From a9cb81bee9c3f82515c5a1713e2cc905021efc8b Mon Sep 17 00:00:00 2001
From: mutouyun <orz@orzz.org>
Date: Mon, 20 Sep 2021 16:05:35 +0800
Subject: [PATCH] missing file

---
 src/libipc/waiter.h | 70 +++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 70 insertions(+)
 create mode 100644 src/libipc/waiter.h

diff --git a/src/libipc/waiter.h b/src/libipc/waiter.h
new file mode 100644
index 0000000..6c2cb45
--- /dev/null
+++ b/src/libipc/waiter.h
@@ -0,0 +1,70 @@
+#pragma once
+
+#include <utility>
+#include <string>
+#include <mutex>
+
+#include "libipc/def.h"
+#include "libipc/mutex.h"
+#include "libipc/condition.h"
+#include "libipc/platform/detail.h"
+
+namespace ipc {
+namespace detail {
+
+class waiter {
+    ipc::sync::condition cond_;
+    ipc::sync::mutex     lock_;
+
+public:
+    waiter() = default;
+    waiter(char const *name) {
+        open(name);
+    }
+
+    ~waiter() {
+        close();
+    }
+
+    bool valid() const noexcept {
+        return cond_.valid() && lock_.valid();
+    }
+
+    bool open(char const *name) noexcept {
+        if (!cond_.open((std::string{"_waiter_cond_"} + name).c_str())) {
+            return false;
+        }
+        if (!lock_.open((std::string{"_waiter_lock_"} + name).c_str())) {
+            cond_.close();
+            return false;
+        }
+        return valid();
+    }
+
+    void close() noexcept {
+        cond_.close();
+        lock_.close();
+    }
+
+    template <typename F>
+    bool wait_if(F &&pred, std::uint64_t tm = ipc::invalid_value) noexcept {
+        IPC_UNUSED_ std::lock_guard<ipc::sync::mutex> guard {lock_};
+        while (std::forward<F>(pred)()) {
+            if (!cond_.wait(lock_, tm)) return false;
+        }
+        return true;
+    }
+
+    bool notify() noexcept {
+        std::lock_guard<ipc::sync::mutex>{lock_}; // barrier
+        return cond_.notify();
+    }
+
+    bool broadcast() noexcept {
+        std::lock_guard<ipc::sync::mutex>{lock_}; // barrier
+        return cond_.broadcast();
+    }
+};
+
+} // namespace detail
+} // namespace ipc