gecko/xpcom/base/MemoryInfoDumper.cpp

611 lines
18 KiB
C++

/* -*- Mode: C++; tab-width: 50; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* vim: set sw=2 ts=50 et cin 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 "mozilla/MemoryInfoDumper.h"
#include "mozilla/ClearOnShutdown.h"
#include "mozilla/FileUtils.h"
#include "mozilla/StaticPtr.h"
#include "mozilla/unused.h"
#include "mozilla/dom/ContentParent.h"
#include "mozilla/dom/ContentChild.h"
#include "nsIConsoleService.h"
#include "nsICycleCollectorListener.h"
#include "nsDirectoryServiceDefs.h"
#include "nsGZFileWriter.h"
#include "nsJSEnvironment.h"
#include "nsPrintfCString.h"
#ifdef XP_WIN
#include <process.h>
#define getpid _getpid
#else
#include <unistd.h>
#endif
#ifdef XP_LINUX
#include <fcntl.h>
#endif
#ifdef ANDROID
#include <sys/types.h>
#include <sys/stat.h>
#endif
using namespace mozilla;
using namespace mozilla::dom;
namespace mozilla {
namespace {
class DumpMemoryReportsRunnable : public nsRunnable
{
public:
DumpMemoryReportsRunnable(const nsAString& aIdentifier,
bool aMinimizeMemoryUsage,
bool aDumpChildProcesses)
: mIdentifier(aIdentifier)
, mMinimizeMemoryUsage(aMinimizeMemoryUsage)
, mDumpChildProcesses(aDumpChildProcesses)
{}
NS_IMETHOD Run()
{
MemoryInfoDumper::DumpMemoryReportsToFile(
mIdentifier, mMinimizeMemoryUsage, mDumpChildProcesses);
return NS_OK;
}
private:
const nsString mIdentifier;
const bool mMinimizeMemoryUsage;
const bool mDumpChildProcesses;
};
class GCAndCCLogDumpRunnable : public nsRunnable
{
public:
GCAndCCLogDumpRunnable(const nsAString& aIdentifier,
bool aDumpChildProcesses)
: mIdentifier(aIdentifier)
, mDumpChildProcesses(aDumpChildProcesses)
{}
NS_IMETHOD Run()
{
MemoryInfoDumper::DumpGCAndCCLogsToFile(
mIdentifier, mDumpChildProcesses);
return NS_OK;
}
private:
const nsString mIdentifier;
const bool mDumpChildProcesses;
};
} // anonymous namespace
#ifdef XP_LINUX // {
namespace {
/*
* The following code supports dumping about:memory upon receiving a signal.
*
* We listen for the following signals:
*
* - SIGRTMIN: Dump our memory reporters (and those of our child
* processes),
* - SIGRTMIN + 1: Dump our memory reporters (and those of our child
* processes) after minimizing memory usage, and
* - SIGRTMIN + 2: Dump the GC and CC logs in this and our child processes.
*
* When we receive one of these signals, we write the signal number to a pipe.
* The IO thread then notices that the pipe has been written to, and kicks off
* the appropriate task on the main thread.
*
* This scheme is similar to using signalfd(), except it's portable and it
* doesn't require the use of sigprocmask, which is problematic because it
* masks signals received by child processes.
*
* In theory, we could use Chromium's MessageLoopForIO::CatchSignal() for this.
* But that uses libevent, which does not handle the realtime signals (bug
* 794074).
*/
// It turns out that at least on some systems, SIGRTMIN is not a compile-time
// constant, so these have to be set at runtime.
static int sDumpAboutMemorySignum; // SIGRTMIN
static int sDumpAboutMemoryAfterMMUSignum; // SIGRTMIN + 1
static int sGCAndCCDumpSignum; // SIGRTMIN + 2
// This is the write-end of a pipe that we use to notice when a
// dump-about-memory signal occurs.
static int sDumpAboutMemoryPipeWriteFd;
void
DumpAboutMemorySignalHandler(int aSignum)
{
// This is a signal handler, so everything in here needs to be
// async-signal-safe. Be careful!
