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add to contract docs
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Max Charlamb committed Nov 21, 2024
1 parent 09b30a4 commit 6610aa6
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Showing 14 changed files with 740 additions and 51 deletions.
72 changes: 70 additions & 2 deletions docs/design/datacontracts/CodeVersions.md
Original file line number Diff line number Diff line change
Expand Up @@ -4,6 +4,29 @@ This contract encapsulates support for [code versioning](../features/code-versio

## APIs of contract

```csharp
internal readonly struct ILCodeVersionHandle
{
internal readonly TargetPointer Module;
internal readonly uint MethodDefinition;
internal readonly TargetPointer ILCodeVersionNode;
internal ILCodeVersionHandle(TargetPointer module, uint methodDef, TargetPointer ilCodeVersionNodeAddress)
{
if (module != TargetPointer.Null && ilCodeVersionNodeAddress != TargetPointer.Null)
throw new ArgumentException("Both MethodDesc and ILCodeVersionNode cannot be non-null");

if (module != TargetPointer.Null && methodDef == 0)
throw new ArgumentException("MethodDefinition must be non-zero if Module is non-null");

Module = module;
MethodDefinition = methodDef;
ILCodeVersionNode = ilCodeVersionNodeAddress;
}
public static ILCodeVersionHandle Invalid => new ILCodeVersionHandle(TargetPointer.Null, 0, TargetPointer.Null);
public bool IsValid => Module != TargetPointer.Null || ILCodeVersionNode != TargetPointer.Null;
}
```

```csharp
internal struct NativeCodeVersionHandle
{
Expand All @@ -26,10 +49,19 @@ internal struct NativeCodeVersionHandle
```

```csharp
// Return a handle to the active version of the IL code for a given method descriptor
public virtual ILCodeVersionHandle GetActiveILCodeVersion(TargetPointer methodDesc);
// Return a handle to the IL code version representing the given native code version
public virtual ILCodeVersionHandle GetILCodeVersion(NativeCodeVersionHandle codeVersionHandle);
// Return all of the IL code versions for a given method descriptor
public virtual IEnumerable<ILCodeVersionHandle> GetILCodeVersions(TargetPointer methodDesc);

// Return a handle to the version of the native code that includes the given instruction pointer
public virtual NativeCodeVersionHandle GetNativeCodeVersionForIP(TargetCodePointer ip);
// Return a handle to the active version of the native code for a given method descriptor
public virtual NativeCodeVersionHandle GetActiveNativeCodeVersion(TargetPointer methodDesc);
// Return a handle to the active version of the native code for a given method descriptor and IL code version. The IL code version and method descriptor must represent the same method
public virtual NativeCodeVersionHandle GetActiveNativeCodeVersionForILCodeVersion(TargetPointer methodDesc, ILCodeVersionHandle ilCodeVersionHandle);

// returns true if the given method descriptor supports multiple code versions
public virtual bool CodeVersionManagerSupportsMethod(TargetPointer methodDesc);
Expand All @@ -52,11 +84,13 @@ Data descriptors used:
| NativeCodeVersionNode | NativeCode | indicates an explicit native code version node |
| NativeCodeVersionNode | Flags | `NativeCodeVersionNodeFlags` flags, see below |
| NativeCodeVersionNode | VersionId | Version ID corresponding to the parent IL code version |
| ILCodeVersioningState | FirstVersionNode | pointer to the first `ILCodeVersionNode` |
| ILCodeVersioningState | ActiveVersionKind | an `ILCodeVersionKind` value indicating which fields of the active version are value |
| ILCodeVersioningState | ActiveVersionNode | if the active version is explicit, the NativeCodeVersionNode for the active version |
| ILCodeVersioningState | ActiveVersionModule | if the active version is synthetic or unknown, the pointer to the Module that defines the method |
| ILCodeVersioningState | ActiveVersionMethodDef | if the active version is synthetic or unknown, the MethodDef token for the method |
| ILCodeVersionNode | VersionId | Version ID of the node |
| ILCodeVersionNode | Next | Pointer to the next `ILCodeVersionNode`|

The flag indicates that the default version of the code for a method desc is active:
```csharp
Expand Down Expand Up @@ -93,6 +127,40 @@ Contracts used:
| Loader |
| RuntimeTypeSystem |

