Don't treat "unsafe" and safe global actor isolation differently with
respect to dynamic data race detection, because this
`@_predatesConcurrency` is only supposed to affect the interface (not
the implementation).
The reason why I am doing this is that we are going to be enabling lexical
lifetimes early in the pipeline so that I can use it for the move operator's
diagnostics.
To make it easy for passes to know whether or not they should support lexical
lifetimes, I included a query on SILOptions called
supportsLexicalLifetimes. This will return true if the pass (given the passed in
option) should insert the lexical lifetime flag. This ensures that passes that
run in both pipelines (e.x.: AllocBoxToStack) know whether or not to set the
lexical lifetime flag without having to locally reason about it.
This is just chopping off layers of a larger patch I am upstreaming.
NOTE: This is technically NFC since it leaves the default alone of not inserting
lexical lifetimes at all.
I am purposely doing this in SILGen rather than at the type system level to
avoid having to have to add a bunch of boilerplate to the type system. Instead
of doing that, I am in SILGen checking for the isNoImplicitCopy bit on the
ParamDecl when we emit arguments. At that point, I set on the specific
SILArgument being emitted the bit that it is no implicit copy. In terms of
printing at the SIL level, I just printed it in front of the function argument
type like @owned, e.x.:
func myFunc(_ x: @_noImplicitCopy T) -> T {
...
}
becomes:
bb0(%0 : @noImplicitCopy @owned $T):
Some notes:
* Just to be explicit, I am making it so that no implicit copy parameters by
default are always passed at +1. The reason why I think this makes sense is
that this is the natural way of working with a move only value.
* As always, one can not write no implicit copy the attribute without passing
the flag -enable-experimental-move-only so this is NFC.
rdar://83957088
Previously, the flag was a LangOptioins. That didn't make much sense because
this isn't really a user-facing behavior. More importantly, as a member
of that type type it couldn't be accessed when setting up pass
pipelines. Here, the flag is moved to SILOptions.
Previously, lexical lifetimes were added for all arguments with non-none
ownership. For guaranteed arguments, that is redundant--they are
already guaranteed to remain alive by the caller. And thanks to the
additional borrow scopes that the inliner adds, that guarantee remains
after inlining. Here, the added lexical lifetimes are limited to only
those arguments whose ownership is owned.
When the frontend flag -enable-experimental-lexical-lifetimes is passed,
arguments of non-trivial, non-address types get lexical borrow scopes.
The borrow scope begins in the function prolog. Usages of the arguments
are actually usages of the borrowed value. The borrow scope is ended
when the function's scope ends.
Literal closures are only ever directly referenced in the context of the expression they're written in,
so it's wasteful to emit them at their fully-substituted calling convention and then reabstract them if
they're passed directly to a generic function. Avoid this by saving the abstraction pattern of the context
before emitting the closure, and then lowering its main entry point's calling convention at that
level of abstraction. Generalize some of the prolog/epilog code to handle converting arguments and returns
to the correct representation for a different abstraction level.
Literal closures are only ever directly referenced in the context of the expression they're written in,
so it's wasteful to emit them at their fully-substituted calling convention and then reabstract them if
they're passed directly to a generic function. Avoid this by saving the abstraction pattern of the context
before emitting the closure, and then lowering its main entry point's calling convention at that
level of abstraction. Generalize some of the prolog/epilog code to handle converting arguments and returns
to the correct representation for a different abstraction level.
Later stages use the name to disambiguate variables and this amgiguity
can lead to incorrect debug info that crashes LLVM. This also makes
the artificial variable names visible in textual SIL output.
rdar://82313550
Those instructions should not be "visible" for debugging and for diagnostic messages.
Fixes a wrong "unreachable code" warning.
https://bugs.swift.org/browse/SR-14873
rdar://80237870
Literal closures are only ever directly referenced in the context of the expression they're written in,
so it's wasteful to emit them at their fully-substituted calling convention and then reabstract them if
they're passed directly to a generic function. Avoid this by saving the abstraction pattern of the context
before emitting the closure, and then lowering its main entry point's calling convention at that
level of abstraction. Generalize some of the prolog/epilog code to handle converting arguments and returns
to the correct representation for a different abstraction level.
with external property wrappers.
Otherwise, the code will attempt to forward the wrapped value type to a
function that accepts the property wrapper type.
emit those auxiliary decls inside the function body brace statement.
This generalizes the old code to work for parameters to any kind of
function (e.g. initializers).
SILGen this builtin to a mandatory hop_to_executor with an actor type
operand.
e.g.
Task.detached {
Builtin.hopToActor(MainActor.shared)
await suspend()
}
Required to fix a bug in _runAsyncMain.
