Loading and caching effects

src/game/main.c

@@ -2,8 +2,10 @@
 #include "runtime/resources.h"
 #include "runtime/threading.h"
 
+#include "gfx/builtin_objects.h"
 #include "gfx/gfx.h"
 #include "gfx/renderer_api.h"
+#include "gfx/effect.h"
 
 #include "asset_compiler/asset_compiler.h"
 
@@ -13,10 +15,33 @@ void RegisterCVars(void) {
 
 static rt_render_graph *_graph;
 
-static rt_result ForwardPassExecute(rt_command_buffer_handle cmdbuf,
+static rt_result ForwardPassExecute(uint32_t pass_id,
+                                    rt_command_buffer_handle cmdbuf,
                                     const rt_render_view *views,
                                     uint32_t view_count,
                                     void *userdata) {
+    RT_ASSERT(view_count == 1, "Expected a single view for the main camera.");
+    rt_render_view view = *views;
+    RT_VERIFY(rtDoViewTypesMatchExact(view, &g_builtin_render_object_types.render_mesh, 1));
+
+    rt_render_list meshes = view.lists[0];
+    if (meshes.length == 0)
+        return RT_SUCCESS;
+
+    rt_pipeline_handle bound_pipeline =
+        (RT_GET_RENDER_LIST_ELEMENT(meshes, rt_render_mesh, 0)).pipeline;
+    g_renderer.CmdBindPipeline(cmdbuf, bound_pipeline);
+
+    for (size_t mesh_idx = 0; mesh_idx < meshes.length; ++mesh_idx) {
+        rt_render_mesh mesh = RT_GET_RENDER_LIST_ELEMENT(meshes, rt_render_mesh, mesh_idx);
+        if (RT_COMPARE_RENDER_HANDLES(bound_pipeline, mesh.pipeline, !=)) {
+            bound_pipeline = mesh.pipeline;
+            g_renderer.CmdBindPipeline(cmdbuf, bound_pipeline);
+        }
+        g_renderer.CmdBindVertexBuffers(cmdbuf, 0, 1, &mesh.vbo, NULL);
+        g_renderer.CmdDraw(cmdbuf, 0, mesh.vertex_count);
+    }
+
     return RT_SUCCESS;
 }
 
@@ -27,6 +52,8 @@ void Init(void) {
 
     rtWaitForAssetProcessing();
 
+    rtRegisterBuiltinRenderObjectTypes();
+
     rt_render_graph_builder builder = g_renderer.CreateRenderGraphBuilder();
     rt_attachment_info backbuffer   = {
           .name    = "backbuffer",
@@ -55,6 +82,21 @@ void Init(void) {
     }
 
     g_renderer.DestroyRenderGraphBuilder(&builder);
+
+    const rt_effect *effect;
+    if (rtLoadEffect(rtGetResourceID("assets/shader/static_object.effect"), &effect) !=
+        RT_SUCCESS) {
+        rtReportError("GAME", "Oh noo...");
+    }
+
+    const rt_effect *effect2;
+    if (rtLoadEffect(rtGetResourceID("assets/shader/static_object.effect"), &effect2) !=
+        RT_SUCCESS) {
+        rtReportError("GAME", "Oh noo...");
+    }
+
+    rtReleaseEffect(effect);
+    rtReleaseEffect(effect2);
 }
 
 /* Called after exiting the main-loop and before the runtime starts its shutdown */
@@ -63,6 +105,9 @@ void Shutdown(void) {
     rtShutdownAssetCompiler();
 }
 
+// Question; How do we move data from update to render.
+// This is where we could fill the render views, but that would
+// mean double/triple buffering the views
 void Update(unsigned int frame_id) {
     RT_UNUSED(frame_id);
 }

src/gfx/builtin_objects.h

@@ -14,6 +14,7 @@ extern "C" {
 #endif
 
 typedef struct {
+    rt_pipeline_handle pipeline;
     rt_buffer_handle vbo;
     rt_buffer_handle ibo;
     uint32_t vertex_count;

src/gfx/effect.c

@@ -1,5 +1,88 @@
 #include "effect.h"
+
+#include "runtime/config.h"
+#include "runtime/ds.h"
+#include "runtime/handles.h"
 #include "runtime/hashing.h"
+#include "runtime/mem_arena.h"
+#include "runtime/threading.h"
+#include "runtime/atomics.h"
+
+#include <stdlib.h>
+#include <string.h>
+
+RT_CVAR_SZ(rt_EffectCacheSize, "The number of slots in the effect cache. Default: 1024", 1024);
+
+typedef struct {
+    rt_resource_id resource;
+    rt_effect effect;
+    _Alignas(4) unsigned int refcount;
+} rt_effect_cache_slot;
+
+/* We use a hashtable to find previously loaded effects.
+ * To reclaim unreferenced slots when we need to, we use a minheap.
+ * The minheap implements a LRU list. To track usage, we use a global running "usage counter",
+ * incremented whenever an effect is loaded.
+ */
+typedef struct {
+    rt_effect_cache_slot *slots;
+    rt_hashtable lut;
+    rt_minheap reclaim_heap;
+
+    /* Linearly allocate slots until we reach capacity */
+    size_t next_free;
+
+    /* Used to track "time" since an effect was loaded */
+    _Alignas(4) int usage_counter;
+
+    void *memory;
+
+    rt_rwlock lock;
+} rt_effect_cache;
+
+static rt_effect_cache _cache;
+
+rt_result InitEffectCache(void) {
+    if (!RT_IS_POWER_OF_TWO(rt_EffectCacheSize.sz)) {
+        rtReportError(
+            "GFX",
+            "The value of \"rt_EffectCacheSize\" must be a power of two.\nConfigured: %zu.",
+            rt_EffectCacheSize.sz);
+        return RT_INVALID_VALUE;
+    }
+
+    rt_create_rwlock_result lock_res = rtCreateRWLock();
+    if (!lock_res.ok)
+        return RT_UNKNOWN_ERROR;
+    _cache.lock = lock_res.lock;
+
+    size_t mem_required = sizeof(rt_effect_cache_slot) * rt_EffectCacheSize.sz +
+                          RT_HASH_TABLE_MEMORY_REQUIRED(
+                              2 * rt_EffectCacheSize.sz) +      /* double to keep performance up */
+                          sizeof(int) * rt_EffectCacheSize.sz + /* heap keys */
+                          sizeof(size_t) * rt_EffectCacheSize.sz; /* heap values */
+    _cache.memory = malloc(mem_required);
+    if (!_cache.memory) {
+        rtDestroyRWLock(&_cache.lock);
+        return RT_OUT_OF_MEMORY;
+    }
+    _cache.lut = rtCreateHashtable(rt_EffectCacheSize.sz, _cache.memory, NULL, NULL);
+
+    int *keys =
+        (int *)((char *)_cache.memory + RT_HASH_TABLE_MEMORY_REQUIRED(2 * rt_EffectCacheSize.sz));
+    size_t *values       = (size_t *)(keys + rt_EffectCacheSize.sz);
+    _cache.reclaim_heap  = rtCreateMinheap(keys, values, sizeof(size_t), rt_EffectCacheSize.sz, 0);
+    _cache.usage_counter = 0;
+
+    _cache.slots = (rt_effect_cache_slot *)(values + rt_EffectCacheSize.sz);
+    memset(_cache.slots, 0, sizeof(rt_effect_cache_slot) * rt_EffectCacheSize.sz);
+
+    return RT_SUCCESS;
+}
+
+void ShutdownEffectCache(void) {
+    free(_cache.memory);
+}
 
