// Add a work item to the worker queue.
private static void AddWorkItem(WorkItem item)
{
if (!Thread.CanStartThreads())
{
// Add the item to the end of the worker queue.
if (lastWorkItem != null)
{
lastWorkItem.next = item;
}
else
{
workItems = item;
}
lastWorkItem = item;
// We don't have threads, so execute the items now.
WorkItem next = ItemToDispatch();
while (next != null)
{
next.Execute();
next = ItemToDispatch();
}
}
else
{
lock (typeof(ThreadPool))
{
if (lastWorkItem != null)
{
lastWorkItem.next = item;
}
else
{
workItems = item;
}
lastWorkItem = item;
// Determine if we need to spawn a new worker thread.
if (workItems != null &&
numWorkerThreads < MaxWorkerThreads)
{
if (workerThreads == null)
{
workerThreads = new Thread [MaxWorkerThreads];
}
Thread thread = new Thread(new ThreadStart(Work));
#if !ECMA_COMPAT
thread.inThreadPool = true;
#endif
workerThreads[numWorkerThreads++] = thread;
thread.IsBackground = true;
thread.Start();
}
Monitor.Pulse(typeof(ThreadPool));
}
}
}
// Run a worker thread.
private static void Work()
{
// Assert unrestricted permissions for this thread.
// The permissions will be modified for each work item
// to reflect the context that created the work item.
ClrSecurity.SetPermissions(null, 0);
// Wait for and dispatch work items.
WorkItem item = null;
for (;;)
{
lock (typeof(ThreadPool))
{
do
{
item = ItemToDispatch();
if (item == null)
{
Monitor.Wait(typeof(ThreadPool));
}
}while(item == null);
}
try
{
Interlocked.Increment(ref usedWorkerThreads);
item.Execute();
}
finally
{
item = null;
Interlocked.Decrement(ref usedWorkerThreads);
}
}
}
// Add a work item to the completion queue.
private static void AddCompletionItem(WorkItem item)
{
if (!Thread.CanStartThreads())
{
// Add the item to the end of the worker queue.
if (lastCompletionItem != null)
{
lastCompletionItem.next = item;
}
else
{
completionItems = item;
}
lastCompletionItem = item;
// We don't have threads, so execute the items now.
WorkItem next = CompletionItemToDispatch();
while (next != null)
{
next.Execute();
next = CompletionItemToDispatch();
}
}
else
{
lock (completionWait)
{
if (lastCompletionItem != null)
{
lastCompletionItem.next = item;
}
else
{
completionItems = item;
}
lastCompletionItem = item;
queuedCompletionItems++;
if (completionThreads == null)
{
completionThreads =
new Thread [MaxCompletionThreads];
}
//
// We need to make sure that there are enough threads to
// handle the entire queue.
//
// There is a small possibility here that there is a thread
// about to end that could take this work unit, but we have no
// way of knowing that.
//
int needThreads = usedCompletionThreads + queuedCompletionItems;
// Determine if we need to spawn a new completion thread.
if (needThreads > numCompletionThreads)
{
if (needThreads > MaxCompletionThreads)
// throw new SystemException("Number of completion threads required exceeds maximum");
{
// Don't throw. Leave on the queue and pulse the lock if there are any waiting threads
if (usedCompletionThreads < numCompletionThreads)
{
Monitor.Pulse(completionWait);
}
return;
}
Thread thread =
new Thread(new ThreadStart(Complete));
#if !ECMA_COMPAT
thread.inThreadPool = true;
#endif
completionThreads[numCompletionThreads++] = thread;
thread.IsBackground = true;
thread.Start();
}
else
{
// Signal one of our waiting threads
Monitor.Pulse(completionWait);
}
}
}
}