NAME¶

uthreads, cthreads, javathreads - Trace thread creation events in Java or pthreads.

SYNOPSIS¶

cthreads [-h] [-v] pid javathreads [-h] [-v] pid uthreads [-h] [-l {c,java,none}] [-v] pid

DESCRIPTION¶

This traces thread creation events in Java processes, or pthread creation events in any process. When a thread is created, its name or start address is printed.

Since this uses BPF, only the root user can use this tool.

REQUIREMENTS¶

CONFIG_BPF and bcc.

OPTIONS¶

-l {c,java,none}

The language to trace. C and none select tracing pthreads only, regardless of the runtime being traced.

-v

Print the resulting BPF program, for debugging purposes.

pid

The process id to trace.

EXAMPLES¶

Trace Java thread creations:

# uthreads -l java 148

Trace pthread creations:

# uthreads 1802

FIELDS¶

TIME

The event's time in seconds from the beginning of the trace.

ID

The thread's ID. The information in this column depends on the runtime.

TYPE

Event type -- thread start, stop, or pthread event.

DESCRIPTION

The thread's name or start address function name.

OVERHEAD¶

Thread start and stop events are usually not very frequent, which makes this tool's overhead negligible.

SOURCE¶

This is from bcc.

https://github.com/iovisor/bcc

Also look in the bcc distribution for a companion _example.txt file containing example usage, output, and commentary for this tool.

OS¶

Linux

AUTHOR¶

Sasha Goldshtein

SEE ALSO¶

ustat(8), trace(8)