ea93b331a7
The URLPreloader's initialization code accesses the Omnijar cache off-main thread. It can do so safely only as long as the main thread is blocked, or running code which is guaranteed never to touch Omnijar, while its critical section runs. While that was guaranteed for previous versions of the code, some invariants changed when we began using the component loader's shared global for initial compilation. Once the global is created, we can safely use it to initialize compilation. But creating the global invokes a large amount of Gecko code, some of which touches Omnijar in the process. MozReview-Commit-ID: 48WoIZtGPTo
1110 lines
35 KiB
C++
1110 lines
35 KiB
C++
/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
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/* vim: set ts=8 sts=4 et sw=4 tw=99: */
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/* This Source Code Form is subject to the terms of the Mozilla Public
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* License, v. 2.0. If a copy of the MPL was not distributed with this
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* file, You can obtain one at http://mozilla.org/MPL/2.0/. */
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#include "ScriptPreloader-inl.h"
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#include "mozilla/ScriptPreloader.h"
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#include "mozJSComponentLoader.h"
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#include "mozilla/loader/ScriptCacheActors.h"
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#include "mozilla/URLPreloader.h"
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#include "mozilla/ArrayUtils.h"
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#include "mozilla/ClearOnShutdown.h"
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#include "mozilla/FileUtils.h"
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#include "mozilla/Logging.h"
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#include "mozilla/ScopeExit.h"
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#include "mozilla/Services.h"
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#include "mozilla/Unused.h"
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#include "mozilla/dom/ContentChild.h"
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#include "mozilla/dom/ContentParent.h"
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#include "MainThreadUtils.h"
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#include "nsDebug.h"
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#include "nsDirectoryServiceUtils.h"
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#include "nsIFile.h"
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#include "nsIObserverService.h"
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#include "nsJSUtils.h"
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#include "nsProxyRelease.h"
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#include "nsThreadUtils.h"
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#include "nsXULAppAPI.h"
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#include "xpcpublic.h"
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#define DELAYED_STARTUP_TOPIC "browser-delayed-startup-finished"
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#define DOC_ELEM_INSERTED_TOPIC "document-element-inserted"
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#define CLEANUP_TOPIC "xpcom-shutdown"
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#define SHUTDOWN_TOPIC "quit-application-granted"
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#define CACHE_INVALIDATE_TOPIC "startupcache-invalidate"
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namespace mozilla {
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namespace {
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static LazyLogModule gLog("ScriptPreloader");
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#define LOG(level, ...) MOZ_LOG(gLog, LogLevel::level, (__VA_ARGS__))
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}
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using mozilla::dom::AutoJSAPI;
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using mozilla::dom::ContentChild;
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using mozilla::dom::ContentParent;
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using namespace mozilla::loader;
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ProcessType ScriptPreloader::sProcessType;
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nsresult
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ScriptPreloader::CollectReports(nsIHandleReportCallback* aHandleReport,
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nsISupports* aData, bool aAnonymize)
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{
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MOZ_COLLECT_REPORT(
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"explicit/script-preloader/heap/saved-scripts", KIND_HEAP, UNITS_BYTES,
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SizeOfHashEntries<ScriptStatus::Saved>(mScripts, MallocSizeOf),
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"Memory used to hold the scripts which have been executed in this "
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"session, and will be written to the startup script cache file.");
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MOZ_COLLECT_REPORT(
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"explicit/script-preloader/heap/restored-scripts", KIND_HEAP, UNITS_BYTES,
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SizeOfHashEntries<ScriptStatus::Restored>(mScripts, MallocSizeOf),
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"Memory used to hold the scripts which have been restored from the "
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"startup script cache file, but have not been executed in this session.");
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MOZ_COLLECT_REPORT(
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"explicit/script-preloader/heap/other", KIND_HEAP, UNITS_BYTES,
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ShallowHeapSizeOfIncludingThis(MallocSizeOf),
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"Memory used by the script cache service itself.");
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MOZ_COLLECT_REPORT(
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"explicit/script-preloader/non-heap/memmapped-cache", KIND_NONHEAP, UNITS_BYTES,
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mCacheData.nonHeapSizeOfExcludingThis(),
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"The memory-mapped startup script cache file.");
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return NS_OK;
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}
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ScriptPreloader&
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ScriptPreloader::GetSingleton()
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{
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static RefPtr<ScriptPreloader> singleton;
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if (!singleton) {
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if (XRE_IsParentProcess()) {
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singleton = new ScriptPreloader();
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singleton->mChildCache = &GetChildSingleton();
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Unused << singleton->InitCache();
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} else {
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singleton = &GetChildSingleton();
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}
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ClearOnShutdown(&singleton);
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}
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return *singleton;
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}
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// The child singleton is available in all processes, including the parent, and
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// is used for scripts which are expected to be loaded into child processes
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// (such as process and frame scripts), or scripts that have already been loaded
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// into a child. The child caches are managed as follows:
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//
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// - Every startup, we open the cache file from the last session, move it to a
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// new location, and begin pre-loading the scripts that are stored in it. There
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// is a separate cache file for parent and content processes, but the parent
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// process opens both the parent and content cache files.
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//
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// - Once startup is complete, we write a new cache file for the next session,
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// containing only the scripts that were used during early startup, so we don't
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// waste pre-loading scripts that may not be needed.
