# BST-TIMEOUT: 600   # ~150 cases; the probe's guarded groups can each cost 20 s
#                    # of wall clock on a platform whose relative timers stall
. "$BST_LIB"

# libev 4.33 -- "a full-featured and high-performance event loop that is loosely
# modelled after libevent" (meta-oe recipes-connectivity/libev). What ships is
# /usr/lib/libev.a plus ev.h and ev++.h. There is no program, no pkg-config file
# and no shared object.
#
# ---------------------------------------------------------------------------
# WHY THIS SUITE RUNS A PROBE
#
# libev installs NO PROGRAM and ships NO TEST SUITE -- the 4.33 tarball has no
# tests/ directory at all, so unlike libsmi (whose CLI is its own coverage) or
# libevent (whose upstream ptest is), there is nothing here that could exercise
# the library from the target's own command line. A suite that only checked the
# payload's shape would go green on a library that returns silently wrong
# answers, which is the BRINTOS-217 lesson: oniguruma compiled and packaged
# perfectly and then handed every caller wrong offsets.
#
# data/libev-probe (src/libev_probe.c) is the consumer that closes that gap. It
# is cross-linked with wasmcc-glibc against THE VERY libev.a THAT SHIPS -- the
# suite re-checks that identity below rather than asserting it -- and it drives
# the loop the way the ticket scopes it: over timers and a pipe, with no socket
# peer and no device.
#
# ---------------------------------------------------------------------------
# THE ORACLE IS A NATIVE x86_64 CONTROL
#
# data/libev-native.txt is the same probe's output against a build of the
# IDENTICAL tarball (sha256 507eb7b8..., no patches -- meta-oe's recipe carries
# none) on x86_64, generated by src/libev_mknative.sh. The probe prints only
# what cannot legitimately differ between two machines: booleans, counts,
# callback-order strings and literal payload text. No pointer, no pid, no clock
# reading, no sizeof. So every EV- line must match byte for byte, and the three
# values that DO legitimately differ -- the pointer width and the backend
# bitmasks -- are printed with an EVX- prefix, kept out of the control, and
# asserted separately below.
#
# ---------------------------------------------------------------------------
# THE PROBE SPLITS PAST-DUE TIMERS FROM RELATIVE ONES, AND SO DOES THIS SUITE
#
# Group F arms timers with a NEGATIVE timeout, so `at` is already in the past and
# the order they fire in is fixed by libev's timer heap -- a result no clock can
# influence. Group G arms real relative timeouts, which only work if the
# platform's clock advances and its poll timeout is honoured; this arm has an
# open defect about exactly that (relative timer accuracy,
# brintos/linux-in-the-browser#120). Keeping them apart is what lets a reader
# tell "libev is broken here" from "the clock is": a red F is the library's, a
# red G beside a green F is the platform's.
#
# G's loops each carry an always-ready guard fd, so libev polls with a zero
# timeout and a platform whose relative timers never fire spins out to a bound
# and says so, instead of blocking until the runner kills the suite.

lib=/usr/lib/libev.a
incd=/usr/include
DATA=$BST_DATA
NATIVE=$DATA/libev-native.txt
PROBE=$DATA/libev-probe
TMP=${TMPDIR:-/tmp}
nl='
'

if [ ! -f "$lib" ]; then
  bst_skip libev/present "libev not installed on this image"
  exit 0
fi
bst_ok libev/present

hasfile() { if [ -s "$2" ]; then bst_ok "$1"; else bst_notok "$1" "absent or empty: $2"; fi; }
hasline() { case "$nl$3$nl" in *"$nl$2$nl"*) bst_ok "$1" ;; *) bst_notok "$1" "not in archive: $2" ;; esac; }

# --- payload shape -----------------------------------------------------------
hasfile libev/archive     "$lib"
hasfile libev/header-ev   "$incd/ev.h"
hasfile libev/header-evpp "$incd/ev++.h"

# The distro is static-only: upstream packages ${libdir}/libev.so.*, which must
# match nothing. A shared object here means --disable-shared stopped being
# honoured and the image grew a package it does not want.
if [ -e /usr/lib/libev.so ] || [ -e /usr/lib/libev.so.4 ]; then
  bst_notok libev/no-shared-object "a libev shared object shipped on a static-only distro"
else
  bst_ok libev/no-shared-object
fi