### Finding all of the ILCodeVersions for a method
```csharp
IEnumerable<ILCodeVersionHandle> ICodeVersions.GetILCodeVersions(TargetPointer methodDesc)
{
// CodeVersionManager::GetILCodeVersions
IRuntimeTypeSystem rts = _target.Contracts.RuntimeTypeSystem;
MethodDescHandle md = rts.GetMethodDescHandle(methodDesc);
TargetPointer mtAddr = rts.GetMethodTable(md);
TypeHandle typeHandle = rts.GetTypeHandle(mtAddr);
TargetPointer module = rts.GetModule(typeHandle);
uint methodDefToken = rts.GetMethodToken(md);

ModuleHandle moduleHandle = _target.Contracts.Loader.GetModuleHandle(module);
TargetPointer ilCodeVersionTable = _target.Contracts.Loader.GetLookupTables(moduleHandle).MethodDefToILCodeVersioningState;
TargetPointer ilVersionStateAddress = _target.Contracts.Loader.GetModuleLookupMapElement(ilCodeVersionTable, methodDefToken, out var _);

// always add the synthetic version
yield return new ILCodeVersionHandle(module, methodDefToken, TargetPointer.Null);

// if explicit versions exist, iterate linked list and return them
if (ilVersionStateAddress != TargetPointer.Null)
{
Data.ILCodeVersioningState ilState = _target.ProcessedData.GetOrAdd<Data.ILCodeVersioningState>(ilVersionStateAddress);
TargetPointer nodePointer = ilState.FirstVersionNode;
while (nodePointer != TargetPointer.Null)
{
Data.ILCodeVersionNode current = _target.ProcessedData.GetOrAdd<Data.ILCodeVersionNode>(nodePointer);
yield return new ILCodeVersionHandle(TargetPointer.Null, 0, nodePointer);
nodePointer = current.Next;
}
}
}
```

### Finding the start of a specific native code version

```csharp
Expand Down Expand Up @@ -235,7 +303,7 @@ bool IsActiveNativeCodeVersion(NativeCodeVersionHandle nativeCodeVersion)

NativeCodeVersionHandle FindActiveNativeCodeVersion(ILCodeVersionHandle methodDefActiveVersion, TargetPointer methodDescAddress)
{
TargetNUInt? ilVersionId = default;
TargetNUInt ilVersionId = GetId(ilcodeVersion);
if (methodDefActiveVersion.Module != TargetPointer.Null)
{
NativeCodeVersionHandle provisionalHandle = new NativeCodeVersionHandle(methodDescAddress: methodDescAddress, codeVersionNodeAddress: TargetPointer.Null);
Expand All @@ -256,7 +324,7 @@ NativeCodeVersionHandle FindActiveNativeCodeVersion(ILCodeVersionHandle methodDe
MethodDescHandle md = rts.GetMethodDescHandle(methodDescAddress);
return FindFirstCodeVersion(rts, md, (codeVersion) =>
{
return (!ilVersionId.HasValue || ilVersionId.Value.Value == codeVersion.ILVersionId.Value)
return (ilVersionId == codeVersion.ILVersionId)
&& ((NativeCodeVersionNodeFlags)codeVersion.Flags).HasFlag(NativeCodeVersionNodeFlags.IsActiveChild);
});
}
Expand Down
82 changes: 82 additions & 0 deletions docs/design/datacontracts/ReJIT.md
Original file line number Diff line number Diff line change
Expand Up @@ -4,8 +4,20 @@ This contract encapsulates support for [ReJIT](../features/code-versioning.md) i

## APIs of contract