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//
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// - For content processes, opening and writing the cache file is handled in the
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// parent process. The first content process of each type sends back the data
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// for scripts that were loaded in early startup, and the parent merges them and
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// writes them to a cache file.
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//
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// - Currently, content processes only benefit from the cache data written
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// during the *previous* session. Ideally, new content processes should probably
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// use the cache data written during this session if there was no previous cache
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// file, but I'd rather do that as a follow-up.
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ScriptPreloader&
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ScriptPreloader::GetChildSingleton()
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{
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static RefPtr<ScriptPreloader> singleton;
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if (!singleton) {
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singleton = new ScriptPreloader();
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if (XRE_IsParentProcess()) {
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Unused << singleton->InitCache(NS_LITERAL_STRING("scriptCache-child"));
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}
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ClearOnShutdown(&singleton);
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}
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return *singleton;
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}
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void
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ScriptPreloader::InitContentChild(ContentParent& parent)
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{
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auto& cache = GetChildSingleton();
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// We want startup script data from the first process of a given type.
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// That process sends back its script data before it executes any
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// untrusted code, and then we never accept further script data for that
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// type of process for the rest of the session.
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//
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// The script data from each process type is merged with the data from the
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// parent process's frame and process scripts, and shared between all
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// content process types in the next session.
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//
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// Note that if the first process of a given type crashes or shuts down
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// before sending us its script data, we silently ignore it, and data for
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// that process type is not included in the next session's cache. This
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// should be a sufficiently rare occurrence that it's not worth trying to
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// handle specially.
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auto processType = GetChildProcessType(parent.GetRemoteType());
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bool wantScriptData = !cache.mInitializedProcesses.contains(processType);
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cache.mInitializedProcesses += processType;
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auto fd = cache.mCacheData.cloneFileDescriptor();
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// Don't send original cache data to new processes if the cache has been
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// invalidated.
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if (fd.IsValid() && !cache.mCacheInvalidated) {
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Unused << parent.SendPScriptCacheConstructor(fd, wantScriptData);
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} else {
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Unused << parent.SendPScriptCacheConstructor(NS_ERROR_FILE_NOT_FOUND, wantScriptData);
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}
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}
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ProcessType
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ScriptPreloader::GetChildProcessType(const nsAString& remoteType)
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{
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if (remoteType.EqualsLiteral(EXTENSION_REMOTE_TYPE)) {
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return ProcessType::Extension;
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}
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return ProcessType::Web;
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}
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namespace {
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static void
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TraceOp(JSTracer* trc, void* data)
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{
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auto preloader = static_cast<ScriptPreloader*>(data);
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preloader->Trace(trc);
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}
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} // anonymous namespace
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void
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ScriptPreloader::Trace(JSTracer* trc)
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{
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for (auto& script : IterHash(mScripts)) {
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JS::TraceEdge(trc, &script->mScript, "ScriptPreloader::CachedScript.mScript");
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}
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}
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ScriptPreloader::ScriptPreloader()
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: mMonitor("[ScriptPreloader.mMonitor]")
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, mSaveMonitor("[ScriptPreloader.mSaveMonitor]")
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{
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if (XRE_IsParentProcess()) {
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sProcessType = ProcessType::Parent;
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} else {
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sProcessType = GetChildProcessType(dom::ContentChild::GetSingleton()->GetRemoteType());
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}
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nsCOMPtr<nsIObserverService> obs = services::GetObserverService();
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MOZ_RELEASE_ASSERT(obs);
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if (XRE_IsParentProcess()) {
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// In the parent process, we want to freeze the script cache as soon
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// as delayed startup for the first browser window has completed.
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obs->AddObserver(this, DELAYED_STARTUP_TOPIC, false);
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} else {
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// In the child process, we need to freeze the script cache before any
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// untrusted code has been executed. The insertion of the first DOM
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// document element may sometimes be earlier than is ideal, but at
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// least it should always be safe.
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obs->AddObserver(this, DOC_ELEM_INSERTED_TOPIC, false);
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}
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obs->AddObserver(this, SHUTDOWN_TOPIC, false);
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obs->AddObserver(this, CLEANUP_TOPIC, false);
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obs->AddObserver(this, CACHE_INVALIDATE_TOPIC, false);
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AutoSafeJSAPI jsapi;
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JS_AddExtraGCRootsTracer(jsapi.cx(), TraceOp, this);
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}
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void
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ScriptPreloader::ForceWriteCacheFile()
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{
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if (mSaveThread) {
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MonitorAutoLock mal(mSaveMonitor);
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// Make sure we've prepared scripts, so we don't risk deadlocking while
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// dispatching the prepare task during shutdown.
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PrepareCacheWrite();
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// Unblock the save thread, so it can start saving before we get to
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// XPCOM shutdown.
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mal.Notify();
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}
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}
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void
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ScriptPreloader::Cleanup()
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{
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if (mSaveThread) {
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MonitorAutoLock mal(mSaveMonitor);
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// Make sure the save thread is not blocked dispatching a sync task to
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// the main thread, or we will deadlock.
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MOZ_RELEASE_ASSERT(!mBlockedOnSyncDispatch);
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while (!mSaveComplete && mSaveThread) {
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mal.Wait();
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}
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}
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// Wait for any pending parses to finish before clearing the mScripts
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// hashtable, since the parse tasks depend on memory allocated by those
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// scripts.