 RT_DLLEXPORT uint32_t rtCalculateRenderTargetID(const char *name, size_t len) {
     uint32_t id = rtHashBytes32(name, len);
@@ -14,3 +97,163 @@ RT_DLLEXPORT uint32_t rtCalculateRenderPassID(const char *name, size_t len) {
         id = ~id;
     return id;
 }
+
+static void ReleaseEffect(rt_effect *effect) {
+    for (unsigned int i = 0; i < effect->pass_count; ++i) {
+        g_renderer.DestroyPipeline(effect->passes[i].pipeline);
+    }
+}
+
+/* Returns the index of the reserved slot */
+static size_t ReserveSlot(rt_resource_id id) {
+    if (_cache.next_free < rt_EffectCacheSize.sz) {
+        size_t slot = _cache.next_free++;
+        RT_ASSERT(_cache.slots[slot].refcount == 0, "Got a slot that is still in use.");
+        _cache.slots[slot].refcount = 1;
+
+        if (rtHashtableInsert(&_cache.lut, id, slot) != RT_SUCCESS) {
+            rtLog("GFX", "Failed to insert effect %x into the lookup table.", id);
+            _cache.slots[slot].refcount = 0;
+            rtMinheapPush(&_cache.reclaim_heap, _cache.usage_counter, &slot);
+            return SIZE_MAX;
+        }
+        _cache.slots[slot].resource = id;
+        return slot;
+    } else if (!rtMinheapIsEmpty(&_cache.reclaim_heap)) {
+        size_t slot;
+        rtMinheapPop(&_cache.reclaim_heap, &slot);
+        RT_ASSERT(_cache.slots[slot].refcount == 0, "Got a slot that is still in use.");
+        _cache.slots[slot].refcount = 1;
+
+        rt_resource_id old_id       = _cache.slots[slot].resource;
+        RT_ASSERT(old_id != RT_INVALID_RESOURCE_ID, "The slot should contain an old effect.");
+        ReleaseEffect(&_cache.slots[slot].effect);
+        rtHashtableRemove(&_cache.lut, old_id);
+
+        if (rtHashtableInsert(&_cache.lut, id, slot) != RT_SUCCESS) {
+            rtLog("GFX", "Failed to insert effect %x into the lookup table.", id);
+            _cache.slots[slot].refcount = 0;
+            rtMinheapPush(&_cache.reclaim_heap, _cache.usage_counter, &slot);
+            return SIZE_MAX;
+        }
+        _cache.slots[slot].resource = id;
+        return slot;
+    } else {
+        rtLog("GFX",
+              "Could not insert effect %x into the cache, because the effect cache is full.",
+              id);
+        return SIZE_MAX;
+    }
+}
+
+/* Load resource to memory allocated on the given arena */
+static rt_result LoadResource(rt_resource_id id, void **p_out, rt_arena *arena) {
+    size_t size = rtGetResourceSize(id);
+    if (!size) {
+        rtLog("GFX", "ID %x is not a valid resource.", id);
+        return RT_INVALID_VALUE;
+    }
+    void *dst = rtArenaPush(arena, size);
+    if (!dst) {
+        rtLog("GFX", "Failed to allocate %zu bytes of temporary storage.", size);
+        return RT_OUT_OF_MEMORY;
+    }
+    *p_out = dst;
+    return rtGetResource(id, dst);
+}
+
+static rt_result LoadEffect(rt_resource_id id, rt_effect *effect) {
+    rt_temp_arena temp = rtGetTemporaryArena(NULL, 0);
+    if (!temp.arena) {
+        rtLog("GFX", "Could not get a temporary arena.");
+        return RT_OUT_OF_MEMORY;
+    }
+    const rt_resource *resource = NULL;
+    rt_result res               = LoadResource(id, &resource, temp.arena);
+    if (res != RT_SUCCESS) {
+        rtReturnTemporaryArena(temp);
+        return res;
+    }
+    if (resource->type != RT_RESOURCE_EFFECT) {
+        rtReturnTemporaryArena(temp);
+        rtLog("GFX", "Resource %x does not refer to an effect resource.", id);
+        return RT_INVALID_VALUE;
+    }
+    const rt_effect_info *effect_info = resource->data;
+    effect->pass_count                = effect_info->pass_count;
+
+    for (unsigned int i = 0; i < effect_info->pass_count; ++i) {
+        rt_resource *pipeline_resource = NULL;
+        res = LoadResource(effect_info->passes[i].pipeline, &pipeline_resource, temp.arena);
+        if (res != RT_SUCCESS) {
+            rtReturnTemporaryArena(temp);
+            return res;
+        }
+        if (pipeline_resource->type != RT_RESOURCE_PIPELINE) {
+            rtReturnTemporaryArena(temp);
+            rtLog("GFX", "Resource %x does not refer to a pipeline resource.", id);
+            return RT_INVALID_VALUE;
+        }
+        rt_pipeline_info *pipeline_info = pipeline_resource->data;
+        rt_pipeline_handle pipeline     = g_renderer.CompilePipeline(pipeline_info);
+        if (!RT_IS_HANDLE_VALID(pipeline)) {
+            rtReturnTemporaryArena(temp);
+            rtLog("GFX",
+                  "Failed to compile the pipeline of pass %d (%x).",
+                  i,
+                  effect_info->passes[i].pass_id);
+            return RT_UNKNOWN_ERROR;
+        }
+        effect->passes[i].pass_id  = effect_info->passes[i].pass_id;
+        effect->passes[i].pipeline = pipeline;
+    }
+
+    rtReturnTemporaryArena(temp);
+
+    return RT_SUCCESS;
+}
+
+RT_DLLEXPORT rt_result rtLoadEffect(rt_resource_id id, const rt_effect **effect) {
+    rtAtomic32Inc(&_cache.usage_counter);
+
+    /* Check if the effect is already loaded */
+    rtLockRead(&_cache.lock);
+    uint64_t slot = rtHashtableLookup(&_cache.lut, id, UINT64_MAX);
+    if (slot != UINT64_MAX) {
+
+        RT_ASSERT(_cache.slots[slot].resource == id, "Got the wrong effect");
+        rtAtomic32Inc(&_cache.slots[slot].refcount);
+        *effect = &_cache.slots[slot].effect;
+        rtUnlockRead(&_cache.lock);
+        return RT_SUCCESS;
+    }
+    rtUnlockRead(&_cache.lock);
+
+    /* Load the effect */
+    rtLockWrite(&_cache.lock);
+    if (rtHashtableLookup(&_cache.lut, id, UINT64_MAX) != UINT64_MAX) {
+        /* Another thread was faster than we, just retry */
+        rtUnlockWrite(&_cache.lock);
+        return rtLoadEffect(id, effect);
+    }
+    slot = ReserveSlot(id);
+    if (slot == SIZE_MAX) {
+        rtUnlockWrite(&_cache.lock);
+        return RT_OUT_OF_MEMORY;
+    }
+    rt_result res = LoadEffect(id, &_cache.slots[slot].effect);
+    rtUnlockWrite(&_cache.lock);
+    *effect = &_cache.slots[slot].effect;
+    return res;
+}
+
+RT_DLLEXPORT void rtReleaseEffect(const rt_effect *effect) {
+    RT_VERIFY(effect);
+    rt_effect_cache_slot *slot = (rt_effect_cache_slot *)((char *)effect - offsetof(rt_effect_cache_slot, effect));
+    if (rtAtomic32Dec(&slot->refcount) == 0) {
+        rtLockWrite(&_cache.lock);
+        size_t slot_index = (size_t)(slot - _cache.slots);
+        rtMinheapPush(&_cache.reclaim_heap, _cache.usage_counter, &slot_index);
+        rtUnlockWrite(&_cache.lock);
+    }
+}

src/gfx/effect.h

@@ -7,8 +7,11 @@
  */
 
 #include "gfx.h"
+#include "renderer_api.h"
 #include "runtime/resources.h"
 
+/* *** Resource types *** */
+
 typedef struct rt_pipeline_info_s {
     rt_resource_id vertex_shader;
     rt_resource_id fragment_shader;
@@ -28,7 +31,30 @@ typedef struct {
     rt_effect_pass_info passes[RT_MAX_SUBRESOURCES];
 } rt_effect_info;
 
+/* *** Runtime types *** */
+
+typedef struct {
+    uint32_t pass_id;
+    rt_pipeline_handle pipeline;
+} rt_effect_pass;
+
+typedef struct {
+    uint32_t pass_count;
+    rt_effect_pass passes[RT_MAX_SUBRESOURCES];
+} rt_effect;
+
 RT_DLLEXPORT uint32_t rtCalculateRenderTargetID(const char *name, size_t len);
 RT_DLLEXPORT uint32_t rtCalculateRenderPassID(const char *name, size_t len);
 
