Endpoint syscalls implemented

zion/object/reply_port.cpp

@@ -0,0 +1,41 @@
+#include "object/reply_port.h"
+
+#include "scheduler/scheduler.h"
+
+glcr::RefPtr<ReplyPort> ReplyPort::Create() {
+  return glcr::AdoptPtr(new ReplyPort);
+}
+
+uint64_t ReplyPort::Write(uint64_t num_bytes, const void* data,
+                          uint64_t num_caps, uint64_t* caps) {
+  MutexHolder h(mutex_);
+  RET_ERR(message_holder_.PushBack(num_bytes, data, num_caps, caps));
+
+  if (blocked_thread_) {
+    // FIXME: We need to handle the case where the blocked thread has died I
+    // think.
+    blocked_thread_->SetState(Thread::RUNNABLE);
+    gScheduler->Enqueue(blocked_thread_);
+    blocked_thread_ = nullptr;
+  }
+  return glcr::OK;
+}
+
+uint64_t ReplyPort::Read(uint64_t* num_bytes, void* data, uint64_t* num_caps,
+                         uint64_t* caps) {
+  mutex_.Lock();
+  if (message_holder_.empty()) {
+    // Multiple threads can't block on a reply port.
+    if (blocked_thread_) {
+      mutex_.Unlock();
+      return glcr::FAILED_PRECONDITION;
+    }
+    blocked_thread_ = gScheduler->CurrentThread();
+    blocked_thread_->SetState(Thread::BLOCKED);
+    mutex_.Unlock();
+    gScheduler->Yield();
+    mutex_.Lock();
+  }
+
+  return message_holder_.PopFront(num_bytes, data, num_caps, caps);
+}