Commit Graph

25 Commits

Author SHA1 Message Date
Sven Sauleau
5bdb13297f [wasm] merge js constants file in module-builder
We noticed that almost every call site were loading both files,
the split isn't necessary anymore.

In some message tests, removed the absolute line number to allow future
changes.

Bug: v8:8726
Change-Id: I8527f0a1ecfa685aa01a5e2f5f47ddf1cb13a545
Reviewed-on: https://chromium-review.googlesource.com/c/1446452
Commit-Queue: Sven Sauleau <ssauleau@igalia.com>
Reviewed-by: Ben Titzer <titzer@chromium.org>
Reviewed-by: Andreas Haas <ahaas@chromium.org>
Cr-Commit-Position: refs/heads/master@{#59220}
2019-01-30 22:10:34 +00:00
Michael Starzinger
6d20218ed1 [wasm] Remove {WasmCompiledModule} object type.
R=clemensh@chromium.org

Change-Id: I01b0b4948973ebbe0386ae8ae08e722ad16bcab8
Reviewed-on: https://chromium-review.googlesource.com/1114616
Reviewed-by: Clemens Hammacher <clemensh@chromium.org>
Commit-Queue: Michael Starzinger <mstarzinger@chromium.org>
Cr-Commit-Position: refs/heads/master@{#54058}
2018-06-27 14:02:51 +00:00
Michael Starzinger
56e8b09936 Reland "[wasm] Maintain link from Instance to Module."
This is a reland of a0c57368a9

Original change's description:
> [wasm] Maintain link from Instance to Module.
> 
> This moves the link from a {WasmInstanceObject} to its corresponding
> {WasmModuleObject} into the right place and also makes it strong. This
> ensures that an instance always keeps the underlying module alive and
> hence removes the situation of an "orphaned instance".
> 
> R=clemensh@chromium.org
> 
> Change-Id: Id59f6a49740af8ef0248679c3d2c696bb9776944
> Reviewed-on: https://chromium-review.googlesource.com/1041691
> Reviewed-by: Clemens Hammacher <clemensh@chromium.org>
> Commit-Queue: Michael Starzinger <mstarzinger@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#52942}

Change-Id: I9854400bfc1d22bd258f17118fcb7460cdc3acd5
Reviewed-on: https://chromium-review.googlesource.com/1043786
Reviewed-by: Clemens Hammacher <clemensh@chromium.org>
Commit-Queue: Michael Starzinger <mstarzinger@chromium.org>
Cr-Commit-Position: refs/heads/master@{#52985}
2018-05-04 10:16:58 +00:00
Michael Achenbach
79a99dfc10 Revert "[wasm] Maintain link from Instance to Module."
This reverts commit a0c57368a9.

Reason for revert: Speculative revert due to failures with custom
snapshot:
https://build.chromium.org/p/client.v8/builders/V8%20Linux64%20GC%20Stress%20-%20custom%20snapshot/builds/19061

Local bisect also points to this change:
http://shortn/_IhVxU2FKLu

Original change's description:
> [wasm] Maintain link from Instance to Module.
> 
> This moves the link from a {WasmInstanceObject} to its corresponding
> {WasmModuleObject} into the right place and also makes it strong. This
> ensures that an instance always keeps the underlying module alive and
> hence removes the situation of an "orphaned instance".
> 
> R=​clemensh@chromium.org
> 
> Change-Id: Id59f6a49740af8ef0248679c3d2c696bb9776944
> Reviewed-on: https://chromium-review.googlesource.com/1041691
> Reviewed-by: Clemens Hammacher <clemensh@chromium.org>
> Commit-Queue: Michael Starzinger <mstarzinger@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#52942}

TBR=mstarzinger@chromium.org,clemensh@chromium.org

Change-Id: I1830e6ce14314f06f918a0c428182bfd68354ad9
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Reviewed-on: https://chromium-review.googlesource.com/1041968
Reviewed-by: Michael Achenbach <machenbach@chromium.org>
Commit-Queue: Michael Achenbach <machenbach@chromium.org>
Cr-Commit-Position: refs/heads/master@{#52949}
2018-05-03 11:56:25 +00:00
Michael Starzinger
a0c57368a9 [wasm] Maintain link from Instance to Module.
This moves the link from a {WasmInstanceObject} to its corresponding
{WasmModuleObject} into the right place and also makes it strong. This
ensures that an instance always keeps the underlying module alive and
hence removes the situation of an "orphaned instance".

