Bug 1192304 - Common up the checks when entering GC API; r=jonco

--HG--
extra : rebase_source : 54b0d9cd8add99515ac48369cf6d74ea6dbf36a2

js/src/gc/GCRuntime.h

@@ -887,12 +887,22 @@ class GCRuntime
 
     void requestMajorGC(JS::gcreason::Reason reason);
     SliceBudget defaultBudget(JS::gcreason::Reason reason, int64_t millis);
-    void collect(bool incremental, SliceBudget budget, JS::gcreason::Reason reason);
-    bool gcCycle(bool incremental, SliceBudget& budget, JS::gcreason::Reason reason);
-    gcstats::ZoneGCStats scanZonesBeforeGC();
     void budgetIncrementalGC(SliceBudget& budget);
     void resetIncrementalGC(const char* reason);
+
+    // Assert if the system state is such that we should never
+    // receive a request to do GC work.
+    void checkCanCallAPI();
+
+    // Check if the system state is such that GC has been supressed
+    // or otherwise delayed.
+    bool checkIfGCAllowedInCurrentState(JS::gcreason::Reason reason);
+
+    gcstats::ZoneGCStats scanZonesBeforeGC();
+    void collect(bool incremental, SliceBudget budget, JS::gcreason::Reason reason);
+    bool gcCycle(bool incremental, SliceBudget& budget, JS::gcreason::Reason reason);
     void incrementalCollectSlice(SliceBudget& budget, JS::gcreason::Reason reason);
+
     void pushZealSelectedObjects();
     void purgeRuntime();
     bool beginMarkPhase(JS::gcreason::Reason reason);

js/src/jsgc.cpp

@@ -6133,7 +6133,7 @@ GCRuntime::scanZonesBeforeGC()
 }
 
 void
-GCRuntime::collect(bool incremental, SliceBudget budget, JS::gcreason::Reason reason)
+GCRuntime::checkCanCallAPI()
 {
     JS_AbortIfWrongThread(rt);
 
@@ -6144,18 +6144,34 @@ GCRuntime::collect(bool incremental, SliceBudget budget, JS::gcreason::Reason re
     MOZ_ASSERT(!rt->currentThreadHasExclusiveAccess());
 
     MOZ_ASSERT(isAllocAllowed());
+}
 
+bool
+GCRuntime::checkIfGCAllowedInCurrentState(JS::gcreason::Reason reason)
+{
     if (rt->mainThread.suppressGC)
-        return;
-
-    TraceLoggerThread* logger = TraceLoggerForMainThread(rt);
-    AutoTraceLog logGC(logger, TraceLogger_GC);
+        return false;
 
 #ifdef JS_GC_ZEAL
     if (deterministicOnly && !IsDeterministicGCReason(reason))
-        return;
+        return false;
 #endif
 
+    return true;
+}
+
+void
+GCRuntime::collect(bool incremental, SliceBudget budget, JS::gcreason::Reason reason)
+{
+    // Checks run for each request, even if we do not actually GC.
+    checkCanCallAPI();
+
+    // Check if we are allowed to GC at this time before proceeding.
+    if (!checkIfGCAllowedInCurrentState(reason))
+        return;
+
+    AutoTraceLog logGC(TraceLoggerForMainThread(rt), TraceLogger_GC);
+
     AutoStopVerifyingBarriers av(rt, reason == JS::gcreason::SHUTDOWN_CC ||
                                      reason == JS::gcreason::DESTROY_RUNTIME);
 
@@ -6276,10 +6292,7 @@ GCRuntime::finishGC(JS::gcreason::Reason reason)
 void
 GCRuntime::abortGC()
 {
-    JS_AbortIfWrongThread(rt);
-
-    MOZ_RELEASE_ASSERT(!rt->isHeapBusy());
-    MOZ_ASSERT(!rt->currentThreadHasExclusiveAccess());
+    checkCanCallAPI();
     MOZ_ASSERT(!rt->mainThread.suppressGC);
 
     AutoStopVerifyingBarriers av(rt, false);