+/* Load an effect from a resource file.
+ * Returns:
+ * - RT_SUCCESS
+ * - RT_OUT_OF_MEMORY, if temporary memory allocations failed
+ * - RT_INVALID_VALUE, if id does not refer to an effect resource.
+ * - RT_UNKNOWN_ERROR, if a pipeline failed to compile
+ * - errors returned by rtGetResource() */
+RT_DLLEXPORT rt_result rtLoadEffect(rt_resource_id id, const rt_effect **effect);
+
+RT_DLLEXPORT void rtReleaseEffect(const rt_effect *effect);
+
 #endif

src/gfx/gfx_main.c

@@ -23,7 +23,7 @@ static bool _renderer_loaded = false;
 
 RT_DLLEXPORT
 RT_CVAR_S(rt_Renderer,
-          "Select the render backend. Available options: [vk, null], Default: vk",
+          "Select the render backend. Available options: [vk, dx11, null], Default: vk",
           "dx11");
 
 extern rt_cvar rt_RenderViewArenaSize;
@@ -59,7 +59,8 @@ extern void RT_RENDERER_API_FN(DestroyRenderGraphBuilder)(rt_render_graph_builde
 extern rt_result RT_RENDERER_API_FN(ExecuteRenderGraph)(rt_render_graph *);
 extern void RT_RENDERER_API_FN(SubmitRenderView)(rt_render_graph *render_graph,
                                                  uint32_t pass_id,
-                                                 rt_render_view view);
+                                                 rt_render_view view,
+                                                 unsigned int frame_id);
 extern void RT_RENDERER_API_FN(ResetRenderGraph)(rt_render_graph *graph);
 
 extern void RT_RENDERER_API_FN(CmdBeginPass)(rt_command_buffer_handle,
@@ -81,10 +82,12 @@ extern void RT_RENDERER_API_FN(CmdDraw)(rt_command_buffer_handle, uint32_t, uint
 
 extern rt_result InitRenderLists(void);
 extern void ShutdownRenderLists(void);
-extern void ResetRenderLists(void);
+extern void ResetRenderLists(unsigned int frame_id);
 extern rt_result InitRenderViews(void);
 extern void ShutdownRenderViews(void);
-extern void ResetRenderViews(void);
+extern void ResetRenderViews(unsigned int frame_id);
+extern rt_result InitEffectCache(void);
+extern void ShutdownEffectCache(void);
 
 static bool LoadRenderer(void) {
 
@@ -196,10 +199,14 @@ RT_DLLEXPORT rt_result rtInitGFX(rt_renderer_init_info *renderer_info) {
     if ((result = InitRenderViews()) != RT_SUCCESS)
         return result;
 
+    if ((result = InitEffectCache()) != RT_SUCCESS)
+        return result;
+
     return result;
 }
 
 RT_DLLEXPORT void rtShutdownGFX(void) {
+    ShutdownEffectCache();
     ShutdownRenderViews();
     ShutdownRenderLists();
     g_renderer.Shutdown();
@@ -211,6 +218,6 @@ RT_DLLEXPORT void rtBeginGFXFrame(unsigned int frame_id) {
 
 RT_DLLEXPORT void rtEndGFXFrame(unsigned int frame_id) {
     g_renderer.EndFrame(frame_id);
-    ResetRenderLists();
+    ResetRenderLists(frame_id);
-    ResetRenderViews();
+    ResetRenderViews(frame_id);
 }

src/gfx/render_list.c

@@ -1,8 +1,9 @@
 #include "render_list.h"
+#include "renderer_api.h"
 
-#include "runtime/threading.h"
-#include "runtime/mem_arena.h"
 #include "runtime/config.h"
+#include "runtime/mem_arena.h"
+#include "runtime/threading.h"
 
 #include <string.h>
 
@@ -20,15 +21,22 @@ typedef struct rt_list_pool_s {
     struct rt_list_pool_s *next;
 } rt_list_pool;
 
+typedef struct {
+    rt_mutex *lock;
+    rt_list_pool *first_free;
+    rt_arena arena;
+
+    unsigned int access_frame_id;
+} rt_frame_lists;
+
 #define DEFAULT_LIST_CAPACITY RT_KB(1)
 
 static rt_render_object_type_data _types[RT_MAX_RENDER_OBJECT_TYPE + 1];
 static unsigned int _type_count = 0;
 static rt_rwlock _type_lock;
 
-static rt_arena _list_arena;
+static rt_frame_lists _frame_lists[4];
-static rt_list_pool *_first_free_list;
+static unsigned int _max_frames_in_flight;
-static rt_mutex *_list_lock;
 
 rt_result InitRenderLists(void) {
     rt_create_rwlock_result lock_res = rtCreateRWLock();
@@ -36,26 +44,37 @@ rt_result InitRenderLists(void) {
         return RT_UNKNOWN_ERROR;
     _type_lock = lock_res.lock;
 
+    _max_frames_in_flight = g_renderer.GetMaxFramesInFlight();
+    RT_ASSERT(_max_frames_in_flight > 0 && _max_frames_in_flight < RT_ARRAY_COUNT(_frame_lists),
+              "Invalid maxium number of in-flight frames.");
+
+    for (unsigned int i = 0; i < _max_frames_in_flight; ++i) {
         rt_create_arena_result arena_res = rtCreateArena(NULL, (size_t)rt_RenderListPoolSize.i);
         if (!arena_res.ok) {
             rtDestroyRWLock(&_type_lock);
             return RT_OUT_OF_MEMORY;
         }
-    _list_arena = arena_res.arena;
+        _frame_lists[i].arena = arena_res.arena;
 
-    _list_lock = rtCreateMutex();
+        _frame_lists[i].lock = rtCreateMutex();
-    if (!_list_lock) {
+        if (!_frame_lists[i].lock) {
-        rtReleaseArena(&_list_arena);
+            rtReleaseArena(&_frame_lists[i].arena);
             rtDestroyRWLock(&_type_lock);
         }
 
+        _frame_lists[i].first_free      = NULL;
+        _frame_lists[i].access_frame_id = 0;
+    }
+
     return RT_SUCCESS;
 }
 
 void ShutdownRenderLists(void) {
     rtDestroyRWLock(&_type_lock);
-    rtDestroyMutex(_list_lock);
+    for (unsigned int i = 0; i < _max_frames_in_flight; ++i) {
-    rtReleaseArena(&_list_arena);
+        rtDestroyMutex(_frame_lists[i].lock);
+        rtReleaseArena(&_frame_lists[i].arena);
+    }
 }
 
 RT_DLLEXPORT rt_render_object_type rtRegisterRenderObjectType(size_t object_size,
@@ -83,7 +102,6 @@ RT_DLLEXPORT  rt_render_object_type rtRegisterRenderObjectType(size_t object_siz
     return type;
 }
 
-
 RT_DLLEXPORT size_t rtGetRenderObjectSize(rt_render_object_type type) {
     size_t size = 0;
     rtLockRead(&_type_lock);
@@ -102,13 +120,18 @@ RT_DLLEXPORT const char *rtGetRenderObjectTypeDebugName(rt_render_object_type ty
     return name;
 }
 
-static rt_create_render_list_result CreateNewList(rt_render_object_type type, size_t capacity) {
+static rt_create_render_list_result
+CreateNewList(rt_render_object_type type, unsigned int frame_id, size_t capacity) {
     rt_create_render_list_result res = {.ok = false};
-    rtLockMutex(_list_lock);
+    unsigned int slot                = frame_id % _max_frames_in_flight;
+    rtLockMutex(_frame_lists[slot].lock);
 
