Commit Graph

342 Commits

Author SHA1 Message Date
Ryan Macnak da8f17762c [vm, gc] Allocate card tables up front.
This avoids data races when multiple mutators compete to install the card table, and allows removing the initialization check from the write barrier.

TEST=ci, tsan
Bug: https://github.com/dart-lang/sdk/issues/56895
Change-Id: I30fe4687d3ca771f6c00dfa59e8dadec23d557a3
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/390023
Reviewed-by: Siva Annamalai <asiva@google.com>
Commit-Queue: Ryan Macnak <rmacnak@google.com>
2024-10-16 21:25:17 +00:00
Alexander Markov 8fbca8ba67 [vm] Initial implementation of dynamic modules in the VM/AOT
TEST=Manually tested dynamic modules

Change-Id: Icb2616e414167bd1fbd10f01dea64c57dbdeeac7
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/380281
Reviewed-by: Slava Egorov <vegorov@google.com>
Commit-Queue: Alexander Markov <alexmarkov@google.com>
2024-08-15 14:09:52 +00:00
Alexander Markov bf2fba78e0 [vm] Fix ObjectPtr::IsSmi and other ObjectPtr::Is* methods to account for Smis
Arbitrary ObjectPtr can be a non-heap object (Smi), so methods
ObjectPtr::Is* which test class id should account for Smi.

Changed ObjectPtr::GetClassId to account for Smi similarly to
Object::GetClassId. Added unsafe ObjectPtr::GetClassIdOfHeapObject
which can be used when caller knows the heap nature of the object.

This change also fixes Integer::GetInt64Value which was relying on ObjectPtr::IsSmi.

TEST=vm/cc/Smi, vm/cc/Mint

Change-Id: I1391600e2acedc7b2a8f35c814df113ec9ba8698
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/380280
Reviewed-by: Ryan Macnak <rmacnak@google.com>
Commit-Queue: Alexander Markov <alexmarkov@google.com>
2024-08-14 17:09:07 +00:00
Ryan Macnak 6694cae4d7 [vm, gc] Incremental compaction, take 3.
- Use atomics to mark remembered cards in the write barrier stub.

TEST=ci
Bug: https://github.com/dart-lang/sdk/issues/52513
Bug: https://github.com/dart-lang/sdk/issues/55754
Change-Id: I1f78c6b680a6ae9170613ba328a244335a6343e2
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/368480
Reviewed-by: Siva Annamalai <asiva@google.com>
Commit-Queue: Ryan Macnak <rmacnak@google.com>
2024-05-30 21:01:39 +00:00
Daco Harkes b732c96e8a Revert "[vm, gc] Incremental compaction, take 2."
This reverts commit 9077bf991f.

Reason for revert: CBuild and TGP crashes in random Dart code which
look a lot like arbitrary memory corruption.

Original change's description:
> [vm, gc] Incremental compaction, take 2.
>
> - Fix missing store buffer flush when --marker_tasks=0.
> - Fix passing untagged pointer to store barrier check on ARM/ARM64 (6bc417dd17).
> - Fix passing uninitialized header to store barrier check on ARM64/RISCV (1447193053).
>
> TEST=ci
> Bug: https://github.com/dart-lang/sdk/issues/52513
> Bug: https://github.com/dart-lang/sdk/issues/55754
> Change-Id: Id2aa95b6d776b82d83464cde0d00e6f3b29b7b77
> Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/367202
> Commit-Queue: Ryan Macnak <rmacnak@google.com>
> Reviewed-by: Alexander Aprelev <aam@google.com>

Bug: https://github.com/dart-lang/sdk/issues/52513
Bug: https://github.com/dart-lang/sdk/issues/55754
Change-Id: I1d70d33c65fe6bf7089b8c1422d59f9146ae7ebf
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/367962
Bot-Commit: Rubber Stamper <rubber-stamper@appspot.gserviceaccount.com>
Reviewed-by: Slava Egorov <vegorov@google.com>
Auto-Submit: Daco Harkes <dacoharkes@google.com>
Commit-Queue: Slava Egorov <vegorov@google.com>
2024-05-23 19:00:50 +00:00
Ryan Macnak 9077bf991f [vm, gc] Incremental compaction, take 2.
- Fix missing store buffer flush when --marker_tasks=0.
- Fix passing untagged pointer to store barrier check on ARM/ARM64 (6bc417dd17).
- Fix passing uninitialized header to store barrier check on ARM64/RISCV (1447193053).

TEST=ci
Bug: https://github.com/dart-lang/sdk/issues/52513
Bug: https://github.com/dart-lang/sdk/issues/55754
Change-Id: Id2aa95b6d776b82d83464cde0d00e6f3b29b7b77
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/367202
Commit-Queue: Ryan Macnak <rmacnak@google.com>
Reviewed-by: Alexander Aprelev <aam@google.com>
2024-05-21 16:33:00 +00:00
Ryan Macnak 42ec219908 Revert "[vm, gc] Incremental compaction."
This reverts commit bc0f02e4c8.

Reason for revert: https://github.com/dart-lang/sdk/issues/55754

Original change's description:
> [vm, gc] Incremental compaction.
>
> At the beginning of a major GC cycle, select some mostly-empty pages to be evacuated. Mark the pages and the objects on these pages. Apply a write barrier for stores creating old -> evacuation candidate pointers, and discover any such pointers that already exist during marking.
>
> At the end of a major GC cycle, evacuate objects from these pages. Forward pointers of objects in the remembered set and new-space. Free the evacuated pages.
>
> This compaction is incremental in the sense that creating the remembered set is interleaved with mutator execution. The evacuation step, however, is stop-the-world.
>
> Write-barrier elimination for x.slot = x is removed. Write-barrier elimination for x.slot = constant is removed in the JIT, kept for AOT but snapshot pages are marked as never-evacuate.
>
> TEST=ci
> Bug: https://github.com/dart-lang/sdk/issues/52513
> Change-Id: Icbc29ef7cb662ef8759b8c1d7a63b7af60766281
> Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/357760
> Reviewed-by: Alexander Aprelev <aam@google.com>
> Commit-Queue: Ryan Macnak <rmacnak@google.com>

Bug: https://github.com/dart-lang/sdk/issues/52513
Change-Id: I565ad6c0fca283d33f605c10f181bc0a59e7d2b2
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/366965
Reviewed-by: Ryan Macnak <rmacnak@google.com>
Bot-Commit: Rubber Stamper <rubber-stamper@appspot.gserviceaccount.com>
Commit-Queue: Alexander Aprelev <aam@google.com>
Auto-Submit: Ryan Macnak <rmacnak@google.com>
Reviewed-by: Alexander Aprelev <aam@google.com>
2024-05-17 18:03:42 +00:00
Ryan Macnak bc0f02e4c8 [vm, gc] Incremental compaction.
At the beginning of a major GC cycle, select some mostly-empty pages to be evacuated. Mark the pages and the objects on these pages. Apply a write barrier for stores creating old -> evacuation candidate pointers, and discover any such pointers that already exist during marking.

At the end of a major GC cycle, evacuate objects from these pages. Forward pointers of objects in the remembered set and new-space. Free the evacuated pages.

This compaction is incremental in the sense that creating the remembered set is interleaved with mutator execution. The evacuation step, however, is stop-the-world.

Write-barrier elimination for x.slot = x is removed. Write-barrier elimination for x.slot = constant is removed in the JIT, kept for AOT but snapshot pages are marked as never-evacuate.

TEST=ci
Bug: https://github.com/dart-lang/sdk/issues/52513
Change-Id: Icbc29ef7cb662ef8759b8c1d7a63b7af60766281
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/357760
Reviewed-by: Alexander Aprelev <aam@google.com>
Commit-Queue: Ryan Macnak <rmacnak@google.com>
2024-05-16 23:26:08 +00:00
Alexander Markov 17d6ba15b6 [vm] Remove external strings
This change removes support for external strings from the VM along with
Dart_NewExternalLatin1String, Dart_NewExternalUTF16String and
Dart_IsExternalString Dart C API functions.

External strings are not used by the VM nor any known embedder, but
Dart VM was paying the maintenance and performance price for
the external string implementation classes.

