Using FindFirstFileA() instead of CreateFileA() to get the file size

Since we already call FindFirstFileA() and it returns the size there is
no need to open/close every file to get it's size

lf_mpmc.h

@@ -185,7 +185,7 @@ static void mpmc_push(MPMCQueue *q, void *item) {
 }
 
 /* ----------------------------------------------------------- */
-/* POP */
+/* POP (blocking with semaphore) */
 /* ----------------------------------------------------------- */
 static void *mpmc_pop(MPMCQueue *q) {
 
@@ -228,6 +228,52 @@ static void *mpmc_pop(MPMCQueue *q) {
   return data;
 }
 
+/* ----------------------------------------------------------- */
+/* TRY POP (non blocking) */
+/* ----------------------------------------------------------- */
+static b32 mpmc_try_pop(MPMCQueue *q, void **out) {
+
+  if (!plat_sem_trywait(&q->items_sem))
+    return false;
+
+  MPMCSlot *slot;
+  size_t pos;
+
+  int spins = 0;
+
+  for (;;) {
+
+    pos = atomic_load_explicit(&q->head, memory_order_relaxed);
+    slot = &q->slots[pos & q->mask];
+
+    size_t seq = atomic_load_explicit(&slot->seq, memory_order_acquire);
+    intptr_t diff = (intptr_t)seq - (intptr_t)(pos + 1);
+
+    if (likely(diff == 0)) {
+
+      if (atomic_compare_exchange_weak_explicit(&q->head, &pos, pos + 1,
+                                                memory_order_relaxed,
+                                                memory_order_relaxed))
+        break;
+
+    } else {
+
+      if (++spins > 10) {
+        SwitchToThread();
+        spins = 0;
+      } else {
+        cpu_pause();
+      }
+    }
+  }
+
+  *out = slot->data;
+
+  atomic_store_explicit(&slot->seq, pos + q->capacity, memory_order_release);
+
+  return true;
+}
+
 /* ----------------------------------------------------------- */
 /* PUSH POISON */
 /* ----------------------------------------------------------- */