1Demonstrations of uthreads. 2 3 4uthreads traces thread creation events in Java or raw (C) pthreads, and prints 5details about the newly created thread. For Java threads, the thread name is 6printed; for pthreads, the thread's start function is printed, if there is 7symbol information to resolve it. 8 9For example, trace all Java thread creation events: 10 11# ./uthreads -l java 27420 12Tracing thread events in process 27420 (language: java)... Ctrl-C to quit. 13TIME ID TYPE DESCRIPTION 1418.596 R=9/N=0 start SIGINT handler 1518.596 R=4/N=0 stop Signal Dispatcher 16^C 17 18The ID column in the preceding output shows the thread's runtime ID and native 19ID, when available. The accuracy of this information depends on the Java 20runtime. 21 22 23Next, trace only pthread creation events in some native application: 24 25# ./uthreads 27450 26Tracing thread events in process 27450 (language: c)... Ctrl-C to quit. 27TIME ID TYPE DESCRIPTION 280.924 27462 pthread primes_thread [primes] 290.927 27463 pthread primes_thread [primes] 300.928 27464 pthread primes_thread [primes] 310.928 27465 pthread primes_thread [primes] 32^C 33 34The thread name ("primes_thread" in this example) is resolved from debuginfo. 35If symbol information is not present, the thread's start address is printed 36instead. 37 38 39USAGE message: 40 41# ./uthreads -h 42usage: uthreads.py [-h] [-l {c,java,none}] [-v] pid 43 44Trace thread creation/destruction events in high-level languages. 45 46positional arguments: 47 pid process id to attach to 48 49optional arguments: 50 -h, --help show this help message and exit 51 -l {c,java,none}, --language {c,java,none} 52 language to trace (none for pthreads only) 53 -v, --verbose verbose mode: print the BPF program (for debugging 54 purposes) 55 56examples: 57 ./uthreads -l java 185 # trace Java threads in process 185 58 ./uthreads -l none 12245 # trace only pthreads in process 12245 59