-    if (!_first_free_list || _first_free_list->capacity < capacity) { /* Allocate a new list */
+    _frame_lists[slot].access_frame_id = frame_id;
-        rt_list_pool *pool =
+
-            rtArenaPush(&_list_arena, sizeof(rt_list_pool) + capacity);
+    if (!_frame_lists[slot].first_free ||
+        _frame_lists[slot].first_free->capacity < capacity) { /* Allocate a new list */
+        rt_list_pool *pool = rtArenaPush(&_frame_lists[slot].arena,
+                                         sizeof(rt_list_pool) + sizeof(unsigned int) + capacity);
         if (!pool) {
             rtReportError("GFX",
                           "Out of render list pool space! Configured space: %d kiB",
@@ -116,49 +139,62 @@ static rt_create_render_list_result CreateNewList(rt_render_object_type type, si
             goto out;
         }
         pool->capacity                = capacity;
-        pool->next       = _first_free_list;
+        pool->next                    = _frame_lists[slot].first_free;
-        _first_free_list = pool;
+        _frame_lists[slot].first_free = pool;
     }
     rt_render_list list;
-    list.data        = (char *)_first_free_list + sizeof(rt_list_pool);
+    unsigned int *frame_id_store =
+        (unsigned int *)((char *)_frame_lists[slot].first_free + sizeof(rt_list_pool));
+    *frame_id_store = frame_id;
+    list.data = (char *)_frame_lists[slot].first_free + sizeof(rt_list_pool) + sizeof(unsigned int);
     list.type = type;
     list.length                   = 0;
     res.ok                        = true;
     res.list                      = list;
-    _first_free_list = _first_free_list->next;
+    _frame_lists[slot].first_free = _frame_lists[slot].first_free->next;
 out:
-    rtUnlockMutex(_list_lock);
+    rtUnlockMutex(_frame_lists[slot].lock);
     return res;
 }
 
-RT_DLLEXPORT rt_create_render_list_result rtCreateRenderList(rt_render_object_type type) {
+RT_DLLEXPORT rt_create_render_list_result rtCreateRenderList(rt_render_object_type type,
-    return CreateNewList(type, DEFAULT_LIST_CAPACITY);
+                                                             unsigned int frame_id) {
+    return CreateNewList(type, frame_id, DEFAULT_LIST_CAPACITY);
 }
 
-void ResetRenderLists(void) {
+void ResetRenderLists(unsigned int frame_id) {
-    rtLockMutex(_list_lock);
+    unsigned int slot = frame_id % _max_frames_in_flight;
-    _first_free_list = NULL;
+    RT_ASSERT(_frame_lists[slot].access_frame_id == frame_id ||
-    rtArenaClear(&_list_arena);
+                  _frame_lists[slot].access_frame_id == 0,
-    rtUnlockMutex(_list_lock);
+              "Frame id mismatch");
+    rtLockMutex(_frame_lists[slot].lock);
+    _frame_lists[slot].first_free      = NULL;
+    _frame_lists[slot].access_frame_id = 0;
+    rtArenaClear(&_frame_lists[slot].arena);
+    rtUnlockMutex(_frame_lists[slot].lock);
 }
 
 RT_DLLEXPORT bool rtPushRenderListEntry(rt_render_list *list, const void *object) {
     size_t object_size = rtGetRenderObjectSize(list->type);
-    rt_list_pool *pool = (rt_list_pool *)((char *)list->data - sizeof(rt_list_pool));
+    rt_list_pool *pool =
+        (rt_list_pool *)((char *)list->data - sizeof(rt_list_pool) - sizeof(unsigned int));
+    unsigned int frame_id = *(unsigned int *)((char *)list->data - sizeof(unsigned int));
     size_t list_capacity  = pool->capacity / object_size;
 
     if (list->length == list_capacity) {
         /* "Grow" the list */
-        rt_create_render_list_result list_res = CreateNewList(list->type, pool->capacity * 2);
+        rt_create_render_list_result list_res =
+            CreateNewList(list->type, frame_id, pool->capacity * 2);
         if (!list_res.ok)
             return false;
 
         memcpy(list_res.list.data, list->data, list->length * object_size);
 
-        rtLockMutex(_list_lock);
+        unsigned int slot = frame_id % _max_frames_in_flight;
-        pool->next = _first_free_list;
+        rtLockMutex(_frame_lists[slot].lock);
-        _first_free_list = pool;
+        pool->next                    = _frame_lists[slot].first_free;
-        rtUnlockMutex(_list_lock);
+        _frame_lists[slot].first_free = pool;
+        rtUnlockMutex(_frame_lists[slot].lock);
 
         list_res.list.length = list->length;
         *list                = list_res.list;

src/gfx/render_list.h

@@ -58,7 +58,7 @@ typedef struct {
 /* Create a render list for a particular object type.
  *
  * Render Lists have a lifetime of one frame. */
-RT_DLLEXPORT rt_create_render_list_result rtCreateRenderList(rt_render_object_type type);
+RT_DLLEXPORT rt_create_render_list_result rtCreateRenderList(rt_render_object_type type, unsigned int frame_id);
 
 /* Append a render object to a list. The object must be of the correct type. */
 RT_DLLEXPORT bool rtPushRenderListEntry(rt_render_list *list, const void *object);

src/gfx/render_view.c

@@ -9,34 +9,50 @@ RT_CVAR_I(rt_RenderViewArenaSize,
           "Size of the memory arena used for allocating render views. Default: 1 MB",
           RT_MB(1));
 
-static rt_arena _view_arena;
+typedef struct {
-static rt_mutex *_view_lock;
+    rt_arena arena;
+    rt_mutex *lock;
+    uint32_t frame_id;
+} rt_frame_views;
+
+static rt_frame_views _frames[4];
+static unsigned int _max_frames_in_flight;
 
 rt_result InitRenderViews(void) {
+    _max_frames_in_flight = g_renderer.GetMaxFramesInFlight();
+    RT_ASSERT(_max_frames_in_flight > 0 && _max_frames_in_flight < RT_ARRAY_COUNT(_frames),
+              "Invalid maximum number of in-flight frames.");
+
+    for (unsigned int i = 0; i < _max_frames_in_flight; ++i) {
         rt_create_arena_result arena_res = rtCreateArena(NULL, (size_t)rt_RenderViewArenaSize.i);
         if (!arena_res.ok)
             return RT_OUT_OF_MEMORY;
-    _view_arena = arena_res.arena;
+        _frames[i].arena = arena_res.arena;
-    _view_lock  = rtCreateMutex();
+        _frames[i].lock  = rtCreateMutex();
-    if (!_view_lock) {
+        if (!_frames[i].lock) {
-        rtReleaseArena(&_view_arena);
+            rtReleaseArena(&_frames[i].arena);
             return RT_UNKNOWN_ERROR;
         }
+        _frames[i].frame_id = 0;
+    }
     return RT_SUCCESS;
 }
 
 void ShutdownRenderViews(void) {
-    rtDestroyMutex(_view_lock);
+    for (unsigned int i = 0; i < _max_frames_in_flight; ++i) {
-    rtReleaseArena(&_view_arena);
+        rtDestroyMutex(_frames[i].lock);
+        rtReleaseArena(&_frames[i].arena);
+    }
 }
 
-void ResetRenderViews(void) {
+void ResetRenderViews(unsigned int frame_id) {
-    rtArenaClear(&_view_arena);
+    unsigned int slot = frame_id % _max_frames_in_flight;
+    rtArenaClear(&_frames[slot].arena);
 }
 
 RT_DLLEXPORT rt_create_render_view_result rtCreateRenderView(const rt_render_object_type *types,
-                                                             uint32_t type_count) {
+                                                             uint32_t type_count,
-
+                                                             unsigned int frame_id) {
 #ifdef RT_DEBUG
     for (uint32_t i = 0; i < type_count - 1; ++i) {
         for (uint32_t j = i + 1; j < type_count; ++j) {
@@ -45,10 +61,13 @@ RT_DLLEXPORT rt_create_render_view_result rtCreateRenderView(const rt_render_obj
     }
 #endif
 
+    unsigned int slot = frame_id % _max_frames_in_flight;
+
     size_t size = type_count * (sizeof(rt_render_list) + sizeof(rt_render_list));
-    rtLockMutex(_view_lock);
+    rtLockMutex(_frames[slot].lock);
-    void *storage = rtArenaPush(&_view_arena, size);
+    void *storage = rtArenaPush(&_frames[slot].arena, size);
-    rtUnlockMutex(_view_lock);
+    _frames[slot].frame_id = frame_id;
+    rtUnlockMutex(_frames[slot].lock);
     if (!storage) {
         return (rt_create_render_view_result){
             .ok = false,
@@ -59,6 +78,20 @@ RT_DLLEXPORT rt_create_render_view_result rtCreateRenderView(const rt_render_obj
     view.lists      = storage;
     view.list_types = (rt_render_object_type *)(view.lists + type_count);
     view.list_count = type_count;
+    view.type_mask  = 0; 
+
+    for (uint32_t i = 0; i < type_count; ++i) {
+        rt_create_render_list_result list_res = rtCreateRenderList(types[i], frame_id);
+        if (!list_res.ok) {
+            return (rt_create_render_view_result){
+                .ok = false,
+            };
+        }
+        view.lists[i] = list_res.list;
+        view.list_types[i] = types[i];
+        view.type_mask |= RT_RENDER_OBJECT_TYPE_BIT(types[i]);
+    }
+
     return (rt_create_render_view_result){.ok = true, .view = view};
 }
 
