Files
sx/examples/ffi-objc-arc-00b-multi-instance.sx
agra 8c3831acd2 test: M4.0 allocator-threading regression coverage
Two regression tests pinning down the silent-error surface in M4.0:

ffi-objc-arc-00 — single sx-defined-class instance round-trips
through a TrackingAllocator-wrapped GPA. Captures alloc/dealloc
deltas around the lifecycle, verifies (+1, +1). Pre-M4.0 the +alloc
IMP used libc malloc and -dealloc used libc free; tracker would
have observed (+0, +0) and missed the leak silently.

ffi-objc-arc-00b — three instances alloc'd and released. Catches
bugs where:
- the captured allocator becomes shared (one global slot vs
  per-instance);
- alloc captures the wrong allocator on the 2nd+ instance;
- dealloc reads garbage if state[0] is overwritten between
  instances.

Both tests are macos-only (libobjc + NSObject must be present at
runtime). Both wrap the lifecycle in `push Context.{ allocator =
xx tracker }` so the threading path is exercised.

Important authoring note: `print` inside the push-block also routes
through tracker (string formatting allocs), polluting the leak
delta. Tests capture before/after counts WITHOUT any prints between
alloc and release, then verify the BALANCE — every alloc paired
with a dealloc — rather than absolute counts. Discovered while
writing 00: an initial naive "leak_count() == 0" assertion failed
not because M4.0 was broken but because print's string allocs
weren't freed at scope exit.

187/187 example tests pass.
2026-05-26 22:46:56 +03:00

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// ffi-objc-arc-00b — multi-instance allocator threading.
//
// Verifies that EACH sx-defined-class instance captures its own
// allocator and round-trips through it. Catches bugs where:
// - the captured allocator is shared across instances (one global
// slot instead of per-instance).
// - alloc captures the wrong allocator on the 2nd+ instance.
// - dealloc reads garbage if state[0] is overwritten between
// instances.
//
// Three instances → three alloc events → three dealloc events. The
// tracker observes exactly +3 / +3 deltas.
#import "modules/std.sx";
#import "modules/allocators.sx";
#import "modules/std/objc.sx";
#import "modules/compiler.sx";
SxMultiProbe :: #objc_class("SxMultiProbe") {
#extends NSObject;
a: s32;
b: s32;
alloc :: () -> *SxMultiProbe;
}
main :: () -> s32 {
inline if OS == .macos {
gpa := GPA.init();
tracker := TrackingAllocator.init(xx gpa);
push Context.{ allocator = xx tracker, data = null } {
alloc_before := tracker.alloc_count;
dealloc_before := tracker.dealloc_count;
f1 := SxMultiProbe.alloc();
f2 := SxMultiProbe.alloc();
f3 := SxMultiProbe.alloc();
alloc_after_three := tracker.alloc_count - alloc_before;
f1.release();
f2.release();
f3.release();
alloc_delta := tracker.alloc_count - alloc_before;
dealloc_delta := tracker.dealloc_count - dealloc_before;
// alloc_delta MAY include extras from autorelease/etc. but
// each SxMultiProbe.alloc contributes at least 1. Check the
// BALANCE: every alloc paired with a dealloc.
if dealloc_delta != alloc_delta {
print("FAIL: alloc/dealloc unbalanced; alloc={} dealloc={}\n",
alloc_delta, dealloc_delta);
return 1;
}
if alloc_after_three < 3 {
print("FAIL: 3 SxMultiProbe.alloc()s should produce >= 3 tracker allocs; saw {}\n",
alloc_after_three);
return 1;
}
if dealloc_delta < 3 {
print("FAIL: 3 release()s should produce >= 3 tracker deallocs; saw {}\n",
dealloc_delta);
return 1;
}
}
print("multi-instance round-trip: ok\n");
}
inline if OS != .macos {
print("skipped (not macos)\n");
}
0;
}