TEST=ci

Change-Id: I094cd2d2b7ec0840e9f09e1ca9e5a7acd4e78c28
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/358760
Reviewed-by: Ryan Macnak <rmacnak@google.com>
Reviewed-by: Siva Annamalai <asiva@google.com>
Commit-Queue: Alexander Markov <alexmarkov@google.com>
2024-03-20 20:08:13 +00:00
Ryan Macnak 4e6cd29eef [vm, gc] Mark through new-space.
- Initial and final marking no longer visit all of new-space, reducing the STW pause for major GC.
 - A scavenge during concurrent marking must forward / filter objects in the marking worklist that are moved / collected, increasing the STW pause for minor GC.
 - Unreachable intergenerational cycles and weak references are collected in the next mark-sweep instead of first requiring enough scavenges to promote the whole cycle or weak target into old-space.
 - Artificial minor GCs are no longer needed to avoid memory leaks from back-to-back major GCs.
 - reachabilityBarrier is now just a count of major GCs.

TEST=ci
Change-Id: I1e653c9b5d3e02e45b280302c832157a75788db6
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/345350
Commit-Queue: Ryan Macnak <rmacnak@google.com>
Reviewed-by: Siva Annamalai <asiva@google.com>
2024-01-26 18:58:54 +00:00
Siva Annamalai 94c8d341d7 Revert "[vm, gc] Mark through new-space."
This reverts commit a3b7c323b0.

Reason for revert: We are seeing crashes in some internal testing
si_signo=Segmentation fault(11), si_code=SEGV_ACCERR(2), si_addr=0x7f1cadb85bc6
version=3.3.0-edge+google3-v2 (google3) (google3) on "linux_x64"
pid=8967, thread=8969, isolate_group=main(0x5583571aaaf0), isolate=(nil)((nil))
os=linux, arch=x64, comp=no, sim=no
isolate_instructions=7f1cad8b7e40, vm_instructions=7f1cad8b1000
fp=7f1cacc7ebc0, sp=7f1cacc7eb90, pc=5583568155bc
  pc 0x00005583568155bc fp 0x00007f1cacc7ebc0 dart::MarkingVisitorBase<true>::VisitPointers(dart::ObjectPtr*, dart::ObjectPtr*)+0x15c
  pc 0x0000558356975a1d fp 0x00007f1cacc7ec60 dart::StackFrame::VisitObjectPointers(dart::ObjectPointerVisitor*)+0x1bd
  pc 0x0000558356935c29 fp 0x00007f1cacc7ecc0 dart::UntaggedSuspendState::VisitSuspendStatePointers(dart::SuspendStatePtr, dart::ObjectPointerVisitor*)+0x89
  pc 0x0000558356815948 fp 0x00007f1cacc7ed10 dart::MarkingVisitorBase<true>::DrainMarkingStackWithPauseChecks()+0x128
  pc 0x0000558356815749 fp 0x00007f1cacc7ed80 dart::ConcurrentMarkTask::Run()+0x69

Original change's description:
> [vm, gc] Mark through new-space.
>
>  - Initial and final marking no longer visit all of new-space, reducing the STW pause for major GC.
>  - A scavenge during concurrent marking must forward / filter objects in the marking worklist that are moved / collected, increasing the STW pause for minor GC.
>  - Unreachable intergenerational cycles and weak references are collected in the next mark-sweep instead of first requiring enough scavenges to promote the whole cycle or weak target into old-space.
>  - Artificial minor GCs are no longer needed to avoid memory leaks from back-to-back major GCs.
>  - reachabilityBarrier is now just a count of major GCs.
>
> TEST=ci
> Change-Id: Ic7754e8d972763654eae2b7faa8670735d9cda3f
> Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/340644
> Reviewed-by: Siva Annamalai <asiva@google.com>
> Commit-Queue: Ryan Macnak <rmacnak@google.com>

Change-Id: Ice07b4eb5bef3b41c9618ef0ca7759de006ffe00
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/343060
Bot-Commit: Rubber Stamper <rubber-stamper@appspot.gserviceaccount.com>
Commit-Queue: Siva Annamalai <asiva@google.com>
Reviewed-by: Alexander Aprelev <aam@google.com>
2023-12-21 21:02:38 +00:00
Ryan Macnak a3b7c323b0 [vm, gc] Mark through new-space.
- Initial and final marking no longer visit all of new-space, reducing the STW pause for major GC.
 - A scavenge during concurrent marking must forward / filter objects in the marking worklist that are moved / collected, increasing the STW pause for minor GC.
 - Unreachable intergenerational cycles and weak references are collected in the next mark-sweep instead of first requiring enough scavenges to promote the whole cycle or weak target into old-space.
 - Artificial minor GCs are no longer needed to avoid memory leaks from back-to-back major GCs.
 - reachabilityBarrier is now just a count of major GCs.

TEST=ci
Change-Id: Ic7754e8d972763654eae2b7faa8670735d9cda3f
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/340644
Reviewed-by: Siva Annamalai <asiva@google.com>
Commit-Queue: Ryan Macnak <rmacnak@google.com>
2023-12-12 01:56:15 +00:00
Slava Egorov 425a42e3be Revert "[vm, gc] Mark through new-space."
This reverts commit 5daaa7d9eb.

Reason for revert: internal crashes

Original change's description:
> [vm, gc] Mark through new-space.
>
>   - Initial and final marking no longer visit all of new-space, reducing the STW pause for major GC.
>   - A scavenge during concurrent marking must forward / filter objects in the marking worklist that are moved / collected, increasing the STW pause for minor GC.
>   - Unreachable intergenerational cycles and weak references are collected in the next mark-sweep instead of first requiring enough scavenges to promote the whole cycle or weak target into old-space.
>   - Artificial minor GCs are no longer needed to avoid memory leaks from back-to-back major GCs.
>   - reachabilityBarrier is now just a count of major GCs.
>
> TEST=ci
> Change-Id: I4a6a23273d8ecb78c640f054731d4ceb737bfc4d
> Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/325840
> Reviewed-by: Siva Annamalai <asiva@google.com>
> Commit-Queue: Ryan Macnak <rmacnak@google.com>

Change-Id: I8a50074db343c63c14f0487ae8b4f5fee2c4ae76
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/330720
Reviewed-by: Ryan Macnak <rmacnak@google.com>
Commit-Queue: Slava Egorov <vegorov@google.com>
Bot-Commit: Rubber Stamper <rubber-stamper@appspot.gserviceaccount.com>
2023-10-18 07:47:39 +00:00
Ryan Macnak 5daaa7d9eb [vm, gc] Mark through new-space.
- Initial and final marking no longer visit all of new-space, reducing the STW pause for major GC.
  - A scavenge during concurrent marking must forward / filter objects in the marking worklist that are moved / collected, increasing the STW pause for minor GC.
  - Unreachable intergenerational cycles and weak references are collected in the next mark-sweep instead of first requiring enough scavenges to promote the whole cycle or weak target into old-space.
  - Artificial minor GCs are no longer needed to avoid memory leaks from back-to-back major GCs.
  - reachabilityBarrier is now just a count of major GCs.

TEST=ci
Change-Id: I4a6a23273d8ecb78c640f054731d4ceb737bfc4d
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/325840
Reviewed-by: Siva Annamalai <asiva@google.com>
Commit-Queue: Ryan Macnak <rmacnak@google.com>
2023-10-10 19:15:12 +00:00
Emmanuel Pellereau a675a79f39 Revert "Reland "[vm, gc] Mark through new-space.""
This reverts commit 095171e937.