```chsarp
public enum RejitState
{
Requested,
Active
}
```

```csharp
bool IsEnabled();

RejitState GetRejitState(ILCodeVersionHandle codeVersionHandle);
TargetNUInt GetRejitId(ILCodeVersionHandle codeVersionHandle);
IEnumerable<TargetNUInt> GetRejitIds(TargetPointer methodDesc)
```

## Version 1
Expand All @@ -14,6 +26,8 @@ Data descriptors used:
| Data Descriptor Name | Field | Meaning |
| --- | --- | --- |
| ProfControlBlock | GlobalEventMask | an `ICorProfiler` `COR_PRF_MONITOR` value |
| ILCodeVersionNode | VersionId | `ILCodeVersion` ReJIT id
| ILCodeVersionNode | RejitState | a `RejitFlags` value |

Global variables used:
| Global Name | Type | Purpose |
Expand All @@ -23,6 +37,7 @@ Global variables used:
Contracts used:
| Contract Name |
| --- |
| CodeVersions |

```csharp
// see src/coreclr/inc/corprof.idl
Expand All @@ -32,6 +47,21 @@ private enum COR_PRF_MONITOR
COR_PRF_ENABLE_REJIT = 0x00040000,
}

// see src/coreclr/vm/codeversion.h
[Flags]
public enum RejitFlags : uint
{
kStateRequested = 0x00000000,

kStateGettingReJITParameters = 0x00000001,

kStateActive = 0x00000002,

kStateMask = 0x0000000F,

kSuppressParams = 0x80000000
}

bool IsEnabled()
{
TargetPointer address = target.ReadGlobalPointer("ProfilerControlBlock");
Expand All @@ -40,4 +70,56 @@ bool IsEnabled()
bool clrConfigEnabledReJit = /* host process does not have environment variable DOTNET_ProfAPI_ReJitOnAttach set to 0 */;
return profEnabledReJIT || clrConfigEnabledReJIT;
}

RejitState GetRejitState(ILCodeVersionHandle codeVersion)
{
// ILCodeVersion::GetRejitState
if (codeVersion is not explicit)
{
// for non explicit ILCodeVersions, ReJITState is always kStateActive
return RejitState.Active;
}
else
{
// ILCodeVersionNode::GetRejitState
ILCodeVersionNode codeVersionNode = AsNode(codeVersion);
return ((RejitFlags)ilCodeVersionNode.RejitState & RejitFlags.kStateMask) switch
{
RejitFlags.kStateRequested => RejitState.Requested,
RejitFlags.kStateActive => RejitState.Active,
_ => throw new NotImplementedException($"Unknown ReJIT state: {ilCodeVersionNode.RejitState}"),
};
}
}

TargetNUInt GetRejitId(ILCodeVersionHandle codeVersion)
{
// ILCodeVersion::GetVersionId
if (codeVersion is not explicit)
{
// for non explicit ILCodeVersions, ReJITId is always 0
return new TargetNUInt(0);
}
else
{
// ILCodeVersionNode::GetVersionId
ILCodeVersionNode codeVersionNode = AsNode(codeVersion);
return codeVersionNode.VersionId;
}
}

IEnumerable<TargetNUInt> GetRejitIds(TargetPointer methodDesc)
{
// ReJitManager::GetReJITIDs
ICodeVersions cv = _target.Contracts.CodeVersions;
IEnumerable<ILCodeVersionHandle> ilCodeVersions = cv.GetILCodeVersions(methodDesc);

