remove unused threadpool class

include/mbgl/util/threadpool.hpp

@@ -1,46 +0,0 @@
-#ifndef MBGL_UTIL_THREADPOOL
-#define MBGL_UTIL_THREADPOOL
-
-#include <pthread.h>
-#include <forward_list>
-#include <queue>
-#include <memory>
-
-namespace mbgl {
-namespace util {
-
-class Threadpool {
-private:
-    class Worker {
-    public:
-        Worker(Threadpool& pool);
-        ~Worker();
-        static void *loop(void *ptr);
-
-    private:
-        Threadpool& pool;
-        pthread_t thread;
-    };
-
-public:
-    Threadpool(int max_workers = 4);
-    typedef void (*Callback)(void *);
-    void add(Callback callback, void *data);
-
-private:
-    typedef std::pair<Callback, void *> Task;
-    const int max_workers;
-    pthread_mutex_t mutex = PTHREAD_MUTEX_INITIALIZER;
-    pthread_cond_t condition = PTHREAD_COND_INITIALIZER;
-    std::forward_list<Worker> workers;
-    int worker_count = 0;
-    std::queue<Task> tasks;
-};
-
-extern std::unique_ptr<Threadpool> threadpool;
-
-}
-}
-
-#endif
-

src/util/threadpool.cpp

@@ -1,54 +0,0 @@
-#include <mbgl/util/threadpool.hpp>
-#include <mbgl/util/std.hpp>
-#include <thread>
-#include <memory>
-
-using namespace mbgl::util;
-
-std::unique_ptr<Threadpool> mbgl::util::threadpool = std::make_unique<Threadpool>(std::thread::hardware_concurrency());
-
-Threadpool::Threadpool(int max_workers)
-    : max_workers(max_workers) {
-}
-
-void Threadpool::add(Callback callback, void *data) {
-    if (worker_count < max_workers) {
-        worker_count++;
-        workers.emplace_front(*this);
-    }
-
-    pthread_mutex_lock(&mutex);
-    tasks.push(std::make_pair(callback, data));
-    pthread_mutex_unlock(&mutex);
-    pthread_cond_signal(&condition);
-}
-
-Threadpool::Worker::Worker(Threadpool& pool)
-    : pool(pool) {
-    pthread_create(&thread, nullptr, loop, (void *)this);
-}
-
-Threadpool::Worker::~Worker() {
-    pthread_cancel(thread);
-}
-
-
-void *Threadpool::Worker::loop(void *ptr) {
-    Worker *worker = static_cast<Worker *>(ptr);
-    Threadpool& pool = worker->pool;
-
-    pthread_mutex_lock(&pool.mutex);
-    while (true) {
-        if (pool.tasks.size()) {
-            Threadpool::Task task = pool.tasks.front();
-            pool.tasks.pop();
-            pthread_mutex_unlock(&pool.mutex);
-            task.first(task.second);
-            pthread_mutex_lock(&pool.mutex);
-        } else {
-            pthread_cond_wait(&pool.condition, &pool.mutex);
-        }
-    }
-
-    return nullptr;
-}