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{
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MonitorAutoLock mal(mMonitor);
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FinishPendingParses(mal);
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mScripts.Clear();
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}
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AutoSafeJSAPI jsapi;
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JS_RemoveExtraGCRootsTracer(jsapi.cx(), TraceOp, this);
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UnregisterWeakMemoryReporter(this);
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}
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void
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ScriptPreloader::InvalidateCache()
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{
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mMonitor.AssertNotCurrentThreadOwns();
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MonitorAutoLock mal(mMonitor);
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mCacheInvalidated = true;
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// Wait for pending off-thread parses to finish, since they depend on the
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// memory allocated by our CachedScripts, and can't be canceled
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// asynchronously.
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FinishPendingParses(mal);
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// Pending scripts should have been cleared by the above, and new parses
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// should not have been queued.
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MOZ_ASSERT(mParsingScripts.empty());
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MOZ_ASSERT(mParsingSources.empty());
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MOZ_ASSERT(mPendingScripts.isEmpty());
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for (auto& script : IterHash(mScripts))
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script.Remove();
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// If we've already finished saving the cache at this point, start a new
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// delayed save operation. This will write out an empty cache file in place
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// of any cache file we've already written out this session, which will
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// prevent us from falling back to the current session's cache file on the
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// next startup.
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if (mSaveComplete && mChildCache) {
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mSaveComplete = false;
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// Make sure scripts are prepared to avoid deadlock when invalidating
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// the cache during shutdown.
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PrepareCacheWriteInternal();
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Unused << NS_NewNamedThread("SaveScripts",
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getter_AddRefs(mSaveThread), this);
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}
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}
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nsresult
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ScriptPreloader::Observe(nsISupports* subject, const char* topic, const char16_t* data)
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{
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nsCOMPtr<nsIObserverService> obs = services::GetObserverService();
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if (!strcmp(topic, DELAYED_STARTUP_TOPIC)) {
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obs->RemoveObserver(this, DELAYED_STARTUP_TOPIC);
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MOZ_ASSERT(XRE_IsParentProcess());
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mStartupFinished = true;
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if (mChildCache) {
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Unused << NS_NewNamedThread("SaveScripts",
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getter_AddRefs(mSaveThread), this);
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}
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} else if (!strcmp(topic, DOC_ELEM_INSERTED_TOPIC)) {
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obs->RemoveObserver(this, DOC_ELEM_INSERTED_TOPIC);
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MOZ_ASSERT(XRE_IsContentProcess());
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mStartupFinished = true;
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if (mChildActor) {
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mChildActor->SendScriptsAndFinalize(mScripts);
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}
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} else if (!strcmp(topic, SHUTDOWN_TOPIC)) {
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ForceWriteCacheFile();
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} else if (!strcmp(topic, CLEANUP_TOPIC)) {
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Cleanup();
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} else if (!strcmp(topic, CACHE_INVALIDATE_TOPIC)) {
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InvalidateCache();
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}
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return NS_OK;
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}
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Result<nsCOMPtr<nsIFile>, nsresult>
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ScriptPreloader::GetCacheFile(const nsAString& suffix)
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{
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nsCOMPtr<nsIFile> cacheFile;
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MOZ_TRY(mProfD->Clone(getter_AddRefs(cacheFile)));
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MOZ_TRY(cacheFile->AppendNative(NS_LITERAL_CSTRING("startupCache")));
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Unused << cacheFile->Create(nsIFile::DIRECTORY_TYPE, 0777);
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MOZ_TRY(cacheFile->Append(mBaseName + suffix));
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return Move(cacheFile);
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}
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static const uint8_t MAGIC[] = "mozXDRcachev001";
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Result<Ok, nsresult>
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ScriptPreloader::OpenCache()
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{
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MOZ_TRY(NS_GetSpecialDirectory("ProfLDS", getter_AddRefs(mProfD)));
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nsCOMPtr<nsIFile> cacheFile;
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MOZ_TRY_VAR(cacheFile, GetCacheFile(NS_LITERAL_STRING(".bin")));
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bool exists;
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MOZ_TRY(cacheFile->Exists(&exists));
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if (exists) {
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MOZ_TRY(cacheFile->MoveTo(nullptr, mBaseName + NS_LITERAL_STRING("-current.bin")));
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} else {
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MOZ_TRY(cacheFile->SetLeafName(mBaseName + NS_LITERAL_STRING("-current.bin")));
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MOZ_TRY(cacheFile->Exists(&exists));
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if (!exists) {
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return Err(NS_ERROR_FILE_NOT_FOUND);
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}
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}
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MOZ_TRY(mCacheData.init(cacheFile));
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return Ok();
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}
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// Opens the script cache file for this session, and initializes the script
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// cache based on its contents. See WriteCache for details of the cache file.
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Result<Ok, nsresult>
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ScriptPreloader::InitCache(const nsAString& basePath)
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{
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mCacheInitialized = true;
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mBaseName = basePath;
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RegisterWeakMemoryReporter(this);
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if (!XRE_IsParentProcess()) {
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return Ok();
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}
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// Grab the compilation scope before initializing the URLPreloader, since
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// it's not safe to run component loader code during its critical section.
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AutoSafeJSAPI jsapi;
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JS::RootedObject scope(jsapi.cx(), CompilationScope(jsapi.cx()));
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// Note: Code on the main thread *must not access Omnijar in any way* until
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// this AutoBeginReading guard is destroyed.
