ci: restore EL7 stresstest coverage, add nightly EL7 functional tests - #805

Keeps the 3-JDK sweep nightly but lets one JDK's worth of EL7 functional
coverage run on every pipeline, so it isn't gated entirely on the
nightly schedule.

Co-Authored-By: Claude Sonnet 5 <[email protected]>

Built and pushed successfully in pipeline 138399627, job 2056785023.

Co-Authored-By: Claude Sonnet 5 <[email protected]>

…r probe

stresstest:x64 failed with "No C++ compiler found": ConfigurationPresets.
setupStandardConfigurations() calls PlatformUtils.findCompiler() unconditionally
at project-configuration time, before -Pskip-native is consulted, so an
image with no compiler at all fails to even configure the build.

The stock EL7 gcc-c++ (4.8.5, base repo, no EPEL) satisfies that --version
probe; -Pskip-native still gates every real compile/link task onlyIf, so
it's never invoked to build anything. Verified the image still builds and
g++ --version succeeds.

This needs another `REBUILD_IMAGES="x64-el7"` run and a re-pin of
BUILD_IMAGE_X64_EL7 before the fix takes effect.

Co-Authored-By: Claude Sonnet 5 <[email protected]>

Rebuilt in pipeline 138438605 with the gcc-c++ fix from the previous
commit; pushed and signed successfully before the rebuild-images log
cuts off (mid-way through the unrelated datadog-ci image build).

Co-Authored-By: Claude Sonnet 5 <[email protected]>

functional:x64-el7-jdk8 failed with "Permission denied" — the script
was committed as mode 100644 instead of 100755.

Co-Authored-By: Claude Sonnet 5 <[email protected]>

ContendedCallTraceStorageTest OOM'd with "GC overhead limit exceeded"
on jdk8: it drives availableProcessors()*2 threads of CPU/allocation
load against the standard -Xmx512m test heap, and the GitLab shared
runner pod apparently gives it less headroom than GitHub's ubuntu-latest
runners do.

Adds an opt-in -PtestMaxHeap gradle property to ddprof-test (appended
after the plugin's default -Xmx512m, so the last -Xmx wins) and passes
-PtestMaxHeap=1536m from functional-tests.sh only. The shared default
used by every other caller (GH Actions matrix, stresstest, etc.) is
untouched.

Co-Authored-By: Claude Sonnet 5 <[email protected]>

Several ddprof-test suites (NativeThread, DynamicNativeThread,
ThreadEntryDetectionTest, ...) need ddprof-test-native's small JNI test
helper on java.library.path regardless of which profiler binary is
under test. Bare -Pskip-native disabled ALL native compilation
project-wide, so those suites failed with UnsatisfiedLinkError/
NoClassDefFoundError on the EL7 functional job, which needs to skip
only ddprof-lib's own build (substituted via -Pwith-libs) while still
compiling that helper for real.

PlatformUtils.isNativeSkipped() now supports -Pskip-native=<comma
list of project names>, skipping only those; bare -Pskip-native (no
value) keeps skipping everywhere, unchanged for every existing caller
(stresstests.sh, build.sh, GH Actions). SimpleNativeLibPlugin (used by
ddprof-test-native and malloc-shim) and ddprof-lib/build.gradle.kts's
own skip-native check now go through it.

functional-tests.sh passes -Pskip-native=ddprof-lib,malloc-shim
(malloc-shim excluded too: it's unrelated to ddprof-test and its
-std=c++17 flag doesn't compile under EL7's stock gcc 4.8.5).

Verified locally: with -Pskip-native=ddprof-lib,malloc-shim,
ddprof-test-native:linkLib actually compiles and links, while
ddprof-lib:assembleDebugJar only runs copyExternalLibs (no native
compile task in the graph at all).

Co-Authored-By: Claude Sonnet 5 <[email protected]>

Now that -Pskip-native=ddprof-lib,malloc-shim actually compiles
ddprof-test-native for the EL7 functional job, nativealloc.c failed:

  error: 'for' loop initial declarations are only allowed in C99 mode

EL7's stock gcc (4.8.5) still defaults to gnu89; every other Linux gcc/
clang this project builds on already defaults to a C99+ dialect, so
this was latent until a compiler this old actually built the file.
Adds an explicit -std=gnu99.

Verified against the real EL7 toolchain (oraclelinux:7 + gcc 4.8.5):
all three ddprof-test-native source files compile and link.

Co-Authored-By: Claude Sonnet 5 <[email protected]>

build:x64 (build.sh) only ever produces and ships the release-config
libjavaProfiler.so -- that IS the shipped artifact this job exists to
exercise. Running testDebug set ddprof_test.config=debug while the
loaded library was actually release-built, so debug-only assertions
failed outright instead of assumeTrue-skipping correctly, e.g.
JVMAccessTest.agentOnLoadVMFlagDetectionTest checking for
[TEST::INFO] log lines that only exist in debug builds
("initLibrary not found", "DebugNonSafepoints flag lookup log line
was not observed").

