Invalid mem access in BufferBuilderTrait

[alamb]

Note: migrated from original JIRA: https://issues.apache.org/jira/browse/ARROW-8627

Currently, there is an invalid access happening through the append_n method to a mutable location with multiple shared refs. Happens when benchmark code executes with bench_bool.

Happens on (rustc 1.44.0-nightly (45d050cde 2020-04-21))

 

bt shown below:

 * thread #1, queue = 'com.apple.main-thread', stop reason = EXC_BAD_ACCESS (code=1, address=0x1004e7000)
 * frame #0: 0x0000000100150d37 builder-6a49123b1fedb178`_$LT$arrow..array..builder..BufferBuilder$LT$arrow..datatypes..BooleanType$GT$$u20$as$u20$arrow..array..builder..BufferBuilderTrait$LT$arrow..datatypes..BooleanType$GT$$GT$::append_n::h6ae4d34cca93d03c + 311
 frame #1: 0x0000000100007303 builder-6a49123b1fedb178`arrow::array::builder::PrimitiveBuilder$LT$T$GT$::append_slice::h8d33144acea1616b + 51
 frame #2: 0x000000010001b143 builder-6a49123b1fedb178`criterion::Bencher$LT$M$GT$::iter::hfcae173a53b56e6f + 259
 frame #3: 0x0000000100003136 builder-6a49123b1fedb178`_$LT$criterion..routine..Function$LT$M$C$F$C$T$GT$$u20$as$u20$criterion..routine..Routine$LT$M$C$T$GT$$GT$::warm_up::h5b415f52c0951798 + 102
 frame #4: 0x000000010000373b builder-6a49123b1fedb178`criterion::routine::Routine::sample::h2802012b9b92a2a5 + 203
 frame #5: 0x00000001000287a2 builder-6a49123b1fedb178`criterion::analysis::common::h1eabf5af2afe42e5 + 834
 frame #6: 0x0000000100023a83 builder-6a49123b1fedb178`_$LT$criterion..benchmark..Benchmark$LT$M$GT$$u20$as$u20$criterion..benchmark..BenchmarkDefinition$LT$M$GT$$GT$::run::hf631a3f91617ae46 + 1507
 frame #7: 0x00000001000109b8 builder-6a49123b1fedb178`builder::main::he83c09c3b2c8f318 + 216
 frame #8: 0x0000000100021c96 builder-6a49123b1fedb178`std::rt::lang_start::_$u7b$$u7b$closure$u7d$$u7d$::hfb404fc983af2389 + 6
 frame #9: 0x00000001001e9499 builder-6a49123b1fedb178`std::rt::lang_start_internal::h434140244059d623 [inlined] std::rt::lang_start_internal::_$u7b$$u7b$closure$u7d$$u7d$::h096599b40842db82 at rt.rs:52:13 [opt]
 frame #10: 0x00000001001e948e builder-6a49123b1fedb178`std::rt::lang_start_internal::h434140244059d623 [inlined] std::panicking::try::do_call::h1c9f73590350b657 at panicking.rs:331 [opt]
 frame #11: 0x00000001001e948e builder-6a49123b1fedb178`std::rt::lang_start_internal::h434140244059d623 [inlined] std::panicking::try::hca6829be93a31f1b at panicking.rs:274 [opt]
 frame #12: 0x00000001001e948e builder-6a49123b1fedb178`std::rt::lang_start_internal::h434140244059d623 [inlined] std::panic::catch_unwind::hb3c8ad89db0960bd at panic.rs:394 [opt]
 frame #13: 0x00000001001e948e builder-6a49123b1fedb178`std::rt::lang_start_internal::h434140244059d623 at rt.rs:51 [opt]
 frame #14: 0x0000000100010b49 builder-6a49123b1fedb178`main + 41
 frame #15: 0x00007fff691c07fd libdyld.dylib`start + 1
 frame #16: 0x00007fff691c07fd libdyld.dylib`start + 1