if (sDumpAboutMemoryPipeWriteFd != 0) {
uint8_t signum = static_cast<int>(aSignum);
write(sDumpAboutMemoryPipeWriteFd, &signum, sizeof(signum));
}
}
class SignalPipeWatcher : public MessageLoopForIO::Watcher
{
public:
SignalPipeWatcher()
{}
~SignalPipeWatcher()
{
// This is somewhat paranoid, but we want to avoid the race condition where
// we close sDumpAboutMemoryPipeWriteFd before setting it to 0, then we
// reuse that fd for some other file, and then the signal handler runs.
int pipeWriteFd = sDumpAboutMemoryPipeWriteFd;
PR_ATOMIC_SET(&sDumpAboutMemoryPipeWriteFd, 0);
// Stop watching the pipe's file descriptor /before/ we close it!
mReadWatcher.StopWatchingFileDescriptor();
close(pipeWriteFd);
close(mPipeReadFd);
}
NS_INLINE_DECL_THREADSAFE_REFCOUNTING(SignalPipeWatcher)
bool Start()
{
MOZ_ASSERT(XRE_GetIOMessageLoop() == MessageLoopForIO::current());
sDumpAboutMemorySignum = SIGRTMIN;
sDumpAboutMemoryAfterMMUSignum = SIGRTMIN + 1;
sGCAndCCDumpSignum = SIGRTMIN + 2;
// Create a pipe. When we receive a signal in our signal handler, we'll
// write the signum to the write-end of this pipe.
int pipeFds[2];
if (pipe(pipeFds)) {
NS_WARNING("Failed to create pipe.");
return false;
}
// Close this pipe on calls to exec().
fcntl(pipeFds[0], F_SETFD, FD_CLOEXEC);
fcntl(pipeFds[1], F_SETFD, FD_CLOEXEC);
mPipeReadFd = pipeFds[0];
sDumpAboutMemoryPipeWriteFd = pipeFds[1];
struct sigaction action;
memset(&action, 0, sizeof(action));
sigemptyset(&action.sa_mask);
action.sa_handler = DumpAboutMemorySignalHandler;
if (sigaction(sDumpAboutMemorySignum, &action, nullptr)) {
NS_WARNING("Failed to register about:memory dump signal handler.");
}
if (sigaction(sDumpAboutMemoryAfterMMUSignum, &action, nullptr)) {
NS_WARNING("Failed to register about:memory dump after MMU signal handler.");
}
if (sigaction(sGCAndCCDumpSignum, &action, nullptr)) {
NS_WARNING("Failed to register GC+CC dump signal handler.");
}
// Start watching the read end of the pipe on the IO thread.
return MessageLoopForIO::current()->WatchFileDescriptor(
mPipeReadFd, /* persistent = */ true,
MessageLoopForIO::WATCH_READ,
&mReadWatcher, this);
}
virtual void OnFileCanReadWithoutBlocking(int aFd)
{
MOZ_ASSERT(XRE_GetIOMessageLoop() == MessageLoopForIO::current());
uint8_t signum;
ssize_t numReceived = read(aFd, &signum, sizeof(signum));
if (numReceived != sizeof(signum)) {
NS_WARNING("Error reading from buffer in "
"SignalPipeWatcher::OnFileCanReadWithoutBlocking.");
return;
}
if (signum == sDumpAboutMemorySignum ||
signum == sDumpAboutMemoryAfterMMUSignum) {
// Dump our memory reports (but run this on the main thread!).
bool doMMUFirst = signum == sDumpAboutMemoryAfterMMUSignum;
nsRefPtr<DumpMemoryReportsRunnable> runnable =
new DumpMemoryReportsRunnable(
/* identifier = */ EmptyString(),
doMMUFirst,
/* dumpChildProcesses = */ true);
NS_DispatchToMainThread(runnable);
}
else if (signum == sGCAndCCDumpSignum) {
// Dump GC and CC logs (from the main thread).