Reason for revert: breaks google3 (b/296014654)

Original change's description:
> Reland "[vm, gc] Mark through new-space."
>
>  - Adjust allocation stub write barrier elimination compensation to check if result is no longer in an active TLAB.
>
> TEST=ci
> Change-Id: I5d24602ae76ee861f2d009d67272251b04da3592
> Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/322448
> Commit-Queue: Ryan Macnak <rmacnak@google.com>
> Reviewed-by: Siva Annamalai <asiva@google.com>

Change-Id: I73b60f799dda755028b65653ac21f27c13e009e3
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/322682
Reviewed-by: Tess Strickland <sstrickl@google.com>
Reviewed-by: Martin Kustermann <kustermann@google.com>
Commit-Queue: Emmanuel Pellereau <emmanuelp@google.com>
Bot-Commit: Rubber Stamper <rubber-stamper@appspot.gserviceaccount.com>
Reviewed-by: Ivan Inozemtsev <iinozemtsev@google.com>
Reviewed-by: Alexander Thomas <athom@google.com>
Commit-Queue: Ivan Inozemtsev <iinozemtsev@google.com>
2023-08-28 14:34:21 +00:00
Ryan Macnak 095171e937 Reland "[vm, gc] Mark through new-space."
- Adjust allocation stub write barrier elimination compensation to check if result is no longer in an active TLAB.

TEST=ci
Change-Id: I5d24602ae76ee861f2d009d67272251b04da3592
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/322448
Commit-Queue: Ryan Macnak <rmacnak@google.com>
Reviewed-by: Siva Annamalai <asiva@google.com>
2023-08-25 21:13:02 +00:00
Ivan Inozemtsev 3176cfcd21 Revert "[vm, gc] Mark through new-space."
This reverts commit 3fb88e4c66.

Reason for revert: b/297175670

Original change's description:
> [vm, gc] Mark through new-space.
>
>  - Initial and final marking no longer visit all of new-space, reducing the STW pause for major GC.
>  - A scavenge during concurrent marking must forward / filter objects in the marking worklist that are moved / collected, increasing the STW pause for minor GC.
>  - Unreachable intergenerational cycles and weak references are collected in the next mark-sweep instead of first requiring enough scavenges to promote the whole cycle or weak target into old-space.
>  - Artificial minor GCs are no longer needed to avoid memory leaks from back-to-back major GCs.
>  - reachabilityBarrier is now just a count of major GCs.
>
> TEST=ci
> Change-Id: I6362802cd93ba5ba9c39f116ddff82e4feb4c312
> Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/321304
> Commit-Queue: Ryan Macnak <rmacnak@google.com>
> Reviewed-by: Siva Annamalai <asiva@google.com>

Change-Id: I33075156160dc35861355d738a5776b74dce88b9
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/322344
Reviewed-by: Martin Kustermann <kustermann@google.com>
Auto-Submit: Ivan Inozemtsev <iinozemtsev@google.com>
Commit-Queue: Martin Kustermann <kustermann@google.com>
2023-08-23 13:13:28 +00:00
Ryan Macnak 3fb88e4c66 [vm, gc] Mark through new-space.
- Initial and final marking no longer visit all of new-space, reducing the STW pause for major GC.
 - A scavenge during concurrent marking must forward / filter objects in the marking worklist that are moved / collected, increasing the STW pause for minor GC.
 - Unreachable intergenerational cycles and weak references are collected in the next mark-sweep instead of first requiring enough scavenges to promote the whole cycle or weak target into old-space.
 - Artificial minor GCs are no longer needed to avoid memory leaks from back-to-back major GCs.
 - reachabilityBarrier is now just a count of major GCs.

TEST=ci
Change-Id: I6362802cd93ba5ba9c39f116ddff82e4feb4c312
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/321304
Commit-Queue: Ryan Macnak <rmacnak@google.com>
Reviewed-by: Siva Annamalai <asiva@google.com>
2023-08-22 16:19:06 +00:00
Ilya Yanok 92ca7985a5 Revert "[vm, gc] Mark through new-space."
This reverts commit e95e7b8e96.

Reason for revert: suspected cause to non-deterministic AOT binaries crashes, b/296014654

Original change's description:
> [vm, gc] Mark through new-space.
>
>  - Initial and final marking no longer visit all of new-space, reducing the STW pause for major GC.
>  - A scavenge during concurrent marking must forward / filter objects in the marking worklist that are moved / collected, increasing the STW pause for minor GC.
>  - Unreachable intergenerational cycles and weak references are collected in the next mark-sweep instead of first requiring enough scavenges to promote the whole cycle or weak target into old-space.
>  - Artificial minor GCs are no longer needed to avoid memory leaks from back-to-back major GCs.
>  - reachabilityBarrier is now just a count of major GCs.
>
> TEST=ci
> Change-Id: I8c2c64b120766571b62d3bd8dab37ae81c2dca98
> Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/319583
> Commit-Queue: Ryan Macnak <rmacnak@google.com>
> Reviewed-by: Siva Annamalai <asiva@google.com>

Change-Id: Idda542c7c657d4f14c836423b173c9b067132212
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/320820
Reviewed-by: Martin Kustermann <kustermann@google.com>
Bot-Commit: Rubber Stamper <rubber-stamper@appspot.gserviceaccount.com>
Commit-Queue: Ilya Yanok <yanok@google.com>
2023-08-15 11:09:20 +00:00
Ryan Macnak e95e7b8e96 [vm, gc] Mark through new-space.
- Initial and final marking no longer visit all of new-space, reducing the STW pause for major GC.
 - A scavenge during concurrent marking must forward / filter objects in the marking worklist that are moved / collected, increasing the STW pause for minor GC.
 - Unreachable intergenerational cycles and weak references are collected in the next mark-sweep instead of first requiring enough scavenges to promote the whole cycle or weak target into old-space.
 - Artificial minor GCs are no longer needed to avoid memory leaks from back-to-back major GCs.
 - reachabilityBarrier is now just a count of major GCs.

TEST=ci
Change-Id: I8c2c64b120766571b62d3bd8dab37ae81c2dca98
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/319583
Commit-Queue: Ryan Macnak <rmacnak@google.com>
Reviewed-by: Siva Annamalai <asiva@google.com>
2023-08-14 18:16:05 +00:00
Ryan Macnak a7e20dd2b0 Revert "[vm, gc] Mark through new-space."
This reverts commit 6194209b28.

Reason for revert: issues on arm32

Original change's description:
> [vm, gc] Mark through new-space.
>
>  - Initial and final marking no longer visit all of new-space, reducing the STW pause for major GC.
>  - A scavenge during concurrent marking must forward / filter objects in the marking worklist that are moved / collected, increasing the STW pause for minor GC.
>  - Unreachable intergenerational cycles and weak references are collected in the next mark-sweep instead of first requiring enough scavenges to promote the whole cycle or weak target into old-space.
>  - Artificial minor GCs are no longer needed to avoid memory leaks from back-to-back major GCs.
>  - reachabilityBarrier is now just a count of major GCs.
>
> TEST=ci
> Change-Id: I3668a2e56821f9eadf96e38c228dab27be656016
> Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/309826
> Reviewed-by: Siva Annamalai <asiva@google.com>
> Commit-Queue: Ryan Macnak <rmacnak@google.com>

Change-Id: I434eb595c9e7858efc8c9b07cbca954e5649f506
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/319321
Commit-Queue: Ryan Macnak <rmacnak@google.com>
Reviewed-by: Siva Annamalai <asiva@google.com>
2023-08-09 18:13:17 +00:00
Ryan Macnak 6194209b28 [vm, gc] Mark through new-space.
- Initial and final marking no longer visit all of new-space, reducing the STW pause for major GC.
 - A scavenge during concurrent marking must forward / filter objects in the marking worklist that are moved / collected, increasing the STW pause for minor GC.
 - Unreachable intergenerational cycles and weak references are collected in the next mark-sweep instead of first requiring enough scavenges to promote the whole cycle or weak target into old-space.
 - Artificial minor GCs are no longer needed to avoid memory leaks from back-to-back major GCs.
 - reachabilityBarrier is now just a count of major GCs.

TEST=ci
Change-Id: I3668a2e56821f9eadf96e38c228dab27be656016
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/309826
Reviewed-by: Siva Annamalai <asiva@google.com>
Commit-Queue: Ryan Macnak <rmacnak@google.com>
2023-08-09 15:57:17 +00:00
Alexander Markov 2ee6fcf514 [vm] Remove TypeRef
TypeRef type wraps around another type and it was used to represent
a graph of recursive types. After [0], the only use of TypeRef is
for TypeParameter.bound which may indirectly reference the same
TypeParameter.

