From 68ffac250ae2d1c2d5d961304d2c61f6755ab033 Mon Sep 17 00:00:00 2001 From: bunnei Date: Fri, 5 Mar 2021 22:10:03 -0800 Subject: common: fiber: Use weak_ptr when yielding. - Avoids a memory leak, as taking a strong reference of the fiber here causes a circular reference. - Supersedes #6006 with a more narrow fix. --- src/common/fiber.cpp | 19 ++++++++++++------- 1 file changed, 12 insertions(+), 7 deletions(-) (limited to 'src/common/fiber.cpp') diff --git a/src/common/fiber.cpp b/src/common/fiber.cpp index 3c1eefcb7..b06fdc258 100644 --- a/src/common/fiber.cpp +++ b/src/common/fiber.cpp @@ -116,16 +116,21 @@ void Fiber::Rewind() { boost::context::detail::jump_fcontext(impl->rewind_context, this); } -void Fiber::YieldTo(std::shared_ptr from, std::shared_ptr to) { - ASSERT_MSG(from != nullptr, "Yielding fiber is null!"); +void Fiber::YieldTo(std::weak_ptr weak_from, std::shared_ptr to) { ASSERT_MSG(to != nullptr, "Next fiber is null!"); + to->impl->guard.lock(); - to->impl->previous_fiber = from; + to->impl->previous_fiber = weak_from.lock(); + auto transfer = boost::context::detail::jump_fcontext(to->impl->context, to.get()); - ASSERT(from->impl->previous_fiber != nullptr); - from->impl->previous_fiber->impl->context = transfer.fctx; - from->impl->previous_fiber->impl->guard.unlock(); - from->impl->previous_fiber.reset(); + + // "from" might no longer be valid if the thread was killed + if (auto from = weak_from.lock(); from != nullptr) { + ASSERT(from->impl->previous_fiber != nullptr); + from->impl->previous_fiber->impl->context = transfer.fctx; + from->impl->previous_fiber->impl->guard.unlock(); + from->impl->previous_fiber.reset(); + } } std::shared_ptr Fiber::ThreadToFiber() { -- cgit v1.2.3