nsRefPtr<GCAndCCLogDumpRunnable> runnable =
new GCAndCCLogDumpRunnable(
/* identifier = */ EmptyString(),
/* dumpChildProcesses = */ true);
NS_DispatchToMainThread(runnable);
}
else {
NS_WARNING("Got unexpected signum.");
}
}
virtual void OnFileCanWriteWithoutBlocking(int aFd)
{}
private:
int mPipeReadFd;
MessageLoopForIO::FileDescriptorWatcher mReadWatcher;
};
StaticRefPtr<SignalPipeWatcher> sSignalPipeWatcher;
void
InitializeSignalWatcher()
{
MOZ_ASSERT(NS_IsMainThread());
MOZ_ASSERT(!sSignalPipeWatcher);
sSignalPipeWatcher = new SignalPipeWatcher();
ClearOnShutdown(&sSignalPipeWatcher);
XRE_GetIOMessageLoop()->PostTask(
FROM_HERE,
NewRunnableMethod(sSignalPipeWatcher.get(),
&SignalPipeWatcher::Start));
}
} // anonymous namespace
#endif // } XP_LINUX
/* static */ void
MemoryInfoDumper::Initialize()
{
#ifdef XP_LINUX
InitializeSignalWatcher();
#endif
}
static void
EnsureNonEmptyIdentifier(nsAString& aIdentifier)
{
if (!aIdentifier.IsEmpty()) {
return;
}
// If the identifier is empty, set it to the number of whole seconds since the
// epoch. This identifier will appear in the files that this process
// generates and also the files generated by this process's children, allowing
// us to identify which files are from the same memory report request.
aIdentifier.AppendInt(static_cast<int64_t>(PR_Now()) / 1000000);
}
/* static */ void
MemoryInfoDumper::DumpMemoryReportsToFile(
const nsAString& aIdentifier,
bool aMinimizeMemoryUsage,
bool aDumpChildProcesses)
{
nsString identifier(aIdentifier);
EnsureNonEmptyIdentifier(identifier);
// Kick off memory report dumps in our child processes, if applicable. We
// do this before doing our own report because writing a report may be I/O
// bound, in which case we want to busy the CPU with other reports while we
// work on our own.
if (aDumpChildProcesses) {
nsTArray<ContentParent*> children;
ContentParent::GetAll(children);
for (uint32_t i = 0; i < children.Length(); i++) {
unused << children[i]->SendDumpMemoryReportsToFile(
identifier, aMinimizeMemoryUsage, aDumpChildProcesses);
}
}
if (aMinimizeMemoryUsage) {
// Minimize memory usage, then run DumpMemoryReportsToFile again.
nsRefPtr<DumpMemoryReportsRunnable> callback =
new DumpMemoryReportsRunnable(identifier,
/* minimizeMemoryUsage = */ false,
/* dumpChildProcesses = */ false);
nsCOMPtr<nsIMemoryReporterManager> mgr =
do_GetService("@mozilla.org/memory-reporter-manager;1");
NS_ENSURE_TRUE(mgr,);
mgr->MinimizeMemoryUsage(callback);
}
DumpMemoryReportsToFileImpl(identifier);
}
/* static */ void
MemoryInfoDumper::DumpGCAndCCLogsToFile(
const nsAString& aIdentifier,
bool aDumpChildProcesses)
{
nsString identifier(aIdentifier);
EnsureNonEmptyIdentifier(identifier);
if (aDumpChildProcesses) {
nsTArray<ContentParent*> children;
ContentParent::GetAll(children);
for (uint32_t i = 0; i < children.Length(); i++) {
unused << children[i]->SendDumpGCAndCCLogsToFile(
identifier, aDumpChildProcesses);
}
}
nsCOMPtr<nsICycleCollectorListener> logger =
do_CreateInstance("@mozilla.org/cycle-collector-logger;1");
logger->SetFilenameIdentifier(identifier);
nsJSContext::CycleCollectNow(logger);
}
#define DUMP(o, s) \
do { \
nsresult rv = (o)->Write(s); \
NS_ENSURE_SUCCESS(rv, rv); \
} while (0)
static nsresult
DumpReport(nsIGZFileWriter *aWriter, bool aIsFirst,
const nsACString &aProcess, const nsACString &aPath, int32_t aKind,
int32_t aUnits, int64_t aAmount, const nsACString &aDescription)
{
DUMP(aWriter, aIsFirst ? "[" : ",");
// We only want to dump reports for this process. If |aProcess| is
// non-NULL that means we've received it from another process in response
// to a "child-memory-reporter-request" event; ignore such reports.
if (!aProcess.IsEmpty()) {
return NS_OK;
}
// Generate the process identifier, which is of the form "$PROCESS_NAME
// (pid $PID)", or just "(pid $PID)" if we don't have a process name. If
// we're the main process, we let $PROCESS_NAME be "Main Process".
