lib: add generic resource allocator

kernel-src/include/resource_allocator.h

@@ -0,0 +1,28 @@
+#ifndef _RESOURCE_ALLOCATOR_H
+#define _RESOURCE_ALLOCATOR_H
+
+// simple FIFO allocator for an arbritary resource
+
+#include <kernel/scheduler.h>
+#include <mutex.h>
+
+// TODO move this to a proper dequeue abstraction
+typedef struct resource_allocator_waiter_t {
+	size_t requested;
+	thread_t *thread;
+	struct resource_allocator_waiter_t *next;
+} resource_allocator_waiter_t;
+
+typedef struct {
+	mutex_t mutex;
+	resource_allocator_waiter_t *queue;
+	resource_allocator_waiter_t *tail;
+	size_t resource_current;
+	size_t allocate_max;
+} resource_allocator_t;
+
+void resource_allocator_init(resource_allocator_t *allocator, size_t resource_total, size_t allocate_max);
+void resource_allocate(resource_allocator_t *allocator, size_t count);
+void resource_free(resource_allocator_t *allocator, size_t count);
+
+#endif