Feature #9162: Read/Write operations in Tracepoint

• Status: Rejected
• Assignee: ko1 (Koichi Sasada)
• Target version: -

[davidann (David Weiser)]

Is there a way to access when variables are read/assigned in Tracepoint? Specifically, I'm interested in creating a tool which does dynamic, threading analysis of Ruby code to find atomicity violations, dead-locks and race conditions. However, to do so would require the ability to know when a variable is written to, or read from, and the thread in which the operation happened.

I looked in vm_trace.c and did not find the events that would be needed to do this type of analysis.

Can I use Tracepoint to get this information? Or should I use some other approach?

[nobu (Nobuyoshi Nakada)]

• Category set to core
• Status changed from Open to Assigned
• Assignee set to ko1 (Koichi Sasada)

[ko1 (Koichi Sasada)]

• Status changed from Assigned to Rejected

Is there a way to access when variables are read/assigned in Tracepoint?

No. I reject this approach because of performance (without enabling these trace).
But there is no proof of my assumption. Please try and measure.

Or should I use some other approach?

I planned dynamic instrumentation.
But there is still C-extension problem.