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URLPreloader::AutoBeginReading abr;
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MOZ_TRY(OpenCache());
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return InitCacheInternal(scope);
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}
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Result<Ok, nsresult>
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ScriptPreloader::InitCache(const Maybe<ipc::FileDescriptor>& cacheFile, ScriptCacheChild* cacheChild)
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{
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MOZ_ASSERT(XRE_IsContentProcess());
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mCacheInitialized = true;
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mChildActor = cacheChild;
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RegisterWeakMemoryReporter(this);
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if (cacheFile.isNothing()){
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return Ok();
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}
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MOZ_TRY(mCacheData.init(cacheFile.ref()));
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return InitCacheInternal();
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}
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Result<Ok, nsresult>
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ScriptPreloader::InitCacheInternal(JS::HandleObject scope)
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{
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auto size = mCacheData.size();
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uint32_t headerSize;
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if (size < sizeof(MAGIC) + sizeof(headerSize)) {
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return Err(NS_ERROR_UNEXPECTED);
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}
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auto data = mCacheData.get<uint8_t>();
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auto end = data + size;
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if (memcmp(MAGIC, data.get(), sizeof(MAGIC))) {
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return Err(NS_ERROR_UNEXPECTED);
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}
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data += sizeof(MAGIC);
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headerSize = LittleEndian::readUint32(data.get());
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data += sizeof(headerSize);
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if (data + headerSize > end) {
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return Err(NS_ERROR_UNEXPECTED);
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}
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{
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auto cleanup = MakeScopeExit([&] () {
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mScripts.Clear();
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});
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LinkedList<CachedScript> scripts;
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Range<uint8_t> header(data, data + headerSize);
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data += headerSize;
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InputBuffer buf(header);
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size_t offset = 0;
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while (!buf.finished()) {
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auto script = MakeUnique<CachedScript>(*this, buf);
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MOZ_RELEASE_ASSERT(script);
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auto scriptData = data + script->mOffset;
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if (scriptData + script->mSize > end) {
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return Err(NS_ERROR_UNEXPECTED);
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}
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// Make sure offsets match what we'd expect based on script ordering and
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// size, as a basic sanity check.
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if (script->mOffset != offset) {
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return Err(NS_ERROR_UNEXPECTED);
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}
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offset += script->mSize;
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script->mXDRRange.emplace(scriptData, scriptData + script->mSize);
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// Don't pre-decode the script unless it was used in this process type during the
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// previous session.
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if (script->mOriginalProcessTypes.contains(CurrentProcessType())) {
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scripts.insertBack(script.get());
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} else {
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|
script->mReadyToExecute = true;
|
|
}
|
|
|
|
mScripts.Put(script->mCachePath, script.get());
|
|
Unused << script.release();
|
|
}
|
|
|
|
if (buf.error()) {
|
|
return Err(NS_ERROR_UNEXPECTED);
|
|
}
|
|
|
|
mPendingScripts = Move(scripts);
|
|
cleanup.release();
|
|
}
|
|
|
|
DecodeNextBatch(OFF_THREAD_FIRST_CHUNK_SIZE, scope);
|
|
return Ok();
|
|
}
|
|
|
|
void
|
|
ScriptPreloader::PrepareCacheWriteInternal()
|
|
{
|
|
MOZ_ASSERT(NS_IsMainThread());
|
|
|
|
mMonitor.AssertCurrentThreadOwns();
|
|
|
|
auto cleanup = MakeScopeExit([&] () {
|
|
if (mChildCache) {
|
|
mChildCache->PrepareCacheWrite();
|
|
}
|
|
});
|
|
|
|
if (mDataPrepared) {
|
|
return;
|
|
}
|
|
|
|
AutoSafeJSAPI jsapi;
|
|
bool found = false;
|
|
for (auto& script : IterHash(mScripts, Match<ScriptStatus::Saved>())) {
|
|
// Don't write any scripts that are also in the child cache. They'll be
|
|
// loaded from the child cache in that case, so there's no need to write
|
|
// them twice.
|
|
CachedScript* childScript = mChildCache ? mChildCache->mScripts.Get(script->mCachePath) : nullptr;
|
|
if (childScript && !childScript->mProcessTypes.isEmpty()) {
|
|
childScript->UpdateLoadTime(script->mLoadTime);
|
|
childScript->mProcessTypes += script->mProcessTypes;
|
|
script.Remove();
|
|
continue;
|
|
}
|
|
|
|
if (!(script->mProcessTypes == script->mOriginalProcessTypes)) {
|
|
// Note: EnumSet doesn't support operator!=, hence the weird form above.
|
|
found = true;
|
|
}
|
|
|
|
if (!script->mSize && !script->XDREncode(jsapi.cx())) {
|
|
script.Remove();
|
|
}
|
|
}
|
|
|
|
if (!found) {
|
|
mSaveComplete = true;
|
|
return;
|
|
}
|
|
|
|
mDataPrepared = true;
|
|
}
|
|
|
|
void
|
|
ScriptPreloader::PrepareCacheWrite()
|
|
{
|
|
MonitorAutoLock mal(mMonitor);
|
|
|
|
PrepareCacheWriteInternal();
|
|
}
|
|
|
|
// Writes out a script cache file for the scripts accessed during early
|
|
// startup in this session. The cache file is a little-endian binary file with
|
|
// the following format:
|
|
//
|
|
// - A uint32 containing the size of the header block.
