION(!mSavedStrongReporters, "failed to restore strong reporters");
    NS_ASSERTION(!mSavedWeakReporters, "failed to restore weak reporters");
}

//#define DEBUG_CHILD_PROCESS_MEMORY_REPORTING 1

#ifdef DEBUG_CHILD_PROCESS_MEMORY_REPORTING
#define MEMORY_REPORTING_LOG(format, ...) \
    fprintf(stderr, "++++ MEMORY REPORTING: " format, ##__VA_ARGS__);
#else
#define MEMORY_REPORTING_LOG(...)
#endif

void
nsMemoryReporterManager::IncrementNumChildProcesses()
{
    if (!NS_IsMainThread()) {
        MOZ_CRASH();
    }
    mNumChildProcesses++;
    MEMORY_REPORTING_LOG("IncrementNumChildProcesses --> %d\n",
                         mNumChildProcesses);
}

void
nsMemoryReporterManager::DecrementNumChildProcesses()
{
    if (!NS_IsMainThread()) {
        MOZ_CRASH();
    }
    MOZ_ASSERT(mNumChildProcesses > 0);
    mNumChildProcesses--;
    MEMORY_REPORTING_LOG("DecrementNumChildProcesses --> %d\n",
                         mNumChildProcesses);
}

NS_IMETHODIMP
nsMemoryReporterManager::GetReports(
    nsIHandleReportCallback* aHandleReport,
    nsISupports* aHandleReportData,
    nsIFinishReportingCallback* aFinishReporting,
    nsISupports* aFinishReportingData)
{
    // Memory reporters are not necessarily threadsafe, so this function must
    // be called from the main thread.
    if (!NS_IsMainThread()) {
        MOZ_CRASH();
    }

    uint32_t generation = mNextGeneration++;

    if (mGetReportsState) {
        // A request is in flight.  Don't start another one.  And don't report
        // an error;  just ignore it, and let the in-flight request finish.
        MEMORY_REPORTING_LOG("GetReports (gen=%u, s->gen=%u): abort\n",
                             generation, mGetReportsState->mGeneration);
        return NS_OK;
    }

    MEMORY_REPORTING_LOG("GetReports (gen=%u, %d child(ren) present)\n",
                         generation, mNumChildProcesses);

    if (mNumChildProcesses > 0) {
        // Request memory reports from child processes.  We do this *before*
        // collecting reports for this process so each process can collect
        // reports in parallel.
        nsCOMPtr<nsIObserverService> obs =
            do_GetService("@mozilla.org/observer-service;1");
        NS_ENSURE_STATE(obs);

        // Casting the uint32_t generation to |const char16_t*| is a hack, but
        // simpler than converting the number to an actual string.
        obs->NotifyObservers(nullptr, "child-memory-reporter-request",
                             (const char16_t*)(uintptr_t)generation);

        nsCOMPtr<nsITimer> timer = do_CreateInstance(NS_TIMER_CONTRACTID);
        NS_ENSURE_TRUE(timer, NS_ERROR_FAILURE);
        nsresult rv = timer->InitWithFuncCallback(TimeoutCallback,
                                                  this, kTimeoutLengthMS,
                                                  nsITimer::TYPE_ONE_SHOT);
        NS_ENSURE_SUCCESS(rv, rv);

        mGetReportsState = new GetReportsState(generation,
                                               timer,
                                               mNumChildProcesses,
                                               aHandleReport,
                                               aHandleReportData,
                                               aFinishReporting,
                                               aFinishReportingData);
    }

    // Get reports for this process.
    GetReportsForThisProcess(aHandleReport, aHandleReportData);

    // If there are no child processes, we can finish up immediately.
    return (mNumChildProcesses == 0)
         ? aFinishReporting->Callback(aFinishReportingData)
         : NS_OK;
}

