#!/usr/bin/env python3
"""fnsample.py — active RIP sampling of all threads via PTRACE_INTERRUPT
during the offline-render burst. Finds which code ACTUALLY executes."""
import ctypes
import glob
import os
import signal
import struct
import subprocess
import sys
import time

MOD_LO, MOD_HI = 0x180001000, 0x181baa000
DUR = float(os.environ.get('SAMP_DUR', '2.5'))

PTRACE_CONT = 7
PTRACE_GETREGS = 12
PTRACE_INTERRUPT = 0x4207
PTRACE_SEIZE = 0x4206
PTRACE_O_TRACECLONE = 2

libc = ctypes.CDLL('libc.so.6', use_errno=True)


class UserRegs(ctypes.Structure):
    _fields_ = [(n, ctypes.c_ulonglong) for n in (
        'r15', 'r14', 'r13', 'r12', 'rbp', 'rbx', 'r11', 'r10',
        'r9', 'r8', 'rax', 'rcx', 'rdx', 'rsi', 'rdi', 'orig_rax',
        'rip', 'cs', 'eflags', 'rsp', 'ss', 'fs_base', 'gs_base',
        'ds', 'es', 'fs', 'gs')]


def pt(req, pid, addr=0, data=0):
    libc.ptrace.restype = ctypes.c_long
    r = libc.ptrace(req, pid, ctypes.c_void_p(addr), ctypes.c_void_p(data))
    return None if r == -1 else r


def find_host():
    for p in glob.glob('/proc/[0-9]*'):
        pid = int(os.path.basename(p))
        try:
            cmd = open(f'/proc/{pid}/cmdline', 'rb').read().replace(b'\0', b' ').decode('utf8', 'replace')
            maps = open(f'/proc/{pid}/maps').read()
        except Exception:
            continue
        if 'soothe2' in maps and 'reaper' not in cmd:
            return pid
    return None


def main():
    subprocess.run("pkill -9 -x reaper; pkill -9 -f '[y]abridge'; sleep 1", shell=True)
    proc = subprocess.Popen(['/usr/bin/reaper', '-nosplash', '-ignoreerrors',
                             '-renderproject', '/home/m/soothe-bt/dual_b1q_0.5.rpp'],
                            stdout=open('/dev/null', 'w'), stderr=subprocess.STDOUT)
    host = None
    t0 = time.time()
    while time.time() - t0 < 30 and not host:
        host = find_host()
        time.sleep(0.002)
    if not host:
        print('NO HOST')
        return 1
    print('host %d at %.3fs' % (host, time.time() - t0), flush=True)

    seized = {host}
    pt(PTRACE_SEIZE, host, 0, PTRACE_O_TRACECLONE)
    pt(PTRACE_CONT, host, 0, 0)

    ips = {}
    t_end = time.time() + DUR
    t_start = None
    nsamp = 0
    while time.time() < t_end:
        # resweep tids occasionally
        for tid_s in glob.glob(f'/proc/{host}/task/*'):
            tid = int(os.path.basename(tid_s))
            if tid not in seized:
                if pt(PTRACE_SEIZE, tid, 0, PTRACE_O_TRACECLONE) is not None:
                    seized.add(tid)
        for tid in list(seized):
            if pt(PTRACE_INTERRUPT, tid) is None:
                continue
            got = False
            for _ in range(20):
                try:
                    pid, status = os.waitpid(tid, os.WUNTRACED | os.WNOHANG)
                except ChildProcessError:
                    break
                if pid == tid:
                    got = True
                    break
                time.sleep(0.0002)
            if got:
                regs = UserRegs()
                if pt(PTRACE_GETREGS, tid, 0, ctypes.addressof(regs)) is not None:
                    nsamp += 1
                    if t_start is None:
                        t_start = time.time()
                    if MOD_LO <= regs.rip < MOD_HI:
                        b = regs.rip >> 4 << 4
                        ips[b] = ips.get(b, 0) + 1
            pt(PTRACE_CONT, tid, 0, 0)
    print('samples=%d in-module=%d unique64=%d window=%.2fs..%.2fs'
          % (nsamp, sum(ips.values()), len(ips),
             (t_start or t0) - t0, time.time() - t0))
    core = {a: c for a, c in ips.items() if 0x180520000 <= a < 0x180560000}
    for a, c in sorted(core.items(), key=lambda x: -x[1])[:18]:
        print('CORE %#x %d' % (a, c))
    for b, c in sorted(ips.items(), key=lambda x: -x[1])[:6]:
        print('%#x %d' % (b, c))
    proc.kill()
    return 0


if __name__ == '__main__':
    sys.exit(main())