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Add some GC diagnostics functions
This commit is contained in:
Eelco Dolstra
parent
4d74e67aa8
commit
3ce1ecd63b
2 changed files with 199 additions and 40 deletions
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@ -245,6 +245,8 @@ void GC::gc()
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processStack();
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}
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auto afterMark = steady_time_point::clock::now();
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// Reset all the freelists.
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for (auto & freeList : freeLists)
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freeList.front = nullptr;
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@ -253,28 +255,71 @@ void GC::gc()
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// appropriate freelists.
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size_t totalObjectsFreed = 0;
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size_t totalWordsFreed = 0;
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size_t totalObjectsKept = 0;
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size_t totalWordsKept = 0;
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for (auto & arena : arenas) {
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auto [objectsFreed, wordsFreed] = freeUnmarked(arena);
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auto [objectsFreed, wordsFreed, objectsKept, wordsKept] = freeUnmarked(arena);
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totalObjectsFreed += objectsFreed;
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totalWordsFreed += wordsFreed;
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totalObjectsKept += objectsKept;
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totalWordsKept += wordsKept;
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}
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auto after = steady_time_point::clock::now();
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auto durationMs = std::chrono::duration_cast<std::chrono::milliseconds>(after - before).count();
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auto markDurationMs = std::chrono::duration_cast<std::chrono::milliseconds>(afterMark - before).count();
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auto sweepDurationMs = std::chrono::duration_cast<std::chrono::milliseconds>(after - afterMark).count();
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debug("freed %d bytes in %d dead objects, keeping %d objects, in %d ms",
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totalWordsFreed * WORD_SIZE, totalObjectsFreed, marked, durationMs);
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printError("freed %d dead objects (%d bytes), keeping %d/%d objects (%d bytes), marked in %d ms, swept in %d ms",
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totalObjectsFreed, totalWordsFreed * WORD_SIZE,
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marked, totalObjectsKept, totalWordsKept * WORD_SIZE,
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markDurationMs, sweepDurationMs);
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allTimeWordsFreed += totalWordsFreed;
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totalDurationMs += durationMs;
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totalDurationMs += markDurationMs + sweepDurationMs;
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}
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std::pair<size_t, size_t> GC::freeUnmarked(Arena & arena)
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size_t GC::getObjectSize(Object * obj)
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{
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auto tag = obj->type;
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if (tag >= tInt && tag <= tFloat) {
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return ((Value *) obj)->words();
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} else {
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switch (tag) {
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case tFree:
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return ((Free *) obj)->words();
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break;
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case tString:
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return ((String *) obj)->words();
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break;
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case tBindings:
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return ((Bindings *) obj)->words();
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break;
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case tValueList:
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return ((PtrList<Value> *) obj)->words();
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break;
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case tEnv:
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case tWithExprEnv:
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case tWithAttrsEnv:
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return ((Env *) obj)->words();
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break;
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case tContext:
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return ((Context *) obj)->getSize() + 1;
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break;
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default:
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printError("GC encountered invalid object with tag %d", tag);
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abort();
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}
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}
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}
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std::tuple<size_t, size_t, size_t, size_t> GC::freeUnmarked(Arena & arena)
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{
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size_t objectsFreed = 0;
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size_t wordsFreed = 0;
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size_t objectsKept = 0;
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size_t wordsKept = 0;
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auto end = arena.start + arena.size;
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auto pos = arena.start;
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@ -289,38 +334,8 @@ std::pair<size_t, size_t> GC::freeUnmarked(Arena & arena)
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while (pos < end) {
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auto obj = (Object *) pos;
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auto tag = obj->type;
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size_t objSize;
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if (tag >= tInt && tag <= tFloat) {
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objSize = ((Value *) obj)->words();
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} else {
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switch (tag) {
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case tFree:
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objSize = ((Free *) obj)->words();
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break;
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case tString:
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objSize = ((String *) obj)->words();
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break;
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case tBindings:
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objSize = ((Bindings *) obj)->words();
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break;
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case tValueList:
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objSize = ((PtrList<Value> *) obj)->words();
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break;
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case tEnv:
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case tWithExprEnv:
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case tWithAttrsEnv:
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objSize = ((Env *) obj)->words();
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break;
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case tContext:
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objSize = ((Context *) obj)->getSize() + 1;
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break;
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default:
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printError("GC encountered invalid object with tag %d", tag);
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abort();
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}
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}
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auto objSize = getObjectSize(obj);
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// Merge current object into the previous free object.