foreach (ILCodeVersionHandle ilCodeVersionHandle in ilCodeVersions)
{
if (GetRejitState(ilCodeVersionHandle) == RejitState.Active)
{
yield return GetRejitId(ilCodeVersionHandle);
}
}
}
```
3 changes: 3 additions & 0 deletions src/coreclr/debug/runtimeinfo/datadescriptor.h
Original file line number Diff line number Diff line change
Expand Up @@ -483,6 +483,7 @@ CDAC_TYPE_END(CodeHeapListNode)

CDAC_TYPE_BEGIN(ILCodeVersioningState)
CDAC_TYPE_INDETERMINATE(ILCodeVersioningState)
CDAC_TYPE_FIELD(ILCodeVersioningState, /*pointer*/, FirstVersionNode, cdac_data<ILCodeVersioningState>::FirstVersionNode)
CDAC_TYPE_FIELD(ILCodeVersioningState, /*uint32*/, ActiveVersionKind, cdac_data<ILCodeVersioningState>::ActiveVersionKind)
CDAC_TYPE_FIELD(ILCodeVersioningState, /*pointer*/, ActiveVersionNode, cdac_data<ILCodeVersioningState>::ActiveVersionNode)
CDAC_TYPE_FIELD(ILCodeVersioningState, /*pointer*/, ActiveVersionModule, cdac_data<ILCodeVersioningState>::ActiveVersionModule)
Expand All @@ -501,6 +502,8 @@ CDAC_TYPE_END(NativeCodeVersionNode)
CDAC_TYPE_BEGIN(ILCodeVersionNode)
CDAC_TYPE_INDETERMINATE(ILCodeVersionNode)
CDAC_TYPE_FIELD(ILCodeVersionNode, /*nuint*/, VersionId, cdac_data<ILCodeVersionNode>::VersionId)
CDAC_TYPE_FIELD(ILCodeVersionNode, /*pointer*/, Next, cdac_data<ILCodeVersionNode>::Next)
CDAC_TYPE_FIELD(ILCodeVersionNode, /*uint32*/, RejitState, cdac_data<ILCodeVersionNode>::RejitState)
CDAC_TYPE_END(ILCodeVersionNode)

CDAC_TYPE_BEGIN(ProfControlBlock)
Expand Down
3 changes: 3 additions & 0 deletions src/coreclr/vm/codeversion.h
Original file line number Diff line number Diff line change
Expand Up @@ -419,6 +419,8 @@ template<>
struct cdac_data<ILCodeVersionNode>
{
static constexpr size_t VersionId = offsetof(ILCodeVersionNode, m_rejitId);
static constexpr size_t Next = offsetof(ILCodeVersionNode, m_pNextILVersionNode);
static constexpr size_t RejitState = offsetof(ILCodeVersionNode, m_rejitState);
};

class ILCodeVersionCollection
Expand Down Expand Up @@ -543,6 +545,7 @@ class ILCodeVersioningState
template<>
struct cdac_data<ILCodeVersioningState>
{
static constexpr size_t FirstVersionNode = offsetof(ILCodeVersioningState, m_pFirstVersionNode);
static constexpr size_t ActiveVersionKind = offsetof(ILCodeVersioningState, m_activeVersion.m_storageKind);
static constexpr size_t ActiveVersionNode = offsetof(ILCodeVersioningState, m_activeVersion.m_pVersionNode);
static constexpr size_t ActiveVersionModule = offsetof(ILCodeVersioningState, m_activeVersion.m_synthetic.m_pModule);
Expand Down
Original file line number Diff line number Diff line change
Expand Up @@ -2,23 +2,53 @@
// The .NET Foundation licenses this file to you under the MIT license.

using System;
using System.Collections.Generic;

namespace Microsoft.Diagnostics.DataContractReader.Contracts;

internal interface ICodeVersions : IContract
{
static string IContract.Name { get; } = nameof(CodeVersions);

public virtual ILCodeVersionHandle GetActiveILCodeVersion(TargetPointer methodDesc) => throw new NotImplementedException();

public virtual ILCodeVersionHandle GetILCodeVersion(NativeCodeVersionHandle codeVersionHandle) => throw new NotImplementedException();

public virtual IEnumerable<ILCodeVersionHandle> GetILCodeVersions(TargetPointer methodDesc) => throw new NotImplementedException();

public virtual NativeCodeVersionHandle GetNativeCodeVersionForIP(TargetCodePointer ip) => throw new NotImplementedException();