* [Distributed] Initial distributed checking
* [Distributed] initial types shapes and conform to DistributedActor
* [Distributed] Require Codable params and return types
* [Distributed] initial synthesis of fields and constructors
* [Distributed] Field and initializer synthesis
* [Distributed] Codable requirement on distributed funcs; also handle <T: Codable>
* [Distributed] handle generic type params which are Codable in dist func
[Distributed] conformsToProtocol after all
* [Distributed] Implement remote flag on actors
* Implement remote flag on actors
* add test
* actor initializer that sets remote flag
[Distributed] conformances getting there
* [Distributed] dont require async throws; cleanup compile tests
* [Distributed] do not synthesize default implicit init, only our special ones
* [Distributed] properly synth inits and properties; mark actorTransport as _distributedActorIndependent
Also:
- do not synthesize default init() initializer for dist actor
* [Distributed] init(transport:) designated and typechecking
* [Distributed] dist actor initializers MUST delegate to local-init
* [Distributed] check if any ctors in delegation call init(transport:)
* [Distributed] check init(transport:) delegation through many inits; ban invoking init(resolve:using:) explicitly
* [Distributed] disable IRGen test for now
* [Distributed] Rebase cleanups
* [Concurrent] transport and address are concurrent value
* [Distributed] introduce -enable-experimental-distributed flag
* rebase adjustments again
* rebase again...
* [Distributed] distributed functions are implicitly async+throws outside the actor
* [Distributed] implicitly throwing and async distributed funcs
* remove printlns
* add more checks to implicit function test
* [Distributed] resolve initializer now marks the isRemote actor flag
* [Distributed] distributedActor_destroy invoked instead, rather than before normal
* [Distributed] Generate distributed thunk for actors
* [distributed] typechecking for _remote_ functions existing, add tests for remote funcs
* adding one XFAIL'ed task & actor lifetime test
The `executor_deinit1` test fails 100% of the time
(from what I've seen) so I thought we could track
and see when/if someone happens to fix this bug.
Also, added extra coverage for #36298 via `executor_deinit2`
* Fix a memory issue with actors in the runtime system, by @phausler
* add new test that now passes because of patch by @phausler
See previous commit in this PR.
Test is based on one from rdar://74281361
* fix all tests that require the _remote_ function stubs
* Do not infer @actorIndependent onto `let` decls
* REVERT_ME: remove some tests that hacky workarounds will fail
* another flaky test, help build toolchain
* [Distributed] experimental distributed implies experimental concurrency
* [Distributed] Allow distributed function that are not marked async or throws
* [Distributed] make attrs SIMPLE to get serialization generated
* [Distributed] ActorAddress must be Hashable
* [Distributed] Implement transport.actorReady call in local init
* cleanup after rebase
* [Distributed] add availability attributes to all distributed actor code
* cleanup - this fixed some things
* fixing up
* fixing up
* [Distributed] introduce new Distributed module
* [Distributed] diagnose when missing 'import _Distributed'
* [Distributed] make all tests import the module
* more docs on address
* [Distributed] fixup merge issues
* cleanup: remove unnecessary code for now SIMPLE attribute
* fix: fix getActorIsolationOfContext
* [Distributed] cmake: depend on _concurrency module
* fixing tests...
* Revert "another flaky test, help build toolchain"
This reverts commit 83ae6654dd.
* remove xfail
* clenup some IR and SIL tests
* cleanup
* [Distributed] fix cmake test and ScanDependencies/can_import_with_map.swift
* [Distributed] fix flags/build tests
* cleanup: use isDistributed wherever possible
* [Distributed] don't import Dispatch in tests
* dont link distributed in stdlib unittest
* trying always append distributed module
* cleanups
* [Distributed] move all tests to Distributed/ directory
* [lit] try to fix lit test discovery
* [Distributed] update tests after diagnostics for implicit async changed
* [Distributed] Disable remote func tests on Windows for now
* Review cleanups
* [Distributed] fix typo, fixes Concurrency/actor_isolation_objc.swift
* [Distributed] attributes are DistributedOnly (only)
* cleanup
* [Distributed] cleanup: rely on DistributedOnly for guarding the keyword
* Update include/swift/AST/ActorIsolation.h
Co-authored-by: Doug Gregor <dgregor@apple.com>
* introduce isAnyThunk, minor cleanup
* wip
* [Distributed] move some type checking to TypeCheckDistributed.cpp
* [TypeCheckAttr] remove extra debug info
* [Distributed/AutoDiff] fix SILDeclRef creation which caused AutoDiff issue
* cleanups
* [lit] remove json import from lit test suite, not needed after all
* [Distributed] distributed functions only in DistributedActor protocols
* [Distributed] fix flag overlap & build setting
* [Distributed] Simplify noteIsolatedActorMember to not take bool distributed param
* [Distributed] make __isRemote not public
* [Distributed] Fix availability and remove actor class tests
* [actorIndependent] do not apply actorIndependent implicitly to values where it would be illegal to apply
* [Distributed] disable tests until issue fixed
Co-authored-by: Dario Rexin <drexin@apple.com>
Co-authored-by: Kavon Farvardin <kfarvardin@apple.com>
Co-authored-by: Doug Gregor <dgregor@apple.com>
* Revert "[Distributed] disable tests until issue fixed"
This reverts commit 0a04278920.
