Make SelectionCache and EvaluationCache thread-safe

[Zoxc]

Split out from #49558

r? @nikomatsakis

[TimNN]

Your PR failed on Travis (raw log). Through arcane magic we have determined that the following fragments from the build log may contain information about the problem.

Click to expand the log.

Resolving deltas: 100% (613496/613496), completed with 4872 local objects.
---
[00:00:41] configure: rust.quiet-tests     := True
---
[00:37:20] thread 'main' panicked at 'assertion failed: *old == value', librustc_data_structures/sync.rs:236:42

I'm a bot! I can only do what humans tell me to, so if this was not helpful or you have suggestions for improvements, please ping or otherwise contact @TimNN. (Feature Requests)

[nikic]

Given the comment above, should this also use insert_same()?

[Zoxc]

The inserted type doesn't implement Eq.

[nikomatsakis]

@bors r+

[bors]

📌 Commit 9d48917 has been approved by nikomatsakis

[Zoxc]

This doesn't work since insert_evaluation_cache overwrites values.

@bors r-

[bors]

☔ The latest upstream changes (presumably #49558) made this pull request unmergeable. Please resolve the merge conflicts.

[rust-highfive]

Your PR failed on Travis (raw log). Through arcane magic we have determined that the following fragments from the build log may contain information about the problem.

Click to expand the log.

[00:01:07] configure: rust.quiet-tests     := True
---
[00:42:45] thread 'main' panicked at 'assertion failed: *old == value', librustc_data_structures/sync.rs:241:42
---
[00:43:33] command did not execute successfully: "/checkout/obj/build/x86_64-unknown-linux-gnu/stage0/bin/cargo" "doc" "--target" "x86_64-unknown-linux-gnu" "--release" "--locked" "--color" "always" "--features" "panic-unwind jemalloc backtrace" "--manifest-path" "/checkout/src/libstd/Cargo.toml" "--no-deps" "-p" "alloc" "-p" "core" "-p" "std" "-p" "std_unicode"
[00:43:33] expected success, got: exit code: 101
[00:43:33]
[00:43:33]
[00:43:33] failed to run: /checkout/obj/build/bootstrap/debug/bootstrap doc
[00:43:33] Build completed unsuccessfully in 0:05:47
[00:43:33] make: *** [all] Error 1
[00:43:33] Makefile:28: recipe for target 'all' failed
---
$ ls -lat $HOME/Library/Logs/DiagnosticReports/
ls: cannot access /home/travis/Library/Logs/DiagnosticReports/: No such file or directory
travis_time:end:2705b080:start=1523980841568033483,finish=1523980841575288725,duration=7255242
travis_fold:end:after_failure.2
travis_fold:start:after_failure.3
travis_time:start:294834ea
$ find $HOME/Library/Logs/DiagnosticReports -type f -name '*.crash' -not -name '*.stage2-*.crash' -not -name 'com.apple.CoreSimulator.CoreSimulatorService-*.crash' -exec printf travis_fold":start:crashlog\n\033[31;1m%s\033[0m\n" {} \; -exec head -750 {} \; -exec echo travis_fold":"end:crashlog \; || true
find: `/home/travis/Library/Logs/DiagnosticReports': No such file or directory
travis_time:end:294834ea:start=1523980841581578671,finish=1523980841588508966,duration=6930295
travis_fold:end:after_failure.3
travis_fold:start:after_failure.4
travis_time:start:09c17180
$ dmesg | grep -i kill
[   10.544864] init: failsafe main process (1093) killed by TERM signal

I'm a bot! I can only do what humans tell me to, so if this was not helpful or you have suggestions for improvements, please ping or otherwise contact @TimNN. (Feature Requests)

[nikomatsakis]

@Zoxc to be honest I didn't think too hard here-- and I still haven't. =) Can you spell out the problem, and do you have any ideas for how to solve?

[Zoxc]

@nikomatsakis I though maps in SelectionCache and EvaluationCache would have values which are deterministically based on their keys. That is not true for EvaluationCache at least, since it will change the value of aty::PolyTraitRef<'tcx> key to a different WithDepNode<EvaluationResult>. I'm wondering if this is expected behavior, and if so, how to make these caches thread-safe?

[shepmaster]

Ping from triage, @Zoxc and @nikomatsakis ! Will you have time to make progress on this in the near future?

[rust-highfive]

The job x86_64-gnu-llvm-3.9 of your PR failed on Travis (raw log). Through arcane magic we have determined that the following fragments from the build log may contain information about the problem.

Click to expand the log.

