Commit b0370355 authored by Lars T Hansen's avatar Lars T Hansen
Browse files

Bug 1599659 - Predicate to test context for live SABs. r=jonco 

SABs become foreground-finalizable so that we can access the runtime
during finalization.  Then a simple counter on the runtime will track
live SABs for the runtime, and the predicate on the context can get
its information from the runtime.

Fallout: SABs are now enabled on the globals used for jsapi-tests.

Differential Revision: https://phabricator.services.mozilla.com/D55783

--HG--
extra : moz-landing-system : lando
parent d6200622

js/src/jsapi-tests/moz.build

+1 −0
Original line number Diff line number Diff line
@@ -92,6 +92,7 @@ UNIFIED_SOURCES += [ 
    'testRegExp.cpp',

    'testResolveRecursion.cpp',

    'tests.cpp',

    'testSABAccounting.cpp',

    'testSameValue.cpp',

    'testSavedStacks.cpp',

    'testScriptInfo.cpp',

js/src/jsapi-tests/testSABAccounting.cpp

0 → 100644
+34 −0
Original line number Diff line number Diff line 
#include "jsapi.h"

#include "jsfriendapi.h"



#include "builtin/TestingFunctions.h"

#include "js/SharedArrayBuffer.h"

#include "jsapi-tests/tests.h"



BEGIN_TEST(testSABAccounting) {

  // Purge what we can

  JS::PrepareForFullGC(cx);

  NonIncrementalGC(cx, GC_SHRINK, GCReason::API);



  // Self-hosting and chrome code should not use SABs, or the point of this

  // predicate is completely lost.

  CHECK(!JS_ContainsSharedArrayBuffer(cx));



  JS::RootedObject obj(cx), obj2(cx);

  CHECK(obj = JS::NewSharedArrayBuffer(cx, 4096));

  CHECK(JS_ContainsSharedArrayBuffer(cx));

  CHECK(obj2 = JS::NewSharedArrayBuffer(cx, 4096));

  CHECK(JS_ContainsSharedArrayBuffer(cx));



  // Discard those objects again.

  obj = nullptr;

  obj2 = nullptr;

  JS::PrepareForFullGC(cx);

  NonIncrementalGC(cx, GC_SHRINK, GCReason::API);



  // Should be back to base state.

  CHECK(!JS_ContainsSharedArrayBuffer(cx));



  return true;

}

END_TEST(testSABAccounting)

js/src/jsapi-tests/tests.cpp

+2 −1
Original line number Diff line number Diff line
@@ -92,7 +92,8 @@ JSObject* JSAPITest::createGlobal(JSPrincipals* principals) { 
      .setStreamsEnabled(true)

      .setFieldsEnabled(true)

      .setAwaitFixEnabled(true)

      .setWeakRefsEnabled(true);

      .setWeakRefsEnabled(true)

      .setSharedMemoryAndAtomicsEnabled(true);

  newGlobal = JS_NewGlobalObject(cx, getGlobalClass(), principals,

                                 JS::FireOnNewGlobalHook, options);

  if (!newGlobal) {

js/src/jsapi.cpp

+4 −0
Original line number Diff line number Diff line
@@ -390,6 +390,10 @@ JS_PUBLIC_API void JS_SetFutexCanWait(JSContext* cx) { 
  cx->fx.setCanWait(true);

}



JS_PUBLIC_API bool JS_ContainsSharedArrayBuffer(JSContext* cx) {

  return cx->runtime()->hasLiveSABs();

}



JS_PUBLIC_API JSRuntime* JS_GetParentRuntime(JSContext* cx) {

  return cx->runtime()->parentRuntime ? cx->runtime()->parentRuntime

                                      : cx->runtime();

js/src/jsapi.h

+6 −0
Original line number Diff line number Diff line
@@ -344,6 +344,12 @@ extern JS_PUBLIC_API JSRuntime* JS_GetRuntime(JSContext* cx); 


extern JS_PUBLIC_API void JS_SetFutexCanWait(JSContext* cx);



// Returns true if there are any live SharedArrayBuffer objects, including those

// for wasm memories, associated with the context.  This is conservative,

// because it does not run GC.  Some dead objects may not have been collected

// yet and thus will be thought live.

extern JS_PUBLIC_API bool JS_ContainsSharedArrayBuffer(JSContext* cx);



namespace js {



void AssertHeapIsIdle();