* Revert "[Distributed] Initial `distributed` actors and functions and new module (#37109)"
This reverts commit 814ede0cf3.
* [Distributed] Initial distributed checking
* [Distributed] initial types shapes and conform to DistributedActor
* [Distributed] Require Codable params and return types
* [Distributed] initial synthesis of fields and constructors
* [Distributed] Field and initializer synthesis
* [Distributed] Codable requirement on distributed funcs; also handle <T: Codable>
* [Distributed] handle generic type params which are Codable in dist func
[Distributed] conformsToProtocol after all
* [Distributed] Implement remote flag on actors
* Implement remote flag on actors
* add test
* actor initializer that sets remote flag
[Distributed] conformances getting there
* [Distributed] dont require async throws; cleanup compile tests
* [Distributed] do not synthesize default implicit init, only our special ones
* [Distributed] properly synth inits and properties; mark actorTransport as _distributedActorIndependent
Also:
- do not synthesize default init() initializer for dist actor
* [Distributed] init(transport:) designated and typechecking
* [Distributed] dist actor initializers MUST delegate to local-init
* [Distributed] check if any ctors in delegation call init(transport:)
* [Distributed] check init(transport:) delegation through many inits; ban invoking init(resolve:using:) explicitly
* [Distributed] disable IRGen test for now
* [Distributed] Rebase cleanups
* [Concurrent] transport and address are concurrent value
* [Distributed] introduce -enable-experimental-distributed flag
* rebase adjustments again
* rebase again...
* [Distributed] distributed functions are implicitly async+throws outside the actor
* [Distributed] implicitly throwing and async distributed funcs
* remove printlns
* add more checks to implicit function test
* [Distributed] resolve initializer now marks the isRemote actor flag
* [Distributed] distributedActor_destroy invoked instead, rather than before normal
* [Distributed] Generate distributed thunk for actors
* [distributed] typechecking for _remote_ functions existing, add tests for remote funcs
* adding one XFAIL'ed task & actor lifetime test
The `executor_deinit1` test fails 100% of the time
(from what I've seen) so I thought we could track
and see when/if someone happens to fix this bug.
Also, added extra coverage for #36298 via `executor_deinit2`
* Fix a memory issue with actors in the runtime system, by @phausler
* add new test that now passes because of patch by @phausler
See previous commit in this PR.
Test is based on one from rdar://74281361
* fix all tests that require the _remote_ function stubs
* Do not infer @actorIndependent onto `let` decls
* REVERT_ME: remove some tests that hacky workarounds will fail
* another flaky test, help build toolchain
* [Distributed] experimental distributed implies experimental concurrency
* [Distributed] Allow distributed function that are not marked async or throws
* [Distributed] make attrs SIMPLE to get serialization generated
* [Distributed] ActorAddress must be Hashable
* [Distributed] Implement transport.actorReady call in local init
* cleanup after rebase
* [Distributed] add availability attributes to all distributed actor code
* cleanup - this fixed some things
* fixing up
* fixing up
* [Distributed] introduce new Distributed module
* [Distributed] diagnose when missing 'import _Distributed'
* [Distributed] make all tests import the module
* more docs on address
* [Distributed] fixup merge issues
* cleanup: remove unnecessary code for now SIMPLE attribute
* fix: fix getActorIsolationOfContext
* [Distributed] cmake: depend on _concurrency module
* fixing tests...
* Revert "another flaky test, help build toolchain"
This reverts commit 83ae6654dd.