[00:37:03] Documenting book redirect pages (x86_64-unknown-linux-gnu)
[00:37:04] Documenting stage2 std (x86_64-unknown-linux-gnu)
[00:37:04]    Compiling core v0.0.0 (file:///checkout/src/libcore)
[00:37:04]  Documenting core v0.0.0 (file:///checkout/src/libcore)
[00:37:17] overwriting key/trait_ref: Binder(<isize as marker::Freeze>) with EvaluationResult WithDepNode { dep_node: 150890, cached_value: EvaluatedToOk }
[00:37:17]  old value: WithDepNode { dep_node: 150889, cached_value: EvaluatedToOk }
[00:37:17] thread 'main' panicked at 'assertion failed: *old == value', librustc_data_structures/sync.rs:241:42
[00:37:17] 
[00:37:17] error: internal compiler error: unexpected panic
[00:37:17] 
[00:37:17] 
[00:37:17] note: the compiler unexpectedly panicked. this is a bug.
[00:37:17] 
[00:37:17] note: we would appreciate a bug report: https://github.com/rust-lang/rust/blob/master/CONTRIBUTING.md#bug-reports
[00:37:17] 
[00:37:17] note: rustc 1.27.0-dev running on x86_64-unknown-linux-gnu
[00:37:17] 
[00:37:17] note: compiler flags: -Z force-unstable-if-unmarked -C debug-assertions=off -C overflow-checks=on -C incremental -C prefer-dynamic -C debug-assertions=y -C link-args=-Wl,-rpath,$ORIGIN/../lib --crate-type lib
[00:37:17] 
[00:37:17] note: some of the compiler flags provided by cargo are hidden
[00:37:17] error: Could not compile `core`.
[00:37:17] warning: build failed, waiting for other jobs to finish...
[00:37:49] warning: [1] cannot be resolved, ignoring it...
[00:37:49] 
---
[00:37:51] 
[00:37:55] error: build failed
[00:37:55] 
[00:37:55] 
[00:37:55] command did not execute successfully: "/checkout/obj/build/x86_64-unknown-linux-gnu/stage0/bin/cargo" "doc" "--target" "x86_64-unknown-linux-gnu" "--release" "--locked" "--color" "always" "--features" "panic-unwind jemalloc backtrace" "--manifest-path" "/checkout/src/libstd/Cargo.toml" "--no-deps" "-p" "alloc" "-p" "core" "-p" "std" "-p" "std_unicode"
[00:37:55] 
[00:37:55] 
[00:37:55] failed to run: /checkout/obj/build/bootstrap/debug/bootstrap doc
[00:37:55] Build completed unsuccessfully in 0:05:15
[00:37:55] Build completed unsuccessfully in 0:05:15
[00:37:55] Makefile:28: recipe for target 'all' failed
[00:37:55] make: *** [all] Error 1
2174820 ./obj
2174788 ./obj/build
1566936 ./obj/build/x86_64-unknown-linux-gnu
725072 ./src
---
149120 ./src/llvm-emscripten/test
144660 ./obj/build/bootstrap/debug/incremental
128084 ./obj/build/x86_64-unknown-linux-gnu/stage1-std
123692 ./obj/build/bootstrap/debug/incremental/bootstrap-1wl4zjaz72e5d
123688 ./obj/build/bootstrap/debug/incremental/bootstrap-1wl4zjaz72e5d/s-f0msmdn1je-1ia77dq-6gvofocobazn
121820 ./obj/build/x86_64-unknown-linux-gnu/stage1-rustc/x86_64-unknown-linux-gnu/release
105360 ./obj/build/x86_64-unknown-linux-gnu/crate-docs
103452 ./obj/build/x86_64-unknown-linux-gnu/stage0-tools/x86_64-unknown-linux-gnu
103448 ./obj/build/x86_64-unknown-linux-gnu/stage0-tools/x86_64-unknown-linux-gnu/release

I'm a bot! I can only do what humans tell me to, so if this was not helpful or you have suggestions for improvements, please ping or otherwise contact @TimNN. (Feature Requests)

[shepmaster]

Ping from triage, @Zoxc ! You have test failures.

[Zoxc]

I've created #50507 for the bug which overwrites the cache and added a fixme to use insert_same when that is fixed.

[nikomatsakis]

@bors r+

[bors]

📌 Commit f741ee1 has been approved by nikomatsakis

[bors]

⌛ Testing commit f741ee1 with merge e5f80f2...

[bors]

☀️ Test successful - status-appveyor, status-travis
Approved by: nikomatsakis
Pushing e5f80f2 to master...