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auto mergeFree = [&]() {
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@ -329,7 +344,7 @@ std::pair<size_t, size_t> GC::freeUnmarked(Arena & arena)
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curFree->setSize(curFree->words() + objSize);
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};
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if (tag == tFree) {
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if (obj->type == tFree) {
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//debug("KEEP FREE %x %d", obj, obj->getMisc());
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if (curFree) {
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// Merge this object into the previous free
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@ -345,6 +360,8 @@ std::pair<size_t, size_t> GC::freeUnmarked(Arena & arena)
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//debug("KEEP OBJECT %x %d %d", obj, obj->type, objSize);
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linkCurFree();
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obj->unmark();
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objectsKept += 1;
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wordsKept += objSize;
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} else {
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//debug("FREE OBJECT %x %d %d", obj, obj->type, objSize);
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#if GC_DEBUG
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@ -371,7 +388,7 @@ std::pair<size_t, size_t> GC::freeUnmarked(Arena & arena)
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assert(pos == end);
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return {objectsFreed, wordsFreed};
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return {objectsFreed, wordsFreed, objectsKept, wordsKept};
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}
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bool GC::isObject(void * p)
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@ -382,4 +399,139 @@ bool GC::isObject(void * p)
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return false;
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}
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std::tuple<size_t, size_t> GC::getObjectClosureSize(Object * p)
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{
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std::unordered_set<Object *> seen;
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// FIXME: cut&paste.
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std::stack<Object *> stack;
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// FIXME: ensure this gets inlined.
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auto push = [&](Object * p) { if (p) { assertObject(p); stack.push(p); } };
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auto pushPointers = [&](Object * obj) {
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switch (obj->type) {
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case tFree:
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printError("reached a freed object at %x", obj);
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abort();
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case tBindings: {
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auto obj2 = (Bindings *) obj;
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for (auto i = obj2->attrs; i < obj2->attrs + obj2->size_; ++i)
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push(i->value);
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break;
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}
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case tValueList: {
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auto obj2 = (PtrList<Object> *) obj;
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for (auto i = obj2->elems; i < obj2->elems + obj2->size(); ++i)
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push(*i);
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break;
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}
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case tEnv: {
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auto obj2 = (Env *) obj;
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push(obj2->up);
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for (auto i = obj2->values; i < obj2->values + obj2->getSize(); ++i)
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push(*i);
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break;
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}
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case tWithExprEnv: {
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auto obj2 = (Env *) obj;
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push(obj2->up);
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break;
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}
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case tWithAttrsEnv: {
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auto obj2 = (Env *) obj;
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push(obj2->up);
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push(obj2->values[0]);
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break;
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}
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case tString:
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case tContext:
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case tInt:
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case tBool:
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case tNull:
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case tList0:
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case tFloat:
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case tShortString:
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case tStaticString:
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break;
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case tLongString: {
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auto obj2 = (Value *) obj;
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push(obj2->string.s);
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// See setContext().
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if (!(((ptrdiff_t) obj2->string.context) & 1))
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push(obj2->string.context);
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break;
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}
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case tPath:
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push(((Value *) obj)->path);
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break;
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case tAttrs:
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push(((Value *) obj)->attrs);
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break;
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case tList1:
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push(((Value *) obj)->smallList[0]);
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break;
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case tList2:
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push(((Value *) obj)->smallList[0]);
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push(((Value *) obj)->smallList[1]);
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break;
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case tListN:
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push(((Value *) obj)->bigList);
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break;
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case tThunk:
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case tBlackhole:
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push(((Value *) obj)->thunk.env);
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break;
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case tApp:
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case tPrimOpApp:
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push(((Value *) obj)->app.left);
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push(((Value *) obj)->app.right);
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break;
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case tLambda:
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push(((Value *) obj)->lambda.env);
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break;
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case tPrimOp:
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// FIXME: GC primops?
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break;
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default:
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printError("don't know how to traverse object at %x (tag %d)", obj, obj->type);
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abort();
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}
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};
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stack.push(p);
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size_t totalSize = 0;
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while (!stack.empty()) {
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auto obj = stack.top();
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stack.pop();
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if (seen.insert(obj).second) {
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pushPointers(obj);
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totalSize += getObjectSize(obj);
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}
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}
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return {seen.size(), totalSize};
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}
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}
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@ -286,13 +286,20 @@ public:
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#endif
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}
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/* Return the size in words of object 'obj'. */
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static size_t getObjectSize(Object * obj);
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/* Return the number and size in words of the objects reachable
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from object 'obj'. */
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std::tuple<size_t, size_t> getObjectClosureSize(Object * obj);
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private:
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void addArena(size_t arenaSize);
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void addToFreeList(Free * obj);
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std::pair<size_t, size_t> freeUnmarked(Arena & arena);
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std::tuple<size_t, size_t, size_t, size_t> freeUnmarked(Arena & arena);
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};
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extern GC gc;
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