This change replaces TypeParameter.bound with TypeParameter.owner and
removes TypeRef entirely. Various parts of the VM no longer need to
handle and support TypeRefs.

TypeParameter.owner can reference a FunctionType, Class,
or, as an optimization, it can be set to null in order to share
class type parameters among different classes.

With the exception of the 'TypeParameter.owner' back pointer,
VM types are now not recursive and can be visited without
additional tracking.

Caveats:

* Generic FunctionType cannot be cloned in a shallow way:
  when copying a FunctionType, type parameters should be cloned too
  and their owners should be updated. For that reason,
  a mapping between 'from' and 'to' function types
  (FunctionTypeMapping) is maintained during type transformations
  such as InstantiateFrom.
  FunctionType::Clone is used instead of Object::Clone where
  appropriate.

* When testing types for subtyping and equivalence, mapping
  between function types is passed to make sure
  type parameters belong to the equivalent function types.

* IL serializer needs to serialize function types as a whole before
  serializing any types potentially pointing into the middle of a
  function type (such as return type 'List<Y0>' pointing into
  the middle of a function type 'List<Y0> Function<Y0>()').

[0] https://dart-review.googlesource.com/c/sdk/+/296300

TEST=ci

Change-Id: I67c2fd0117c6183a45e183919a7847fd1af70b3e
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/294165
Reviewed-by: Ryan Macnak <rmacnak@google.com>
Commit-Queue: Alexander Markov <alexmarkov@google.com>
2023-04-28 19:29:36 +00:00
Ryan Macnak 78daab15b3 [vm] Remove FindObject.
Before the calling convention change during the introduction of AOT, this was used to get code metadata associated with a frame. Its remaining non-test use is forming service IDs for code object, which can  use the regular visitors.

TEST=ci
Change-Id: Ica8eafe988d19eba8d905d9dc5907afbfd559118
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/296705
Commit-Queue: Ryan Macnak <rmacnak@google.com>
Reviewed-by: Siva Annamalai <asiva@google.com>
2023-04-21 22:41:28 +00:00
Ryan Macnak f9a6a5bdd2 [vm] Update NULL to nullptr in runtime/vm.
TEST=build
Change-Id: I2834ef7cf7cb7c8770f8167a2438cbedcee5c623
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/292063
Commit-Queue: Ryan Macnak <rmacnak@google.com>
Reviewed-by: Alexander Aprelev <aam@google.com>
2023-04-10 18:15:12 +00:00
Ryan Macnak 63e6041ca9 [vm] Update to variadic FATAL.
TEST=ci
Change-Id: Ic6bc784605e10760bb28ea6df34242336a33b4d0
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/286947
Reviewed-by: Alexander Aprelev <aam@google.com>
Commit-Queue: Ryan Macnak <rmacnak@google.com>
2023-03-06 22:06:59 +00:00
Ryan Macnak f3067e8740 [vm] Add WeakArray; to be used to create weak canonical sets.
TEST=ci
Bug: https://github.com/dart-lang/sdk/issues/50648
Change-Id: I788a8e3e5e8383c0b8d6f248d64a33dc67013260
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/278860
Reviewed-by: Siva Annamalai <asiva@google.com>
Commit-Queue: Ryan Macnak <rmacnak@google.com>
2023-01-17 20:33:03 +00:00
Josh Soref 0633041729 Spelling runtime vm
Closes https://github.com/dart-lang/sdk/pull/50786

TEST=ci

GitOrigin-RevId: 781a38e2925ba505f0223ecd578faa9be8e1485c
Change-Id: Ia3c615012d1bac3f0cf64dc01c2ceb40d50d1193
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/276684
Reviewed-by: Alexander Markov <alexmarkov@google.com>
Commit-Queue: Martin Kustermann <kustermann@google.com>
2022-12-29 10:18:02 +00:00
Alexander Markov 3675fd25f4 [vm] Packed representation of record shape
The representation of record shape in record instances and record
types is changed from a pair

  int num_fields
  Array field_names

to a single integer - packed bitfield

  int num_fields(16)
  int field_names_index(kSmiBits-16)

where field names index is an index in the array available from
ObjectStore.

With the new representation of record shapes:
1) Size of record instances is reduced.
2) Number of comparisons for a shape test reduced from 2 to 1
(shape test is used during type checks).
3) A few operations removed from Record.hashCode.
4) Type testing stubs (TTS) are now supported for record types with
named fields. Previously it was not possible to check shape of records
with named fields in TTS as TTS cannot access object pool and cannot
load field names array).

TEST=existing

Issue: https://github.com/dart-lang/sdk/issues/49719

Change-Id: I7cdcbb53938aba5d561cd24dc99530395dbbea7e
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/276201
Reviewed-by: Ryan Macnak <rmacnak@google.com>
Commit-Queue: Alexander Markov <alexmarkov@google.com>
2022-12-20 20:11:48 +00:00
Ryan Macnak 9182d5e535 [vm] Raise the limit on the number of classes.
Some large applications are bumping up against the 16-bit limit.

The object header changes from hash:32,cid:16,size:8,gc:8 to hash:32,cid:20,size:4,gc:8.

Because the CID field is no longer a power of two, it takes two instructions to load instead of one, increasing code size. The alternative change to cid:32,hash:24,gc:8 was considered and rejected because the reduction in hash bits very noticeably affects performance in applications with large data sets.

TEST=ci
Bug: b/255934984
Change-Id: I5fa36ba48a6852359d994393cf80c6a761c5d84c
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/269120
Reviewed-by: Martin Kustermann <kustermann@google.com>
Commit-Queue: Ryan Macnak <rmacnak@google.com>
2022-11-17 20:35:47 +00:00
Ryan Macnak c29f994023 [vm] Removed dead parameter from VisitPointersPrecise.
TEST=ci
Change-Id: I7ca38b2ebb659cdf1b20cc7ab7bed9b0958e6330
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/269980
Reviewed-by: Siva Annamalai <asiva@google.com>
Commit-Queue: Ryan Macnak <rmacnak@google.com>
2022-11-15 23:47:45 +00:00
Ryan Macnak a2de36e708 [vm] Rename the default implementation classes of Map and Set.
_InternalLinkedHashMap => _Map
_InternalImmutableLinkedHashMap => _ConstMap
_InternalLinkedHashSet => _Set
_InternalImmutableLinkedHashSet => _ConstSet

This makes things nicer to read in places that display implementation names, such as stack traces, debuggers, profilers and inspectors.

TEST=ci
Change-Id: Iec851c80ea2086cbe79934565dbf35f04809a836
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/266303
Reviewed-by: Daco Harkes <dacoharkes@google.com>
Commit-Queue: Ryan Macnak <rmacnak@google.com>
Reviewed-by: Chloe Stefantsova <cstefantsova@google.com>
2022-11-15 17:15:58 +00:00
Alexander Markov 10e9606861 [vm] More efficient 'is' tests for record types
'is' tests against record types are split into series of 'is' tests of
record fields. This is more efficient as record instances cannot be
added to subtype test caches (because type of a record instance
depends on types of its fields).

This change also adds canonicalization and constant evaluation of
LoadFieldInstr for record fields.

Performance on a trivial micro-benchmark (on x64):
JIT (RunTime): 4519104.5 -> 20031.5
AOT (RunTime): 4352583.0 -> 26281.6

TEST=ci
Issue: https://github.com/dart-lang/sdk/issues/49719
Change-Id: I2ed464cd3b31f365b17805f4e7debe1d6d1051fa
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/268080
Reviewed-by: Ryan Macnak <rmacnak@google.com>
Reviewed-by: Slava Egorov <vegorov@google.com>
Commit-Queue: Alexander Markov <alexmarkov@google.com>
2022-11-07 22:27:31 +00:00
Ryan Macnak efbf68f306 [vm, gc] Common page structure for both generations.
- Prep work for non-moving promotion.
 - The generations still have different alignment offsets.
 - Old-space pages now participate in the page cache.
 - Fix boolean/null bit tricks to assert the right requirements on the alignment of a page's first object.

