托管到非托管代码调用有时会导致访问冲突

此代码导致以下异常, :

“试图读或写保护 另一个内存已损坏“

private static TOKEN_GROUPS GetTokenGroups(IntPtr tokenHandle)
{
    var groups = new TOKEN_GROUPS();
    uint tokenInfoLength = 0;
    uint returnLength;

    var res = GetTokenInformation(tokenHandle, TOKEN_INFORMATION_CLASS.TokenGroups, IntPtr.Zero,
                                  tokenInfoLength, out returnLength);

    if (!res && returnLength > 0)
    {
        tokenInfoLength = returnLength;
        var tokenInfo = Marshal.AllocHGlobal((int) tokenInfoLength);
        res = GetTokenInformation(tokenHandle,
                                  TOKEN_INFORMATION_CLASS.TokenGroups,
                                  tokenInfo,
                                  tokenInfoLength,
                                  out returnLength);
        if(res)
        {
            groups = (TOKEN_GROUPS)Marshal.PtrToStructure(tokenInfo, typeof (TOKEN_GROUPS));
        }

        Marshal.FreeHGlobal(tokenInfo);
        CloseHandle(tokenHandle);
    }
    else
    {
        var error = new Win32Exception(Marshal.GetLastWin32Error());
        _log.WarnFormat("Failed evaluate the call to get process token information. {0}", error.Message);
    }
    return groups;
}

失败的线路是 groups = (TOKEN_GROUPS)Marshal.PtrToStructure(tokenInfo, typeof (TOKEN_GROUPS)); 我想说异常发生在每20次调用这个方法的1次调用中。一旦它开始发生,之后的每个调用都会抛出异常。重新启动进程会导致错误消失。

IntPtr tokenHandle

var processId = GetCurrentProcess();

            _log.InfoFormat("Process ID [{0}]", processId.ToString());

            if (processId != IntPtr.Zero)
            {
                IntPtr tokenHandle;
                if (OpenProcessToken(processId, TOKEN_READ, out tokenHandle))
                {
                    groups = GetTokenGroups(tokenHandle);
                }

编辑 希望这不是信息过载,但以下是pinvoke声明:

     struct TOKEN_GROUPS
    {
        public uint GroupCount;
        [MarshalAs(UnmanagedType.ByValArray, SizeConst = 4000)]
        public SID_AND_ATTRIBUTES[] Groups;
    }

    [StructLayout(LayoutKind.Sequential)]
    struct SID_AND_ATTRIBUTES
    {
        public IntPtr SID;
        public uint Attributes;
    }

    [DllImport("advapi32.dll", SetLastError = true)]
    static extern bool GetTokenInformation(
        IntPtr TokenHandle,
        TOKEN_INFORMATION_CLASS TokenInformationClass,
        IntPtr TokenInformation,
        uint TokenInformationLength,
        out uint ReturnLength);

    [DllImport("advapi32.dll", SetLastError = true)]
    [return: MarshalAs(UnmanagedType.Bool)]
    static extern bool OpenProcessToken(IntPtr ProcessHandle,
        UInt32 DesiredAccess, out IntPtr TokenHandle);

    [DllImport("kernel32.dll")]
    static extern IntPtr GetCurrentProcess();

    enum TOKEN_INFORMATION_CLASS
    {
        TokenUser = 1,
        TokenGroups,
        TokenPrivileges,
        TokenOwner,
        TokenPrimaryGroup,
        TokenDefaultDacl,
        TokenSource,
        TokenType,
        TokenImpersonationLevel,
        TokenStatistics,
        TokenRestrictedSids,
        TokenSessionId,
        TokenGroupsAndPrivileges,
        TokenSessionReference,
        TokenSandBoxInert,
        TokenAuditPolicy,
        TokenOrigin
    }