Introduction
When tracking down the causes of process hangs, it is often helpful to obtain a process dump while the process is experiencing a hang. This article describes how to get a process dump with Task Manager on Windows. (To get a process dump for Thunderbird or some other product, substitute the product name where ever you see Firefox in these instructions.)
Caution
The memory dump that will be created through this process is a complete snapshot of the state of Firefox when you create the file, so it contains URLs of active tabs, history information, and possibly even passwords depending on what you are doing when the snapshot is taken. It is advisable to create a new, blank profile to use when reproducing the hang and capturing the memory dump. Please ask for help doing this!
Requirements
- Windows
- To get a process dump, you need to be using Windows Vista or above.
- A Firefox nightly or release
- You need a Firefox version for which symbols are available from the Mozilla symbol server. You can use any official nightly build or released version of Firefox from Mozilla. You can find the latest trunk nightly builds under https://ftp.mozilla.org/pub/mozilla.o.../latest-trunk/.
Creating the Dump File
Ensure that Firefox is not already running.
Run Firefox, reproduce the hang
Start Firefox and perform whatever steps are necessary to cause Firefox to hang. Once the browser hangs, continue with the steps below.
After the hang
- Open Windows Task Manager (CTRL+SHIFT+ESC).
- Find Firefox.exe among the list of processes.
- Right-click Firefox.exe and select "Create dump file". Task manager should indicate where the dump file was written to.