Commit c1b18767 authored by Kris Maglione's avatar Kris Maglione
Browse files

Bug 1359653: Part 9 - Observe "startupcache-invalidate" and flush the cache when received. r=erahm 

Flushing the cache at startup is already handled automatically by the
AppStartup code, which removes the entire startupCache directory when
necessary. The add-on manager requires being able to flush the cache at
runtime, though, for the sake of updating bootstrapped add-ons.

MozReview-Commit-ID: LIdiNHrXYXu

--HG--
extra : rebase_source : e5b16490f47e20c78d081ad03dec02c6b2874fc3
extra : absorb_source : 6cd94504c8247f375161b2afdca5c61d59cf8f01
parent 42440e7f

js/xpconnect/loader/ScriptPreloader.cpp

+57 −0
Original line number Diff line number Diff line
@@ -29,6 +29,7 @@ 
#define DELAYED_STARTUP_TOPIC "browser-delayed-startup-finished"

#define CLEANUP_TOPIC "xpcom-shutdown"

#define SHUTDOWN_TOPIC "quit-application-granted"

#define CACHE_FLUSH_TOPIC "startupcache-invalidate"



namespace mozilla {

namespace {
@@ -124,6 +125,7 @@ ScriptPreloader::ScriptPreloader() 
    obs->AddObserver(this, DELAYED_STARTUP_TOPIC, false);

    obs->AddObserver(this, SHUTDOWN_TOPIC, false);

    obs->AddObserver(this, CLEANUP_TOPIC, false);

    obs->AddObserver(this, CACHE_FLUSH_TOPIC, false);



    AutoSafeJSAPI jsapi;

    JS_AddExtraGCRootsTracer(jsapi.cx(), TraceOp, this);
@@ -161,6 +163,44 @@ ScriptPreloader::Cleanup() 
    UnregisterWeakMemoryReporter(this);

}



void

ScriptPreloader::FlushScripts(LinkedList<CachedScript>& scripts)

{

    for (auto next = scripts.getFirst(); next; ) {

        auto script = next;

        next = script->getNext();



        // We can only purge finished scripts here. Async scripts that are

        // still being parsed off-thread have a non-refcounted reference to

        // this script, which needs to stay alive until they finish parsing.

        if (script->mReadyToExecute) {

            script->Cancel();

            script->remove();

            delete script;

        }

    }

}



void

ScriptPreloader::FlushCache()

{

    MonitorAutoLock mal(mMonitor);



    FlushScripts(mSavedScripts);

    FlushScripts(mRestoredScripts);



    // If we've already finished saving the cache at this point, start a new

    // delayed save operation. This will write out an empty cache file in place

    // of any cache file we've already written out this session, which will

    // prevent us from falling back to the current session's cache file on the

    // next startup.

    if (mSaveComplete) {

        mSaveComplete = false;



        Unused << NS_NewNamedThread("SaveScripts",

                                    getter_AddRefs(mSaveThread), this);

    }

}



nsresult

ScriptPreloader::Observe(nsISupports* subject, const char* topic, const char16_t* data)
@@ -179,6 +219,8 @@ ScriptPreloader::Observe(nsISupports* subject, const char* topic, const char16_t 
        ForceWriteCacheFile();

    } else if (!strcmp(topic, CLEANUP_TOPIC)) {

        Cleanup();

    } else if (!strcmp(topic, CACHE_FLUSH_TOPIC)) {

        FlushCache();

    }



    return NS_OK;
@@ -609,6 +651,7 @@ ScriptPreloader::OffThreadDecodeCallback(void* token, void* context) 
    mal.NotifyAll();

}



inline

ScriptPreloader::CachedScript::CachedScript(InputBuffer& buf)

{

    Code(buf);
@@ -631,6 +674,20 @@ ScriptPreloader::CachedScript::XDREncode(JSContext* cx) 
    return false;

}



void

ScriptPreloader::CachedScript::Cancel()

{

    if (mToken) {

        GetSingleton().mMonitor.AssertCurrentThreadOwns();



        AutoSafeJSAPI jsapi;

        JS::CancelOffThreadScriptDecoder(jsapi.cx(), mToken);



        mReadyToExecute = true;

        mToken = nullptr;

    }

}



JSScript*

ScriptPreloader::CachedScript::GetJSScript(JSContext* cx)

{

js/xpconnect/loader/ScriptPreloader.h

+5 −0
Original line number Diff line number Diff line
@@ -111,6 +111,8 @@ private: 
            cache.mScripts.Remove(mCachePath);

        }



        void Cancel();



        // Encodes this script into XDR data, and stores the result in mXDRData.

        // Returns true on success, false on failure.

        bool XDREncode(JSContext* cx);
@@ -210,6 +212,9 @@ private: 
    void ForceWriteCacheFile();

    void Cleanup();



    void FlushCache();

    void FlushScripts(LinkedList<CachedScript>& scripts);



    // Opens the cache file for reading.

    Result<Ok, nsresult> OpenCache();