R=clemensh@chromium.org

Change-Id: Id59f6a49740af8ef0248679c3d2c696bb9776944
Reviewed-on: https://chromium-review.googlesource.com/1041691
Reviewed-by: Clemens Hammacher <clemensh@chromium.org>
Commit-Queue: Michael Starzinger <mstarzinger@chromium.org>
Cr-Commit-Position: refs/heads/master@{#52942}
2018-05-03 09:36:38 +00:00
Ben L. Titzer
a6d974fe00 [wasm] Merge the WasmContext into WasmInstanceObject
This change makes lifetime management of WasmCode much simpler.
By using the WasmInstanceObject as the context for WASM code execution,
including the pointer to the memory base and indirect function tables,
this keeps the instance alive when WASM code is on the stack, since
the instance object is passed as a parameter and spilled onto the stack.
This is in preparation of sharing the code between instances and
isolates.

Bug: v8:7424

R=mstarzinger@chromium.org

Change-Id: Ia35a3ce91a8f6135767fa764e185cde8bbc889f4
Reviewed-on: https://chromium-review.googlesource.com/997932
Commit-Queue: Ben Titzer <titzer@chromium.org>
Reviewed-by: Michael Starzinger <mstarzinger@chromium.org>
Reviewed-by: Clemens Hammacher <clemensh@chromium.org>
Cr-Commit-Position: refs/heads/master@{#52436}
2018-04-06 12:13:26 +00:00
Ben Titzer
8adb94fc81 Revert "[wasm] Merge the WasmContext into WasmInstanceObject"
This reverts commit 57bf0bfefb.

Reason for revert: <INSERT REASONING HERE>

Original change's description:
> [wasm] Merge the WasmContext into WasmInstanceObject
> 
> This change makes lifetime management of WasmCode much simpler.
> By using the WasmInstanceObject as the context for WASM code execution,
> including the pointer to the memory base and indirect function tables,
> this keeps the instance alive when WASM code is on the stack, since
> the instance object is passed as a parameter and spilled onto the stack.
> This is in preparation of sharing the code between instances and
> isolates.
> 
> Bug: v8:7424
> 
> Change-Id: Ic2e4b7bcc2feb20001d0553a615a8a9dff36317e
> Reviewed-on: https://chromium-review.googlesource.com/958520
> Commit-Queue: Ben Titzer <titzer@chromium.org>
> Reviewed-by: Clemens Hammacher <clemensh@chromium.org>
> Reviewed-by: Andreas Haas <ahaas@chromium.org>
> Reviewed-by: Michael Starzinger <mstarzinger@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#52361}

TBR=mstarzinger@chromium.org,titzer@chromium.org,ahaas@chromium.org,clemensh@chromium.org

Change-Id: I653e27b46dbc43ad773eda4292d521a508f42d79
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Bug: v8:7424
Reviewed-on: https://chromium-review.googlesource.com/995418
Reviewed-by: Ben Titzer <titzer@chromium.org>
Commit-Queue: Ben Titzer <titzer@chromium.org>
Cr-Commit-Position: refs/heads/master@{#52364}
2018-04-04 17:08:02 +00:00
Ben L. Titzer
57bf0bfefb [wasm] Merge the WasmContext into WasmInstanceObject
This change makes lifetime management of WasmCode much simpler.
By using the WasmInstanceObject as the context for WASM code execution,
including the pointer to the memory base and indirect function tables,
this keeps the instance alive when WASM code is on the stack, since
the instance object is passed as a parameter and spilled onto the stack.
This is in preparation of sharing the code between instances and
isolates.

Bug: v8:7424

Change-Id: Ic2e4b7bcc2feb20001d0553a615a8a9dff36317e
Reviewed-on: https://chromium-review.googlesource.com/958520
Commit-Queue: Ben Titzer <titzer@chromium.org>
Reviewed-by: Clemens Hammacher <clemensh@chromium.org>
Reviewed-by: Andreas Haas <ahaas@chromium.org>
Reviewed-by: Michael Starzinger <mstarzinger@chromium.org>
Cr-Commit-Position: refs/heads/master@{#52361}
2018-04-04 16:34:50 +00:00
Mircea Trofin
b22fb03a49 Revert "Revert "[wasm] Reference indirect tables as addresses of global handles""
This reverts commit af37f6b970.