NS_IMETHODIMP
nsMemoryReporterManager::GetReportsForThisProcess(
    nsIHandleReportCallback* aHandleReport,
    nsISupports* aHandleReportData)
{
    // Memory reporters are not necessarily threadsafe, so this function must
    // be called from the main thread.
    if (!NS_IsMainThread()) {
        MOZ_CRASH();
    }

    nsRefPtr<ReporterEnumerator> e;
    {
        mozilla::MutexAutoLock autoLock(mMutex);
        e = new ReporterEnumerator(mStrongReporters, mWeakReporters);
    }
    bool more;
    while (NS_SUCCEEDED(e->HasMoreElements(&more)) && more) {
        nsCOMPtr<nsIMemoryReporter> r;
        e->GetNext(getter_AddRefs(r));
        r->CollectReports(aHandleReport, aHandleReportData);
    }

    return NS_OK;
}

// This function has no return value.  If something goes wrong, there's no
// clear place to report the problem to, but that's ok -- we will end up
// hitting the timeout and executing TimeoutCallback().
void
nsMemoryReporterManager::HandleChildReports(
    const uint32_t& aGeneration,
    const InfallibleTArray<dom::MemoryReport>& aChildReports)
{
    // Memory reporting only happens on the main thread.
    if (!NS_IsMainThread()) {
        MOZ_CRASH();
    }

    GetReportsState* s = mGetReportsState;

    if (!s) {
        // If we reach here, either:
        //
        // - A child process reported back too late, and no subsequent request
        //   is in flight.
        //
        // - (Unlikely) A "child-memory-reporter-request" notification was
        //   triggered from somewhere other than GetReports(), causing child
        //   processes to report back when the nsMemoryReporterManager wasn't
        //   expecting it.
        //
        // Either way, there's nothing to be done.  Just ignore it.
        MEMORY_REPORTING_LOG(
            "HandleChildReports: no request in flight (aGen=%u)\n",
            aGeneration);
        return;
    }

    if (aGeneration != s->mGeneration) {
        // If we reach here, a child process must have reported back, too late,
        // while a subsequent (higher-numbered) request is in flight.  Again,
        // ignore it.
        MOZ_ASSERT(aGeneration < s->mGeneration);
        MEMORY_REPORTING_LOG(
            "HandleChildReports: gen mismatch (aGen=%u, s->gen=%u)\n",
            aGeneration, s->mGeneration);
        return;
    }

    // Process the reports from the child process.
    for (uint32_t i = 0; i < aChildReports.Length(); i++) {
        const dom::MemoryReport& r = aChildReports[i];

        // Child reports should have a non-empty process.
        MOZ_ASSERT(!r.process().IsEmpty());

        // If the call fails, ignore and continue.
        s->mHandleReport->Callback(r.process(), r.path(), r.kind(),
                                   r.units(), r.amount(), r.desc(),
                                   s->mHandleReportData);
    }

    // If all the child processes have reported, we can cancel the timer and
    // finish up.  Otherwise, just return.

    s->mNumChildProcessesCompleted++;
    MEMORY_REPORTING_LOG("HandleChildReports (aGen=%u): completed child %d\n",
                         aGeneration, s->mNumChildProcessesCompleted);

    if (s->mNumChildProcessesCompleted == s->mNumChildProcesses) {
         s->mTimer->Cancel();
         FinishReporting();
    }
}

/* static */ void
nsMemoryReporterManager::TimeoutCallback(nsITimer* aTimer, void* aData)
{
    nsMemoryReporterManager* mgr =
        static_cast<nsMemoryReporterManager*>(aData);

    MOZ_ASSERT(mgr->mGetReportsState);
    MEMORY_REPORTING_LOG("TimeoutCallback (s->gen=%u)\n",
                         mgr->mGetReportsState->mGeneration);

    // We don't bother sending any kind of cancellation message to the child
    // processes that haven't reported back.

    mgr->FinishReporting();
}

void
nsMemoryReporterManager::FinishReporting()
{
    // Memory reporting only happens on the main thread.
    if (!NS_IsMainThread()) {
        MOZ_CRASH();
    }

    MOZ_ASSERT(mGetReportsState);
    MEMORY_REPORTING_LOG("FinishReporting (s->gen=%u)\n",
                         mGetReportsState->mGeneration);