TEST=ci
Change-Id: I4369d8c6af73228e162c226d411914868bafed33
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/260401
Reviewed-by: Siva Annamalai <asiva@google.com>
Commit-Queue: Ryan Macnak <rmacnak@google.com>
2022-09-27 21:34:05 +00:00
Vyacheslav Egorov 83ab5d5ca3 [vm] Remove dynamic field unboxing in JIT
Instead apply the same approach as we do in AOT: unbox based on the
static type information. There are no TFA results available in JIT,
but we could still unbox fields when running in sound null-safety.

TEST=ci

Cq-Include-Trybots: luci.dart.try:vm-kernel-reload-linux-release-x64-try,vm-kernel-reload-linux-debug-x64-try,vm-kernel-reload-rollback-linux-debug-x64-try,vm-kernel-reload-rollback-linux-release-x64-try,vm-kernel-precomp-linux-debug-x64-try,vm-kernel-precomp-linux-product-x64-try,vm-kernel-precomp-linux-release-x64-try,vm-kernel-precomp-nnbd-linux-release-simarm64-try,vm-kernel-linux-debug-simriscv64-try,vm-kernel-precomp-linux-debug-simriscv64-try,vm-kernel-nnbd-linux-release-ia32-try,vm-kernel-nnbd-linux-debug-x64-try,vm-kernel-nnbd-linux-debug-ia32-try,vm-kernel-nnbd-linux-release-simarm-try,vm-kernel-nnbd-linux-release-simarm64-try
Change-Id: Ide2e78c6659261ef8d245a4586cf699ea0fbb459
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/256211
Reviewed-by: Ryan Macnak <rmacnak@google.com>
Commit-Queue: Slava Egorov <vegorov@google.com>
Reviewed-by: Martin Kustermann <kustermann@google.com>
Reviewed-by: Alexander Markov <alexmarkov@google.com>
2022-09-20 13:42:45 +00:00
Alexander Markov c94103ae05 [vm] Initial implementation of record instances
TEST=ci

Issue: https://github.com/dart-lang/sdk/issues/49719
Change-Id: I82ba571d1935d616fe3d4d6d579e59eb57d65a43
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/256804
Commit-Queue: Alexander Markov <alexmarkov@google.com>
Reviewed-by: Ryan Macnak <rmacnak@google.com>
2022-09-12 22:41:57 +00:00
Alexander Markov 9a023aeae9 [vm] Initial implementation of record types
TEST=language/record_type_test

Issue: https://github.com/dart-lang/sdk/issues/49719
Change-Id: Ib2100c23513395c9fa9c541320eacbb33a2a119e
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/256802
Reviewed-by: Ryan Macnak <rmacnak@google.com>
Reviewed-by: Martin Kustermann <kustermann@google.com>
Commit-Queue: Alexander Markov <alexmarkov@google.com>
2022-09-12 22:40:57 +00:00
Vyacheslav Egorov 4a4eedd860 [vm] Clean up ClassTable
* Merge ClassTable and SharedClassTable back together;
* Simplify handling of multiple arrays growing in sync;
* Refactor how reload deals with ClassTable.

The last change is the most important because it makes it
much easier to reason about the code. We move away from
copying bits and pieces of the class table and shared
class table into reload contexts.

Having two class table fields in the isolate group makes
it easier to reason about. One field contains program
class table (one modified by kernel loader and accessed
by various program structure cid lookups) and heap
walk class table (used by GC visitors). Normally these
two fields point to the same class table, but during
hot reload we temporary split them apart: original
class table is kept as a heap walk class table, while
program class table is replaced by a clone and updated
by reload.

If reload succeeds we drop original class table and
set program class table as heap walk one.

If reload fails we drop the program class table and
restore original one from heap walk table.

TEST=ci

Cq-Include-Trybots: luci.dart.try:vm-kernel-reload-linux-release-x64-try,vm-kernel-reload-linux-debug-x64-try,vm-kernel-reload-rollback-linux-debug-x64-try,vm-kernel-reload-rollback-linux-release-x64-try,vm-kernel-linux-debug-x64-try,vm-kernel-precomp-tsan-linux-release-x64-try,vm-kernel-tsan-linux-release-x64-try,vm-kernel-precomp-asan-linux-release-x64-try,vm-kernel-asan-linux-release-x64-try
Change-Id: I8b66259fcc474dea7dd2af063e4772df99be06c4
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/258361
Commit-Queue: Slava Egorov <vegorov@google.com>
Reviewed-by: Ryan Macnak <rmacnak@google.com>
2022-09-10 15:12:35 +00:00
Ryan Macnak c1e67ac84f [vm] Recognize unmodifiable typed data views.
These types now work with Dart_TypedDataAcquireData.

The presence of these types no longer degrades the performance of typed data indexed loads.

The presence of these types degrades the performance of typed data indexed stores much less. The performance of indexed stores is somewhat regressed if these types were not used.

TEST=ci
Bug: https://github.com/dart-lang/sdk/issues/32028
Bug: https://github.com/dart-lang/sdk/issues/40924
Bug: https://github.com/dart-lang/sdk/issues/42785
Change-Id: Iffad865708501acf96db418985cd5a69bd9afa55
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/254501
Reviewed-by: Martin Kustermann <kustermann@google.com>
Commit-Queue: Ryan Macnak <rmacnak@google.com>
2022-08-11 18:10:48 +00:00
Ryan Macnak 10bf1cfe58 Revert "[vm] Recognize unmodifiabled typed data views."
This reverts commit d1112d37bd.

Reason for revert: b/242043014

Original change's description:
> [vm] Recognize unmodifiabled typed data views.
>
> These types now work with Dart_TypedDataAcquireData.
>
> The presence of these types no longer degrades the performance of typed data indexed loads.
>
> The presence of these types degrades the performance of typed data indexed stores much less. The performance of indexed stores is somewhat regressed if these types were not used.
>
> TEST=ci
> Bug: https://github.com/dart-lang/sdk/issues/32028
> Bug: https://github.com/dart-lang/sdk/issues/40924
> Bug: https://github.com/dart-lang/sdk/issues/42785
> Change-Id: I05ac5c9543f6f61ac37533b9efe511254778caed
> Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/253700
> Reviewed-by: Aske Simon Christensen <askesc@google.com>
> Reviewed-by: Martin Kustermann <kustermann@google.com>
> Commit-Queue: Ryan Macnak <rmacnak@google.com>

TBR=kustermann@google.com,rmacnak@google.com,askesc@google.com

TEST=ci
Change-Id: I32c1c460fc30c51bc0d42e7cfaafe72bf5630069
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Bug: https://github.com/dart-lang/sdk/issues/32028
Bug: https://github.com/dart-lang/sdk/issues/40924
Bug: https://github.com/dart-lang/sdk/issues/42785
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/254560
Reviewed-by: Siva Annamalai <asiva@google.com>
Reviewed-by: Ryan Macnak <rmacnak@google.com>
Commit-Queue: Ryan Macnak <rmacnak@google.com>
2022-08-10 20:08:22 +00:00
Ryan Macnak d1112d37bd [vm] Recognize unmodifiabled typed data views.
These types now work with Dart_TypedDataAcquireData.

The presence of these types no longer degrades the performance of typed data indexed loads.

The presence of these types degrades the performance of typed data indexed stores much less. The performance of indexed stores is somewhat regressed if these types were not used.

TEST=ci
Bug: https://github.com/dart-lang/sdk/issues/32028
Bug: https://github.com/dart-lang/sdk/issues/40924
Bug: https://github.com/dart-lang/sdk/issues/42785
Change-Id: I05ac5c9543f6f61ac37533b9efe511254778caed
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/253700
Reviewed-by: Aske Simon Christensen <askesc@google.com>
Reviewed-by: Martin Kustermann <kustermann@google.com>
Commit-Queue: Ryan Macnak <rmacnak@google.com>
2022-08-09 20:57:05 +00:00
Alexander Markov af4da780be [vm] New async/async* implementation in JIT mode
The new implementation is based on suspend/resume stubs and doesn't
use desugaring of async functions on kernel AST.

Previously, new implementation of async/async* was only supported in
AOT mode. This change adds all necessary bits for the JIT mode:

 * Suspending variable-length frames (for unoptimized code).
 * Handling of Code and pool pointers in Dart stack frames.
 * OSR.
 * Deoptimization.
 * Hot reload.
 * Debugger.