Reason for revert: Reverted dependency fixed.

Original change's description:
> Revert "[wasm] Reference indirect tables as addresses of global handles"
> 
> This reverts commit 186099d49f.
> 
> Reason for revert: Need to revert:
> https://chromium-review.googlesource.com/c/613880
> 
> Original change's description:
> > [wasm] Reference indirect tables as addresses of global handles
> > 
> > This sets us up for getting the wasm code generation off the GC heap.
> > We reference tables as global handles, which have a stable address. This
> > requires an extra instruction when attempting to make an indirect call,
> > per table (i.e. one for the signature table and one for the function
> > table).
> > 
> > Bug: 
> > Change-Id: I83743ba0f1dfdeba9aee5d27232f8823981288f8
> > Reviewed-on: https://chromium-review.googlesource.com/612322
> > Commit-Queue: Mircea Trofin <mtrofin@chromium.org>
> > Reviewed-by: Brad Nelson <bradnelson@chromium.org>
> > Cr-Commit-Position: refs/heads/master@{#47444}
> 
> TBR=bradnelson@chromium.org,titzer@chromium.org,mtrofin@chromium.org
> 
> Change-Id: Ic3dff87410a51a2072ddc16cfc83a230526d4c56
> No-Presubmit: true
> No-Tree-Checks: true
> No-Try: true
> Reviewed-on: https://chromium-review.googlesource.com/622568
> Reviewed-by: Michael Achenbach <machenbach@chromium.org>
> Commit-Queue: Michael Achenbach <machenbach@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#47450}

TBR=bradnelson@chromium.org,machenbach@chromium.org,titzer@chromium.org,mtrofin@chromium.org

Change-Id: I3dc5dc8be26b5462703edac954cbedbb8f504c1e
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Reviewed-on: https://chromium-review.googlesource.com/622035
Reviewed-by: Mircea Trofin <mtrofin@chromium.org>
Commit-Queue: Mircea Trofin <mtrofin@chromium.org>
Cr-Commit-Position: refs/heads/master@{#47455}
2017-08-19 16:35:34 +00:00
Michael Achenbach
af37f6b970 Revert "[wasm] Reference indirect tables as addresses of global handles"
This reverts commit 186099d49f.

Reason for revert: Need to revert:
https://chromium-review.googlesource.com/c/613880

Original change's description:
> [wasm] Reference indirect tables as addresses of global handles
> 
> This sets us up for getting the wasm code generation off the GC heap.
> We reference tables as global handles, which have a stable address. This
> requires an extra instruction when attempting to make an indirect call,
> per table (i.e. one for the signature table and one for the function
> table).
> 
> Bug: 
> Change-Id: I83743ba0f1dfdeba9aee5d27232f8823981288f8
> Reviewed-on: https://chromium-review.googlesource.com/612322
> Commit-Queue: Mircea Trofin <mtrofin@chromium.org>
> Reviewed-by: Brad Nelson <bradnelson@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#47444}

TBR=bradnelson@chromium.org,titzer@chromium.org,mtrofin@chromium.org

Change-Id: Ic3dff87410a51a2072ddc16cfc83a230526d4c56
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Reviewed-on: https://chromium-review.googlesource.com/622568
Reviewed-by: Michael Achenbach <machenbach@chromium.org>
Commit-Queue: Michael Achenbach <machenbach@chromium.org>
Cr-Commit-Position: refs/heads/master@{#47450}
2017-08-19 07:25:12 +00:00
Mircea Trofin
186099d49f [wasm] Reference indirect tables as addresses of global handles
This sets us up for getting the wasm code generation off the GC heap.
We reference tables as global handles, which have a stable address. This
requires an extra instruction when attempting to make an indirect call,
per table (i.e. one for the signature table and one for the function
table).