    // Call this before deleting |mGetReportsState|.  That way, if
    // |mFinishReportData| calls GetReports(), it will silently abort, as
    // required.
    (void)mGetReportsState->mFinishReporting->Callback(
        mGetReportsState->mFinishReportingData);

    delete mGetReportsState;
    mGetReportsState = nullptr;
}

static void
CrashIfRefcountIsZero(nsISupports* aObj)
{
    // This will probably crash if the object's refcount is 0.
    uint32_t refcnt = NS_ADDREF(aObj);
    if (refcnt <= 1) {
        MOZ_CRASH("CrashIfRefcountIsZero: refcount is zero");
    }
    NS_RELEASE(aObj);
}

nsresult
nsMemoryReporterManager::RegisterReporterHelper(
    nsIMemoryReporter* aReporter, bool aForce, bool aStrong)
{
    // This method is thread-safe.
    mozilla::MutexAutoLock autoLock(mMutex);

    if (mIsRegistrationBlocked && !aForce) {
        return NS_ERROR_FAILURE;
    }

    if (mStrongReporters->Contains(aReporter) ||
        mWeakReporters->Contains(aReporter))
    {
        return NS_ERROR_FAILURE;
    }

    // If |aStrong| is true, |aReporter| may have a refcnt of 0, so we take
    // a kung fu death grip before calling PutEntry.  Otherwise, if PutEntry
    // addref'ed and released |aReporter| before finally addref'ing it for
    // good, it would free aReporter!  The kung fu death grip could itself be
    // problematic if PutEntry didn't addref |aReporter| (because then when the
    // death grip goes out of scope, we would delete the reporter).  In debug
    // mode, we check that this doesn't happen.
    //
    // If |aStrong| is false, we require that |aReporter| have a non-zero
    // refcnt.
    //
    if (aStrong) {
        nsCOMPtr<nsIMemoryReporter> kungFuDeathGrip = aReporter;
        mStrongReporters->PutEntry(aReporter);
        CrashIfRefcountIsZero(aReporter);
    } else {
        CrashIfRefcountIsZero(aReporter);
        nsCOMPtr<nsIXPConnectWrappedJS> jsComponent =
            do_QueryInterface(aReporter);
        if (jsComponent) {
            // We cannot allow non-native reporters (WrappedJS), since we'll be
            // holding onto a raw pointer, which would point to the wrapper,
            // and that wrapper is likely to go away as soon as this register
            // call finishes.  This would then lead to subsequent crashes in
            // CollectReports().
            return NS_ERROR_XPC_BAD_CONVERT_JS;
        }
        mWeakReporters->PutEntry(aReporter);
    }

    return NS_OK;
}

NS_IMETHODIMP
nsMemoryReporterManager::RegisterStrongReporter(nsIMemoryReporter* aReporter)
{
    return RegisterReporterHelper(aReporter, /* force = */ false,
                                  /* strong = */ true);
}

NS_IMETHODIMP
nsMemoryReporterManager::RegisterWeakReporter(nsIMemoryReporter* aReporter)
{
    return RegisterReporterHelper(aReporter, /* force = */ false,
                                  /* strong = */ false);
}

NS_IMETHODIMP
nsMemoryReporterManager::RegisterStrongReporterEvenIfBlocked(
    nsIMemoryReporter* aReporter)
{
    return RegisterReporterHelper(aReporter, /* force = */ true,
                                  /* strong = */ true);
}

NS_IMETHODIMP
nsMemoryReporterManager::UnregisterStrongReporter(nsIMemoryReporter* aReporter)
{
    // This method is thread-safe.
    mozilla::MutexAutoLock autoLock(mMutex);

    MOZ_ASSERT(!mWeakReporters->Contains(aReporter));

    if (mStrongReporters->Contains(aReporter)) {
        mStrongReporters->RemoveEntry(aReporter);
        return NS_OK;
    }

    return NS_ERROR_FAILURE;
}

NS_IMETHODIMP
nsMemoryReporterManager::UnregisterWeakReporter(nsIMemoryReporter* aReporter)
{
    // This method is thread-safe.
    mozilla::MutexAutoLock autoLock(mMutex);