Co-Authored-By: Claude Sonnet 5 <[email protected]>

functional:x64-el7-jdk8 has NativeSocketEvent count: 0 across every
retry (zero, not just fewer-than-expected), suggesting the send/recv/
write/read hooks (libraryPatcher_linux.cpp's GOT patching) never
actually get installed in this environment -- but that can't be told
apart from "installed but never firing" without the debug-only
hook-fire counters, which only exist in a debug-config build.

build:x64-debug-diag builds a real debug-config libjavaProfiler.so on
the same AlmaLinux 8 toolchain build:x64 uses (release configs don't
carry NativeSocketSampler's #ifdef DEBUG counters/TEST_LOG calls).
functional:x64-el7-debug-diag runs just the NativeSocket* suite
against it on the EL7 runtime (via functional-tests.sh's new
TESTS_FILTER -> -Ptests passthrough), so --info output shows whether
send_hook/recv_hook/write_hook/read_hook ever get called at all.

Both are marked TEMPORARY and should be removed once this is
root-caused.

Co-Authored-By: Claude Sonnet 5 <[email protected]>

build:x64-debug-diag's first attempt failed to load on EL7:

  UnsatisfiedLinkError: libstdc++.so.6: version GLIBCXX_3.4.20 not found

Debug configs link libstdc++ dynamically (only release gets
-static-libstdc++), so the .so needed a newer GLIBCXX than EL7's stock
gcc 4.8.5 provides. Statically linking (gated behind
-Dddprof.debugStaticLibstdcxx=true, diagnostic-only) then surfaced a
second, unrelated issue: -static-libstdc++ transitively pulls in
libstdc++.a's cow-string-inst.o (legacy ABI string instantiations),
which references std::random_device::_M_init -> getentropy@GLIBC_2.25
-- traced via the linker map (-Wl,-Map). That's dead code
configureRelease's -Wl,--gc-sections already strips; debug's
linkerArgs never had that flag. Adding --gc-sections and
--exclude-libs,ALL alongside the static libstdc++ flags (same
diagnostic gate) fixes both.

Verified end to end: rebuilt in the real AlmaLinux 8 image, confirmed
via objdump that the result has no libstdc++.so.6 NEEDED entry, no
getentropy reference, and a max GLIBC_2.17 requirement, then loaded
it inside the real EL7 image and saw VM::initLibrary log successfully.

Co-Authored-By: Claude Sonnet 5 <[email protected]>

build:x64-debug-diag and functional:x64-el7-debug-diag did their job:
they showed the socket hooks fire correctly on EL7 (send/recv/write/
read all called, PLT-patched libjvm.so/libnio.so/libnet.so), and that
the real cause of NativeSocketEvent count: 0 is the sampler's rate
limiter legitimately rejecting nearly every call because
NativeSocketTestBase.doTcpTransfer()'s "the send buffer fills after
~32 iterations and blocks" assumption doesn't hold on this runner's
network stack -- a real test bug, not a CI/EL7 problem. That will be
quarantined separately now that #777 is merged.

Drops the diagnostic-only -Dddprof.debugStaticLibstdcxx gate in
ConfigurationPresets.kt and the now-unused TESTS_FILTER passthrough
in functional-tests.sh along with the jobs that were the only callers
of either.

Co-Authored-By: Claude Sonnet 5 <[email protected]>

"(rebuilt with gcc-c++ added, see el7/Dockerfile)" and "restoring the
runtime coverage build:x64 lost when it moved to AlmaLinux 8 (PR #790)"
tell a reader what changed relative to old code, not why the current
code is the way it is -- and the -std=gnu99 comment named the exact
source construct that motivated it, which goes stale the moment that
code changes. State the current rationale only.

Co-Authored-By: Claude Sonnet 5 <[email protected]>

…sistency

- .gitlab-ci.yml: drop "unchanged from before" -- describes the diff
  against the file's prior state, not the current mechanism.
- ddprof-lib/build.gradle.kts: its own skip-native check still used
  bare hasProperty("skip-native"), not PlatformUtils.isNativeSkipped().
  Both agree today (every caller either omits the property, uses it
  bare, or lists "ddprof-lib" whenever it's meant to be skipped), so
  this isn't a behavior change -- confirmed locally: assembleDebugJar
  still runs only copyExternalLibs under
  -Pskip-native=ddprof-lib,malloc-shim, and still depends on the real
  compile/link without it. But a future -Pskip-native=<list not
  containing ddprof-lib> would silently skip ddprof-lib's own build
  too under the old bare check, contradicting isNativeSkipped()'s own
  doc comment. Fixes the one call site the new scoped semantics
  didn't reach.

Co-Authored-By: Claude Sonnet 5 <[email protected]>

Flagged in review: functional-tests.sh's .jdk-cache/ was never in any
cache paths -- .cache-config/.cache-config-pull only cover
.gradle/caches/, .gradle/wrapper/, .m2/repository/ -- so every run
re-downloaded the JDK tarball from Adoptium.

Gives .functional_job its own two-entry cache instead of extending
.cache-config-pull: the JDK tarball's natural cache key is the major
version (TEST_JDK), not the branch/commit the Gradle cache is keyed
on, and it doesn't change per-branch the way the Gradle cache's
gradle-wrapper.properties hash does, so it gets pull-push with a
static, ref-independent key while the Gradle entry stays pull-only
exactly as before.

Co-Authored-By: Claude Sonnet 5 <[email protected]>