1.1 --- /dev/null Thu Jan 01 00:00:00 1970 +0000
1.2 +++ b/xpcom/build/LateWriteChecks.cpp Wed Dec 31 06:09:35 2014 +0100
1.3 @@ -0,0 +1,254 @@
1.4 +/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
1.5 +/* vim:set ts=4 sw=4 sts=4 ci et: */
1.6 +/* This Source Code Form is subject to the terms of the Mozilla Public
1.7 + * License, v. 2.0. If a copy of the MPL was not distributed with this
1.8 + * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
1.9 +
1.10 +#include <algorithm>
1.11 +
1.12 +#include "mozilla/IOInterposer.h"
1.13 +#include "mozilla/PoisonIOInterposer.h"
1.14 +#include "mozilla/ProcessedStack.h"
1.15 +#include "mozilla/SHA1.h"
1.16 +#include "mozilla/Scoped.h"
1.17 +#include "mozilla/StaticPtr.h"
1.18 +#include "mozilla/Telemetry.h"
1.19 +#include "nsAppDirectoryServiceDefs.h"
1.20 +#include "nsDirectoryServiceUtils.h"
1.21 +#include "nsPrintfCString.h"
1.22 +#include "nsStackWalk.h"
1.23 +#include "plstr.h"
1.24 +
1.25 +#ifdef XP_WIN
1.26 +#define NS_T(str) L ## str
1.27 +#define NS_SLASH "\\"
1.28 +#include <fcntl.h>
1.29 +#include <io.h>
1.30 +#include <stdio.h>
1.31 +#include <stdlib.h>
1.32 +#include <sys/stat.h>
1.33 +#include <windows.h>
1.34 +#else
1.35 +#define NS_SLASH "/"
1.36 +#endif
1.37 +
1.38 +#include "LateWriteChecks.h"
1.39 +
1.40 +#if !defined(XP_WIN) || (!defined(MOZ_OPTIMIZE) || defined(MOZ_PROFILING) || defined(DEBUG))
1.41 +#define OBSERVE_LATE_WRITES
1.42 +#endif
1.43 +
1.44 +using namespace mozilla;
1.45 +
1.46 +/*************************** Auxiliary Declarations ***************************/
1.47 +
1.48 +// This a wrapper over a file descriptor that provides a Printf method and
1.49 +// computes the sha1 of the data that passes through it.
1.50 +class SHA1Stream
1.51 +{
1.52 +public:
1.53 + explicit SHA1Stream(FILE *stream)
1.54 + : mFile(stream)
1.55 + {
1.56 + MozillaRegisterDebugFILE(mFile);
1.57 + }
1.58 +
1.59 + void Printf(const char *aFormat, ...)
1.60 + {
1.61 + MOZ_ASSERT(mFile);
1.62 + va_list list;
1.63 + va_start(list, aFormat);
1.64 + nsAutoCString str;
1.65 + str.AppendPrintf(aFormat, list);
1.66 + va_end(list);
1.67 + mSHA1.update(str.get(), str.Length());
1.68 + fwrite(str.get(), 1, str.Length(), mFile);
1.69 + }
1.70 + void Finish(SHA1Sum::Hash &aHash)
1.71 + {
1.72 + int fd = fileno(mFile);
1.73 + fflush(mFile);
1.74 + MozillaUnRegisterDebugFD(fd);
1.75 + fclose(mFile);
1.76 + mSHA1.finish(aHash);
1.77 + mFile = nullptr;
1.78 + }
1.79 +private:
1.80 + FILE *mFile;
1.81 + SHA1Sum mSHA1;
1.82 +};
1.83 +
1.84 +static void RecordStackWalker(void *aPC, void *aSP, void *aClosure)
1.85 +{
1.86 + std::vector<uintptr_t> *stack =
1.87 + static_cast<std::vector<uintptr_t>*>(aClosure);
1.88 + stack->push_back(reinterpret_cast<uintptr_t>(aPC));
1.89 +}
1.90 +
1.91 +/**************************** Late-Write Observer ****************************/
1.92 +
1.93 +/**
1.94 + * An implementation of IOInterposeObserver to be registered with IOInterposer.
