Endpoint syscalls implemented

zion/object/endpoint.cpp

@@ -0,0 +1,43 @@
+#include "object/endpoint.h"
+
+#include "scheduler/scheduler.h"
+
+glcr::RefPtr<Endpoint> Endpoint::Create() {
+  return glcr::AdoptPtr(new Endpoint);
+}
+
+glcr::ErrorCode Endpoint::Write(uint64_t num_bytes, const void* data,
+                                z_cap_t reply_port_cap) {
+  MutexHolder h(mutex_);
+  RET_ERR(message_queue_.PushBack(num_bytes, data, 1, &reply_port_cap));
+
+  if (blocked_threads_.size() > 0) {
+    auto thread = blocked_threads_.PopFront();
+    thread->SetState(Thread::RUNNABLE);
+    gScheduler->Enqueue(thread);
+  }
+
+  return glcr::OK;
+}
+glcr::ErrorCode Endpoint::Read(uint64_t* num_bytes, void* data,
+                               z_cap_t* reply_port_cap) {
+  mutex_.Lock();
+  while (message_queue_.empty()) {
+    auto thread = gScheduler->CurrentThread();
+    thread->SetState(Thread::BLOCKED);
+    mutex_.Unlock();
+    gScheduler->Yield();
+    mutex_.Lock();
+  }
+  mutex_.Unlock();
+
+  MutexHolder h(mutex_);
+
+  uint64_t num_caps = 1;
+  RET_ERR(message_queue_.PopFront(num_bytes, data, &num_caps, reply_port_cap));
+
+  if (num_caps != 1) {
+    return glcr::INTERNAL;
+  }
+  return glcr::OK;
+}

zion/object/endpoint.h

@@ -0,0 +1,37 @@
+#pragma once
+
+#include <glacier/container/intrusive_list.h>
+#include <glacier/memory/ref_ptr.h>
+#include <glacier/status/error.h>
+
+#include "lib/message_queue.h"
+#include "lib/mutex.h"
+#include "object/kernel_object.h"
+
+class Endpoint;
+class ReplyPort;
+
+template <>
+struct KernelObjectTag<Endpoint> {
+  static const uint64_t type = KernelObject::ENDPOINT;
+};
+
+class Endpoint : public KernelObject {
+ public:
+  uint64_t TypeTag() override { return KernelObject::ENDPOINT; }
+  static glcr::RefPtr<Endpoint> Create();
+
+  glcr::ErrorCode Write(uint64_t num_bytes, const void* data,
+                        z_cap_t reply_port_cap);
+
+  glcr::ErrorCode Read(uint64_t* num_bytes, void* data,
+                       z_cap_t* reply_port_cap);
+
+ private:
+  Mutex mutex_{"endpoint"};
+  UnboundedMessageQueue message_queue_;
+
+  glcr::IntrusiveList<Thread> blocked_threads_;
+
+  Endpoint() {}
+};

zion/object/kernel_object.h

@@ -12,6 +12,8 @@ class KernelObject : public glcr::RefCounted<KernelObject> {
     MEMORY_OBJECT = 0x4,
     CHANNEL = 0x5,
     PORT = 0x6,
+    ENDPOINT = 0x7,
+    REPLY_PORT = 0x8,
   };
 
   virtual uint64_t TypeTag() = 0;

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);
+}

zion/object/reply_port.h

@@ -0,0 +1,33 @@
+#pragma once
+
+#include <glacier/memory/ref_ptr.h>
+
+#include "lib/message_queue.h"
+#include "lib/mutex.h"
+#include "object/kernel_object.h"
+
+class ReplyPort;
+
+template <>
+struct KernelObjectTag<ReplyPort> {
+  static const uint64_t type = KernelObject::REPLY_PORT;
+};
+
+class ReplyPort : public KernelObject {
+ public:
+  uint64_t TypeTag() override { return KernelObject::REPLY_PORT; }
+  static glcr::RefPtr<ReplyPort> Create();
+
+  uint64_t Write(uint64_t num_bytes, const void* data, uint64_t num_caps,
+                 uint64_t* caps);
+  uint64_t Read(uint64_t* num_bytes, void* data, uint64_t* num_caps,
+                uint64_t* caps);
+
+ private:
+  Mutex mutex_{"reply_port"};
+  SingleMessageQueue message_holder_;
+
+  glcr::RefPtr<Thread> blocked_thread_;
+
+  ReplyPort() {}
+};