@@ -72,6 +105,18 @@ rtPushRenderObjectToView(rt_render_view *view, rt_render_object_type type, const
 }
 
 RT_DLLEXPORT void
-rtSubmitRenderView(rt_render_view view, rt_render_graph *render_graph, uint32_t pass_id) {
+rtSubmitRenderView(rt_render_view view, rt_render_graph *render_graph, uint32_t pass_id, unsigned int frame_id) {
-    g_renderer.SubmitRenderView(render_graph, pass_id, view);
+    g_renderer.SubmitRenderView(render_graph, pass_id, view, frame_id);
+}
+
+RT_DLLEXPORT int rtDoViewTypesMatchExact(rt_render_view view,
+                                         const rt_render_object_type *types,
+                                         uint32_t type_count) {
+    if (view.list_count != type_count)
+        return 0;
+    for (uint32_t i = 0; i < type_count; ++i) {
+        if (view.list_types[i] != types[i])
+            return 0;
+    }
+    return 1;
 }

src/gfx/render_view.h

@@ -12,6 +12,7 @@ typedef struct {
     rt_render_list *lists;
     rt_render_object_type *list_types;
     uint32_t list_count;
+    rt_render_object_type_mask type_mask;
 } rt_render_view;
 
 typedef struct {
@@ -24,13 +25,36 @@ extern "C" {
 #endif
 
 RT_DLLEXPORT rt_create_render_view_result rtCreateRenderView(const rt_render_object_type *types,
-                                                             uint32_t type_count);
+                                                             uint32_t type_count,
+                                                             unsigned int frame_id);
 
 RT_DLLEXPORT bool
 rtPushRenderObjectToView(rt_render_view *view, rt_render_object_type type, const void *object);
 
-RT_DLLEXPORT void
+RT_DLLEXPORT void rtSubmitRenderView(rt_render_view view,
-rtSubmitRenderView(rt_render_view view, rt_render_graph *render_graph, uint32_t pass_id);
+                                     rt_render_graph *render_graph,
+                                     uint32_t pass_id,
+                                     unsigned int frame_id);
+
+/* Checks if the view contains exactly the given types in the given order */
+RT_DLLEXPORT int rtDoViewTypesMatchExact(rt_render_view view,
+                                         const rt_render_object_type *types,
+                                         uint32_t type_count);
+
+/* Checks if the view contains exactly the given types, in any order */
+RT_INLINE static int
+rtDoViewTypesMatch(rt_render_view view, const rt_render_object_type *types, uint32_t type_count) {
+    rt_render_object_type_mask in_mask = 0;
+    for (uint32_t i = 0; i < type_count; ++i) {
+        in_mask |= RT_RENDER_OBJECT_TYPE_BIT(types[i]);
+    }
+    return view.type_mask == in_mask;
+}
+
+RT_INLINE static int rtDoesViewContainTypes(rt_render_view view,
+                                            rt_render_object_type_mask type_mask) {
+    return (int)(view.type_mask & type_mask);
+}
 
 #ifdef __cplusplus
 }

src/gfx/renderer_api.h

@@ -36,6 +36,8 @@ RT_RENDER_BACKEND_HANDLE(rt_buffer_handle);
 
 #undef RT_RENDER_BACKEND_HANDLE
 
+#define RT_COMPARE_RENDER_HANDLES(_A, _B, _Comp) ((*(uint32_t *)&(_A)) _Comp (*(uint32_t *)&(_B)))
+
 /* Init data for the renderer */
 
 #ifdef _WIN32
@@ -243,7 +245,8 @@ typedef struct {
 } rt_pass_info;
 
 typedef struct rt_render_graph_s rt_render_graph;
-typedef rt_result rt_execute_render_pass_fn(rt_command_buffer_handle cmdbuf,
+typedef rt_result rt_execute_render_pass_fn(uint32_t pass_id,
+                                            rt_command_buffer_handle cmdbuf,
                                             const rt_render_view *views,
                                             unsigned int view_count,
                                             void *userdata);
@@ -298,7 +301,7 @@ typedef rt_render_graph_builder rt_create_render_graph_builder_fn(void);
 typedef void rt_destroy_render_graph_builder_fn(rt_render_graph_builder *builder);
 typedef rt_result rt_execute_render_graph_fn(rt_render_graph *rgraph);
 typedef void
-rt_submit_render_view_fn(rt_render_graph *render_graph, uint32_t pass_id, rt_render_view view);
+rt_submit_render_view_fn(rt_render_graph *render_graph, uint32_t pass_id, rt_render_view view, unsigned int frame_id);
 typedef void rt_reset_render_graph_fn(rt_render_graph *graph);
 
 typedef void rt_cmd_begin_pass_fn(rt_command_buffer_handle cmdbuf,

src/renderer/common/common_render_graph.c

@@ -671,12 +671,15 @@ static uint32_t *DeterminePassExecutionLevels(rt_render_graph_builder_obj *obj,
     return execution_levels;
 }
 
-static rt_render_graph *CreateRenderGraph(rt_render_graph_builder_obj *obj, const uint32_t *order, const uint32_t *execution_levels) {
+static rt_render_graph *CreateRenderGraph(rt_render_graph_builder_obj *obj,
-
+                                          const uint32_t *order,
+                                          const uint32_t *execution_levels) {
+    size_t runtime_data_size = obj->platform_cbs.GetRuntimeDataSize();
     size_t required_size     = sizeof(rt_render_graph);
     required_size += obj->phys_render_target_count * sizeof(rt_render_target_handle);
     required_size += obj->sync_point_count * sizeof(rt_gpu_semaphore_handle);
     required_size += obj->pass_count * sizeof(rt_render_pass);
+    required_size += obj->pass_count * runtime_data_size;
 
     size_t pass_attachment_size = 0;
 
@@ -699,7 +702,8 @@ static rt_render_graph *CreateRenderGraph(rt_render_graph_builder_obj *obj, cons
         (rt_gpu_semaphore_handle *)(graph->render_targets + obj->phys_render_target_count);
     graph->passes            = (rt_render_pass *)(graph->semaphores + obj->sync_point_count);
     char *attachment_storage = (char *)(graph->passes + obj->pass_count);
-    char *names              = attachment_storage + pass_attachment_size;
+    char *runtime_data       = attachment_storage + pass_attachment_size;
+    char *names              = runtime_data + runtime_data_size * obj->pass_count;
     char *next_name          = names;
 
     graph->render_target_count = obj->phys_render_target_count;
@@ -771,6 +775,8 @@ static rt_render_graph *CreateRenderGraph(rt_render_graph_builder_obj *obj, cons
             }
         }
 
+        graph->passes[i].runtime_data = (void *)(runtime_data + i * runtime_data_size);
+
         graph->passes[i].name = next_name;
         next_name += namelen + 1;
         memcpy((char *)graph->passes[i].name, obj->passes[passidx].name, namelen + 1);

src/renderer/common/common_render_graph.h

@@ -17,14 +17,14 @@ typedef struct {
 typedef rt_render_target_handle
 rt_rgb_create_render_target_fn(const rt_physical_render_target_info *rt_info);
 typedef int rt_rgb_require_explicit_synchronization_fn(void);
+typedef size_t rt_rgb_get_runtime_data_size_fn(void);
 
 typedef struct {
     rt_rgb_create_render_target_fn *CreateRenderTarget;
     rt_rgb_require_explicit_synchronization_fn *RequireExplicitSynchronization;
+    rt_rgb_get_runtime_data_size_fn *GetRuntimeDataSize;
 } rt_render_graph_builder_platform_callbacks;
 
