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Implement file locking in SQLite on Posix #1938

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merged 1 commit into from
Apr 4, 2025
Merged

Implement file locking in SQLite on Posix #1938

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14 changes: 14 additions & 0 deletions src/extensions/IronPython.SQLite/IronPython.SQLite.csproj
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Original file line number Diff line number Diff line change
Expand Up @@ -23,6 +23,20 @@
<DefineConstants>NET_40;$(DefineConstants);$(SQLiteCommon);$(SQLiteCommonOmit);SQLITE_MUTEX_W32;SQLITE_THREADSAFE;NDEBUG</DefineConstants>
</PropertyGroup>

<ItemGroup Condition=" '$(IsFullFramework)' == 'true' ">
<Reference Include="Mono.Posix" Version="4.0.0">
<Private>True</Private>
<HintPath>$(UtilsDir)\References\Mono.Posix.dll</HintPath>
</Reference>
</ItemGroup>
<ItemGroup Condition=" '$(IsFullFramework)' != 'true' ">
<PackageReference Include="Mono.Unix" Version="7.1.0-final.1.21458.1" />
</ItemGroup>

<ItemGroup>
<Compile Include="../../core/IronPython/FakeInteropServices.cs" />
</ItemGroup>

<ItemGroup>
<ProjectReference Include="..\..\core\IronPython\IronPython.csproj" Private="false" />
<ProjectReference Include="..\..\dlr\Src\Microsoft.Scripting\Microsoft.Scripting.csproj" Private="false" />
Expand Down
81 changes: 58 additions & 23 deletions src/extensions/IronPython.SQLite/c#sqlite/os_win_c.cs
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Original file line number Diff line number Diff line change
Expand Up @@ -21,6 +21,9 @@
#elif WINDOWS_PHONE || SQLITE_SILVERLIGHT
using System.IO.IsolatedStorage;
#endif
#if !FEATURE_RUNTIMEINFORMATION
using IronPython;
#endif
namespace Community.CsharpSqlite
{
public partial class Sqlite3
Expand Down Expand Up @@ -3713,27 +3716,53 @@ static extern bool LockFileEx( IntPtr hFile, uint dwFlags, uint dwReserved,

const int LOCKFILE_FAIL_IMMEDIATELY = 1;
#endif
public virtual void LockFile( sqlite3_file pFile, long offset, long length )

private int LockUnix( sqlite3_file pFile, long offset, long length, bool locking, bool shared = false)
{
int fd = pFile.fs.Handle.ToInt32();
Mono.Unix.Native.Flock flock = new() {
l_whence = Mono.Unix.Native.SeekFlags.SEEK_SET,
l_start = offset,
l_len = length,
l_type = !locking ? Mono.Unix.Native.LockType.F_UNLCK
: shared ? Mono.Unix.Native.LockType.F_RDLCK
: Mono.Unix.Native.LockType.F_WRLCK,
};

int result = Mono.Unix.Native.Syscall.fcntl(fd, Mono.Unix.Native.FcntlCommand.F_SETLK, ref flock);
return result != -1 ? 1 : 0;
}

public virtual void LockFile( sqlite3_file pFile, long offset, long length )
{
if (RuntimeInformation.IsOSPlatform(OSPlatform.OSX) || RuntimeInformation.IsOSPlatform(OSPlatform.Linux))
{
#pragma warning disable CA1416 // Validate platform compatibility
pFile.fs.Lock( offset, length );
#pragma warning restore CA1416 // Validate platform compatibility
LockUnix( pFile, offset, length, locking: true );
}
else
{
pFile.fs.Lock( offset, length );
}
}

public virtual int SharedLockFile( sqlite3_file pFile, long offset, long length )
{
{
#if !(SQLITE_SILVERLIGHT || WINDOWS_MOBILE || SQLITE_WINRT)
#if FEATURE_RUNTIMEINFORMATION
Debug.Assert(RuntimeInformation.IsOSPlatform(OSPlatform.Windows));
#endif
Debug.Assert( length == SHARED_SIZE );
Debug.Assert( offset == SHARED_FIRST );
NativeOverlapped ovlp = new NativeOverlapped();
ovlp.OffsetLow = (int)offset;
ovlp.OffsetHigh = 0;
ovlp.EventHandle = IntPtr.Zero;

return LockFileEx( pFile.fs.Handle, LOCKFILE_FAIL_IMMEDIATELY, 0, (uint)length, 0, ref ovlp ) ? 1 : 0;
if (RuntimeInformation.IsOSPlatform(OSPlatform.Windows))
{
Debug.Assert( length == SHARED_SIZE );
Debug.Assert( offset == SHARED_FIRST );
NativeOverlapped ovlp = new NativeOverlapped();
ovlp.OffsetLow = (int)offset;
ovlp.OffsetHigh = 0;
ovlp.EventHandle = IntPtr.Zero;

return LockFileEx( pFile.fs.Handle, LOCKFILE_FAIL_IMMEDIATELY, 0, (uint)length, 0, ref ovlp ) ? 1 : 0;
}
else
{
return LockUnix( pFile, offset, length, locking: true, shared: true );
}
#else
return 1;
#endif
Expand All @@ -3742,9 +3771,14 @@ public virtual int SharedLockFile( sqlite3_file pFile, long offset, long length
public virtual void UnlockFile( sqlite3_file pFile, long offset, long length )
{
#if !(SQLITE_SILVERLIGHT || WINDOWS_MOBILE || SQLITE_WINRT)
#pragma warning disable CA1416 // Validate platform compatibility
pFile.fs.Unlock( offset, length );
#pragma warning restore CA1416 // Validate platform compatibility
if (RuntimeInformation.IsOSPlatform(OSPlatform.OSX) || RuntimeInformation.IsOSPlatform(OSPlatform.Linux))
{
LockUnix( pFile, offset, length, locking: false );
}
else
{
pFile.fs.Unlock( offset, length );
}
#endif
}
}
Expand All @@ -3762,9 +3796,10 @@ public override int SharedLockFile( sqlite3_file pFile, long offset, long length
Debug.Assert( offset == SHARED_FIRST );
try
{
#pragma warning disable CA1416 // Validate platform compatibility
pFile.fs.Lock( offset + pFile.sharedLockByte, 1 );
#pragma warning restore CA1416 // Validate platform compatibility
if (!RuntimeInformation.IsOSPlatform(OSPlatform.OSX))
{
pFile.fs.Lock( offset + pFile.sharedLockByte, 1 );
}
}
catch ( IOException )
{
Expand All @@ -3781,7 +3816,7 @@ public static bool IsRunningMediumTrust() {
// placeholder method
// this is where it needs to check if it's running in an ASP.Net MediumTrust or lower environment
// in order to pick the appropriate locking strategy
return Environment.OSVersion.Platform == PlatformID.Unix;
return false;
}

#if SQLITE_WINRT
Expand Down