1.95 + * This observer logs all writes as late writes.
1.96 + */
1.97 +class LateWriteObserver MOZ_FINAL : public IOInterposeObserver
1.98 +{
1.99 +public:
1.100 + LateWriteObserver(const char* aProfileDirectory)
1.101 + : mProfileDirectory(PL_strdup(aProfileDirectory))
1.102 + {
1.103 + }
1.104 + ~LateWriteObserver() {
1.105 + PL_strfree(mProfileDirectory);
1.106 + mProfileDirectory = nullptr;
1.107 + }
1.108 +
1.109 + void Observe(IOInterposeObserver::Observation& aObservation);
1.110 +private:
1.111 + char* mProfileDirectory;
1.112 +};
1.113 +
1.114 +void LateWriteObserver::Observe(IOInterposeObserver::Observation& aOb)
1.115 +{
1.116 +#ifdef OBSERVE_LATE_WRITES
1.117 + // Crash if that is the shutdown check mode
1.118 + if (gShutdownChecks == SCM_CRASH) {
1.119 + MOZ_CRASH();
1.120 + }
1.121 +
1.122 + // If we have shutdown mode SCM_NOTHING or we can't record then abort
1.123 + if (gShutdownChecks == SCM_NOTHING || !Telemetry::CanRecord()) {
1.124 + return;
1.125 + }
1.126 +
1.127 + // Write the stack and loaded libraries to a file. We can get here
1.128 + // concurrently from many writes, so we use multiple temporary files.
1.129 + std::vector<uintptr_t> rawStack;
1.130 +
1.131 + NS_StackWalk(RecordStackWalker, /* skipFrames */ 0, /* maxFrames */ 0,
1.132 + reinterpret_cast<void*>(&rawStack), 0, nullptr);
1.133 + Telemetry::ProcessedStack stack = Telemetry::GetStackAndModules(rawStack);
1.134 +
1.135 + nsPrintfCString nameAux("%s%s%s", mProfileDirectory,
1.136 + NS_SLASH, "Telemetry.LateWriteTmpXXXXXX");
1.137 + char *name;
1.138 + nameAux.GetMutableData(&name);
1.139 +
1.140 + // We want the sha1 of the entire file, so please don't write to fd
1.141 + // directly; use sha1Stream.
1.142 + FILE *stream;
1.143 +#ifdef XP_WIN
1.144 + HANDLE hFile;
1.145 + do {
1.146 + // mkstemp isn't supported so keep trying until we get a file
1.147 + int result = _mktemp_s(name, strlen(name) + 1);
1.148 + hFile = CreateFileA(name, GENERIC_WRITE, 0, nullptr, CREATE_NEW,
1.149 + FILE_ATTRIBUTE_NORMAL, nullptr);
1.150 + } while (GetLastError() == ERROR_FILE_EXISTS);
1.151 +
1.152 + if (hFile == INVALID_HANDLE_VALUE) {
1.153 + NS_RUNTIMEABORT("Um, how did we get here?");
1.154 + }
1.155 +
1.156 + // http://support.microsoft.com/kb/139640
1.157 + int fd = _open_osfhandle((intptr_t)hFile, _O_APPEND);
1.158 + if (fd == -1) {
1.159 + NS_RUNTIMEABORT("Um, how did we get here?");
1.160 + }
1.161 +
1.162 + stream = _fdopen(fd, "w");
1.163 +#else
1.164 + int fd = mkstemp(name);
1.165 + stream = fdopen(fd, "w");
1.166 +#endif
1.167 +
1.168 + SHA1Stream sha1Stream(stream);
1.169 +
1.170 + size_t numModules = stack.GetNumModules();
1.171 + sha1Stream.Printf("%u\n", (unsigned)numModules);
1.172 + for (size_t i = 0; i < numModules; ++i) {
1.173 + Telemetry::ProcessedStack::Module module = stack.GetModule(i);
1.174 + sha1Stream.Printf("%s %s\n", module.mBreakpadId.c_str(),
1.175 + module.mName.c_str());
1.176 + }
1.177 +
1.178 + size_t numFrames = stack.GetStackSize();
1.179 + sha1Stream.Printf("%u\n", (unsigned)numFrames);
1.180 + for (size_t i = 0; i < numFrames; ++i) {
1.181 + const Telemetry::ProcessedStack::Frame &frame =
1.182 + stack.GetFrame(i);
1.183 + // NOTE: We write the offsets, while the atos tool expects a value with
1.184 + // the virtual address added. For example, running otool -l on the the firefox
1.185 + // binary shows
1.186 + // cmd LC_SEGMENT_64
1.187 + // cmdsize 632
1.188 + // segname __TEXT
1.189 + // vmaddr 0x0000000100000000
1.190 + // so to print the line matching the offset 123 one has to run
1.191 + // atos -o firefox 0x100000123.