|
|
//
|
|
// - A header entry for each file stored in the cache containing:
|
|
// - The URL that the script was originally read from.
|
|
// - Its cache key.
|
|
// - The offset of its XDR data within the XDR data block.
|
|
// - The size of its XDR data in the XDR data block.
|
|
// - A bit field describing which process types the script is used in.
|
|
//
|
|
// - A block of XDR data for the encoded scripts, with each script's data at
|
|
// an offset from the start of the block, as specified above.
|
|
Result<Ok, nsresult>
|
|
ScriptPreloader::WriteCache()
|
|
{
|
|
MOZ_ASSERT(!NS_IsMainThread());
|
|
|
|
if (!mDataPrepared && !mSaveComplete) {
|
|
MOZ_ASSERT(!mBlockedOnSyncDispatch);
|
|
mBlockedOnSyncDispatch = true;
|
|
|
|
MonitorAutoUnlock mau(mSaveMonitor);
|
|
|
|
NS_DispatchToMainThread(
|
|
NewRunnableMethod("ScriptPreloader::PrepareCacheWrite",
|
|
this,
|
|
&ScriptPreloader::PrepareCacheWrite),
|
|
NS_DISPATCH_SYNC);
|
|
}
|
|
|
|
mBlockedOnSyncDispatch = false;
|
|
|
|
if (mSaveComplete) {
|
|
// If we don't have anything we need to save, we're done.
|
|
return Ok();
|
|
}
|
|
|
|
nsCOMPtr<nsIFile> cacheFile;
|
|
MOZ_TRY_VAR(cacheFile, GetCacheFile(NS_LITERAL_STRING("-new.bin")));
|
|
|
|
bool exists;
|
|
MOZ_TRY(cacheFile->Exists(&exists));
|
|
if (exists) {
|
|
MOZ_TRY(cacheFile->Remove(false));
|
|
}
|
|
|
|
{
|
|
AutoFDClose fd;
|
|
MOZ_TRY(cacheFile->OpenNSPRFileDesc(PR_WRONLY | PR_CREATE_FILE, 0644, &fd.rwget()));
|
|
|
|
// We also need to hold mMonitor while we're touching scripts in
|
|
// mScripts, or they may be freed before we're done with them.
|
|
mMonitor.AssertNotCurrentThreadOwns();
|
|
MonitorAutoLock mal(mMonitor);
|
|
|
|
nsTArray<CachedScript*> scripts;
|
|
for (auto& script : IterHash(mScripts, Match<ScriptStatus::Saved>())) {
|
|
scripts.AppendElement(script);
|
|
}
|
|
|
|
// Sort scripts by load time, with async loaded scripts before sync scripts.
|
|
// Since async scripts are always loaded immediately at startup, it helps to
|
|
// have them stored contiguously.
|
|
scripts.Sort(CachedScript::Comparator());
|
|
|
|
OutputBuffer buf;
|
|
size_t offset = 0;
|
|
for (auto script : scripts) {
|
|
script->mOffset = offset;
|
|
script->Code(buf);
|
|
|
|
offset += script->mSize;
|
|
}
|
|
|
|
uint8_t headerSize[4];
|
|
LittleEndian::writeUint32(headerSize, buf.cursor());
|
|
|
|
MOZ_TRY(Write(fd, MAGIC, sizeof(MAGIC)));
|
|
MOZ_TRY(Write(fd, headerSize, sizeof(headerSize)));
|
|
MOZ_TRY(Write(fd, buf.Get(), buf.cursor()));
|
|
for (auto script : scripts) {
|
|
MOZ_TRY(Write(fd, script->Range().begin().get(), script->mSize));
|
|
|
|
if (script->mScript) {
|
|
script->FreeData();
|
|
}
|
|
}
|
|
}
|
|
|
|
MOZ_TRY(cacheFile->MoveTo(nullptr, mBaseName + NS_LITERAL_STRING(".bin")));
|
|
|
|
return Ok();
|
|
}
|
|
|
|
// Runs in the mSaveThread thread, and writes out the cache file for the next
|
|
// session after a reasonable delay.
|
|
nsresult
|
|
ScriptPreloader::Run()
|
|
{
|
|
MonitorAutoLock mal(mSaveMonitor);
|
|
|
|
// Ideally wait about 10 seconds before saving, to avoid unnecessary IO
|
|
// during early startup. But only if the cache hasn't been invalidated,
|
|
// since that can trigger a new write during shutdown, and we don't want to
|
|
// cause shutdown hangs.
|
|
if (!mCacheInvalidated) {
|
|
mal.Wait(10000);
|
|
}
|
|
|
|
auto result = URLPreloader::GetSingleton().WriteCache();
|
|
Unused << NS_WARN_IF(result.isErr());
|
|
|
|
result = WriteCache();
|
|
Unused << NS_WARN_IF(result.isErr());
|
|
|
|
result = mChildCache->WriteCache();
|
|
Unused << NS_WARN_IF(result.isErr());
|
|
|
|
mSaveComplete = true;
|
|
NS_ReleaseOnMainThreadSystemGroup("ScriptPreloader::mSaveThread",
|
|
mSaveThread.forget());
|
|
|
|
mal.NotifyAll();
|
|
return NS_OK;
|
|
}
|
|
|
|
void
|
|
ScriptPreloader::NoteScript(const nsCString& url, const nsCString& cachePath,
|
|
JS::HandleScript jsscript)
|
|
{
|
|
// Don't bother trying to cache any URLs with cache-busting query
|
|
// parameters.