The new implementation is not enabled in JIT mode yet.

Design doc: go/compact-async-await.
TEST=ci

Issue: https://github.com/dart-lang/sdk/issues/48378
Change-Id: I477d6684bdce7cbc1edb179ae2271ff598b7dcc5
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/246081
Reviewed-by: Martin Kustermann <kustermann@google.com>
Reviewed-by: Johnni Winther <johnniwinther@google.com>
Commit-Queue: Alexander Markov <alexmarkov@google.com>
Reviewed-by: Slava Egorov <vegorov@google.com>
2022-06-02 23:39:45 +00:00
Alexander Markov bf4bb95308 [vm] New async/await implementation in the VM, part 2 - vm
The new implementation moves away from desugaring of async
functions on kernel AST, state machine generated in the flow graph and
capturing all local variables in the context.

Instead, async/await is implemented using a few stubs
(InitSuspendableFunction, Suspend, Resume, Return and
AsyncExceptionHandler). The stubs are implemented in a
platform-independent way using (macro-)assembler helpers.
When suspending a function, its frame is copied into a SuspendState
object, and when resuming a function it is copied back onto the stack.
No extra code is generated for accessing local variables.
Callback closures are created lazily on the first await.

Design doc: go/compact-async-await.

Part 1 (kernel): https://dart-review.googlesource.com/c/sdk/+/241842

TEST=ci

Issue: https://github.com/dart-lang/sdk/issues/48378
Change-Id: Ibad757035b7cc438ebdff80b460728b1d3eff1f5
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/242000
Reviewed-by: Ryan Macnak <rmacnak@google.com>
Reviewed-by: Slava Egorov <vegorov@google.com>
2022-04-29 01:03:50 +00:00
Daco Harkes 532c116cd2 [vm] Implement NativeFinalizer
This CL implements `NativeFinalizer` in the GC.

`FinalizerEntry`s are extended to track `external_size` and in which
`Heap::Space` the finalizable value is.

On attaching a native finalizer, the external size is added to the
relevant heap. When the finalizable value is promoted from new to old
space, the external size is promoted as well. And when a native
finalizer is run or is detached, the external size is removed from the
relevant heap again.

In contrast to Dart `Finalizer`s, `NativeFinalizer`s are run on isolate
shutdown.

When the `NativeFinalizer`s themselves are collected, the finalizers are
not run. Users should stick the native finalizer in a global variable to
ensure finalization. We will revisit this design when we add send and
exit support, because there is a design space to explore what to do in
that case. This current solution promises the least to users.

In this implementation native finalizers have a Dart entry to clean up
the entries from the `all_entries` field of the finalizer. We should
consider using another data structure that avoids the need for this Dart
entry. See the TODO left in the code.

Bug: https://github.com/dart-lang/sdk/issues/47777

TEST=runtime/tests/vm/dart(_2)/isolates/fast_object_copy_test.dart
TEST=runtime/vm/object_test.cc
TEST=tests/ffi(_2)/vmspecific_native_finalizer_*

Change-Id: I8f594c80c3c344ad83e1f2de10de028eb8456121
Cq-Include-Trybots: luci.dart.try:vm-kernel-reload-rollback-linux-debug-x64-try,vm-kernel-reload-linux-debug-x64-try,vm-ffi-android-debug-arm64c-try,dart-sdk-mac-arm64-try,vm-kernel-mac-release-arm64-try,pkg-mac-release-arm64-try,vm-kernel-precomp-nnbd-mac-release-arm64-try,vm-kernel-win-debug-x64c-try,vm-kernel-win-debug-x64-try,vm-kernel-precomp-win-debug-x64c-try,vm-kernel-nnbd-win-release-ia32-try,vm-ffi-android-debug-arm-try,vm-precomp-ffi-qemu-linux-release-arm-try,vm-kernel-mac-debug-x64-try,vm-kernel-nnbd-mac-debug-x64-try,vm-kernel-nnbd-linux-debug-ia32-try,benchmark-linux-try,flutter-frontend-try,pkg-linux-debug-try,vm-kernel-asan-linux-release-x64-try,vm-kernel-gcc-linux-try,vm-kernel-optcounter-threshold-linux-release-x64-try,vm-kernel-precomp-linux-debug-simarm_x64-try,vm-kernel-precomp-obfuscate-linux-release-x64-try,vm-kernel-precomp-linux-debug-x64-try,vm-kernel-precomp-linux-debug-x64c-try
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/236320
Reviewed-by: Martin Kustermann <kustermann@google.com>
Reviewed-by: Slava Egorov <vegorov@google.com>
Commit-Queue: Daco Harkes <dacoharkes@google.com>
2022-03-26 09:41:21 +00:00
Daco Harkes e151a81108 Reland "[vm] Implement Finalizer"
Original CL in patchset 1.
Split-off https://dart-review.googlesource.com/c/sdk/+/238341
And pulled in fix https://dart-review.googlesource.com/c/sdk/+/238582
(Should merge cleanly when this lands later.)

This CL implements the `Finalizer` in the GC.

The GC is specially aware of two types of objects for the purposes of
running finalizers.

1) `FinalizerEntry`
2) `Finalizer` (`FinalizerBase`, `_FinalizerImpl`)

A `FinalizerEntry` contains the `value`, the optional `detach` key, and
the `token`, and a reference to the `finalizer`.
An entry only holds on weakly to the value, detach key, and finalizer.
(Similar to how `WeakReference` only holds on weakly to target).

A `Finalizer` contains all entries, a list of entries of which the value
is collected, and a reference to the isolate.

When a the value of an entry is GCed, the enry is added over to the
collected list.
If any entry is moved to the collected list, a message is sent that
invokes the finalizer to call the callback on all entries in that list.

When a finalizer is detached by the user, the entry token is set to the
entry itself and is removed from the all entries set.
This ensures that if the entry was already moved to the collected list,
the finalizer is not executed.

To speed up detaching, we use a weak map from detach keys to list of
entries. This ensures entries can be GCed.

Both the scavenger and marker tasks process finalizer entries in
parallel.
Parallel tasks use an atomic exchange on the head of the collected
entries list, ensuring no entries get lost.
The mutator thread is guaranteed to be stopped when processing entries.
This ensures that we do not need barriers for moving entries into the
finalizers collected list.
Dart reads and replaces the collected entries list also with an atomic
exchange, ensuring the GC doesn't run in between a load/store.

When a finalizer gets posted a message to process finalized objects, it
is being kept alive by the message.
An alternative design would be to pre-allocate a `WeakReference` in the
finalizer pointing to the finalizer, and send that itself.
This would be at the cost of an extra object.

Send and exit is not supported in this CL, support will be added in a
follow up CL. Trying to send will throw.

Bug: https://github.com/dart-lang/sdk/issues/47777

TEST=runtime/tests/vm/dart/finalizer/*
TEST=runtime/tests/vm/dart_2/isolates/fast_object_copy_test.dart
TEST=runtime/vm/object_test.cc

Change-Id: Ibdfeadc16d5d69ade50aae5b9f794284c4c4dbab
Cq-Include-Trybots: luci.dart.try:vm-kernel-reload-rollback-linux-debug-x64-try,vm-kernel-reload-linux-debug-x64-try,vm-ffi-android-debug-arm64c-try,dart-sdk-mac-arm64-try,vm-kernel-mac-release-arm64-try,pkg-mac-release-arm64-try,vm-kernel-precomp-nnbd-mac-release-arm64-try,vm-kernel-win-debug-x64c-try,vm-kernel-win-debug-x64-try,vm-kernel-precomp-win-debug-x64c-try,vm-kernel-nnbd-win-release-ia32-try,vm-ffi-android-debug-arm-try,vm-precomp-ffi-qemu-linux-release-arm-try,vm-kernel-mac-debug-x64-try,vm-kernel-nnbd-mac-debug-x64-try,vm-kernel-nnbd-linux-debug-ia32-try,benchmark-linux-try,flutter-analyze-try,flutter-frontend-try,pkg-linux-debug-try,vm-kernel-asan-linux-release-x64-try,vm-kernel-gcc-linux-try,vm-kernel-optcounter-threshold-linux-release-x64-try,vm-kernel-precomp-linux-debug-simarm_x64-try,vm-kernel-precomp-obfuscate-linux-release-x64-try,vm-kernel-precomp-linux-debug-x64-try,vm-kernel-precomp-linux-debug-x64c-try
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/238086
Reviewed-by: Martin Kustermann <kustermann@google.com>
Reviewed-by: Ryan Macnak <rmacnak@google.com>
Commit-Queue: Daco Harkes <dacoharkes@google.com>
2022-03-25 10:29:30 +00:00
Daco Harkes 37526fc8d7 Revert "[vm] Implement Finalizer"
This reverts commit 7dca34c235.

