/// <summary>
/// this is fully reentrant and multithreading capable, but will itself block.
/// </summary>
private AssemblyDefinition Load(AssemblyNameReference name, string assemblyFilename, ReaderParameters parameters)
{
AssemblyDefinition ret = null;
TaskCompletionSource<AssemblyDefinition> loadingTaskSource = new TaskCompletionSource<AssemblyDefinition>();
bool nameRegistered = false, filenameRegistered = false;
try
{
// First, make sure we are the only one loading.
while (true)
{
Task<AssemblyDefinition> loadingTask;
if (name != null && !nameRegistered)
{
if (loadingTasks.TryGetValue(name.Name, out loadingTask))
{
ret = loadingTask.Result;
return ret;
}
if (!loadingTasks.TryAdd(name.Name, loadingTaskSource.Task))
continue;
nameRegistered = true;
}
if (loadingTasks.TryAdd(assemblyFilename, loadingTaskSource.Task))
{
filenameRegistered = true;
break;
}
if (loadingTasks.TryGetValue(assemblyFilename, out loadingTask))
{
if (loadingTask == loadingTaskSource.Task)
break;
ret = loadingTask.Result;
return ret;
}
}
// now check if it has already been loaded.
if (name != null)
{
if (referencesByName.TryGetValue(name.Name, out ret))
return ret;
}
ret = fileNamesByAssembly.FirstOrDefault(v => v.Value.Equals(assemblyFilename, StringComparison.InvariantCultureIgnoreCase)).Key;
if (ret != null)
return ret;
// now load the assembly.
Console.WriteLine("Loading {0}...", Path.GetFileName(assemblyFilename));
AssemblyDefinition assm = AssemblyDefinition.ReadAssembly(assemblyFilename, parameters);
VerifyFrameworkAssembly(assm, assemblyFilename);
// have to use a lock to update both data structures at the same time.
lock (referencesByName)
{
// now check again by the assembly name if it has been loaded before.
// This can happen if we were only provided a file name
if (!referencesByName.TryAdd(assm.Name.Name, assm))
{
ret = referencesByName[assm.Name.Name];
return ret;
}
fileNamesByAssembly[assm] = assemblyFilename;
}
ret = assm;
// now notify any listeners. note that if we were called on multiple threads
// these might be called reentrantly as well.
if(assemblyLoaded != null)
assemblyLoaded(ret);
if (classLoader != null)
classLoader.LoadAssembly(ret);
// done.
return ret;
}
catch (Exception ex)
{
#if DEBUG
Console.WriteLine(ex.Message);
Console.WriteLine(ex.StackTrace);
#endif
// Log the error
var assemblyName = name==null?assemblyFilename:name.ToString();
DLog.Error(DContext.CompilerAssemblyResolver, "Failed to load assembly {0}: {1}", assemblyName, ex.Message);
// Pass the error on
var exn = new AssemblyResolutionException(name??new AssemblyNameDefinition(assemblyFilename, new Version()));
loadingTaskSource.SetException(exn);
throw exn;
}
finally
{
loadingTaskSource.TrySetResult(ret);
// cleanup our registrations
Task<AssemblyDefinition> ignore;
if (nameRegistered)
loadingTasks.TryRemove(name.Name, out ignore);
if (filenameRegistered)
loadingTasks.TryRemove(assemblyFilename, out ignore);
}
}