-#define RT_MAX_SUBMITTED_VIEWS_PER_PASS 32
-
 typedef struct {
     uint32_t flags;
 
@@ -55,10 +55,8 @@ typedef struct {
     rt_execute_render_pass_fn *Execute;
     void *user_data;
 
-    /* Runtime data. */
+    /* Allocated by the backend, used during runtime */
-    rt_render_view submitted_views[RT_MAX_SUBMITTED_VIEWS_PER_PASS];
+    void *runtime_data;
-    uint32_t submitted_view_count;
-
 
     /* These refer to the semaphores array */
     uint32_t first_wait;

src/renderer/dx11/init.cpp

@@ -108,6 +108,8 @@ extern rt_result InitRenderTargetManagement();
 extern void ShutdownRenderTargetManagement();
 extern rt_result InitBufferManagement();
 extern void ShutdownBufferManagement();
+extern rt_result InitPipelineManagement();
+extern void ShutdownPipelineManagement();
 
 extern "C" rt_result RT_RENDERER_API_FN(Init)(const rt_renderer_init_info *info) {
     constexpr D3D_FEATURE_LEVEL feature_levels[] = {D3D_FEATURE_LEVEL_11_1, D3D_FEATURE_LEVEL_11_0};
@@ -185,6 +187,9 @@ extern "C" rt_result RT_RENDERER_API_FN(Init)(const rt_renderer_init_info *info)
     if (res != RT_SUCCESS)
         return res;
     res = InitBufferManagement();
+    if (res != RT_SUCCESS)
+        return res;
+    res = InitPipelineManagement();
     if (res != RT_SUCCESS)
         return res;
 
@@ -192,6 +197,7 @@ extern "C" rt_result RT_RENDERER_API_FN(Init)(const rt_renderer_init_info *info)
 }
 
 extern "C" void RT_RENDERER_API_FN(Shutdown)(void) {
+    ShutdownPipelineManagement();
     ShutdownBufferManagement();
     ShutdownRenderTargetManagement();
     ShutdownCommandBufferManagement();

src/renderer/dx11/render_graph.cpp

@@ -5,6 +5,14 @@
 #include "device_objects.hpp"
 #include "gpu.hpp"
 
+static constexpr unsigned int MAX_SUBMITTED_VIEWS_PER_PASS = 4;
+
+struct rt_pass_runtime_data {
+    rt_render_view views[MAX_SUBMITTED_VIEWS_PER_PASS];
+    uint32_t view_count;
+    unsigned int views_frame_id;
+};
+
 static rt_render_target_handle CreateRenderTarget(const rt_physical_render_target_info *rtinfo) {
     return rtCreateRenderTarget({.format = rtinfo->format,
                                  .width  = rtinfo->width,
@@ -16,10 +24,15 @@ static int RequireExplicitSynchronization() {
     return 0;
 }
 
+static size_t GetRuntimeDataSize() {
+    return sizeof(rt_pass_runtime_data);
+}
+
 extern "C" rt_render_graph_builder RT_RENDERER_API_FN(CreateRenderGraphBuilder)(void) {
     rt_render_graph_builder_platform_callbacks cbs{};
     cbs.CreateRenderTarget             = CreateRenderTarget;
     cbs.RequireExplicitSynchronization = RequireExplicitSynchronization;
+    cbs.GetRuntimeDataSize             = GetRuntimeDataSize;
     return rtCreateRenderGraphBuilder(&cbs);
 }
 
@@ -29,23 +42,31 @@ extern "C" void RT_RENDERER_API_FN(DestroyRenderGraphBuilder)(rt_render_graph_bu
 
 extern "C" void RT_RENDERER_API_FN(SubmitRenderView)(rt_render_graph *render_graph,
                                                      uint32_t pass_id,
-                                                     rt_render_view view) {
+                                                     rt_render_view view,
+                                                     unsigned int frame_id) {
     for (uint32_t i = 0; i < render_graph->pass_count; ++i) {
         if (render_graph->passes[i].id == pass_id) {
             rt_render_pass *pass = &render_graph->passes[i];
-            if (!RT_VERIFY(pass->submitted_view_count < RT_MAX_SUBMITTED_VIEWS_PER_PASS))
+            rt_pass_runtime_data *runtime_data =
+                reinterpret_cast<rt_pass_runtime_data *>(pass->runtime_data);
+            RT_ASSERT(runtime_data->views_frame_id == frame_id || runtime_data->views_frame_id == 0,
+                      "Tried to submit a view for a not-current frame.");
+            if (!RT_VERIFY(runtime_data->view_count < MAX_SUBMITTED_VIEWS_PER_PASS))
                 return;
-            pass->submitted_views[pass->submitted_view_count++] = view;
+            runtime_data->views[runtime_data->view_count++] = view;
+            runtime_data->views_frame_id                    = frame_id;
         }
     }
 }
 
 extern "C" void RT_RENDERER_API_FN(ResetRenderGraph)(rt_render_graph *graph) {
     for (uint32_t i = 0; i < graph->pass_count; ++i) {
+        rt_pass_runtime_data *runtime_data =
+            reinterpret_cast<rt_pass_runtime_data *>(graph->passes[i].runtime_data);
 #ifdef RT_DEBUG
-        memset(graph->passes[i].submitted_views, 0, sizeof(graph->passes[i].submitted_views));
+        memset(runtime_data->views, 0, sizeof(runtime_data->views));
 #endif
-        graph->passes[i].submitted_view_count = 0;
+        runtime_data->view_count = 0;
     }
 }
 
@@ -99,7 +120,14 @@ static rt_result ExecutePass(rt_render_pass *pass, rt_command_buffer_handle cmdb
 
     cmd->context->OMSetRenderTargets(static_cast<UINT>(pass->color_output_count), rtvs, dsv);
 
-    rt_result res = RT_VERIFY(pass->Execute)(cmdbuf_handle, nullptr, 0, pass->user_data);
+    auto runtime_data = reinterpret_cast<rt_pass_runtime_data *>(pass->runtime_data);
+    RT_VERIFY(runtime_data);
+
+    rt_result res = RT_VERIFY(pass->Execute)(pass->id,
+                                             cmdbuf_handle,
+                                             runtime_data->views,
+                                             runtime_data->view_count,
+                                             pass->user_data);
 
     if (cmd->annotation) {
         cmd->annotation->EndEvent();

src/renderer/null/null.c

@@ -131,10 +131,12 @@ rt_result RT_RENDERER_API_FN(ExecuteRenderGraph)(rt_render_graph *render_graph)
 
 void RT_RENDERER_API_FN(SubmitRenderView)(rt_render_graph *render_graph,
                                           uint32_t pass_id,
-                                          rt_render_view view) {
+                                          rt_render_view view,
+                                          unsigned int frame_id) {
     RT_UNUSED(render_graph);
     RT_UNUSED(pass_id);
     RT_UNUSED(view);
+    RT_UNUSED(frame_id);
 }
 
 void RT_RENDERER_API_FN(ResetRenderGraph)(rt_render_graph *graph) {

src/runtime/atomics.h

@@ -7,13 +7,37 @@
 
 /* Increment and decrement return the new value */
 
-#define rtAtomic32Inc(pa) _InterlockedIncrement((volatile LONG *)(pa))
+#define rtAtomic32Inc(pa) _InterlockedIncrement((volatile long *)(pa))
-#define rtAtomic64Inc(pa) _InterlockedIncrement64((volatile LONG64 *)(pa))
+#define rtAtomic64Inc(pa) _InterlockedIncrement64((volatile __int64 *)(pa))
-#define rtAtomic32Dec(pa) _InterlockedDecrement((volatile LONG *)(pa))
+#define rtAtomic32Dec(pa) _InterlockedDecrement((volatile long *)(pa))
-#define rtAtomic64Dec(pa) _InterlockedDecrement64((volatile LONG64 *)(pa))
+#define rtAtomic64Dec(pa) _InterlockedDecrement64((volatile __int64 *)(pa))
 