    MOZ_ASSERT(!mStrongReporters->Contains(aReporter));

    if (mWeakReporters->Contains(aReporter)) {
        mWeakReporters->RemoveEntry(aReporter);
        return NS_OK;
    }

    return NS_ERROR_FAILURE;
}

NS_IMETHODIMP
nsMemoryReporterManager::BlockRegistrationAndHideExistingReporters()
{
    // This method is thread-safe.
    mozilla::MutexAutoLock autoLock(mMutex);
    if (mIsRegistrationBlocked) {
        return NS_ERROR_FAILURE;
    }
    mIsRegistrationBlocked = true;

    // Hide the existing reporters, saving them for later restoration.
    MOZ_ASSERT(!mSavedStrongReporters);
    MOZ_ASSERT(!mSavedWeakReporters);
    mSavedStrongReporters = mStrongReporters;
    mSavedWeakReporters = mWeakReporters;
    mStrongReporters = new StrongReportersTable();
    mWeakReporters = new WeakReportersTable();

    return NS_OK;
}

NS_IMETHODIMP
nsMemoryReporterManager::UnblockRegistrationAndRestoreOriginalReporters()
{
    // This method is thread-safe.
    mozilla::MutexAutoLock autoLock(mMutex);
    if (!mIsRegistrationBlocked) {
        return NS_ERROR_FAILURE;
    }

    // Banish the current reporters, and restore the hidden ones.
    delete mStrongReporters;
    delete mWeakReporters;
    mStrongReporters = mSavedStrongReporters;
    mWeakReporters = mSavedWeakReporters;
    mSavedStrongReporters = nullptr;
    mSavedWeakReporters = nullptr;

    mIsRegistrationBlocked = false;
    return NS_OK;
}

// This is just a wrapper for int64_t that implements nsISupports, so it can be
// passed to nsIMemoryReporter::CollectReports.
class Int64Wrapper MOZ_FINAL : public nsISupports {
public:
    NS_DECL_ISUPPORTS
    Int64Wrapper() : mValue(0) { }
    int64_t mValue;
};

NS_IMPL_ISUPPORTS0(Int64Wrapper)

class ExplicitCallback MOZ_FINAL : public nsIHandleReportCallback
{
public:
    NS_DECL_ISUPPORTS

    NS_IMETHOD Callback(const nsACString& aProcess, const nsACString& aPath,
                        int32_t aKind, int32_t aUnits, int64_t aAmount,
                        const nsACString& aDescription,
                        nsISupports* aWrappedExplicit)
    {
        // Using the "heap-allocated" reporter here instead of
        // nsMemoryReporterManager.heapAllocated goes against the usual
        // pattern.  But it's for a good reason:  in tests, we can easily
        // create artificial (i.e. deterministic) reporters -- which allows us
        // to precisely test nsMemoryReporterManager.explicit -- but we can't
        // do that for distinguished amounts.
        if (aPath.Equals("heap-allocated") ||
            (aKind == nsIMemoryReporter::KIND_NONHEAP &&
             PromiseFlatCString(aPath).Find("explicit") == 0))
        {
            Int64Wrapper* wrappedInt64 =
                static_cast<Int64Wrapper*>(aWrappedExplicit);
            wrappedInt64->mValue += aAmount;
        }
        return NS_OK;
    }
};

NS_IMPL_ISUPPORTS1(ExplicitCallback, nsIHandleReportCallback)

NS_IMETHODIMP
nsMemoryReporterManager::GetExplicit(int64_t* aAmount)
{
    if (NS_WARN_IF(!aAmount))
        return NS_ERROR_INVALID_ARG;
    *aAmount = 0;
#ifndef HAVE_JEMALLOC_STATS
    return NS_ERROR_NOT_AVAILABLE;
#else

    // For each reporter we call CollectReports and filter out the
    // non-explicit, non-NONHEAP measurements (except for "heap-allocated").
    // That's lots of wasted work, and we used to have a GetExplicitNonHeap()
    // method which did this more efficiently, but it ended up being more
    // trouble than it was worth.