Bug: 
Change-Id: I83743ba0f1dfdeba9aee5d27232f8823981288f8
Reviewed-on: https://chromium-review.googlesource.com/612322
Commit-Queue: Mircea Trofin <mtrofin@chromium.org>
Reviewed-by: Brad Nelson <bradnelson@chromium.org>
Cr-Commit-Position: refs/heads/master@{#47444}
2017-08-18 18:50:27 +00:00
titzer
6e8338865a [wasm] Implement correct 2-level namespace for imports.
R=clemensh@chromium.org
CC=rossberg@chromium.org
BUG=chromium:575167

Review-Url: https://codereview.chromium.org/2591753002
Cr-Commit-Position: refs/heads/master@{#41866}
2016-12-20 15:32:56 +00:00
mstarzinger
e637154b8a [wasm] Fix compiled-module-management lifetime issues.
This makes sure the test in question does not rely on specific lifetime
characteristics for local variables within a function. Note that these
lifetimes are not specified by JavaScript and are not observable within
JavaScript proper. The natives syntax however makes it observable.

BUG=v8:5345
TEST=mjsunit/wasm/compiled-module-management
R=mtrofin@chromium.org

Review-Url: https://codereview.chromium.org/2474053002
Cr-Commit-Position: refs/heads/master@{#40733}
2016-11-03 15:53:56 +00:00
mstarzinger
b4b436de6a [compiler] Ship Ignition for all TurboFan code.
This enables Ignition unconditionally for all code that is destined for
optimization with TurboFan. This ensures all optimization attempts will
go through the BytecodeGraphBuilder and that the AstGraphBuilder pipe is
dried out in practice.

patch from issue 2427953002 at patchset 120001 (http://crrev.com/2427953002#ps120001)

R=mvstanton@chromium.org,rmcilroy@chromium.org

Review-Url: https://codereview.chromium.org/2453973004
Cr-Commit-Position: refs/heads/master@{#40663}
2016-10-31 09:43:43 +00:00
mstarzinger
510b56d3f2 Revert "[compiler] Ship Ignition for all TurboFan code."
Breaks layout tests on Blink builders.

TBR=machenbach@chromium.org

Review-Url: https://chromiumcodereview.appspot.com/2428413004
Cr-Commit-Position: refs/heads/master@{#40471}
2016-10-20 14:09:29 +00:00
mstarzinger
20d29ff036 [compiler] Ship Ignition for all TurboFan code.
This enables Ignition unconditionally for all code that is destined for
optimization with TurboFan. This ensures all optimization attempts will
go through the BytecodeGraphBuilder and that the AstGraphBuilder pipe is
dried out in practice.

R=mvstanton@chromium.org

Review-Url: https://chromiumcodereview.appspot.com/2427953002
Cr-Commit-Position: refs/heads/master@{#40462}
2016-10-20 10:57:58 +00:00
titzer
e97ca6ec47 [wasm] Refactor import handling for 0xC.
Imports and exports in 0xC can be much more than functions, including
tables, memories, and globals. This CL refactors the underlying
organization of imports and exports to support these new import types.

BUG=

Committed: https://crrev.com/599f8a83420346d9cba5ff97bd2a7520468207b6
Review-Url: https://codereview.chromium.org/2390113003
Cr-Original-Commit-Position: refs/heads/master@{#40033}
Cr-Commit-Position: refs/heads/master@{#40050}
2016-10-06 15:43:22 +00:00
hablich
3b1b544c20 Revert of [wasm] Refactor import handling for 0xC. (patchset #10 id:180001 of https://codereview.chromium.org/2390113003/ )
Reason for revert:
Failes a few GC stress tests.https://chromegw.corp.google.com/i/client.v8/builders/V8%20Linux%20-%20gc%20stress/builds/6253

Original issue's description:
> [wasm] Refactor import handling for 0xC.
>
> Imports and exports in 0xC can be much more than functions, including
> tables, memories, and globals. This CL refactors the underlying
> organization of imports and exports to support these new import types.
>
> BUG=
>
> Committed: https://crrev.com/599f8a83420346d9cba5ff97bd2a7520468207b6
> Cr-Commit-Position: refs/heads/master@{#40033}

TBR=mtrofin@chromium.org,ahaas@chromium.org,bradnelson@chromium.org,titzer@chromium.org
# Skipping CQ checks because original CL landed less than 1 days ago.
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG=

Review-Url: https://codereview.chromium.org/2395133002
Cr-Commit-Position: refs/heads/master@{#40038}
2016-10-06 13:43:23 +00:00
titzer
599f8a8342 [wasm] Refactor import handling for 0xC.
Imports and exports in 0xC can be much more than functions, including
tables, memories, and globals. This CL refactors the underlying
organization of imports and exports to support these new import types.

