From 4d914d5c4974f0f8677228c0cc281765d06b0ee7 Mon Sep 17 00:00:00 2001
From: Coldwings <coldwings@me.com>
Date: Wed, 16 Aug 2023 18:58:58 +0800
Subject: [PATCH] async awaiter

---
 common/executor/easyawaiter.h                | 43 +++++++++++
 include/photon/common/executor/easyawaiter.h |  1 +
 include/photon/thread/awaiter.h              |  1 +
 thread/awaiter.h                             | 77 ++++++++++++++++++++
 4 files changed, 122 insertions(+)
 create mode 100644 common/executor/easyawaiter.h
 create mode 120000 include/photon/common/executor/easyawaiter.h
 create mode 120000 include/photon/thread/awaiter.h
 create mode 100644 thread/awaiter.h

diff --git a/common/executor/easyawaiter.h b/common/executor/easyawaiter.h
new file mode 100644
index 00000000..db11dfa0
--- /dev/null
+++ b/common/executor/easyawaiter.h
@@ -0,0 +1,43 @@
+/*
+Copyright 2022 The Photon Authors
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+#pragma once
+
+#include <easy/easy_io.h>
+#include <easy/easy_uthread.h>
+#include <photon/thread/awaiter.h>
+
+namespace photon {
+
+struct EasyContext {};
+
+template <>
+struct Awaiter<EasyContext> {
+    easy_comutex_t mtx;
+    Awaiter() {
+        easy_comutex_init(&mtx);
+        easy_comutex_cond_lock(&mtx);
+    }
+    ~Awaiter() { easy_comutex_cond_unlock(&mtx); }
+    void suspend() { easy_comutex_cond_wait(&mtx); }
+    void resume() {
+        easy_comutex_cond_lock(&mtx);
+        easy_comutex_cond_signal(&mtx);
+        easy_comutex_cond_unlock(&mtx);
+    }
+};
+
+}  // namespace photon
diff --git a/include/photon/common/executor/easyawaiter.h b/include/photon/common/executor/easyawaiter.h
new file mode 120000
index 00000000..a2e8a7c3
--- /dev/null
+++ b/include/photon/common/executor/easyawaiter.h
@@ -0,0 +1 @@
+../../../../common/executor/easyawaiter.h
\ No newline at end of file
diff --git a/include/photon/thread/awaiter.h b/include/photon/thread/awaiter.h
new file mode 120000
index 00000000..39ba20de
--- /dev/null
+++ b/include/photon/thread/awaiter.h
@@ -0,0 +1 @@
+../../../thread/awaiter.h
\ No newline at end of file
diff --git a/thread/awaiter.h b/thread/awaiter.h
new file mode 100644
index 00000000..e419d0d1
--- /dev/null
+++ b/thread/awaiter.h
@@ -0,0 +1,77 @@
+/*
+Copyright 2022 The Photon Authors
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+#pragma once
+
+#include <errno.h>
+#include <photon/thread/thread.h>
+
+#include <atomic>
+#include <future>
+
+namespace photon {
+
+// Special context that supports calling executor in photon thread
+struct PhotonContext {};
+
+// Context for stdthread calling executor
+struct StdContext {};
+
+// Special context that can automaticlly choose `PhotonContext` or `StdContext`
+// by if photon initialized in current environment
+struct AutoContext {};
+
+template <typename T>
+struct Awaiter;
+
+template <>
+struct Awaiter<PhotonContext> {
+    photon::semaphore sem;
+    Awaiter() {}
+    void suspend() { sem.wait(1); }
+    void resume() { sem.signal(1); }
+};
+
+template <>
+struct Awaiter<StdContext> {
+    int err;
+    std::promise<void> p;
+    std::future<void> f;
+    Awaiter() : f(p.get_future()) {}
+    void suspend() { f.get(); }
+    void resume() { return p.set_value(); }
+};
+
+template <>
+struct Awaiter<AutoContext> {
+    Awaiter<PhotonContext> pctx;
+    Awaiter<StdContext> sctx;
+    bool is_photon = false;
+    Awaiter() : is_photon(photon::CURRENT) {}
+    void suspend() {
+        if (is_photon)
+            pctx.suspend();
+        else
+            sctx.suspend();
+    }
+    void resume() {
+        if (is_photon)
+            pctx.resume();
+        else
+            sctx.resume();
+    }
+};
+}  // namespace photon
\ No newline at end of file