public virtual NativeCodeVersionHandle GetActiveNativeCodeVersion(TargetPointer methodDesc) => throw new NotImplementedException();

public virtual bool CodeVersionManagerSupportsMethod(TargetPointer methodDesc) => throw new NotImplementedException();
public virtual NativeCodeVersionHandle GetActiveNativeCodeVersionForILCodeVersion(TargetPointer methodDesc, ILCodeVersionHandle ilCodeVersionHandle) => throw new NotImplementedException();

public virtual TargetCodePointer GetNativeCode(NativeCodeVersionHandle codeVersionHandle) => throw new NotImplementedException();

public virtual bool CodeVersionManagerSupportsMethod(TargetPointer methodDesc) => throw new NotImplementedException();
}

internal readonly struct ILCodeVersionHandle
{
internal readonly TargetPointer Module;
internal readonly uint MethodDefinition;
internal readonly TargetPointer ILCodeVersionNode;
internal ILCodeVersionHandle(TargetPointer module, uint methodDef, TargetPointer ilCodeVersionNodeAddress)
{
if (module != TargetPointer.Null && ilCodeVersionNodeAddress != TargetPointer.Null)
throw new ArgumentException("Both MethodDesc and ILCodeVersionNode cannot be non-null");

if (module != TargetPointer.Null && methodDef == 0)
throw new ArgumentException("MethodDefinition must be non-zero if Module is non-null");

Module = module;
MethodDefinition = methodDef;
ILCodeVersionNode = ilCodeVersionNodeAddress;
}
public static ILCodeVersionHandle Invalid => new ILCodeVersionHandle(TargetPointer.Null, 0, TargetPointer.Null);
public bool IsValid => Module != TargetPointer.Null || ILCodeVersionNode != TargetPointer.Null;
}

internal struct NativeCodeVersionHandle
internal readonly struct NativeCodeVersionHandle
{
// no public constructors
internal readonly TargetPointer MethodDescAddress;
Expand Down
Original file line number Diff line number Diff line change
Expand Up @@ -2,13 +2,27 @@
// The .NET Foundation licenses this file to you under the MIT license.

using System;
using System.Collections.Generic;

namespace Microsoft.Diagnostics.DataContractReader.Contracts;

public enum RejitState
{
Requested,
Active
}

internal interface IReJIT : IContract
{
static string IContract.Name { get; } = nameof(ReJIT);

bool IsEnabled() => throw new NotImplementedException();

RejitState GetRejitState(ILCodeVersionHandle codeVersionHandle) => throw new NotImplementedException();

TargetNUInt GetRejitId(ILCodeVersionHandle codeVersionHandle) => throw new NotImplementedException();

IEnumerable<TargetNUInt> GetRejitIds(TargetPointer methodDesc) => throw new NotImplementedException();
}

internal readonly struct ReJIT : IReJIT
Expand Down
Original file line number Diff line number Diff line change
Expand Up @@ -7,10 +7,20 @@ namespace Microsoft.Diagnostics.DataContractReader;


[DebuggerDisplay("{Hex}")]
public readonly struct TargetNUInt
public readonly struct TargetNUInt : IEquatable<TargetNUInt>
{
public readonly ulong Value;
public TargetNUInt(ulong value) => Value = value;

internal string Hex => $"0x{Value:x}";

public override bool Equals(object? obj) => obj is TargetNUInt other && Equals(other);

public bool Equals(TargetNUInt t) => Value == t.Value;

public override int GetHashCode() => Value.GetHashCode();

public static bool operator ==(TargetNUInt lhs, TargetNUInt rhs) => lhs.Equals(rhs);

public static bool operator !=(TargetNUInt lhs, TargetNUInt rhs) => !(lhs == rhs);
}
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