BUG=

Review-Url: https://codereview.chromium.org/2390113003
Cr-Commit-Position: refs/heads/master@{#40033}
2016-10-06 12:30:50 +00:00
titzer
28392ab196 [wasm] Master CL for Binary 0xC changes.
[0xC] Convert to stack machine semantics.
[0xC] Use section codes instead of names.
[0xC] Add elements section decoding.
[0xC] Decoding of globals section.
[0xC] Decoding of memory section.
[0xC] Decoding of imports section.
[0xC] Decoding of exports section.
[0xC] Decoding of data section.
[0xC] Remove CallImport bytecode.
[0xC] Function bodies have an implicit block.
[0xC] Remove the bottom label from loops.
[0xC] Add signatures to blocks.
[0xC] Remove arities from branches.
Add tests for init expression decoding.
Rework compilation of import wrappers and how they are patched.
Rework function indices in debugging.
Fix ASM->WASM builder for stack machine.
Reorganize asm.js foreign functions due to import indices change.

R=ahaas@chromium.org,rossberg@chromium.org,bradnelson@chromium.org
BUG=chromium:575167
LOG=Y

Committed: https://crrev.com/76eb976a67273b8c03c744f64ad850b0432554b9
Review-Url: https://codereview.chromium.org/2345593003
Cr-Original-Commit-Position: refs/heads/master@{#39678}
Cr-Commit-Position: refs/heads/master@{#39795}
2016-09-27 20:46:30 +00:00
machenbach
e1eee748dd Revert of [wasm] Master CL for Binary 0xC changes. (patchset #26 id:490001 of https://codereview.chromium.org/2345593003/ )
Reason for revert:
Main suspect for tsan:
https://build.chromium.org/p/client.v8/builders/V8%20Linux64%20TSAN/builds/11893

Also changes layout tests:
https://build.chromium.org/p/client.v8.fyi/builders/V8-Blink%20Linux%2064/builds/10036

+mips builder:
https://build.chromium.org/p/client.v8.ports/builders/V8%20Mips%20-%20builder/builds/4032

Original issue's description:
> [wasm] Master CL for Binary 0xC changes.
>
> [0xC] Convert to stack machine semantics.
> [0xC] Use section codes instead of names.
> [0xC] Add elements section decoding.
> [0xC] Decoding of globals section.
> [0xC] Decoding of memory section.
> [0xC] Decoding of imports section.
> [0xC] Decoding of exports section.
> [0xC] Decoding of data section.
> [0xC] Remove CallImport bytecode.
> [0xC] Function bodies have an implicit block.
> [0xC] Remove the bottom label from loops.
> [0xC] Add signatures to blocks.
> [0xC] Remove arities from branches.
> Add tests for init expression decoding.
> Rework compilation of import wrappers and how they are patched.
> Rework function indices in debugging.
> Fix ASM->WASM builder for stack machine.
> Reorganize asm.js foreign functions due to import indices change.
>
> R=ahaas@chromium.org,rossberg@chromium.org,bradnelson@chromium.org
> BUG=chromium:575167
> LOG=Y
>
> Committed: https://crrev.com/76eb976a67273b8c03c744f64ad850b0432554b9
> Cr-Commit-Position: refs/heads/master@{#39678}

TBR=ahaas@chromium.org,bradnelson@chromium.org,mtrofin@chromium.org,rossberg@chromium.org,bradnelson@google.com,titzer@chromium.org
# Skipping CQ checks because original CL landed less than 1 days ago.
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG=chromium:575167

Review-Url: https://codereview.chromium.org/2361053004
Cr-Commit-Position: refs/heads/master@{#39685}
2016-09-23 17:58:24 +00:00
titzer
76eb976a67 [wasm] Master CL for Binary 0xC changes.
[0xC] Convert to stack machine semantics.
[0xC] Use section codes instead of names.
[0xC] Add elements section decoding.
[0xC] Decoding of globals section.
[0xC] Decoding of memory section.
[0xC] Decoding of imports section.
[0xC] Decoding of exports section.
[0xC] Decoding of data section.
[0xC] Remove CallImport bytecode.
[0xC] Function bodies have an implicit block.
[0xC] Remove the bottom label from loops.
[0xC] Add signatures to blocks.
[0xC] Remove arities from branches.
Add tests for init expression decoding.
Rework compilation of import wrappers and how they are patched.
Rework function indices in debugging.
Fix ASM->WASM builder for stack machine.
Reorganize asm.js foreign functions due to import indices change.