# libev 4.33 installs no pkg-config file -- its Makefile.am has no
# pkgconfig_DATA at all. Pinned so a release that starts shipping one is noticed
# and the image can then carry it, rather than the absence being forgiven for
# ever by a case nobody wrote.
if [ -f /usr/lib/pkgconfig/libev.pc ]; then
  bst_notok libev/upstream-no-pkgconfig \
    "libev.pc is now installed -- upstream added pkgconfig_DATA; re-read this case and ship it"
else
  bst_ok libev/upstream-no-pkgconfig
fi

# --- the libevent collision, which this image is the first to be able to hit --
#
# libev ships TWO things in one archive: the library proper (ev.o) and a
# libevent-1.x COMPATIBILITY LAYER (event.o) that defines event_init, event_add,
# event_del, event_base_new, event_base_dispatch and ~25 more. The recipe's
# do_install:append deletes libev's own event.h with the comment "avoid
# conflicting with libevent" -- and that removes the HEADER conflict only. The
# SYMBOLS stay in libev.a.
#
# Until BRINTOS-398 landed, that was theoretical on this image. libevent 2.1.12
# now ships here too, so a consumer that links -lev and -levent gets duplicate
# definitions of the same names from two unrelated implementations. That is
# upstream libev's shape, not a defect of this arm or this port, and it fails
# LOUDLY at link time, which is the correct failure -- so it is pinned here
# rather than worked around.
arcsyms=$(grep -ao 'ev_[a-z0-9_]*' "$lib" 2>/dev/null | sort -u)
evtsyms=$(grep -ao 'event_[a-z0-9_]*' "$lib" 2>/dev/null | sort -u)

# libev's own event.h must NOT be installed. Another package's may be -- and
# libevent's is -- so this is decided by CONTENT, not by the path existing.
if [ -f "$incd/event.h" ] && grep -q 'libevent compatibility header' "$incd/event.h" 2>/dev/null; then
  bst_notok libev/event-h-removed \
    "$incd/event.h is libev's own compatibility header -- do_install:append's rm did not take"
else
  bst_ok libev/event-h-removed
fi

hasline libev/compat-event-init      event_init      "$evtsyms"
hasline libev/compat-event-base-new  event_base_new  "$evtsyms"
hasline libev/compat-event-dispatch  event_dispatch  "$evtsyms"

# The hazard itself, stated as a measurement: if libevent's archive is on this
# image too, the two carry the same names. A future libev that drops the compat
# layer, or a future image that drops libevent, flips this case and the note
# above should be re-read.
if [ -f /usr/lib/libevent.a ]; then
  if grep -aq 'event_base_dispatch' /usr/lib/libevent.a 2>/dev/null; then
    bst_ok libev/libevent-symbol-overlap-known
  else
    bst_notok libev/libevent-symbol-overlap-known \
      "libevent.a no longer carries event_base_dispatch -- re-read the collision note"
  fi
else
  bst_skip libev/libevent-symbol-overlap-known "libevent.a not on this image"
fi

# --- every function the header declares is in the archive --------------------
# Read out of ev.h AS IT SHIPS rather than from a hardcoded list, so a release
# that adds an entry point is checked rather than permanently forgiven. Only
# EV_API_DECL lines are consulted: everything else ev.h offers a caller
# (ev_io_init, ev_is_active, ev_priority, ...) is a MACRO, and a macro is not
# expected in an archive.
hdrsyms=$(grep -E '^EV_API_DECL' "$incd/ev.h" 2>/dev/null \
          | grep -oE '\bev_[a-z0-9_]*[[:space:]]*\(' \
          | sed -e 's/[[:space:]]*(//' | sort -u)

