reapack

commit 43454a2a4751dc2a8e290f67b0c207d877d81542
parent 58eb823e68fd607ca679febf74a5f90a40fa5c4c
Author: cfillion <cfillion@users.noreply.github.com>
Date:   Tue,  7 Feb 2017 02:11:57 -0500

fix possible crash when cleaning up downloads and transactions

The variables captured by a lambda are no longer availabe once that lambda
(std::function) is destroyed. This have been happening frequently since the
improved download thread scheduling code.

https://gist.github.com/cfillion/156f6e32d508155145db1f404fbe30ad

Diffstat:
M
src/download.cpp
 | 
6
+++---
M
src/reapack.cpp
 | 
17
++++++++++-------
M
src/reapack.hpp
 | 
1
+
M
src/transaction.cpp
 | 
4
++--

4 files changed, 16 insertions(+), 12 deletions(-)
diff --git a/src/download.cpp b/src/download.cpp
@@ -250,9 +250,7 @@ void DownloadQueue::push(Download *dl)
   m_onPush(dl);
   m_running.insert(dl);
 
-  dl->setCleanupHandler([=] {
-    delete dl;
-
+  dl->onFinish([=] {
     m_running.erase(dl);
 
     // call m_onDone() only after every onFinish slots ran
@@ -260,6 +258,8 @@ void DownloadQueue::push(Download *dl)
       m_onDone();
   });
 
+  dl->setCleanupHandler([=] { delete dl; });
+
   auto &thread = m_pool[m_running.size() % m_pool.size()];
   if(!thread)
     thread = make_unique<DownloadThread>();
diff --git a/src/reapack.cpp b/src/reapack.cpp
@@ -436,17 +436,20 @@ Transaction *ReaPack::setupTransaction()
       &entries, &m_config->install.promptObsolete) == IDOK;
   });
 
-  m_tx->setCleanupHandler([=] {
-    delete m_tx;
-    m_tx = nullptr;
-
-    // refresh only once all onFinish slots were ran
-    refreshBrowser();
-  });
+  m_tx->setCleanupHandler(bind(&ReaPack::teardownTransaction, this));
 
   return m_tx;
 }
 
+void ReaPack::teardownTransaction()
+{
+  delete m_tx;
+  m_tx = nullptr;
+
+  // refresh only once the registry is close
+  refreshBrowser();
+}
+
 void ReaPack::refreshManager()
 {
   if(m_manager)
diff --git a/src/reapack.hpp b/src/reapack.hpp
@@ -91,6 +91,7 @@ private:
   void registerSelf();
   void doFetchIndex(const Remote &remote, DownloadQueue *, HWND, bool stale);
   IndexPtr loadIndex(const Remote &remote, HWND);
+  void teardownTransaction();
 
   std::map<int, ActionCallback> m_actions;
 
diff --git a/src/transaction.cpp b/src/transaction.cpp
@@ -118,12 +118,12 @@ void Transaction::fetchIndex(const Remote &remote, const function<void()> &cb)
     return;
   }
 
-  m_downloadQueue.push(dl);
-
   dl->onFinish([=] {
     if(saveFile(dl, Index::pathFor(dl->name())))
       cb();
   });
+
+  m_downloadQueue.push(dl);
 }
 
 void Transaction::install(const Version *ver, const bool pin)