-#define rtAtomic32FetchAdd(pa, value) _InterlockedExchangeAdd((volatile LONG *)(pa), (LONG)(value))
+#define rtAtomic32FetchAdd(pa, value) _InterlockedExchangeAdd((volatile long *)(pa), (LONG)(value))
-#define rtAtomic64FetchAdd(pa, value) _InterlockedExchangeAdd64((volatile LONG64 *)(pa), (LONG)(value))
+#define rtAtomic64FetchAdd(pa, value)                                                              \
+    _InterlockedExchangeAdd64((volatile __int64 *)(pa), (LONG)(value))
+
+#if defined(_M_ARM) || defined(_M_ARM64)
+#define rtAtomic32ExchangeAcq(_pDest, _NewVal)                                                     \
+    _InterlockedExchange_acq((volatile long *)(_pDest), (_NewVal))
+#define rtAtomic32ExchangeRel(_pDest, _NewVal)                                                     \
+    _InterlockedExchange_rel((volatile long *)(_pDest), (_NewVal))
+#define rtAtomic32CASAcq(_pDest, _NewVal, _Compare)                                                \
+    _InterlockedCompareExchange_acq((volatile long *)(_pDest), (_NewVal), (_Compare))
+#define rtAtomic32CASRel(_pDest, _NewVal, _Compare) _InterlockedCompareExchange_rel((volatile long *)(_pDest), (_NewVal), (_Compare
+#else
+/* x64/86 does not have acquire/release versions of these */
+#define rtAtomic32ExchangeAcq(_pDest, _NewVal)                                                     \
+    _InterlockedExchange((volatile long *)(_pDest), (_NewVal))
+#define rtAtomic32ExchangeRel(_pDest, _NewVal)                                                     \
+    _InterlockedExchange((volatile long *)(_pDest), (_NewVal))
+#define rtAtomic32CASAcq(_pDest, _NewVal, _Compare)                                                \
+    _InterlockedCompareExchange((volatile long *)(_pDest), (_NewVal), (_Compare))
+#define rtAtomic32CASRel(_pDest, _NewVal, _Compare) _InterlockedCompareExchange((volatile long *)(_pDest), (_NewVal), (_Compare
+#endif
+#define rtAtomic32Exchange(_pDest, _NewVal)                                                        \
+    _InterlockedExchange((volatile long *)(_pDest), (_NewVal))
+#define rtAtomic32CAS(_pDest, _NewVal, _Compare)                                                   \
+    _InterlockedCompareExchange((volatile long *)(_pDest), (_NewVal), (_Compare))
 
 #elif defined(__GNUC__) || defined(__clang__)
 
@@ -23,7 +47,12 @@
 #define rtAtomic64Dec(pa) __atomic_sub_fetch((pa), 1LL, __ATOMIC_SEQ_CST)
 
 #define rtAtomic32FetchAdd(pa, value) __atomic_fetch_add((pa), (value), __ATOMIC_SEQ_CST)
-#define rtAtomic64FetchAdd(pa, value) _-atomic_fetch_add((pa), (value), __ATOMIC_SEQ_CST)
+#define rtAtomic64FetchAdd(pa, value) __atomic_fetch_add((pa), (value), __ATOMIC_SEQ_CST)
+
+/* TODO Linux versions of compare exchange
+https://gcc.gnu.org/onlinedocs/gcc/_005f_005fatomic-Builtins.html
+*/
+
 #endif
 
 #endif

src/runtime/ds.h

@@ -52,6 +52,50 @@ static RT_INLINE int rtMinheapIsEmpty(rt_minheap *minheap) {
     return minheap->size == 0;
 }
 
+/* This function is expected to copy the contents of current (current_size bytes) to the new memory. */
+typedef void *rt_hashtable_grow_memory_fn(void *current, size_t current_size, size_t new_size, void *userdata);
+
+/* A hashtable. 
+ * 
+ * Maps 64 bit keys to 64 bit values. 
+ * The hashtable is _not_ thread safe.
+ */
+typedef struct {
+    uint64_t *keys;
+    uint64_t *values;
+
+    uint64_t capacity;
+    uint64_t used_slots;
+
+    void *grow_memory_userdata;
+    rt_hashtable_grow_memory_fn *GrowMemoryCallback;
+} rt_hashtable;
+
+#define RT_HASH_TABLE_MEMORY_REQUIRED(_capacity) (2 * sizeof(uint64_t) * (_capacity))
+
+/* Default implementation for allocating from an arena */
+RT_DLLEXPORT void *
+rtHashtableGrowMemoryFromArena(void *current, size_t current_size, size_t new_size, void *userdata);
+
+/* Capacity must be a power of two.
+ * If grow_memory_cb is NULL, the hashtable will not support growth above the initial capacity. */
+RT_DLLEXPORT rt_hashtable rtCreateHashtable(uint64_t capacity,
+                                            void *memory,
+                                            rt_hashtable_grow_memory_fn *grow_memory_cb,
+                                            void *userdata);
+
+/* Returns
+ * RT_OUT_OF_MEMORY if the hashtable is full or
+ * RT_SUCCESS. */
+RT_DLLEXPORT rt_result rtHashtableInsert(rt_hashtable *hashtable, uint64_t key, uint64_t value);
+
+/* Returns default_value, if the key is not present in the hashtable */
+RT_DLLEXPORT uint64_t rtHashtableLookup(const rt_hashtable *hashtable,
+                                        uint64_t key,
+                                        uint64_t default_value);
+
+RT_DLLEXPORT void rtHashtableRemove(rt_hashtable *hashtable, uint64_t key);
+
 #ifdef __cplusplus
 }
 #endif

