workpool refine: making it completely usable in non-photon env

by converting mutex to spinlock

Author: lihuiba

thread/workerpool.cpp

@@ -35,7 +35,7 @@ class WorkPool::impl {
     static constexpr uint64_t QUEUE_YIELD_COUNT = 256;
     static constexpr uint64_t QUEUE_YIELD_US = 1024;
 
-    photon::mutex worker_mtx;
+    photon::spinlock worker_lock;
     std::vector<std::thread> owned_std_threads;
     std::vector<photon::vcpu_base *> vcpus;
     std::atomic<uint64_t> vcpu_index{0};
@@ -54,7 +54,7 @@ class WorkPool::impl {
     }
 
     ~impl() { // avoid depending on photon to make it destructible wihout photon
-        for (auto num = vcpus.size(); num; --num) enqueue({});
+        for (auto num = vcpus.size(); num; --num) enqueue({}, PhotonContext());
         for (auto &worker : owned_std_threads) worker.join();
         while (vcpus.size()) std::this_thread::yield();
     }
@@ -81,7 +81,6 @@ class WorkPool::impl {
     }
 
     int get_vcpu_num() {
-        photon::scoped_lock _(worker_mtx);
         return vcpus.size();
     }
 
@@ -92,12 +91,12 @@ class WorkPool::impl {
     }
 
     void add_vcpu() {
-        photon::scoped_lock _(worker_mtx);
+        SCOPED_LOCK(worker_lock);
         vcpus.push_back(photon::get_vcpu());
     }
 
     void remove_vcpu() {
-        photon::scoped_lock _(worker_mtx);
+        SCOPED_LOCK(worker_lock);
         auto v = photon::get_vcpu();
         auto it = std::find(vcpus.begin(), vcpus.end(), v);
         vcpus.erase(it);
@@ -151,6 +150,10 @@ class WorkPool::impl {
         return vcpus[index];
     }
 
+    int thread_migrate(photon::thread* th, size_t index) {
+        return photon::thread_migrate(th, get_vcpu_in_pool(index));
+    }
+
     int join_current_vcpu_into_workpool() {
         if (!photon::CURRENT) return -1;
         main_loop();
@@ -205,8 +208,8 @@ void WorkPool::do_call<PhotonContext>(Delegate<void> call) {
 }
 
 void WorkPool::enqueue(Delegate<void> call) { pImpl->enqueue(call); }
-photon::vcpu_base *WorkPool::get_vcpu_in_pool(size_t index) {
-    return pImpl->get_vcpu_in_pool(index);
+int WorkPool::thread_migrate(photon::thread* th, size_t index) {
+    return pImpl->thread_migrate(th, index);
 }
 int WorkPool::join_current_vcpu_into_workpool() {
     return pImpl->join_current_vcpu_into_workpool();

thread/workerpool.h

@@ -29,7 +29,7 @@ namespace photon {
 class WorkPool {
 public:
     /**
-     * @brief Construct a new Work Pool object
+     * @brief Construct a new Work Pool object; available in non-photon environment
      *
      * @param vcpu_num how many VCPU (std threads) create for this workpool
      * @param ev_engine how to initial event engine as preset VCPUs
@@ -44,21 +44,22 @@ class WorkPool {
     WorkPool(const WorkPool& other) = delete;
     WorkPool& operator=(const WorkPool& rhs) = delete;
 
+    // available in non-photon environment
     ~WorkPool();
 
     /**
      * @brief `hold_as_worker` makes blocks current std thread join workpool, as
-     * a woker member. Noticed that worker should initial environment by self,
+     * a woker member. Note that workers should initialize photon environment by themselves,
      * workpool will not do photon environment for it. When workpool destructed,
      * the function call will be finished, and return 0.
      * @return int 0 for success, and -1 for failure
      */
     int join_current_vcpu_into_workpool();
 
     /**
-     * @brief Get the vcpu num
-     * 
-     * @return int 
+     * @brief Get the vcpu num; available in non-photon environment
+     *
+     * @return int
      */
     int get_vcpu_num();
 
@@ -83,6 +84,7 @@ class WorkPool {
 
     /**
      * @brief `async_call` just like `call`, but do not wait for task done.
+     *        available in non-photon environment.
      *
      * @param task Pointer to async task callable object. Call by lamda could
      * using `workpool.async_call(new auto ([&](){ // some lambda; }));` The
@@ -103,9 +105,7 @@ class WorkPool {
      * [0, vcpu_num), it will choose the next one in pool (round-robin).
      * @return int 0 for success, and <0 means failed to migrate.
      */
-    int thread_migrate(photon::thread* th = CURRENT, size_t index = -1UL) {
-        return photon::thread_migrate(th, get_vcpu_in_pool(index));
-    }
+    int thread_migrate(photon::thread* th = CURRENT, size_t index = -1UL);
 
 protected:
     class impl;  // does not depend on T
@@ -115,7 +115,6 @@ class WorkPool {
     template<typename Context>
     void do_call(Delegate<void> call);
     void enqueue(Delegate<void> call);
-    photon::vcpu_base* get_vcpu_in_pool(size_t index);
 
     template<typename Task>
     static void __async_call_helper(void* task) {