Reason for revert: b/226085355 dart_vm_test crashing. Unclear what
the cause is. Reverting so we can triage the issue.

TEST=This is a revert.

Original change's description:
> [vm] Implement `Finalizer`
>
> This CL implements the `Finalizer` in the GC.
>
> (This CL does not yet implement `NativeFinalizer`.)
>
> The GC is specially aware of two types of objects for the purposes of
> running finalizers.
>
> 1) `FinalizerEntry`
> 2) `Finalizer` (`FinalizerBase`, `_FinalizerImpl`)
>
> A `FinalizerEntry` contains the `value`, the optional `detach` key, and
> the `token`, and a reference to the `finalizer`.
> An entry only holds on weakly to the value, detach key, and finalizer.
> (Similar to how `WeakReference` only holds on weakly to target).
>
> A `Finalizer` contains all entries, a list of entries of which the value
> is collected, and a reference to the isolate.
>
> When a the value of an entry is GCed, the enry is added over to the
> collected list.
> If any entry is moved to the collected list, a message is sent that
> invokes the finalizer to call the callback on all entries in that list.
>
> When a finalizer is detached by the user, the entry token is set to the
> entry itself and is removed from the all entries set.
> This ensures that if the entry was already moved to the collected list,
> the finalizer is not executed.
>
> To speed up detaching, we use a weak map from detach keys to list of
> entries. This ensures entries can be GCed.
>
> Both the scavenger and marker tasks process finalizer entries in
> parallel.
> Parallel tasks use an atomic exchange on the head of the collected
> entries list, ensuring no entries get lost.
> The mutator thread is guaranteed to be stopped when processing entries.
> This ensures that we do not need barriers for moving entries into the
> finalizers collected list.
> Dart reads and replaces the collected entries list also with an atomic
> exchange, ensuring the GC doesn't run in between a load/store.
>
> When a finalizer gets posted a message to process finalized objects, it
> is being kept alive by the message.
> An alternative design would be to pre-allocate a `WeakReference` in the
> finalizer pointing to the finalizer, and send that itself.
> This would be at the cost of an extra object.
>
> Send and exit is not supported in this CL, support will be added in a
> follow up CL. Trying to send will throw.
>
> Bug: https://github.com/dart-lang/sdk/issues/47777
>
> TEST=runtime/tests/vm/dart/finalizer/*
> TEST=runtime/tests/vm/dart_2/isolates/fast_object_copy_test.dart
> TEST=runtime/vm/object_test.cc
>
> Change-Id: I03e6b4a46212316254bf46ba3f2df333abaa686c
> Cq-Include-Trybots: luci.dart.try:vm-kernel-reload-rollback-linux-debug-x64-try,vm-kernel-reload-linux-debug-x64-try,vm-ffi-android-debug-arm64c-try,dart-sdk-mac-arm64-try,vm-kernel-mac-release-arm64-try,pkg-mac-release-arm64-try,vm-kernel-precomp-nnbd-mac-release-arm64-try,vm-kernel-win-debug-x64c-try,vm-kernel-win-debug-x64-try,vm-kernel-precomp-win-debug-x64c-try,vm-kernel-nnbd-win-release-ia32-try,vm-ffi-android-debug-arm-try,vm-precomp-ffi-qemu-linux-release-arm-try,vm-kernel-mac-debug-x64-try,vm-kernel-nnbd-mac-debug-x64-try,vm-kernel-nnbd-linux-debug-ia32-try,benchmark-linux-try,flutter-analyze-try,flutter-frontend-try,pkg-linux-debug-try,vm-kernel-asan-linux-release-x64-try,vm-kernel-gcc-linux-try,vm-kernel-optcounter-threshold-linux-release-x64-try,vm-kernel-precomp-linux-debug-simarm_x64-try,vm-kernel-precomp-obfuscate-linux-release-x64-try,vm-kernel-precomp-linux-debug-x64-try,vm-kernel-precomp-linux-debug-x64c-try
> Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/229544
> Reviewed-by: Lasse Nielsen <lrn@google.com>
> Reviewed-by: Slava Egorov <vegorov@google.com>
> Reviewed-by: Martin Kustermann <kustermann@google.com>
> Reviewed-by: Ryan Macnak <rmacnak@google.com>
> Commit-Queue: Daco Harkes <dacoharkes@google.com>

TBR=lrn@google.com,vegorov@google.com,kustermann@google.com,rmacnak@google.com,dacoharkes@google.com

Change-Id: I991f6e49896d18a8d70210cf315d858b462d66c9
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Bug: https://github.com/dart-lang/sdk/issues/47777
Cq-Include-Trybots: luci.dart.try:vm-kernel-reload-rollback-linux-debug-x64-try,vm-kernel-reload-linux-debug-x64-try,vm-ffi-android-debug-arm64c-try,dart-sdk-mac-arm64-try,vm-kernel-mac-release-arm64-try,pkg-mac-release-arm64-try,vm-kernel-precomp-nnbd-mac-release-arm64-try,vm-kernel-win-debug-x64c-try,vm-kernel-win-debug-x64-try,vm-kernel-precomp-win-debug-x64c-try,vm-kernel-nnbd-win-release-ia32-try,vm-ffi-android-debug-arm-try,vm-precomp-ffi-qemu-linux-release-arm-try,vm-kernel-mac-debug-x64-try,vm-kernel-nnbd-mac-debug-x64-try,vm-kernel-nnbd-linux-debug-ia32-try,benchmark-linux-try,flutter-analyze-try,flutter-frontend-try,pkg-linux-debug-try,vm-kernel-asan-linux-release-x64-try,vm-kernel-gcc-linux-try,vm-kernel-optcounter-threshold-linux-release-x64-try,vm-kernel-precomp-linux-debug-simarm_x64-try,vm-kernel-precomp-obfuscate-linux-release-x64-try,vm-kernel-precomp-linux-debug-x64-try,vm-kernel-precomp-linux-debug-x64c-try
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/238080
Reviewed-by: Slava Egorov <vegorov@google.com>
Reviewed-by: Daco Harkes <dacoharkes@google.com>
Commit-Queue: Daco Harkes <dacoharkes@google.com>
2022-03-22 11:55:38 +00:00
Daco Harkes 7dca34c235 [vm] Implement Finalizer
This CL implements the `Finalizer` in the GC.

(This CL does not yet implement `NativeFinalizer`.)

The GC is specially aware of two types of objects for the purposes of
running finalizers.

1) `FinalizerEntry`
2) `Finalizer` (`FinalizerBase`, `_FinalizerImpl`)

A `FinalizerEntry` contains the `value`, the optional `detach` key, and
the `token`, and a reference to the `finalizer`.
An entry only holds on weakly to the value, detach key, and finalizer.
(Similar to how `WeakReference` only holds on weakly to target).

A `Finalizer` contains all entries, a list of entries of which the value
is collected, and a reference to the isolate.

When a the value of an entry is GCed, the enry is added over to the
collected list.
If any entry is moved to the collected list, a message is sent that
invokes the finalizer to call the callback on all entries in that list.

When a finalizer is detached by the user, the entry token is set to the
entry itself and is removed from the all entries set.
This ensures that if the entry was already moved to the collected list,
the finalizer is not executed.

To speed up detaching, we use a weak map from detach keys to list of
entries. This ensures entries can be GCed.

