The unpac monorepo manager self-hosting as a monorepo using unpac
Merge pull request #13987 from OlivierNicole/fix-tsan-false-alarm
Fix #13427
authored by
Gabriel Scherer
and committed by
GitHub
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Changes
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Changes
···
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does with an unrecognised file.
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(David Allsopp, review by Antonin Décimo and Sébastien Hinderer)
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- #13987: Remove a spurious TSan report in case of benign data race between
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major GC read and write from the mutator (fixes #13427)
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(Olivier Nicole, report by Thomas Leonard, review by Gabriel Scherer)
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- #13966: Enable "generalized polymorphic #install_printer"
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in the debugger
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(Pierre Boutillier and Gabriel Scherer, review by Florian Angeletti)
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runtime/major_gc.c
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runtime/major_gc.c
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mark_stack_prune(stk);
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}
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/* This function is used for reads that may race with a concurrent `caml_modify`
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from the mutator. Without this, TSan would flag it as a race (see section
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3.2 of comment in tsan.c); however, we have decided that these races are
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benign. We therefore use this function instead, ensuring that the read is
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not seen by TSan. */
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static CAMLno_tsan
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#if defined(WITH_THREAD_SANITIZER)
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Caml_noinline
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#endif
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value volatile_load_uninstrumented(volatile value* p) {
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return *p;
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}
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Caml_inline void mark_stack_push_range(struct mark_stack* stk,
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value_ptr start, value_ptr end)
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{
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end = (block_wsz < 8 ? block_wsz : 8);
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for (i = offset; i < end; i++) {
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value v = Field(block, i);
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value v = volatile_load_uninstrumented(&Field(block, i));
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if (Is_markable(v))
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break;
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}
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}
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static CAMLno_tsan
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#if defined(WITH_THREAD_SANITIZER)
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Caml_noinline
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#endif
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value volatile_load_uninstrumented(volatile value* p) {
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return *p;
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}
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Caml_noinline static intnat do_some_marking(struct mark_stack* stk,
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intnat budget) {
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prefetch_buffer_t pb = { .enqueued = 0, .dequeued = 0,
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for (; me.start < scan_end; me.start++) {
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CAMLassert(budget >= 0);
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/* This load may race with a concurrent caml_modify. It does not
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constitute a data race as this is a volatile load. However, TSan will
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wrongly see a race here (see section 3.2 of comment in tsan.c). We
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therefore make sure it is never TSan-instrumented. */
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value child = volatile_load_uninstrumented(me.start);
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budget--;