Branch: refs/heads/main
Home: https://github.com/WebKit/WebKit
Commit: ccf0be33dc3b2f7d60c4cde045955933012e8101
https://github.com/WebKit/WebKit/commit/ccf0be33dc3b2f7d60c4cde045955933012e8101
Author: Mark Lam <mark....@apple.com>
Date: 2025-08-19 (Tue, 19 Aug 2025)
Changed paths:
M Source/JavaScriptCore/CMakeLists.txt
M Source/JavaScriptCore/JavaScriptCore.xcodeproj/project.pbxproj
M Source/JavaScriptCore/Sources.txt
M Source/JavaScriptCore/disassembler/ARM64/A64DOpcode.cpp
M Source/JavaScriptCore/heap/MarkedBlock.cpp
M Source/JavaScriptCore/jsc.cpp
M Source/JavaScriptCore/runtime/VM.cpp
A Source/JavaScriptCore/runtime/VMManager.cpp
A Source/JavaScriptCore/runtime/VMManager.h
M Source/JavaScriptCore/tools/HeapVerifier.cpp
M Source/JavaScriptCore/tools/Integrity.cpp
M Source/JavaScriptCore/tools/IntegrityInlines.h
M Source/JavaScriptCore/tools/VMInspector.cpp
M Source/JavaScriptCore/tools/VMInspector.h
M Source/JavaScriptCore/wasm/WasmCallee.cpp
M Source/JavaScriptCore/wasm/WasmOMGPlan.cpp
Log Message:
-----------
Refactor VMManager out of VMInspector.
https://bugs.webkit.org/show_bug.cgi?id=297578
rdar://158659702
Reviewed by Keith Miller and Yijia Huang.
Previously, we only needed to enumerate VMs for debugging purposes. As a
result, we implemented
a container of VMs in VMInspector to support enumeration and inspection.
However, since then,
production code has come to rely on this container of VMs. Additionally, we
will soon need to
add more code in the area of VM management and coordination. Hence, it makes
sense to refactor
this container code out of VMInspector into a VMManager class of its own.
Changes include:
1. Changing VMManager::forEachVM() to take a ScopedLambda instead of a
Function. forEachVM() is
an iteration mechanism, and the life cycle of the callback does not need to
extend beyond the
iteration operation. Hence, then context of the iteration function can live
on the stack in
a ScopedLambda instead of needing to be malloc'ed in a Function.
2. Some clients were previously using VMInspector's VM iteration simply for the
purpose of
finding a VM matching some criteria. Most of the time, the recent most
added or searched
for VM is the matching one. Hence, we have a s_recentVM cache for that.
However, the
iteration operation should still be holding the g_vmListLock to prevent the
VM instance from
being destructed before we call the client's callback with the VM in
s_recentVM.
Previously, this was done by requiring the client to manually acquire
g_vmListLock before
checking s_recentVM, and subsequently, using VMInspector::iterate() to
iterate the VMs.
This can be a source of bugs if the client does handle the lock correctly.
Additionally,
it requires a lot more of VM container implementation to be exposed as API.
In VMManager, we introduce a findVM() operation that will encapsulate this
synchronization,
checking of s_recentVM, and thereafter, iterating the container if needed.
This makes the
interface more robust and simpler to use correctly.
3. Removed the dependency for VMInspector::isValidExecutableMemory() and
VMInspector::codeBlockForMachinePC() on the VMInspector's lock.
VMInspector::isValidExecutableMemory() never needed the VMInspector lock.
The real lock that
actually needs to be acquired belongs to the ExecutableAllocator instead.
VMInspector::isValidExecutableMemory() already acquires that.
VMInspector::codeBlockForMachinePC() now uses VMManager::forEachVM() which
handles its
locking internally.
* Source/JavaScriptCore/CMakeLists.txt:
* Source/JavaScriptCore/JavaScriptCore.xcodeproj/project.pbxproj:
* Source/JavaScriptCore/Sources.txt:
* Source/JavaScriptCore/disassembler/ARM64/A64DOpcode.cpp:
(JSC::ARM64Disassembler::A64DOpcodeMoveWide::handlePotentialDataPointer):
* Source/JavaScriptCore/heap/MarkedBlock.cpp:
(JSC::MarkedBlock::dumpInfoAndCrashForInvalidHandleV2):
* Source/JavaScriptCore/jsc.cpp:
(startTimeoutTimer):
* Source/JavaScriptCore/runtime/VM.cpp:
(JSC::VM::VM):
(JSC::VM::~VM):
* Source/JavaScriptCore/runtime/VMManager.cpp: Added.
(JSC::WTF_REQUIRES_LOCK):
(JSC::VMManager::add):
(JSC::VMManager::remove):
(JSC::VMManager::isValidVMSlow):
(JSC::VMManager::dumpVMs):
(JSC::VMManager::findVMImpl):
(JSC::VMManager::forEachVMImpl):
(JSC::VMManager::forEachVMWithTimeoutImpl):
* Source/JavaScriptCore/runtime/VMManager.h: Added.
(JSC::VMManager::isValidVM):
(JSC::VMManager::findVM):
(JSC::VMManager::forEachVM):
(JSC::VMManager::forEachVMWithTimeout):
* Source/JavaScriptCore/tools/HeapVerifier.cpp:
(JSC::HeapVerifier::checkIfRecorded):
* Source/JavaScriptCore/tools/Integrity.cpp:
(JSC::Integrity::Analyzer::analyzeVM):
* Source/JavaScriptCore/tools/IntegrityInlines.h:
(JSC::Integrity::doAudit):
* Source/JavaScriptCore/tools/VMInspector.cpp:
(JSC::VMInspector::vmForCallFrame):
(JSC::VMInspector::codeBlockForMachinePC):
(JSC::VMInspector::singleton): Deleted.
(JSC::VMInspector::add): Deleted.
(JSC::VMInspector::remove): Deleted.
(JSC::VMInspector::isValidVMSlow): Deleted.
(JSC::VMInspector::dumpVMs): Deleted.
(JSC::VMInspector::forEachVM): Deleted.
* Source/JavaScriptCore/tools/VMInspector.h:
(JSC::VMInspector::isValidVM): Deleted.
(JSC::VMInspector::WTF_RETURNS_LOCK): Deleted.
(JSC::VMInspector::WTF_REQUIRES_LOCK): Deleted.
* Source/JavaScriptCore/wasm/WasmCallee.cpp:
(JSC::Wasm::Callee::reportToVMsForDestruction):
* Source/JavaScriptCore/wasm/WasmOMGPlan.cpp:
Canonical link: https://commits.webkit.org/298937@main
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