From 00d9697b9dbc2ee09aa08807bdf490716a8e1ea9 Mon Sep 17 00:00:00 2001
From: falsycat <me@falsy.cat>
Date: Tue, 15 Nov 2022 15:41:48 +0900
Subject: [PATCH] add leak checker for nf7::Context

---
 main.cc | 14 ++++++++++++++
 nf7.cc  |  2 ++
 nf7.hh  |  4 ++++
 3 files changed, 20 insertions(+)

diff --git a/main.cc b/main.cc
index f55527b..29d152c 100644
--- a/main.cc
+++ b/main.cc
@@ -170,6 +170,11 @@ class Env final : public nf7::Env {
       }
     }
   }
+  ~Env() noexcept {
+    if (ctx_cnt_ > 0) {
+      std::cout << "context leak detected: " << ctx_cnt_ << std::endl;
+    }
+  }
 
   void TearDownRoot() noexcept {
     if (root_) {
@@ -270,6 +275,13 @@ class Env final : public nf7::Env {
     files_.erase(id);
   }
 
+  void AddContext(nf7::Context&) noexcept override {
+    ++ctx_cnt_;
+  }
+  void RemoveContext(nf7::Context&) noexcept override {
+    --ctx_cnt_;
+  }
+
   void AddWatcher(nf7::File::Id id, nf7::Env::Watcher& w) noexcept override {
     watchers_[id].push_back(&w);
   }
@@ -293,6 +305,8 @@ class Env final : public nf7::Env {
   std::unordered_map<nf7::File::Id, nf7::File*> files_;
 
   std::unordered_map<nf7::File::Id, std::vector<nf7::Env::Watcher*>> watchers_;
+
+  std::atomic<size_t> ctx_cnt_ = 0;
 };
 
 
diff --git a/nf7.cc b/nf7.cc
index 75fc5f8..ea4a549 100644
--- a/nf7.cc
+++ b/nf7.cc
@@ -254,8 +254,10 @@ Context::Context(File& f, const std::shared_ptr<Context>& parent) noexcept :
 Context::Context(Env& env, File::Id initiator, const std::shared_ptr<Context>& parent) noexcept :
     env_(&env), initiator_(initiator),
     parent_(parent), depth_(parent? parent->depth()+1: 0) {
+  env_->AddContext(*this);
 }
 Context::~Context() noexcept {
+  env_->RemoveContext(*this);
 }
 
 File& Env::GetFileOrThrow(File::Id id) const {
diff --git a/nf7.hh b/nf7.hh
index e608117..083b241 100644
--- a/nf7.hh
+++ b/nf7.hh
@@ -301,6 +301,10 @@ class Env {
   virtual File::Id AddFile(File&) noexcept = 0;
   virtual void RemoveFile(File::Id) noexcept = 0;
 
+  friend class nf7::Context;
+  virtual void AddContext(nf7::Context&) noexcept = 0;
+  virtual void RemoveContext(nf7::Context&) noexcept = 0;
+
   virtual void AddWatcher(File::Id, Watcher&) noexcept = 0;
   virtual void RemoveWatcher(File::Id, Watcher&) noexcept = 0;