    nsRefPtr<ExplicitCallback> handleReport = new ExplicitCallback();
    nsRefPtr<Int64Wrapper> wrappedExplicitSize = new Int64Wrapper();

    GetReportsForThisProcess(handleReport, wrappedExplicitSize);

    *aAmount = wrappedExplicitSize->mValue;

    return NS_OK;
#endif // HAVE_JEMALLOC_STATS
}

NS_IMETHODIMP
nsMemoryReporterManager::GetVsize(int64_t* aVsize)
{
#ifdef HAVE_VSIZE_AND_RESIDENT_REPORTERS
    return VsizeDistinguishedAmount(aVsize);
#else
    *aResident = 0;
    return NS_ERROR_NOT_AVAILABLE;
#endif
}

NS_IMETHODIMP
nsMemoryReporterManager::GetVsizeMaxContiguous(int64_t* aAmount)
{
#ifdef HAVE_VSIZE_MAX_CONTIGUOUS_REPORTER
    return VsizeMaxContiguousDistinguishedAmount(aAmount);
#else
    *aAmount = 0;
    return NS_ERROR_NOT_AVAILABLE;
#endif
}

NS_IMETHODIMP
nsMemoryReporterManager::GetResident(int64_t* aAmount)
{
#ifdef HAVE_VSIZE_AND_RESIDENT_REPORTERS
    return ResidentDistinguishedAmount(aAmount);
#else
    *aAmount = 0;
    return NS_ERROR_NOT_AVAILABLE;
#endif
}

NS_IMETHODIMP
nsMemoryReporterManager::GetResidentFast(int64_t* aAmount)
{
#ifdef HAVE_VSIZE_AND_RESIDENT_REPORTERS
    return ResidentFastDistinguishedAmount(aAmount);
#else
    *aAmount = 0;
    return NS_ERROR_NOT_AVAILABLE;
#endif
}

NS_IMETHODIMP
nsMemoryReporterManager::GetHeapAllocated(int64_t* aAmount)
{
#ifdef HAVE_JEMALLOC_STATS
    jemalloc_stats_t stats;
    jemalloc_stats(&stats);
    *aAmount = stats.allocated;
    return NS_OK;
#else
    *aAmount = 0;
    return NS_ERROR_NOT_AVAILABLE;
#endif
}

// This has UNITS_PERCENTAGE, so it is multiplied by 100x.
NS_IMETHODIMP
nsMemoryReporterManager::GetHeapOverheadRatio(int64_t* aAmount)
{
#ifdef HAVE_JEMALLOC_STATS
    jemalloc_stats_t stats;
    jemalloc_stats(&stats);
    *aAmount = HeapOverheadRatio(&stats);
    return NS_OK;
#else
    *aAmount = 0;
    return NS_ERROR_NOT_AVAILABLE;
#endif
}

static nsresult
GetInfallibleAmount(InfallibleAmountFn aAmountFn, int64_t* aAmount)
{
    if (aAmountFn) {
        *aAmount = aAmountFn();
        return NS_OK;
    }
    *aAmount = 0;
    return NS_ERROR_NOT_AVAILABLE;
}

NS_IMETHODIMP
nsMemoryReporterManager::GetJSMainRuntimeGCHeap(int64_t* aAmount)
{
    return GetInfallibleAmount(mAmountFns.mJSMainRuntimeGCHeap, aAmount);
}

NS_IMETHODIMP
nsMemoryReporterManager::GetJSMainRuntimeTemporaryPeak(int64_t* aAmount)
{
    return GetInfallibleAmount(mAmountFns.mJSMainRuntimeTemporaryPeak, aAmount);
}

NS_IMETHODIMP
nsMemoryReporterManager::GetJSMainRuntimeCompartmentsSystem(int64_t* aAmount)
{
    return GetInfallibleAmount(mAmountFns.mJSMainRuntimeCompartmentsSystem,
                               aAmount);
}

NS_IMETHODIMP
nsMemoryReporterManager::GetJSMainRuntimeCompartmentsUser(int64_t* aAmount)
{
    return GetInfallibleAmount(mAmountFns.mJSMainRuntimeCompartmentsUser,
                               aAmount);
}

