#! /usr/bin/env stap
#
# Copyright (C) 2018 Red Hat, Inc.
# By William cohen, Red Hat Inc.
# wcohen@redhat.com
#

global latency = 0  // non-zero to include latency info
global syscalls = 0 // non-zero to include syscalls
global tally
global top = 100000 // High enough limit to be "infinite"
global entry_time%, acc_time

function method_entry(class:string, method:string)
{
  tally[class, method] <<< 1
  if (latency) {
    entry_time[tid(), class, method] = gettimeofday_us()
  }
}

function method_exit(class:string, method:string)
{
  t = entry_time[tid(), class, method] = gettimeofday_us()
  if (t)
    acc_time[class, method] <<< gettimeofday_us() - t
}

# probes for java
probe hotspot.method_entry? {
  if (pid() == target()) method_entry(class, name)
}

probe hotspot.method_return? {
  if (latency && pid() == target()) method_exit(class, name)
}

# probes for perl
probe perl.sub.call? {
  if (pid() == target()) method_entry(filename, sub)
}

probe perl.sub.return? {
  if (latency && pid() == target()) method_exit(filename, sub)
}

# probes for php
probe process("php").mark("function__entry")? {
  if (pid() == target()) {
    class = user_string($arg4)
    method = user_string($arg1)
    method_entry(class, method)
  }
}

probe process("php").mark("function__return")? {
  if (latency && pid() == target()) {
    class = user_string($arg4)
    method = user_string($arg1)
    method_exit(class, method)
  }
}

# probes for python
probe process("/usr/lib*/libpython*.so.1.0").mark("function__entry")? {
  if (pid() == target()) {
    class = user_string($arg1)
    method = user_string($arg2)
    method_entry(class, method)
  }
}

probe process("/usr/lib*/libpython*.so.1.0").mark("function__return")? {
  if (latency && pid() == target()) {
    class = user_string($arg1)
    method = user_string($arg2)
    method_exit(class, method)
  }
}

# probes for ruby
probe ruby.method.entry? {
  if (pid() == target()) method_entry(classname, methodname)
}

probe ruby.method.return? {
  if (latency && pid() == target()) method_exit(classname, methodname)
}

# probes for tcl
# TODO cmd__entry ?
probe process("/usr/lib*/libtcl*.so").mark("proc__entry")? {
  if (pid() == target()) {
    method = user_string($arg1)
    method_entry("", method)
  }
}

probe process("/usr/lib*/libtcl*.so").mark("proc__return")? {
  if (latency && pid() == target()) {
    method = user_string($arg1)
    method_exit("", method)
  }
}

probe syscall_any {
  if (syscalls && pid() == target()) method_entry("syscall", name)
}

probe syscall_any.return {
  if (syscalls && latency && pid() == target()) method_exit("syscall", name)
}

function print_info() {
  printf("%-50s %8s", "METHOD", "# CALLS")
  if (latency) printf(" %9s", "TIME (us)")
  printf("\n")
  foreach([class, method] in tally- limit top){
    class_method = sprintf("%s.%s", class, method)
    printf("%-50s %8d", class_method, @sum(tally[class, method]))
    if (latency) printf(" %9d", @sum(acc_time[class, method]))
    printf("\n")
  }
  printf("\n")
}

probe end
{
  print_info()
  delete tally
  delete entry_time
  delete acc_time
}

probe begin
{
  process_cmdline()
}

/* Handle the "top=<n>", "latency", and "syscall" options */
function process_cmdline ()
{
  for (i=1; i <= argc; i++) {
    argument = tokenize(argv[i], "=")

    if ( argument == "top"){
      top=strtol(tokenize("", "="),10)
      continue;
    }

    if ( argument == "latency"){
      latency = 1
      continue;
    }

    if ( argument == "syscalls"){
      syscalls = 1
      continue;
    }
  }
}