|
|
if (!Active() || cachePath.FindChar('?') >= 0) {
|
|
return;
|
|
}
|
|
|
|
// Don't bother caching files that belong to the mochitest harness.
|
|
NS_NAMED_LITERAL_CSTRING(mochikitPrefix, "chrome://mochikit/");
|
|
if (StringHead(url, mochikitPrefix.Length()) == mochikitPrefix) {
|
|
return;
|
|
}
|
|
|
|
auto script = mScripts.LookupOrAdd(cachePath, *this, url, cachePath, jsscript);
|
|
|
|
if (!script->mScript) {
|
|
MOZ_ASSERT(jsscript);
|
|
script->mScript = jsscript;
|
|
script->mReadyToExecute = true;
|
|
}
|
|
|
|
// If we don't already have bytecode for this script, and it doesn't already
|
|
// exist in the child cache, encode it now, before it's ever executed.
|
|
//
|
|
// Ideally, we would like to do the encoding lazily, during idle slices.
|
|
// There are subtle issues with encoding scripts which have already been
|
|
// executed, though, which makes that somewhat risky. So until that
|
|
// situation is improved, and thoroughly tested, we need to encode eagerly.
|
|
//
|
|
// (See also the TranscodeResult_Failure_RunOnceNotSupported failure case in
|
|
// js::XDRScript)
|
|
if (!script->mSize && !(mChildCache && mChildCache->mScripts.Get(cachePath))) {
|
|
AutoSafeJSAPI jsapi;
|
|
Unused << script->XDREncode(jsapi.cx());
|
|
}
|
|
|
|
script->UpdateLoadTime(TimeStamp::Now());
|
|
script->mProcessTypes += CurrentProcessType();
|
|
}
|
|
|
|
void
|
|
ScriptPreloader::NoteScript(const nsCString& url, const nsCString& cachePath,
|
|
ProcessType processType, nsTArray<uint8_t>&& xdrData,
|
|
TimeStamp loadTime)
|
|
{
|
|
// After data has been prepared, there's no point in noting further scripts,
|
|
// since the cache either has already been written, or is about to be
|
|
// written. Any time prior to the data being prepared, we can safely mutate
|
|
// mScripts without locking. After that point, the save thread is free to
|
|
// access it, and we can't alter it without locking.
|
|
if (mDataPrepared) {
|
|
return;
|
|
}
|
|
|
|
auto script = mScripts.LookupOrAdd(cachePath, *this, url, cachePath, nullptr);
|
|
|
|
if (!script->HasRange()) {
|
|
MOZ_ASSERT(!script->HasArray());
|
|
|
|
script->mSize = xdrData.Length();
|
|
script->mXDRData.construct<nsTArray<uint8_t>>(Forward<nsTArray<uint8_t>>(xdrData));
|
|
|
|
auto& data = script->Array();
|
|
script->mXDRRange.emplace(data.Elements(), data.Length());
|
|
}
|
|
|
|
if (!script->mSize && !script->mScript) {
|
|
// If the content process is sending us a script entry for a script
|
|
// which was in the cache at startup, it expects us to already have this
|
|
// script data, so it doesn't send it.
|
|
//
|
|
// However, the cache may have been invalidated at this point (usually
|
|
// due to the add-on manager installing or uninstalling a legacy
|
|
// extension during very early startup), which means we may no longer
|
|
// have an entry for this script. Since that means we have no data to
|
|
// write to the new cache, and no JSScript to generate it from, we need
|
|
// to discard this entry.
|
|
mScripts.Remove(cachePath);
|
|
return;
|
|
}
|
|
|
|
script->UpdateLoadTime(loadTime);
|
|
script->mProcessTypes += processType;
|
|
}
|
|
|
|
JSScript*
|
|
ScriptPreloader::GetCachedScript(JSContext* cx, const nsCString& path)
|
|
{
|
|
// If a script is used by both the parent and the child, it's stored only
|
|
// in the child cache.
|
|
if (mChildCache) {
|
|
auto script = mChildCache->GetCachedScript(cx, path);
|
|
if (script) {
|
|
return script;
|
|
}
|
|
}
|
|
|
|
auto script = mScripts.Get(path);
|
|
if (script) {
|
|
return WaitForCachedScript(cx, script);
|
|
}
|
|
|
|
return nullptr;
|
|
}
|
|
|
|
JSScript*
|
|
ScriptPreloader::WaitForCachedScript(JSContext* cx, CachedScript* script)
|
|
{
|
|
// Check for finished operations before locking so that we can move onto
|
|
// decoding the next batch as soon as possible after the pending batch is
|
|
// ready. If we wait until we hit an unfinished script, we wind up having at
|
|
// most one batch of buffered scripts, and occasionally under-running that
|
|
// buffer.
|
|
MaybeFinishOffThreadDecode();
|
|
|
|
if (!script->mReadyToExecute) {
|
|
LOG(Info, "Must wait for async script load: %s\n", script->mURL.get());
|
|
auto start = TimeStamp::Now();
|
|
|
|
mMonitor.AssertNotCurrentThreadOwns();
|
|
MonitorAutoLock mal(mMonitor);
|
|
|
|
// Check for finished operations again *after* locking, or we may race
|
|
// against mToken being set between our last check and the time we
|
|
// entered the mutex.