# ev_walk is declared under `#if EV_WALK_ENABLE` and defined under the same
# guard, and ev.h sets EV_WALK_ENABLE to 0 ("not yet"). grep cannot see a
# preprocessor conditional, so the census above picks the declaration up; the
# archive correctly does not carry it. This is upstream's own feature switch
# working as intended -- NOT a missing symbol -- so it is excluded by name and
# then pinned on its own below, where a release that enables it is noticed.
GUARDED_OFF="ev_walk"

nsym=0; nmiss=0; missing=""
for f in $hdrsyms; do
  case "$nl$(printf '%s\n' $GUARDED_OFF)$nl" in *"$nl$f$nl"*) continue ;; esac
  nsym=$((nsym + 1))
  case "$nl$arcsyms$nl" in
    *"$nl$f$nl"*) ;;
    *) nmiss=$((nmiss + 1)); missing="$missing $f" ;;
  esac
done
if [ "$nsym" -ge 60 ]; then bst_ok libev/symbols-counted
else bst_notok libev/symbols-counted "only $nsym ev_* entry points found in ev.h"; fi
if [ "$nmiss" -eq 0 ]; then bst_ok libev/symbols-complete
else bst_notok libev/symbols-complete "$nmiss of $nsym missing:$(_bst_1line "$missing")"; fi

case "$nl$arcsyms$nl" in
  *"${nl}ev_walk$nl"*)
    bst_notok libev/upstream-ev-walk-disabled \
      "ev_walk is now DEFINED -- upstream enabled EV_WALK_ENABLE; drop it from GUARDED_OFF" ;;
  *)
    bst_ok libev/upstream-ev-walk-disabled ;;
esac

# One name per watcher family, so a partially-linked archive is legible rather
# than merely "incomplete".
hasline libev/sym-run          ev_run          "$arcsyms"
hasline libev/sym-loop-new     ev_loop_new     "$arcsyms"
hasline libev/sym-io-start     ev_io_start     "$arcsyms"
hasline libev/sym-timer-start  ev_timer_start  "$arcsyms"
hasline libev/sym-periodic     ev_periodic_start "$arcsyms"
hasline libev/sym-idle-start   ev_idle_start   "$arcsyms"
hasline libev/sym-prepare      ev_prepare_start "$arcsyms"
hasline libev/sym-check-start  ev_check_start  "$arcsyms"
hasline libev/sym-async-send   ev_async_send   "$arcsyms"
hasline libev/sym-signal-start ev_signal_start "$arcsyms"
hasline libev/sym-child-start  ev_child_start  "$arcsyms"
hasline libev/sym-stat-start   ev_stat_start   "$arcsyms"
hasline libev/sym-embed-start  ev_embed_start  "$arcsyms"
hasline libev/sym-verify       ev_verify       "$arcsyms"

# --- the library RUNNING, via the cross-linked probe -------------------------
if [ ! -s "$NATIVE" ]; then
  bst_notok libev/native-present "$NATIVE missing -- no oracle to compare against"
  exit 0
fi
bst_ok libev/native-present

# The probe must be the shipped archive's own consumer. do_install stages data/*
# at 0644 and the deployed rootfs is read-only at browser runtime, so it cannot
# be executed where it lies.
_p=$TMP/bst-libev-probe.$$
cp "$PROBE" "$_p" 2>/dev/null && chmod 0755 "$_p" 2>/dev/null
if [ ! -x "$_p" ]; then
  bst_notok libev/probe-exec "could not stage an executable copy of $PROBE"
  rm -f "$_p"
  exit 0
fi
bst_ok libev/probe-exec

out=$TMP/bst-libev.$$
timeout 240 "$_p" > "$out.out" 2>"$out.err"; prc=$?
rm -f "$_p"
check_eq libev/probe-rc 0 "$prc"

# A truncated run must be distinguishable from a run that legitimately produced
# these lines: with no terminator, a wedge half way through would silently
# reduce the number of compared cases rather than fail one. Every absent tag is
# reported by the comparison below, so a wedge names the group it stopped in.
if [ "$(tail -n 1 "$out.out" 2>/dev/null)" = "EV-Z01-end ALL-LIBEV-DONE" ]; then
  bst_ok libev/probe-complete
else
  bst_notok libev/probe-complete "no terminator; last saw: $(_bst_1line "$(tail -n 2 "$out.out" 2>/dev/null)")"
fi