nsAutoCString processId;
if (XRE_GetProcessType() == GeckoProcessType_Default) {
// We're the main process.
processId.AssignLiteral("Main Process ");
} else if (ContentChild *cc = ContentChild::GetSingleton()) {
// Try to get the process name from ContentChild.
nsAutoString processName;
cc->GetProcessName(processName);
processId.Assign(NS_ConvertUTF16toUTF8(processName));
if (!processId.IsEmpty()) {
processId.AppendLiteral(" ");
}
}
// Add the PID to the identifier.
unsigned pid = getpid();
processId.Append(nsPrintfCString("(pid %u)", pid));
DUMP(aWriter, "\n {\"process\": \"");
DUMP(aWriter, processId);
DUMP(aWriter, "\", \"path\": \"");
nsCString path(aPath);
path.ReplaceSubstring("\\", "\\\\"); /* <backslash> --> \\ */
path.ReplaceSubstring("\"", "\\\""); // " --> \"
DUMP(aWriter, path);
DUMP(aWriter, "\", \"kind\": ");
DUMP(aWriter, nsPrintfCString("%d", aKind));
DUMP(aWriter, ", \"units\": ");
DUMP(aWriter, nsPrintfCString("%d", aUnits));
DUMP(aWriter, ", \"amount\": ");
DUMP(aWriter, nsPrintfCString("%lld", aAmount));
nsCString description(aDescription);
description.ReplaceSubstring("\\", "\\\\"); /* <backslash> --> \\ */
description.ReplaceSubstring("\"", "\\\""); // " --> \"
description.ReplaceSubstring("\n", "\\n"); // <newline> --> \n
DUMP(aWriter, ", \"description\": \"");
DUMP(aWriter, description);
DUMP(aWriter, "\"}");
return NS_OK;
}
class DumpMultiReporterCallback MOZ_FINAL : public nsIMemoryMultiReporterCallback
{
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)
{
nsCOMPtr<nsIGZFileWriter> writer = do_QueryInterface(aData);
NS_ENSURE_TRUE(writer, NS_ERROR_FAILURE);
// The |isFirst = false| assumes that at least one single reporter is
// present and so will have been processed in
// DumpMemoryReportsToFileImpl() below.
return DumpReport(writer, /* isFirst = */ false, aProcess, aPath,
aKind, aUnits, aAmount, aDescription);
return NS_OK;
}
};
NS_IMPL_ISUPPORTS1(
DumpMultiReporterCallback
, nsIMemoryMultiReporterCallback
)
/* static */ nsresult
MemoryInfoDumper::DumpMemoryReportsToFileImpl(
const nsAString& aIdentifier)
{
// Open a new file named something like
//
// incomplete-memory-report-<-identifier>-<pid>-42.json.gz
//
// in NS_OS_TEMP_DIR for writing. When we're finished writing the report,
// we'll rename this file and get rid of the "incomplete-" prefix.
//
// We do this because we don't want scripts which poll the filesystem
// looking for memory report dumps to grab a file before we're finished
// writing to it.
nsCOMPtr<nsIFile> tmpFile;
nsresult rv = NS_GetSpecialDirectory(NS_OS_TEMP_DIR,
getter_AddRefs(tmpFile));
NS_ENSURE_SUCCESS(rv, rv);
// Note that |filename| is missing the "incomplete-" prefix; we'll tack
// that on in a moment.
nsAutoCString filename;
filename.AppendLiteral("memory-report");
if (!aIdentifier.IsEmpty()) {
filename.AppendLiteral("-");
filename.Append(NS_ConvertUTF16toUTF8(aIdentifier));
}
filename.AppendLiteral("-");
filename.AppendInt(getpid());
filename.AppendLiteral(".json.gz");
rv = tmpFile->AppendNative(NS_LITERAL_CSTRING("incomplete-") + filename);
NS_ENSURE_SUCCESS(rv, rv);
// XXX This ifdef does not belong here; it should be pushed down into the
// CreateUnique implementation. Please don't copy/paste this elsewhere.
