From 7f88bd15d11ffc7dbc8bf4303ce05387573e8660 Mon Sep 17 00:00:00 2001
From: Peter Johnson <johnson.peter@gmail.com>
Date: Thu, 13 Oct 2016 00:13:18 -0700
Subject: [PATCH] SinkImpl: Keep enabled count rather than just boolean.

This allows e.g. multiple HTTP streams to individually call Enable() and
Disable().
---
 src/SinkImpl.cpp |  7 +++----
 src/SinkImpl.h   | 14 +++++---------
 2 files changed, 8 insertions(+), 13 deletions(-)

diff --git a/src/SinkImpl.cpp b/src/SinkImpl.cpp
index a48feb1e47..7104a6d390 100644
--- a/src/SinkImpl.cpp
+++ b/src/SinkImpl.cpp
@@ -15,19 +15,18 @@ SinkImpl::SinkImpl(llvm::StringRef name) : m_name{name} {}
 
 SinkImpl::~SinkImpl() {
   if (m_source) {
-    if (m_enabled) m_source->DisableSink();
+    if (m_enabledCount > 0) m_source->DisableSink();
     m_source->RemoveSink();
   }
 }
 
 void SinkImpl::SetSource(std::shared_ptr<SourceImpl> source) {
   std::lock_guard<std::mutex> lock(m_mutex);
-  bool was_enabled = m_enabled;
   if (m_source) {
-    if (m_enabled) m_source->DisableSink();
+    if (m_enabledCount > 0) m_source->DisableSink();
     m_source->RemoveSink();
   }
   m_source = source;
   m_source->AddSink();
-  if (was_enabled) m_source->EnableSink();
+  if (m_enabledCount > 0) m_source->EnableSink();
 }
diff --git a/src/SinkImpl.h b/src/SinkImpl.h
index 716be983cd..95da265068 100644
--- a/src/SinkImpl.h
+++ b/src/SinkImpl.h
@@ -33,18 +33,14 @@ class SinkImpl {
 
   void Enable() {
     std::lock_guard<std::mutex> lock(m_mutex);
-    if (!m_enabled) {
-      m_enabled = true;
-      if (m_source) m_source->EnableSink();
-    }
+    if (m_enabledCount == 0 && m_source) m_source->EnableSink();
+    ++m_enabledCount;
   }
 
   void Disable() {
     std::lock_guard<std::mutex> lock(m_mutex);
-    if (m_enabled) {
-      m_enabled = false;
-      if (m_source) m_source->DisableSink();
-    }
+    --m_enabledCount;
+    if (m_enabledCount == 0 && m_source) m_source->DisableSink();
   }
 
   void SetSource(std::shared_ptr<SourceImpl> source);
@@ -58,7 +54,7 @@ class SinkImpl {
   std::string m_name;
   mutable std::mutex m_mutex;
   std::shared_ptr<SourceImpl> m_source;
-  bool m_enabled{false};
+  int m_enabledCount{0};
 };
 
 }  // namespace cs