* remove xfail
* clenup some IR and SIL tests
* cleanup
* [Distributed] fix cmake test and ScanDependencies/can_import_with_map.swift
* [Distributed] fix flags/build tests
* cleanup: use isDistributed wherever possible
* [Distributed] don't import Dispatch in tests
* dont link distributed in stdlib unittest
* trying always append distributed module
* cleanups
* [Distributed] move all tests to Distributed/ directory
* [lit] try to fix lit test discovery
* [Distributed] update tests after diagnostics for implicit async changed
* [Distributed] Disable remote func tests on Windows for now
* Review cleanups
* [Distributed] fix typo, fixes Concurrency/actor_isolation_objc.swift
* [Distributed] attributes are DistributedOnly (only)
* cleanup
* [Distributed] cleanup: rely on DistributedOnly for guarding the keyword
* Update include/swift/AST/ActorIsolation.h
Co-authored-by: Doug Gregor <dgregor@apple.com>
* introduce isAnyThunk, minor cleanup
* wip
* [Distributed] move some type checking to TypeCheckDistributed.cpp
* [TypeCheckAttr] remove extra debug info
* [Distributed/AutoDiff] fix SILDeclRef creation which caused AutoDiff issue
* cleanups
* [lit] remove json import from lit test suite, not needed after all
* [Distributed] distributed functions only in DistributedActor protocols
* [Distributed] fix flag overlap & build setting
* [Distributed] Simplify noteIsolatedActorMember to not take bool distributed param
* [Distributed] make __isRemote not public
Co-authored-by: Dario Rexin <drexin@apple.com>
Co-authored-by: Kavon Farvardin <kfarvardin@apple.com>
Co-authored-by: Doug Gregor <dgregor@apple.com>
Introduce flags `-enable-actor-data-race-checks` and
`-disable-actor-data-race-checks` to enable/disable emission of code
that checks that we are on the correct actor. Default to `false` for
now but make it easy to enable in the future.
There's a basic prolog emission function, used by value and class constructors, etc, and then there's the full-blown one for functions and closures, which uses the basic version.
An actor's deinit can be invoked from any thread, and does not
(cannot!) synchronize to the actor. However, because "self" is
by definition unique and cannot escape, don't perform data race
checking in it or any local functions/closures within the initializer.
This is an imperfect approximation, because one could introduce a data
race by invoking a concurrent algorithm on "self" that does not
escape the closure but subverts @Sendable checking and concurrently
accesses actor state. However, for the moment we accept this false
negative because the false positives from performing this checking are
much more prevalent.
Through various means, it is possible for a synchronous actor-isolated
function to escape to another concurrency domain and be called from
outside the actor. The problem existed previously, but has become far
easier to trigger now that `@escaping` closures and local functions
can be actor-isolated.
Introduce runtime detection of such data races, where a synchronous
actor-isolated function ends up being called from the wrong executor.
Do this by emitting an executor check in actor-isolated synchronous
functions, where we query the executor in thread-local storage and
ensure that it is what we expect. If it isn't, the runtime complains.
The runtime's complaints can be controlled with the environment
variable `SWIFT_UNEXPECTED_EXECUTOR_LOG_LEVEL`:
0 - disable checking
1 - warn when a data race is detected
2 - error and abort when a data race is detected
At an implementation level, this introduces a new concurrency runtime
entry point `_checkExpectedExecutor` that checks the given executor
(on which the function should always have been called) against the
executor on which is called (which is in thread-local storage). There
is a special carve-out here for `@MainActor` code, where we check
against the OS's notion of "main thread" as well, so that `@MainActor`
code can be called via (e.g.) the Dispatch library's
`DispatchQueue.main.async`.
The new SIL instruction `extract_executor` performs the lowering of an
actor down to its executor, which is implicit in the `hop_to_executor`
instruction. Extend the LowerHopToExecutor pass to perform said
lowering.
The comment in LowerHopToActor explains the design here.
We want SILGen to emit hops to actors, ignoring executors,
because it's easier to fully optimize in a world where deriving
an executor is a non-trivial operation. But we also want something
prior to IRGen to lower the executor derivation because there are
useful static optimizations we can do, such as doing the derivation
exactly once on a dominance path and strength-reducing the derivation
(e.g. exploiting static knowledge that an actor is a default actor).
There are probably phase-ordering problems with doing this so late,
but hopefully they're restricted to situations like actors that
share an executor. We'll want to optimize that eventually, but
in the meantime, this unblocks the executor work.
Don't treat `actorIndependent(unsafe)` as its own kind of isolation.
It was only really used as a bring-up hack to break the isolation model,
but shouldn't be in the user model of the language and causes
complications to the implementation.
Tasks shouldn't normally hog the actor context indefinitely after making a call that's bound to
that actor, since that prevents the actor from potentially taking on other jobs it needs to
be able to address. Set up SILGen so that it saves the current executor (using a new runtime
entry point) and hops back to it after every actor call, not only ones where the caller context
is also actor-bound.
The added executor hopping here also exposed a bug in the runtime implementation while processing
DefaultActor jobs, where if an actor job returned to the processing loop having already yielded
the thread back to a generic executor, we would still attempt to make the actor give up the thread
again, corrupting its state.
rdar://71905765
The strategy for implementing them is integrated with the
PathComponent infrastructure in SILGen in order to correctly
support mixtures of chained accesses and forced optionals, etc.
The actor isolation information is only piped into LValues from
the expressions that might be marked implicitly-async.
With "unsafe" global actor isolation, we only enforce actor isolation
when interacting with other explicitly-isolated code. This allows some
code to be annotated with, e.g., `@MainActor(unsafe)` so that users
who opt into concurrency get proper diagnostics, but existing code
does not change.
