Hi Xiang, the heap resources should still be reclaimed if you call v8::V8::Dispose().
-- Mads On Wed, Nov 25, 2009 at 12:03 PM, Xiang Zhong <[email protected]> wrote: > Hi, Mads and Erik, > > If OOM happens, Are those heap resources still can be reclaimed if we call > v8::V8::Dispose()? > > Or there would be memory leak until we exit the process? > > Cheers~ > Xiang > > > On Wed, Nov 25, 2009 at 4:31 PM, Xiang Zhong <[email protected]> wrote: >> >> Hi， Erik， >> Yes, you are right. >> I confuse setting heap limit with setting stack limit, which have to be >> set seperately by the doc for the latter. >> thanks~ >> /** >> * A set of constraints that specifies the limits of the runtime's memory >> use. >> * You must set the heap size before initializing the VM - the size cannot >> be >> * adjusted after the VM is initialized. >> * >> * If you are using threads then you should hold the V8::Locker lock while >> * setting the stack limit and you must set a non-default stack limit >> separately >> * for each thread. >> */ >> class V8EXPORT ResourceConstraints { >> >> >> On Wed, Nov 25, 2009 at 4:22 PM, Erik Corry <[email protected]> wrote: >>> >>> 2009/11/25 Xiang Zhong <[email protected]>: >>> > Suppose they speficy heap constraint seperately >>> > with SetResourceConstraints(ResourceConstraints* constraints) >>> >>> You can only use that interface once to set the heap size (and you >>> have to do it before initializing V8). It applies to all threads. >>> >>> > >>> > >>> > On Wed, Nov 25, 2009 at 4:15 PM, Xiang Zhong <[email protected]> >>> > wrote: >>> >> >>> >> Hi, Mads， >>> >> >>> >> Yeah, I see. Thanks for your answer. >>> >> Another question :-), if we enable multi-thread by v8::V8::Locker, >>> >> will >>> >> other threads dead too if one thread encounter OOM? >>> >> >>> >> Sincerely~ >>> >> Xiang >>> >> >>> >> >>> >> >>> >> On Wed, Nov 25, 2009 at 3:54 PM, Mads Sig Ager <[email protected]> >>> >> wrote: >>> >>> >>> >>> Nothing like that exists. We do not know in advance that we are >>> >>> going >>> >>> to run out of memory. >>> >>> >>> >>> -- Mads >>> >>> >>> >>> On Wed, Nov 25, 2009 at 8:52 AM, Xiang Zhong <[email protected]> >>> >>> wrote: >>> >>> > >>> >>> > Hi, Mads, >>> >>> > >>> >>> > Is there a way that the caller can get notified before an OOM >>> >>> > situation >>> >>> > happen? >>> >>> > If that is possible, the caller can call >>> >>> > v8::V8::TerminateExecution() >>> >>> > beforehand, and dispose the global object in time to free memory. >>> >>> > That will save v8 from being dead or crashing. >>> >>> > >>> >>> > We can hook a callback through SetGlobalGCEpilogueCallback() after >>> >>> > GC >>> >>> > happen, if we can get a flag some like " >>> >>> > GC_FAIL_GOING_TO_OUT_OF_MEMORY", >>> >>> > then it is possible to check the flag and terminate in time. >>> >>> > Does there exist something like that? >>> >>> > >>> >>> > Wishes~ >>> >>> > Xiang >>> >>> > >>> >>> > On Wed, Nov 25, 2009 at 3:35 PM, Mads Sig Ager <[email protected]> >>> >>> > wrote: >>> >>> >> >>> >>> >> An out of memory situation can leave the VM in an inconsistent >>> >>> >> state, >>> >>> >> so it is not possible to continue. It is therefore the expected >>> >>> >> behavior that we cannot continue here. >>> >>> >> >>> >>> >> Cheers, -- Mads >>> >>> >> >>> >>> >> On Wed, Nov 25, 2009 at 3:45 AM, Xiang <[email protected]> wrote: >>> >>> >> > >>> >>> >> > Hi, All, >>> >>> >> > >>> >>> >> > I have declared v8::V8::IgnoreOutOfMemoryException(), and the >>> >>> >> > out >>> >>> >> > of >>> >>> >> > memory exception is caught by trycatch as expected. >>> >>> >> > >>> >>> >> > However, after disposing the current context, we can't create a >>> >>> >> > new >>> >>> >> > context. >>> >>> >> > >>> >>> >> > The handle is empty. >>> >>> >> > >>> >>> >> > Please check the following UＴ case: >>> >>> >> > >>> >>> >> > Reproduction steps >>> >>> >> > --------------------------------------------------------- >>> >>> >> > Please add the following case to test-api.cc, >>> >>> >> > >>> >>> >> > When creating a new context, >>> >>> >> > v8::Persistent<v8::Context> context = v8::Context::New(0, >>> >>> >> > v8::Handle<v8::ObjectTemplate>(), v8::Handle<v8::Value>()); >>> >>> >> > It will fail >>> >>> >> > >>> >>> >> > TEST(CreateNewContextAfterOutOfMemory) { >>> >>> >> > // It's not possible to read a snapshot into a heap with >>> >>> >> > different >>> >>> >> > dimensions. >>> >>> >> > if (v8::internal::Snapshot::IsEnabled()) return; >>> >>> >> > // Set heap limits. >>> >>> >> > static const int K = 1024; >>> >>> >> > v8::ResourceConstraints constraints; >>> >>> >> > constraints.set_max_young_space_size(256 * K); >>> >>> >> > constraints.set_max_old_space_size(4 * K * K); >>> >>> >> > v8::SetResourceConstraints(&constraints); >>> >>> >> > >>> >>> >> > // Execute a script that causes out of memory. >>> >>> >> > v8::HandleScope scope; >>> >>> >> > { >>> >>> >> > LocalContext context; >>> >>> >> > v8::V8::IgnoreOutOfMemoryException(); >>> >>> >> > Local<Script> script = >>> >>> >> > >>> >>> >> > Script::Compile(String::New(js_code_causing_out_of_memory)); >>> >>> >> > Local<Value> result = script->Run(); >>> >>> >> > >>> >>> >> > // Check for out of memory state. >>> >>> >> > CHECK(result.IsEmpty()); >>> >>> >> > CHECK(context->HasOutOfMemoryException()); >>> >>> >> > } >>> >>> >> > >>> >>> >> > { >>> >>> >> > v8::Persistent<v8::Context> context = v8::Context::New(0, >>> >>> >> > v8::Handle<v8::ObjectTemplate>(), v8::Handle<v8::Value>()); >>> >>> >> > >>> >>> >> > >>> >>> >> > //Check here! >>> >>> >> > >>> >>> >> > //I think we should be allowed to create a new context >>> >>> >> > //And the Handle should not be empty >>> >>> >> > CHECK(!context.IsEmpty()); >>> >>> >> > context.Dispose(); >>> >>> >> > context.Clear(); >>> >>> >> > } >>> >>> >> > } >>> >>> >> > > >>> >>> >> > >>> >>> > >>> >>> > >>> >>> > >>> >>> > > >>> >>> > >>> >>> >>> >>> >>> >> >>> > >>> > >>> > > >>> > >>> >>> >> > > > > > --~--~---------~--~----~------------~-------~--~----~ v8-dev mailing list [email protected] http://groups.google.com/group/v8-dev -~----------~----~----~----~------~----~------~--~---