# libev's own syserr hook prints this and exits 9 rather than abort()ing, so a
# failed syscall inside the library names itself instead of looking like a hang.
if grep -q '^EVX-syserr ' "$out.out" 2>/dev/null; then
  bst_notok libev/no-syserr "$(_bst_1line "$(grep '^EVX-syserr ' "$out.out")")"
else
  bst_ok libev/no-syserr
fi

# --- tag-by-tag against the native control -----------------------------------
# One awk over both files rather than a shell loop of ~116 awk calls: process
# spawn is expensive on this target and the whole comparison is in-memory.
awk '
  NR == FNR {
    if ($0 !~ /^EV-/) next
    k = $1; $1 = ""; sub(/^ /, ""); W[k] = $0; order[++n] = k; next
  }
  /^EV-/ { k = $1; $1 = ""; sub(/^ /, ""); G[k] = $0; seen[k] = 1 }
  END {
    for (i = 1; i <= n; i++) {
      k = order[i]; t = substr(k, 4)
      if (!(k in seen)) { printf "BST not ok libev/cmp-%s : absent from target output\n", t; continue }
      if (G[k] == W[k])   printf "BST ok libev/cmp-%s\n", t
      else              printf "BST not ok libev/cmp-%s : want:%s got:%s\n", t, W[k], G[k]
    }
  }
' "$NATIVE" "$out.out"

# --- the values that legitimately differ, asserted rather than ignored -------
ev_get() { awk -v k="$1" '$1==k { $1=""; sub(/^ /,""); print; exit }' "$out.out"; }

check_eq libev/probe-pointer-width 32 "$(ev_get EVX-pointer-width)"

# Which backends the kernel offers is this arm's answer to give, so it is not
# compared against the control -- but it must be COHERENT, and libev must have
# picked one of them (EV-B02/B03 assert the pick; these two assert the set is
# sane). A supported set of zero would mean libev found no way to poll at all
# and every loop above ran on nothing.
sup=$(ev_get EVX-backends-supported)
rec=$(ev_get EVX-backends-recommended)
case "$sup" in
  0x00000000|"") bst_notok libev/backends-nonempty "ev_supported_backends() = '${sup:-<absent>}'" ;;
  *)             bst_ok libev/backends-nonempty ;;
esac
case "$rec" in
  0x00000000|"") bst_notok libev/backends-recommended-nonempty "ev_recommended_backends() = '${rec:-<absent>}'" ;;
  *)             bst_ok libev/backends-recommended-nonempty ;;
esac

# --- anchored: values libev's own contract fixes, not the control ------------
# These duplicate four of the comparisons above ON PURPOSE. They are the
# invariants a consumer actually depends on, written as literals, so that a
# control regenerated against a broken build could not quietly move them.
#
# The timer heap orders by expiry, NOT by registration: the probe registers
# past-due timers least-past first (-1, -2, -3) and a correct queue fires them
# most-past first. This is the single most load-bearing thing libev does.
check_eq libev/anchor-past-timer-count 3   "$(ev_get EV-F01-past-timers-fired)"
check_eq libev/anchor-past-timer-order abc "$(ev_get EV-F02-past-timer-order)"
# Same expiry, different priority -> the pending queue orders by priority.
check_eq libev/anchor-priority-order   hl  "$(ev_get EV-F09-priority-order)"
# One loop iteration is prepare -> poll -> (queued events, drained from the END
# of the per-priority pending array, so checks precede the io and idle events
# queued before them). Two iterations of that is PCIPCD.
check_eq libev/anchor-callback-order   PCIPCD "$(ev_get EV-E01-callback-order)"
# The pipe carried real bytes, not just a readiness bit.
check_eq libev/anchor-pipe-payload     hello  "$(ev_get EV-D09-read-payload)"
check_eq libev/anchor-pipe-eof         1      "$(ev_get EV-D18-eof-read-returned-zero)"
# The compat layer reports libev's own version and names itself.
check_eq libev/anchor-compat-version   4.33   "$(ev_get EV-J08-compat-event-get-version)"
check_eq libev/anchor-compat-method    libev  "$(ev_get EV-J09-compat-event-get-method)"

rm -f "$out.out" "$out.err"