NS_IMETHODIMP
nsMemoryReporterManager::GetImagesContentUsedUncompressed(int64_t* aAmount)
{
    return GetInfallibleAmount(mAmountFns.mImagesContentUsedUncompressed,
                               aAmount);
}

NS_IMETHODIMP
nsMemoryReporterManager::GetStorageSQLite(int64_t* aAmount)
{
    return GetInfallibleAmount(mAmountFns.mStorageSQLite, aAmount);
}

NS_IMETHODIMP
nsMemoryReporterManager::GetLowMemoryEventsVirtual(int64_t* aAmount)
{
    return GetInfallibleAmount(mAmountFns.mLowMemoryEventsVirtual, aAmount);
}

NS_IMETHODIMP
nsMemoryReporterManager::GetLowMemoryEventsPhysical(int64_t* aAmount)
{
    return GetInfallibleAmount(mAmountFns.mLowMemoryEventsPhysical, aAmount);
}

NS_IMETHODIMP
nsMemoryReporterManager::GetGhostWindows(int64_t* aAmount)
{
    return GetInfallibleAmount(mAmountFns.mGhostWindows, aAmount);
}

NS_IMETHODIMP
nsMemoryReporterManager::GetPageFaultsHard(int64_t* aAmount)
{
#ifdef HAVE_PAGE_FAULT_REPORTERS
    return PageFaultsHardDistinguishedAmount(aAmount);
#else
    *aAmount = 0;
    return NS_ERROR_NOT_AVAILABLE;
#endif
}

NS_IMETHODIMP
nsMemoryReporterManager::GetHasMozMallocUsableSize(bool* aHas)
{
    void* p = malloc(16);
    if (!p) {
        return NS_ERROR_OUT_OF_MEMORY;
    }
    size_t usable = moz_malloc_usable_size(p);
    free(p);
    *aHas = !!(usable > 0);
    return NS_OK;
}

namespace {

/**
 * This runnable lets us implement nsIMemoryReporterManager::MinimizeMemoryUsage().
 * We fire a heap-minimize notification, spin the event loop, and repeat this
 * process a few times.
 *
 * When this sequence finishes, we invoke the callback function passed to the
 * runnable's constructor.
 */
class MinimizeMemoryUsageRunnable : public nsCancelableRunnable
{
public:
  MinimizeMemoryUsageRunnable(nsIRunnable* aCallback)
    : mCallback(aCallback)
    , mRemainingIters(sNumIters)
    , mCanceled(false)
  {}

  NS_IMETHOD Run()
  {
    if (mCanceled) {
      return NS_OK;
    }

    nsCOMPtr<nsIObserverService> os = services::GetObserverService();
    if (!os) {
      return NS_ERROR_FAILURE;
    }

    if (mRemainingIters == 0) {
      os->NotifyObservers(nullptr, "after-minimize-memory-usage",
                          MOZ_UTF16("MinimizeMemoryUsageRunnable"));
      if (mCallback) {
        mCallback->Run();
      }
      return NS_OK;
    }

    os->NotifyObservers(nullptr, "memory-pressure",
                        MOZ_UTF16("heap-minimize"));
    mRemainingIters--;
    NS_DispatchToMainThread(this);

    return NS_OK;
  }

  NS_IMETHOD Cancel()
  {
    if (mCanceled) {
      return NS_ERROR_UNEXPECTED;
    }

    mCanceled = true;

    return NS_OK;
  }

private:
  // Send sNumIters heap-minimize notifications, spinning the event
  // loop after each notification (see bug 610166 comment 12 for an
  // explanation), because one notification doesn't cut it.
  static const uint32_t sNumIters = 3;

  nsCOMPtr<nsIRunnable> mCallback;
  uint32_t mRemainingIters;
  bool mCanceled;
};