1.192 + sha1Stream.Printf("%d %x\n", frame.mModIndex, (unsigned)frame.mOffset);
1.193 + }
1.194 +
1.195 + SHA1Sum::Hash sha1;
1.196 + sha1Stream.Finish(sha1);
1.197 +
1.198 + // Note: These files should be deleted by telemetry once it reads them. If
1.199 + // there were no telemetry runs by the time we shut down, we just add files
1.200 + // to the existing ones instead of replacing them. Given that each of these
1.201 + // files is a bug to be fixed, that is probably the right thing to do.
1.202 +
1.203 + // We append the sha1 of the contents to the file name. This provides a simple
1.204 + // client side deduplication.
1.205 + nsPrintfCString finalName("%s%s", mProfileDirectory,
1.206 + "/Telemetry.LateWriteFinal-");
1.207 + for (int i = 0; i < 20; ++i) {
1.208 + finalName.AppendPrintf("%02x", sha1[i]);
1.209 + }
1.210 + PR_Delete(finalName.get());
1.211 + PR_Rename(name, finalName.get());
1.212 +#endif
1.213 +}
1.214 +
1.215 +/******************************* Setup/Teardown *******************************/
1.216 +
1.217 +static StaticAutoPtr<LateWriteObserver> sLateWriteObserver;
1.218 +
1.219 +namespace mozilla{
1.220 +
1.221 +void InitLateWriteChecks()
1.222 +{
1.223 + nsCOMPtr<nsIFile> mozFile;
1.224 + NS_GetSpecialDirectory(NS_APP_USER_PROFILE_50_DIR, getter_AddRefs(mozFile));
1.225 + if (mozFile) {
1.226 + nsAutoCString nativePath;
1.227 + nsresult rv = mozFile->GetNativePath(nativePath);
1.228 + if (NS_SUCCEEDED(rv) && nativePath.get()) {
1.229 + sLateWriteObserver = new LateWriteObserver(nativePath.get());
1.230 + }
1.231 + }
1.232 +}
1.233 +
1.234 +void BeginLateWriteChecks()
1.235 +{
1.236 + if (sLateWriteObserver) {
1.237 + IOInterposer::Register(
1.238 + IOInterposeObserver::OpWriteFSync,
1.239 + sLateWriteObserver
1.240 + );
1.241 + }
1.242 +}
1.243 +
1.244 +void StopLateWriteChecks()
1.245 +{
1.246 + if (sLateWriteObserver) {
1.247 + IOInterposer::Unregister(
1.248 + IOInterposeObserver::OpAll,
1.249 + sLateWriteObserver
1.250 + );
1.251 + // Deallocation would not be thread-safe, and StopLateWriteChecks() is
1.252 + // called at shutdown and only in special cases.
1.253 + // sLateWriteObserver = nullptr;
1.254 + }
1.255 +}
1.256 +
1.257 +} // namespace mozilla