Both the scavenger and marker tasks process finalizer entries in
parallel.
Parallel tasks use an atomic exchange on the head of the collected
entries list, ensuring no entries get lost.
The mutator thread is guaranteed to be stopped when processing entries.
This ensures that we do not need barriers for moving entries into the
finalizers collected list.
Dart reads and replaces the collected entries list also with an atomic
exchange, ensuring the GC doesn't run in between a load/store.

When a finalizer gets posted a message to process finalized objects, it
is being kept alive by the message.
An alternative design would be to pre-allocate a `WeakReference` in the
finalizer pointing to the finalizer, and send that itself.
This would be at the cost of an extra object.

Send and exit is not supported in this CL, support will be added in a
follow up CL. Trying to send will throw.

Bug: https://github.com/dart-lang/sdk/issues/47777

TEST=runtime/tests/vm/dart/finalizer/*
TEST=runtime/tests/vm/dart_2/isolates/fast_object_copy_test.dart
TEST=runtime/vm/object_test.cc

Change-Id: I03e6b4a46212316254bf46ba3f2df333abaa686c
Cq-Include-Trybots: luci.dart.try:vm-kernel-reload-rollback-linux-debug-x64-try,vm-kernel-reload-linux-debug-x64-try,vm-ffi-android-debug-arm64c-try,dart-sdk-mac-arm64-try,vm-kernel-mac-release-arm64-try,pkg-mac-release-arm64-try,vm-kernel-precomp-nnbd-mac-release-arm64-try,vm-kernel-win-debug-x64c-try,vm-kernel-win-debug-x64-try,vm-kernel-precomp-win-debug-x64c-try,vm-kernel-nnbd-win-release-ia32-try,vm-ffi-android-debug-arm-try,vm-precomp-ffi-qemu-linux-release-arm-try,vm-kernel-mac-debug-x64-try,vm-kernel-nnbd-mac-debug-x64-try,vm-kernel-nnbd-linux-debug-ia32-try,benchmark-linux-try,flutter-analyze-try,flutter-frontend-try,pkg-linux-debug-try,vm-kernel-asan-linux-release-x64-try,vm-kernel-gcc-linux-try,vm-kernel-optcounter-threshold-linux-release-x64-try,vm-kernel-precomp-linux-debug-simarm_x64-try,vm-kernel-precomp-obfuscate-linux-release-x64-try,vm-kernel-precomp-linux-debug-x64-try,vm-kernel-precomp-linux-debug-x64c-try
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/229544
Reviewed-by: Lasse Nielsen <lrn@google.com>
Reviewed-by: Slava Egorov <vegorov@google.com>
Reviewed-by: Martin Kustermann <kustermann@google.com>
Reviewed-by: Ryan Macnak <rmacnak@google.com>
Commit-Queue: Daco Harkes <dacoharkes@google.com>
2022-03-22 10:30:18 +00:00
Daco Harkes 828dcd00e8 [vm] Implement WeakReference in the VM
This CL implements `WeakReference` in the VM.

* This reduces the size of weak references from 2 objects using 8 words
  to 1 object using 4 words.
* This makes loads of weak reference targets a single load instead of
  two.
* This avoids the fix-point in the GC and message object copying for
  weak references. (N.b. Weak references need to be processed _after_
  the fix-point for weak properties.)

The semantics of weak references in messages is that their target gets
set to `null` if the target is not included in the message by a strong
reference.

The tests take particular care to exercise the case where a weak
reference's target is only kept alive because a weak property key is
alive and it refers to the target in its value. This exercises the fact
that weak references need to be processed last.

Does not add support for weak references in the app snapshot. It would
be dead code until we start using weak references in for example the
CFE.

This CL does not try to unify weak references and weak properties in
the GC or messaging (as proposed in go/dart-vm-weakreference), because
their semantics differ enough.

Closes: https://github.com/dart-lang/sdk/issues/48162

TEST=runtime/tests/vm/dart/finalizer/weak_reference_run_gc_test.dart
TEST=runtime/tests/vm/dart/isolates/fast_object_copy_test.dart
TEST=runtime/vm/object_test.cc
TEST=tests/lib/isolate/weak_reference_message_1_test.dart
TEST=tests/lib/isolate/weak_reference_message_2_test.dart

Change-Id: I3810e919a5866f3ae8a95bd9aa23a880a0b0921c
Cq-Include-Trybots: luci.dart.try:app-kernel-linux-debug-x64-try,dart-sdk-mac-arm64-try,vm-canary-linux-debug-try,vm-fuchsia-release-x64-try,vm-kernel-gcc-linux-try,vm-kernel-asan-linux-release-x64-try,vm-kernel-linux-debug-x64c-try,vm-kernel-linux-debug-x64-try,vm-kernel-linux-debug-simriscv64-try,vm-kernel-mac-debug-x64-try,vm-kernel-nnbd-linux-debug-x64-try,vm-kernel-nnbd-linux-release-ia32-try,vm-kernel-nnbd-linux-release-simarm64-try,vm-kernel-nnbd-linux-release-simarm-try,vm-kernel-nnbd-mac-debug-arm64-try,vm-kernel-nnbd-mac-debug-x64-try,vm-kernel-nnbd-win-release-ia32-try,vm-kernel-nnbd-win-release-x64-try,vm-kernel-optcounter-threshold-linux-release-x64-try,vm-kernel-precomp-android-release-arm_x64-try,vm-kernel-precomp-linux-debug-x64-try,vm-kernel-precomp-linux-debug-x64c-try,vm-kernel-precomp-win-debug-x64c-try,vm-kernel-reload-rollback-linux-debug-x64-try,vm-kernel-reload-linux-debug-x64-try,vm-kernel-win-debug-ia32-try,vm-kernel-win-debug-x64-try
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/232087
Reviewed-by: Ryan Macnak <rmacnak@google.com>
Reviewed-by: Martin Kustermann <kustermann@google.com>
Commit-Queue: Daco Harkes <dacoharkes@google.com>
2022-02-10 21:59:41 +00:00
Vyacheslav Egorov 13d27d669d [vm] Improve Code cluster layout for startup
This change bakes binary search table which maps PC ranges
to corresponding stack maps and Code objects (if still present
in the snapshot) into RO data section of the snapshot - instead
of constructing it at load time.

This allows to considerably reduce amount of work done when
loading Code cluster for programs which have majority of their
Code objects discarded (i.e. in DWARF stack traces mode): as
we no longer write / read any information for discarded Code
objects.

This CL also changes program visitor to deduplicate Code objects
if their instructions are deduplicated in AOT mode. Only a single
Code object can be choose as a representative for the given
PC range so it does not make sense to write multiple Code objects
into the snapshot which refer to the same Instructions.

The overall improvement is hard to quantify but ReadProgramSnapshot
shows the following improvement when starting a large
Flutter application on a slow Android device:

  before  223.55±59.94 (192.02 .. 391.74) ms
  after   178.06±47.03 (151.31 .. 291.34) ms

This CL packs CompressedStackMaps next to the binary search table
itself allowing us to address them via offsets instead of
pointers.

Snapshot sizes are actually affected positively by this change. On
the same large Flutter application I see

  DWARF stack traces on:  -1.34% total SO size
  DWARF stack traces off: -1.63% total SO size

Issue https://github.com/dart-lang/sdk/issues/46116

TEST=ci

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Change-Id: Ic997045a33daa81ec68df462a0792915885df66b
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/220766
Reviewed-by: Alexander Markov <alexmarkov@google.com>
Reviewed-by: Martin Kustermann <kustermann@google.com>
Commit-Queue: Slava Egorov <vegorov@google.com>
2021-12-16 10:39:49 +00:00
Vyacheslav Egorov 71c9c2cd83 [vm] Remove support for non-bare AOT snapshots
Every AOT user out there has been using bare instructions mode
and continuing to maintaining non-bare instructions mode simply
adds costs (both in terms of time spent making changes to work
in a mode that is not used and CI resources spent on testing it).

This change removes FLAG_use_bare_instructions and changes the code
to assume that FLAG_precompiled_mode implies bare instructions.

TEST=ci

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Change-Id: I5032b13bfcb613f79865f2cfa139cca8d1b42556
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/220964
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2021-11-24 13:03:52 +00:00