|
|
MaybeFinishOffThreadDecode();
|
|
|
|
if (!script->mReadyToExecute && script->mSize < MAX_MAINTHREAD_DECODE_SIZE) {
|
|
LOG(Info, "Script is small enough to recompile on main thread\n");
|
|
|
|
script->mReadyToExecute = true;
|
|
} else {
|
|
while (!script->mReadyToExecute) {
|
|
mal.Wait();
|
|
|
|
MonitorAutoUnlock mau(mMonitor);
|
|
MaybeFinishOffThreadDecode();
|
|
}
|
|
}
|
|
|
|
LOG(Debug, "Waited %fms\n", (TimeStamp::Now() - start).ToMilliseconds());
|
|
}
|
|
|
|
return script->GetJSScript(cx);
|
|
}
|
|
|
|
|
|
|
|
/* static */ void
|
|
ScriptPreloader::OffThreadDecodeCallback(void* token, void* context)
|
|
{
|
|
auto cache = static_cast<ScriptPreloader*>(context);
|
|
|
|
cache->mMonitor.AssertNotCurrentThreadOwns();
|
|
MonitorAutoLock mal(cache->mMonitor);
|
|
|
|
// First notify any tasks that are already waiting on scripts, since they'll
|
|
// be blocking the main thread, and prevent any runnables from executing.
|
|
cache->mToken = token;
|
|
mal.NotifyAll();
|
|
|
|
// If nothing processed the token, and we don't already have a pending
|
|
// runnable, then dispatch a new one to finish the processing on the main
|
|
// thread as soon as possible.
|
|
if (cache->mToken && !cache->mFinishDecodeRunnablePending) {
|
|
cache->mFinishDecodeRunnablePending = true;
|
|
NS_DispatchToMainThread(
|
|
NewRunnableMethod("ScriptPreloader::DoFinishOffThreadDecode",
|
|
cache,
|
|
&ScriptPreloader::DoFinishOffThreadDecode));
|
|
}
|
|
}
|
|
|
|
void
|
|
ScriptPreloader::FinishPendingParses(MonitorAutoLock& aMal)
|
|
{
|
|
mMonitor.AssertCurrentThreadOwns();
|
|
|
|
mPendingScripts.clear();
|
|
|
|
MaybeFinishOffThreadDecode();
|
|
|
|
// Loop until all pending decode operations finish.
|
|
while (!mParsingScripts.empty()) {
|
|
aMal.Wait();
|
|
MaybeFinishOffThreadDecode();
|
|
}
|
|
}
|
|
|
|
void
|
|
ScriptPreloader::DoFinishOffThreadDecode()
|
|
{
|
|
mFinishDecodeRunnablePending = false;
|
|
MaybeFinishOffThreadDecode();
|
|
}
|
|
|
|
JSObject*
|
|
ScriptPreloader::CompilationScope(JSContext* cx)
|
|
{
|
|
return mozJSComponentLoader::Get()->CompilationScope(cx);
|
|
}
|
|
|
|
void
|
|
ScriptPreloader::MaybeFinishOffThreadDecode()
|
|
{
|
|
if (!mToken) {
|
|
return;
|
|
}
|
|
|
|
auto cleanup = MakeScopeExit([&] () {
|
|
mToken = nullptr;
|
|
mParsingSources.clear();
|
|
mParsingScripts.clear();
|
|
|
|
DecodeNextBatch(OFF_THREAD_CHUNK_SIZE);
|
|
});
|
|
|
|
AutoSafeJSAPI jsapi;
|
|
JSContext* cx = jsapi.cx();
|
|
|
|
JSAutoCompartment ac(cx, CompilationScope(cx));
|
|
JS::Rooted<JS::ScriptVector> jsScripts(cx, JS::ScriptVector(cx));
|
|
|
|
// If this fails, we still need to mark the scripts as finished. Any that
|
|
// weren't successfully compiled in this operation (which should never
|
|
// happen under ordinary circumstances) will be re-decoded on the main
|
|
// thread, and raise the appropriate errors when they're executed.
|
|
//
|
|
// The exception from the off-thread decode operation will be reported when
|
|
// we pop the AutoJSAPI off the stack.
|
|
Unused << JS::FinishMultiOffThreadScriptsDecoder(cx, mToken, &jsScripts);
|
|
|
|
unsigned i = 0;
|
|
for (auto script : mParsingScripts) {
|
|
LOG(Debug, "Finished off-thread decode of %s\n", script->mURL.get());
|
|
if (i < jsScripts.length())
|
|
script->mScript = jsScripts[i++];
|
|
script->mReadyToExecute = true;
|
|
}
|
|
}
|
|
|
|
void
|
|
ScriptPreloader::DecodeNextBatch(size_t chunkSize, JS::HandleObject scope)
|
|
{
|
|
MOZ_ASSERT(mParsingSources.length() == 0);
|
|
MOZ_ASSERT(mParsingScripts.length() == 0);
|
|
|
|
auto cleanup = MakeScopeExit([&] () {
|
|
mParsingScripts.clearAndFree();
|
|
mParsingSources.clearAndFree();
|
|
});
|
|
|
|
auto start = TimeStamp::Now();
|
|
LOG(Debug, "Off-thread decoding scripts...\n");
|
|
|
|
size_t size = 0;
|
|
for (CachedScript* next = mPendingScripts.getFirst(); next;) {
|
|
auto script = next;
|
|
next = script->getNext();
|
|
|
|
// Skip any scripts that we decoded on the main thread rather than
|
|
// waiting for an off-thread operation to complete.