#ifdef ANDROID
// Set umask to 0 while we create the file because on Android the default
// umask is 0077.
mode_t mask = umask(0);
#endif
rv = tmpFile->CreateUnique(nsIFile::NORMAL_FILE_TYPE, 0644);
#ifdef ANDROID
umask(mask);
#endif
NS_ENSURE_SUCCESS(rv, rv);
nsRefPtr<nsGZFileWriter> writer = new nsGZFileWriter();
rv = writer->Init(tmpFile);
NS_ENSURE_SUCCESS(rv, rv);
// Dump the memory reports to the file.
// Increment this number if the format changes.
DUMP(writer, "{\n \"version\": 1,\n");
DUMP(writer, " \"hasMozMallocUsableSize\": ");
nsCOMPtr<nsIMemoryReporterManager> mgr =
do_GetService("@mozilla.org/memory-reporter-manager;1");
NS_ENSURE_STATE(mgr);
DUMP(writer, mgr->GetHasMozMallocUsableSize() ? "true" : "false");
DUMP(writer, ",\n");
DUMP(writer, " \"reports\": ");
// Process single reporters.
bool isFirst = true;
bool more;
nsCOMPtr<nsISimpleEnumerator> e;
mgr->EnumerateReporters(getter_AddRefs(e));
while (NS_SUCCEEDED(e->HasMoreElements(&more)) && more) {
nsCOMPtr<nsIMemoryReporter> r;
e->GetNext(getter_AddRefs(r));
nsCString process;
rv = r->GetProcess(process);
NS_ENSURE_SUCCESS(rv, rv);
nsCString path;
rv = r->GetPath(path);
NS_ENSURE_SUCCESS(rv, rv);
int32_t kind;
rv = r->GetKind(&kind);
NS_ENSURE_SUCCESS(rv, rv);
int32_t units;
rv = r->GetUnits(&units);
NS_ENSURE_SUCCESS(rv, rv);
int64_t amount;
rv = r->GetAmount(&amount);
NS_ENSURE_SUCCESS(rv, rv);
nsCString description;
rv = r->GetDescription(description);
NS_ENSURE_SUCCESS(rv, rv);
rv = DumpReport(writer, isFirst, process, path, kind, units, amount,
description);
NS_ENSURE_SUCCESS(rv, rv);
isFirst = false;
}
// Process multi-reporters.
nsCOMPtr<nsISimpleEnumerator> e2;
mgr->EnumerateMultiReporters(getter_AddRefs(e2));
nsRefPtr<DumpMultiReporterCallback> cb = new DumpMultiReporterCallback();
while (NS_SUCCEEDED(e2->HasMoreElements(&more)) && more) {
nsCOMPtr<nsIMemoryMultiReporter> r;
e2->GetNext(getter_AddRefs(r));
r->CollectReports(cb, writer);
}
DUMP(writer, "\n ]\n}");
rv = writer->Finish();
NS_ENSURE_SUCCESS(rv, rv);
// Rename the file, now that we're done dumping the report. The file's
// ultimate destination is "memory-report<-identifier>-<pid>.json.gz".
nsCOMPtr<nsIFile> dstFile;
rv = NS_GetSpecialDirectory(NS_OS_TEMP_DIR, getter_AddRefs(dstFile));
NS_ENSURE_SUCCESS(rv, rv);
rv = dstFile->AppendNative(filename);
NS_ENSURE_SUCCESS(rv, rv);
rv = dstFile->CreateUnique(nsIFile::NORMAL_FILE_TYPE, 0600);
NS_ENSURE_SUCCESS(rv, rv);
nsAutoString dstFileName;
rv = dstFile->GetLeafName(dstFileName);
NS_ENSURE_SUCCESS(rv, rv);
rv = tmpFile->MoveTo(/* directory */ nullptr, dstFileName);
NS_ENSURE_SUCCESS(rv, rv);
nsCOMPtr<nsIConsoleService> cs =
do_GetService(NS_CONSOLESERVICE_CONTRACTID, &rv);
NS_ENSURE_SUCCESS(rv, rv);
nsString path;
tmpFile->GetPath(path);
NS_ENSURE_SUCCESS(rv, rv);
nsString msg = NS_LITERAL_STRING(
"nsIMemoryReporterManager::dumpReports() dumped reports to ");
msg.Append(path);
return cs->LogStringMessage(msg.get());
}
#undef DUMP
} // namespace mozilla