} // anonymous namespace

NS_IMETHODIMP
nsMemoryReporterManager::MinimizeMemoryUsage(nsIRunnable* aCallback,
                                             nsICancelableRunnable** aResult)
{
  if (NS_WARN_IF(!aResult))
    return NS_ERROR_INVALID_ARG;

  nsRefPtr<nsICancelableRunnable> runnable =
    new MinimizeMemoryUsageRunnable(aCallback);
  NS_ADDREF(*aResult = runnable);

  return NS_DispatchToMainThread(runnable);
}

NS_IMETHODIMP
nsMemoryReporterManager::SizeOfTab(nsIDOMWindow* aTopWindow,
                                   int64_t* aJSObjectsSize,
                                   int64_t* aJSStringsSize,
                                   int64_t* aJSOtherSize,
                                   int64_t* aDomSize,
                                   int64_t* aStyleSize,
                                   int64_t* aOtherSize,
                                   int64_t* aTotalSize,
                                   double*  aJSMilliseconds,
                                   double*  aNonJSMilliseconds)
{
    nsCOMPtr<nsIGlobalObject> global = do_QueryInterface(aTopWindow);
    nsCOMPtr<nsPIDOMWindow> piWindow = do_QueryInterface(aTopWindow);
    if (NS_WARN_IF(!global) || NS_WARN_IF(!piWindow))
      return NS_ERROR_FAILURE;

    TimeStamp t1 = TimeStamp::Now();

    // Measure JS memory consumption (and possibly some non-JS consumption, via
    // |jsPrivateSize|).
    size_t jsObjectsSize, jsStringsSize, jsPrivateSize, jsOtherSize;
    nsresult rv = mSizeOfTabFns.mJS(global->GetGlobalJSObject(),
                                    &jsObjectsSize, &jsStringsSize,
                                    &jsPrivateSize, &jsOtherSize);
    if (NS_WARN_IF(NS_FAILED(rv)))
      return rv;

    TimeStamp t2 = TimeStamp::Now();

    // Measure non-JS memory consumption.
    size_t domSize, styleSize, otherSize;
    mSizeOfTabFns.mNonJS(piWindow, &domSize, &styleSize, &otherSize);

    TimeStamp t3 = TimeStamp::Now();

    *aTotalSize = 0;
    #define DO(aN, n) { *aN = (n); *aTotalSize += (n); }
    DO(aJSObjectsSize, jsObjectsSize);
    DO(aJSStringsSize, jsStringsSize);
    DO(aJSOtherSize,   jsOtherSize);
    DO(aDomSize,       jsPrivateSize + domSize);
    DO(aStyleSize,     styleSize);
    DO(aOtherSize,     otherSize);
    #undef DO

    *aJSMilliseconds    = (t2 - t1).ToMilliseconds();
    *aNonJSMilliseconds = (t3 - t2).ToMilliseconds();

    return NS_OK;
}

namespace mozilla {

nsresult
RegisterStrongMemoryReporter(nsIMemoryReporter* aReporter)
{
    nsCOMPtr<nsIMemoryReporterManager> mgr = do_GetService("@mozilla.org/memory-reporter-manager;1");
    if (!mgr) {
        return NS_ERROR_FAILURE;
    }
    return mgr->RegisterStrongReporter(aReporter);
}

nsresult
RegisterWeakMemoryReporter(nsIMemoryReporter* aReporter)
{
    nsCOMPtr<nsIMemoryReporterManager> mgr = do_GetService("@mozilla.org/memory-reporter-manager;1");
    if (!mgr) {
        return NS_ERROR_FAILURE;
    }
    return mgr->RegisterWeakReporter(aReporter);
}

nsresult
UnregisterWeakMemoryReporter(nsIMemoryReporter* aReporter)
{
    nsCOMPtr<nsIMemoryReporterManager> mgr = do_GetService("@mozilla.org/memory-reporter-manager;1");
    if (!mgr) {
        return NS_ERROR_FAILURE;
    }
    return mgr->UnregisterWeakReporter(aReporter);
}

#define GET_MEMORY_REPORTER_MANAGER(mgr)                                      \
    nsRefPtr<nsMemoryReporterManager> mgr =                                   \
        nsMemoryReporterManager::GetOrCreate();                               \
    if (!mgr) {                                                               \
        return NS_ERROR_FAILURE;                                              \
    }

