Opened on 12/09/2016 at 06:37:43 PM
Last modified on 01/09/2017 at 09:23:14 AM
#4725 new defect
The update function of AdblockPlusEngine leaks a Windows thread instance
| Reported by: | eric@adblockplus.org | Assignee: | |
|---|---|---|---|
| Priority: | Unknown | Milestone: | |
| Module: | Adblock-Plus-for-Internet-Explorer | Keywords: | |
| Cc: | oleksandr | Blocked By: | |
| Blocking: | Platform: | Internet Explorer | |
| Ready: | no | Confidential: | no |
| Tester: | Unknown | Verified working: | no |
| Review URL(s): | |||
Description
Defective behavior
The function Updater::Update in AdblockPlusEngine creates a detached thread to run the download for an update. It system-calls CreateThread, which returns a thread handle, but discards the return value. This leaks the thread.
From MSDN:
The number of threads a process can create is limited by the available virtual memory. By default, every thread has one megabyte of stack space.
[...]
The thread object remains in the system until the thread has terminated and all handles to it have been closed through a call to CloseHandle.
How to reproduce
The defect triggers every time an update download occurs.
How to cure
Using C++11 <thread> library is sufficient. The thread object can be created and detached, after which the runtime library will handle system clean-up when the thread terminates.
I think that instead of creating of yet one thread as it is now we should rather change the code to use currently available message loop (ABPAtlModule::RunMessageLoop).