R=ahaas@chromium.org,rossberg@chromium.org,bradnelson@chromium.org
BUG=chromium:575167
LOG=Y

Review-Url: https://codereview.chromium.org/2345593003
Cr-Commit-Position: refs/heads/master@{#39678}
2016-09-23 15:56:54 +00:00
mtrofin
b4dc310aab [wasm] reuse the first compiled module.
This change avoids needing to keep around an unused compiled
module. Instead, the result of compiling the wasm bytes is
given to the first instance. The module object and that instance object
point to the same compiled module. Instances are, then, cloned from
the compiled module the module object points to. When an instance is
collected, we make sure that the module object still has a clone
available, and, if the last instance is GC-ed, we also reset the compiled
module so that it does not reference its heap, so that it (==heap) may
be collected.

This is achieved by linking the clones in a double-linked list and
registering a finalizer for each. When we create an instance, we tie it
in the front of the list, making the module object point to it (O(1)). When
the finalizer is called, we relink the list over the dying object (O(1)). The
costliest operation is finalizing the last instance, since we need to visit
all wasm functions and reset heap references.

BUG=v8:5316

Committed: https://crrev.com/01f5af515728aebe6c5246f4f7dd6c573e8748af
Review-Url: https://codereview.chromium.org/2305903002
Cr-Original-Commit-Position: refs/heads/master@{#39153}
Cr-Commit-Position: refs/heads/master@{#39361}
2016-09-12 23:13:19 +00:00
machenbach
359a00bf6f Revert of [wasm] reuse the first compiled module (patchset #12 id:220001 of https://codereview.chromium.org/2305903002/ )
Reason for revert:
mac gc stress failures:
https://build.chromium.org/p/client.v8/builders/V8%20Mac%20GC%20Stress/builds/8341

Original issue's description:
> [wasm] reuse the first compiled module.
>
> This change avoids needing to keep around an unused compiled
> module. Instead, the result of compiling the wasm bytes is
> given to the first instance. The module object and that instance object
> point to the same compiled module. Instances are, then, cloned from
> the compiled module the module object points to. When an instance is
> collected, we make sure that the module object still has a clone
> available, and, if the last instance is GC-ed, we also reset the compiled
> module so that it does not reference its heap, so that it (==heap) may
> be collected.
>
> This is achieved by linking the clones in a double-linked list and
> registering a finalizer for each. When we create an instance, we tie it
> in the front of the list, making the module object point to it (O(1)). When
> the finalizer is called, we relink the list over the dying object (O(1)). The
> costliest operation is finalizing the last instance, since we need to visit
> all wasm functions and reset heap references.
>
> BUG=v8:5316
>
> Committed: https://crrev.com/01f5af515728aebe6c5246f4f7dd6c573e8748af
> Cr-Commit-Position: refs/heads/master@{#39153}

TBR=bradnelson@chromium.org,verwaest@chromium.org,vogelheim@chromium.org,yangguo@chromium.org,mtrofin@chromium.org
# Skipping CQ checks because original CL landed less than 1 days ago.
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG=v8:5316

Review-Url: https://codereview.chromium.org/2306403002
Cr-Commit-Position: refs/heads/master@{#39154}
2016-09-05 10:49:53 +00:00
mtrofin
01f5af5157 [wasm] reuse the first compiled module.
This change avoids needing to keep around an unused compiled
module. Instead, the result of compiling the wasm bytes is
given to the first instance. The module object and that instance object
point to the same compiled module. Instances are, then, cloned from
the compiled module the module object points to. When an instance is
collected, we make sure that the module object still has a clone
available, and, if the last instance is GC-ed, we also reset the compiled
module so that it does not reference its heap, so that it (==heap) may
be collected.

This is achieved by linking the clones in a double-linked list and
registering a finalizer for each. When we create an instance, we tie it
in the front of the list, making the module object point to it (O(1)). When
the finalizer is called, we relink the list over the dying object (O(1)). The
costliest operation is finalizing the last instance, since we need to visit
all wasm functions and reset heap references.

BUG=v8:5316

Review-Url: https://codereview.chromium.org/2305903002
Cr-Commit-Position: refs/heads/master@{#39153}
2016-09-05 10:08:44 +00:00