|
|
if (script->mReadyToExecute) {
|
|
script->remove();
|
|
continue;
|
|
}
|
|
// If we have enough data for one chunk and this script would put us
|
|
// over our chunk size limit, we're done.
|
|
if (size > SMALL_SCRIPT_CHUNK_THRESHOLD &&
|
|
size + script->mSize > chunkSize) {
|
|
break;
|
|
}
|
|
if (!mParsingScripts.append(script) ||
|
|
!mParsingSources.emplaceBack(script->Range(), script->mURL.get(), 0)) {
|
|
break;
|
|
}
|
|
|
|
LOG(Debug, "Beginning off-thread decode of script %s (%u bytes)\n",
|
|
script->mURL.get(), script->mSize);
|
|
|
|
script->remove();
|
|
size += script->mSize;
|
|
}
|
|
|
|
if (size == 0 && mPendingScripts.isEmpty()) {
|
|
return;
|
|
}
|
|
|
|
AutoSafeJSAPI jsapi;
|
|
JSContext* cx = jsapi.cx();
|
|
JSAutoCompartment ac(cx, scope ? scope : CompilationScope(cx));
|
|
|
|
JS::CompileOptions options(cx, JSVERSION_DEFAULT);
|
|
options.setNoScriptRval(true)
|
|
.setSourceIsLazy(true);
|
|
|
|
if (!JS::CanCompileOffThread(cx, options, size) ||
|
|
!JS::DecodeMultiOffThreadScripts(cx, options, mParsingSources,
|
|
OffThreadDecodeCallback,
|
|
static_cast<void*>(this))) {
|
|
// If we fail here, we don't move on to process the next batch, so make
|
|
// sure we don't have any other scripts left to process.
|
|
MOZ_ASSERT(mPendingScripts.isEmpty());
|
|
for (auto script : mPendingScripts) {
|
|
script->mReadyToExecute = true;
|
|
}
|
|
|
|
LOG(Info, "Can't decode %lu bytes of scripts off-thread", (unsigned long)size);
|
|
for (auto script : mParsingScripts) {
|
|
script->mReadyToExecute = true;
|
|
}
|
|
return;
|
|
}
|
|
|
|
cleanup.release();
|
|
|
|
LOG(Debug, "Initialized decoding of %u scripts (%u bytes) in %fms\n",
|
|
(unsigned)mParsingSources.length(), (unsigned)size, (TimeStamp::Now() - start).ToMilliseconds());
|
|
}
|
|
|
|
|
|
ScriptPreloader::CachedScript::CachedScript(ScriptPreloader& cache, InputBuffer& buf)
|
|
: mCache(cache)
|
|
{
|
|
Code(buf);
|
|
|
|
// Swap the mProcessTypes and mOriginalProcessTypes values, since we want to
|
|
// start with an empty set of processes loaded into for this session, and
|
|
// compare against last session's values later.
|
|
mOriginalProcessTypes = mProcessTypes;
|
|
mProcessTypes = {};
|
|
}
|
|
|
|
bool
|
|
ScriptPreloader::CachedScript::XDREncode(JSContext* cx)
|
|
{
|
|
JSAutoCompartment ac(cx, mScript);
|
|
JS::RootedScript jsscript(cx, mScript);
|
|
|
|
mXDRData.construct<JS::TranscodeBuffer>();
|
|
|
|
JS::TranscodeResult code = JS::EncodeScript(cx, Buffer(), jsscript);
|
|
if (code == JS::TranscodeResult_Ok) {
|
|
mXDRRange.emplace(Buffer().begin(), Buffer().length());
|
|
mSize = Range().length();
|
|
return true;
|
|
}
|
|
mXDRData.destroy();
|
|
JS_ClearPendingException(cx);
|
|
return false;
|
|
}
|
|
|
|
JSScript*
|
|
ScriptPreloader::CachedScript::GetJSScript(JSContext* cx)
|
|
{
|
|
MOZ_ASSERT(mReadyToExecute);
|
|
if (mScript) {
|
|
return mScript;
|
|
}
|
|
|
|
// If we have no script at this point, the script was too small to decode
|
|
// off-thread, or it was needed before the off-thread compilation was
|
|
// finished, and is small enough to decode on the main thread rather than
|
|
// wait for the off-thread decoding to finish. In either case, we decode
|
|
// it synchronously the first time it's needed.
|
|
MOZ_ASSERT(HasRange());
|
|
|
|
auto start = TimeStamp::Now();
|
|
LOG(Info, "Decoding script %s on main thread...\n", mURL.get());
|
|
|
|
JS::RootedScript script(cx);
|
|
if (JS::DecodeScript(cx, Range(), &script)) {
|
|
mScript = script;
|
|
|
|
if (mCache.mSaveComplete) {
|
|
FreeData();
|
|
}
|
|
}
|
|
|
|
LOG(Debug, "Finished decoding in %fms", (TimeStamp::Now() - start).ToMilliseconds());
|
|
|
|
return mScript;
|
|
}
|
|
|
|
NS_IMPL_ISUPPORTS(ScriptPreloader, nsIObserver, nsIRunnable, nsIMemoryReporter)
|
|
|
|
#undef LOG
|
|
|
|
} // namespace mozilla
|