diff -r bf810176ddb8 -r e5f4d8af567e ui/common/threadpool.c
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/ui/common/threadpool.c	Sun Jun 09 15:43:08 2024 +0200
@@ -0,0 +1,174 @@
+/*
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS HEADER.
+ *
+ * Copyright 2024 Olaf Wintermann. All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *
+ *   1. Redistributions of source code must retain the above copyright
+ *      notice, this list of conditions and the following disclaimer.
+ *
+ *   2. Redistributions in binary form must reproduce the above copyright
+ *      notice, this list of conditions and the following disclaimer in the
+ *      documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+ * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
+ * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+ * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+ * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+ * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+ * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#include "threadpool.h"
+
+#include <pthread.h>
+
+#ifndef _WIN32
+
+
+static threadpool_job kill_job;
+
+UiThreadpool* threadpool_new(int min, int max) {
+    UiThreadpool *pool = malloc(sizeof(UiThreadpool));
+    pool->queue = NULL;
+    pool->queue_len = 0;
+    pool->num_idle = 0;
+    pool->min_threads = min;
+    pool->max_threads = max;
+
+    pthread_mutex_init(&pool->queue_lock, NULL);
+    pthread_mutex_init(&pool->avlbl_lock, NULL);
+    pthread_cond_init(&pool->available, NULL);  
+
+    return pool;
+}
+
+int threadpool_start(UiThreadpool *pool) {
+    /* create pool threads */
+    for(int i=0;i<pool->min_threads;i++) {
+        pthread_t t;
+        if (pthread_create(&t, NULL, threadpool_func, pool) != 0) {
+            fprintf(stderr, "uic: threadpool_start: pthread_create failed: %s", strerror(errno));
+            return 1;
+        }
+    }
+    return 0;
+}
+
+void* threadpool_func(void *data) {
+    UiThreadpool *pool = (UiThreadpool*)data;
+    
+    for(;;) {
+        threadpool_job *job = threadpool_get_job(pool);
+        if(job == &kill_job) {
+            break;
+        }
+
+        job->callback(job->data);
+
+        free(job);
+    }
+    return NULL;
+}
+
+threadpool_job* threadpool_get_job(UiThreadpool *pool) {
+    pthread_mutex_lock(&pool->queue_lock);
+
+    threadpool_job *job = NULL;
+    pool->num_idle++;
+    while(job == NULL) {
+        if(pool->queue_len == 0) {
+            pthread_cond_wait(&pool->available, &pool->queue_lock);
+            continue;
+        } else {
+            pool_queue_t *q = pool->queue;
+            job = q->job;
+            pool->queue = q->next;
+            pool->queue_len--;
+            free(q);
+        }
+    }
+    pool->num_idle--;
+
+    pthread_mutex_unlock(&pool->queue_lock);
+    return job;
+}
+
+void threadpool_run(UiThreadpool *pool, job_callback_f func, void *data) {
+    // TODO: handle errors
+    
+    threadpool_job *job = malloc(sizeof(threadpool_job));
+    job->callback = func;
+    job->data = data;
+
+    pthread_mutex_lock(&pool->queue_lock);
+    threadpool_enqueue_job(pool, job);
+
+    int create_thread = 0;
+    int destroy_thread = 0;
+    int diff = pool->queue_len - pool->num_idle;
+    
+    //if(pool->queue_len == 1) {
+    pthread_cond_signal(&pool->available);
+    //}
+    
+    pthread_mutex_unlock(&pool->queue_lock);
+}
+
+void threadpool_enqueue_job(UiThreadpool *pool, threadpool_job *job) {
+    pool_queue_t *q = malloc(sizeof(pool_queue_t));
+    q->job = job;
+    q->next = NULL;
+    
+    if(pool->queue == NULL) {
+        pool->queue = q;
+    } else {
+        pool_queue_t *last_elem = pool->queue;
+        while(last_elem->next != NULL) {
+            last_elem = last_elem->next;
+        }
+        last_elem->next = q;
+    }
+    pool->queue_len++;
+}
+
+
+
+
+
+
+UiThreadpool* ui_threadpool_create(int nthreads) {
+    return threadpool_new(nthreads, nthreads);
+}
+
+void ui_threadpool_destroy(UiThreadpool* pool) {
+    
+}
+
+static void* ui_threadpool_job_func(void *data) {
+    UiJob *job = data;
+    
+    free(job);
+    return NULL;
+}
+
+void ui_threadpool_job(UiThreadpool* pool, UiObject* obj, ui_threadfunc tf, void* td, ui_callback f, void* fd) {
+    UiJob* job = malloc(sizeof(UiJob));
+    job->obj = obj;
+    job->job_func = tf;
+    job->job_data = td;
+    job->finish_callback = f;
+    job->finish_data = fd;
+    threadpool_run(pool, ui_threadpool_job_func, job);
+}
+
+
+#endif
+