// Macro for generating functions that register distinguished amount functions
// with the memory reporter manager.
#define DEFINE_REGISTER_DISTINGUISHED_AMOUNT(kind, name)                      \
    nsresult                                                                  \
    Register##name##DistinguishedAmount(kind##AmountFn aAmountFn)             \
    {                                                                         \
        GET_MEMORY_REPORTER_MANAGER(mgr)                                      \
        mgr->mAmountFns.m##name = aAmountFn;                                  \
        return NS_OK;                                                         \
    }

#define DEFINE_UNREGISTER_DISTINGUISHED_AMOUNT(name)                          \
    nsresult                                                                  \
    Unregister##name##DistinguishedAmount()                                   \
    {                                                                         \
        GET_MEMORY_REPORTER_MANAGER(mgr)                                      \
        mgr->mAmountFns.m##name = nullptr;                                    \
        return NS_OK;                                                         \
    }

DEFINE_REGISTER_DISTINGUISHED_AMOUNT(Infallible, JSMainRuntimeGCHeap)
DEFINE_REGISTER_DISTINGUISHED_AMOUNT(Infallible, JSMainRuntimeTemporaryPeak)
DEFINE_REGISTER_DISTINGUISHED_AMOUNT(Infallible, JSMainRuntimeCompartmentsSystem)
DEFINE_REGISTER_DISTINGUISHED_AMOUNT(Infallible, JSMainRuntimeCompartmentsUser)

DEFINE_REGISTER_DISTINGUISHED_AMOUNT(Infallible, ImagesContentUsedUncompressed)

DEFINE_REGISTER_DISTINGUISHED_AMOUNT(Infallible, StorageSQLite)
DEFINE_UNREGISTER_DISTINGUISHED_AMOUNT(StorageSQLite)

DEFINE_REGISTER_DISTINGUISHED_AMOUNT(Infallible, LowMemoryEventsVirtual)
DEFINE_REGISTER_DISTINGUISHED_AMOUNT(Infallible, LowMemoryEventsPhysical)

DEFINE_REGISTER_DISTINGUISHED_AMOUNT(Infallible, GhostWindows)

#undef DEFINE_REGISTER_DISTINGUISHED_AMOUNT
#undef DEFINE_UNREGISTER_DISTINGUISHED_AMOUNT

#define DEFINE_REGISTER_SIZE_OF_TAB(name)                                     \
    nsresult                                                                  \
    Register##name##SizeOfTab(name##SizeOfTabFn aSizeOfTabFn)                 \
    {                                                                         \
        GET_MEMORY_REPORTER_MANAGER(mgr)                                      \
        mgr->mSizeOfTabFns.m##name = aSizeOfTabFn;                            \
        return NS_OK;                                                         \
    }

DEFINE_REGISTER_SIZE_OF_TAB(JS);
DEFINE_REGISTER_SIZE_OF_TAB(NonJS);

#undef DEFINE_REGISTER_SIZE_OF_TAB

#undef GET_MEMORY_REPORTER_MANAGER

}

#if defined(MOZ_DMD)

namespace mozilla {
namespace dmd {

class DoNothingCallback MOZ_FINAL : public nsIHandleReportCallback
{
public:
    NS_DECL_ISUPPORTS

    NS_IMETHOD Callback(const nsACString& aProcess, const nsACString& aPath,
                        int32_t aKind, int32_t aUnits, int64_t aAmount,
                        const nsACString& aDescription,
                        nsISupports* aData)
    {
        // Do nothing;  the reporter has already reported to DMD.
        return NS_OK;
    }
};

NS_IMPL_ISUPPORTS1(DoNothingCallback, nsIHandleReportCallback)

void
RunReportersForThisProcess()
{
    nsCOMPtr<nsIMemoryReporterManager> mgr =
        do_GetService("@mozilla.org/memory-reporter-manager;1");

    nsRefPtr<DoNothingCallback> doNothing = new DoNothingCallback();

    mgr->GetReportsForThisProcess(doNothing, nullptr);
}

} // namespace dmd
} // namespace mozilla

#endif  // defined(MOZ_DMD)