src/runtime/ds_hashtable.c

@@ -0,0 +1,157 @@
+#include "ds.h"
+#include "mem_arena.h"
+
+#include <string.h>
+
+#define RT_EMPTY_KEY 0ull
+#define RT_TOMBSTONE 1ull
+
+static uint64_t FixKey(uint64_t key) {
+    if (key < RT_TOMBSTONE + 1)
+        key = UINT64_MAX - key;
+    return key;
+}
+
+RT_DLLEXPORT rt_hashtable rtCreateHashtable(uint64_t capacity,
+                                            void *memory,
+                                            rt_hashtable_grow_memory_fn *grow_memory_cb,
+                                            void *userdata) {
+    RT_ASSERT(RT_IS_POWER_OF_TWO(capacity), "Hashtable capacity must be a power of two.");
+    memset(memory, 0, sizeof(uint64_t) * capacity);
+    rt_hashtable hashtable = {
+        .keys                 = memory,
+        .values               = (uint64_t *)memory + capacity,
+        .capacity             = capacity,
+        .used_slots           = 0,
+        .GrowMemoryCallback   = grow_memory_cb,
+        .grow_memory_userdata = userdata,
+    };
+    return hashtable;
+}
+
+static rt_result Rehash(rt_hashtable *hashtable) {
+    void *newmem = hashtable->GrowMemoryCallback(hashtable->keys,
+                                                 2 * sizeof(uint64_t) * hashtable->capacity,
+                                                 4 * sizeof(uint64_t) * hashtable->capacity,
+                                                 hashtable->grow_memory_userdata);
+    if (!newmem)
+        return RT_OUT_OF_MEMORY;
+    uint64_t old_capacity = hashtable->capacity;
+    hashtable->capacity *= 2;
+    hashtable->keys   = newmem;
+    hashtable->values = hashtable->keys + hashtable->capacity;
+
+    memset(hashtable->keys + old_capacity, 0, sizeof(uint64_t) * old_capacity);
+
+    uint64_t *keys    = hashtable->keys;
+    uint64_t capacity = hashtable->capacity;
+    uint64_t mod      = capacity - 1;
+    for (uint64_t i = 0; i < old_capacity; ++i) {
+        if (keys[i] > RT_TOMBSTONE) {
+            uint64_t key    = keys[i];
+            uint64_t offset = 0;
+            while (offset < capacity) {
+                uint64_t new_slot = (key + offset) & mod;
+                if (keys[new_slot] == key || keys[new_slot] <= RT_TOMBSTONE) {
+                    if (new_slot != i) {
+                        keys[new_slot]              = key;
+                        hashtable->values[new_slot] = hashtable->values[i];
+                        keys[i]                     = RT_TOMBSTONE;
+                    }
+                    break;
+                }
+            }
+            if (offset == capacity) {
+                rtReportError("CORE", "Rehashing failed. This is a bug.");
+                return RT_UNKNOWN_ERROR;
+            }
+        }
+    }
+    return RT_SUCCESS;
+}
+
+RT_DLLEXPORT rt_result rtHashtableInsert(rt_hashtable *hashtable, uint64_t key, uint64_t value) {
+    key = FixKey(key);
+
+    if (hashtable->GrowMemoryCallback && (hashtable->used_slots > (hashtable->capacity >> 1))) {
+        rt_result res = Rehash(hashtable);
+        if (res != RT_SUCCESS)
+            return res;
+    }
+
+    uint64_t *keys    = hashtable->keys;
+    uint64_t capacity = hashtable->capacity;
+    uint64_t mod      = capacity - 1;
+    uint64_t offset   = 0;
+    while (offset < capacity) {
+        uint64_t index = (key + offset) & mod;
+        ++offset;
+
+        if (keys[index] == key || keys[index] <= RT_TOMBSTONE) {
+            keys[index]              = key;
+            hashtable->values[index] = value;
+            ++hashtable->used_slots;
+            return RT_SUCCESS;
+        }
+    }
+    return RT_OUT_OF_MEMORY;
+}
+
+RT_DLLEXPORT uint64_t rtHashtableLookup(const rt_hashtable *hashtable,
+                                        uint64_t key,
+                                        uint64_t default_value) {
+    key = FixKey(key);
+
+    uint64_t capacity = hashtable->capacity;
+    uint64_t mod      = capacity - 1;
+    uint64_t offset   = 0;
+    while (offset < capacity) {
+        uint64_t index = (key + offset) & mod;
+        ++offset;
+
+        if (hashtable->keys[index] == key) {
+            return hashtable->values[index];
+        } else if (hashtable->keys[index] == RT_EMPTY_KEY) {
+            break;
+        }
+    }
+    return default_value;
+}
+
+RT_DLLEXPORT void rtHashtableRemove(rt_hashtable *hashtable, uint64_t key) {
+    key = FixKey(key);
+    uint64_t *keys    = hashtable->keys;
+    uint64_t capacity = hashtable->capacity;
+    uint64_t mod      = capacity - 1;
+    uint64_t offset   = 0;
+    while (offset < capacity) {
+        uint64_t index = (key + offset) & mod;
+        ++offset;
+
+        if (keys[index] == key) {
+            keys[index] = RT_TOMBSTONE;
+        } else if (keys[index] == RT_EMPTY_KEY) {
+            break;
+        }
+    }
+}
+
+RT_DLLEXPORT void *rtHashtableGrowMemoryFromArena(void *current,
+                                                  size_t current_size,
+                                                  size_t new_size,
+                                                  void *userdata) {
+    rt_arena *arena          = userdata;
+    ptrdiff_t current_offset = (uint8_t *)current - (uint8_t *)arena->base;
+    if (current_offset + current_size == arena->at) {
+        /* The current allocation is the one at the end of the arena, so we can simply grow and be
+         * done */
+        if (!rtArenaPush(arena, new_size - current_size))
+            return NULL;
+        return current;
+    } else {
+        void *newmem = rtArenaPush(arena, new_size);
+        if (newmem)
+            memcpy(newmem, current, current_size);
+        return newmem;
+    }
+}

src/runtime/meson.build

@@ -26,6 +26,7 @@ runtime_lib = library('rt',
   'buffer_manager.c',
   'compression.c',
   'config.c',
+  'ds_hashtable.c',
   'ds_minheap.c',
   'dynamic_libs.c',
   'error_report.c',

src/runtime/runtime.h

@@ -203,6 +203,9 @@ static RT_INLINE uint32_t rtNextPowerOfTwo32(uint32_t v) {
     return v;
 }
 
+/* Checks that exactly one bit is set */
+#define RT_IS_POWER_OF_TWO(_n) ((_n) && !((_n) & ((_n)-1)))
+
 /* Runtime init. Initializes basic systems.
  * You need to call this, even if you build a CLI only app. */
 RT_DLLEXPORT rt_result rtInitRuntime(void);

src/runtime/threading.h

@@ -81,6 +81,20 @@ RT_DLLEXPORT void rtSignalSemaphore(rt_semaphore *sem);
 
 RT_DLLEXPORT void rtWaitOnSemaphore(rt_semaphore *sem);
 
+/* Spinlock */
+typedef struct {
+    volatile int lock;
+} rt_spinlock;
+
+static RT_INLINE rt_spinlock rtCreateSpinlock(void) {
+    rt_spinlock l = {0};
+    return l;
+}
+
+RT_DLLEXPORT void rtLockSpinlock(rt_spinlock *lock);
+
+RT_DLLEXPORT void rtUnlockSpinlock(rt_spinlock *lock);
+
 /* Threads */
 
 typedef struct rt_thread_s rt_thread;

src/runtime/threading_spinlock.c

@@ -0,0 +1,13 @@
+#include "atomics.h"
+#include "threading.h"
+
+RT_DLLEXPORT void rtLockSpinlock(rt_spinlock *lock) {
+    int prev;
+    do {
+        prev = rtAtomic32CASAcq(&lock->lock, 1, 0);
+    } while (prev != 0);
+}
+
+RT_DLLEXPORT void rtUnlockSpinlock(rt_spinlock *lock) {
+    rtAtomic32ExchangeRel(&lock->lock, 0);
+}

tests/rttest.c

@@ -1,6 +1,8 @@
 #include <stdio.h>
 
 #include "runtime/config.h"
+#include "runtime/ds.h"
+#include "runtime/mem_arena.h"
 #include "runtime/runtime.h"
 
 #include "gfx/gfx.h"
@@ -69,7 +71,7 @@ static rt_result PushRenderList(void) {
     } dummy_type;
     rt_render_object_type type = rtRegisterRenderObjectType(sizeof(dummy_type), "DummyType");
 
-    rt_create_render_list_result list_res = rtCreateRenderList(type);
+    rt_create_render_list_result list_res = rtCreateRenderList(type, 43);
     if (!list_res.ok) {
         return RT_INVALID_VALUE;
     }
@@ -92,7 +94,7 @@ static rt_result PushLongRenderList(void) {
     } dummy_type;
     rt_render_object_type type = rtRegisterRenderObjectType(sizeof(dummy_type), "DummyType");
 
-    rt_create_render_list_result list_res = rtCreateRenderList(type);
+    rt_create_render_list_result list_res = rtCreateRenderList(type, 43);
     if (!list_res.ok)
         return RT_INVALID_VALUE;
     rt_render_list list = list_res.list;
@@ -119,6 +121,41 @@ static rt_result PushLongRenderList(void) {
     return RT_SUCCESS;
 }
 
+static rt_result HashTableBasics(void) {
+    {
+        uint64_t mem[128];
+        rt_hashtable ht = rtCreateHashtable(64, mem, NULL, NULL);
+
+        for (uint64_t i = 0; i < 64; ++i) {
+            if (rtHashtableInsert(&ht, i, i) != RT_SUCCESS)
+                return RT_UNKNOWN_ERROR;
+            uint64_t found = rtHashtableLookup(&ht, i, UINT64_MAX);
+            if (found != i)
+                return RT_INVALID_VALUE;
+        }
+    }
+
+    {
+        rt_create_arena_result arena_res = rtCreateArena(NULL, RT_KB(4));
+        if (!arena_res.ok)
+            return RT_OUT_OF_MEMORY;
+        rt_arena arena = arena_res.arena;
+        void *mem       = rtArenaPush(&arena, RT_HASH_TABLE_MEMORY_REQUIRED(64));
+        if (!mem)
+            return RT_OUT_OF_MEMORY;
+        rt_hashtable ht = rtCreateHashtable(64, mem, rtHashtableGrowMemoryFromArena, &arena);
+        for (uint64_t i = 0; i < 64; ++i) {
+            if (rtHashtableInsert(&ht, 256+i, i) != RT_SUCCESS)
+                return RT_UNKNOWN_ERROR;
+            uint64_t found = rtHashtableLookup(&ht, 256+i, UINT64_MAX);
+            if (found != i)
+                return RT_INVALID_VALUE;
+        }
+        rtReleaseArena(&arena);
+    }
+    return RT_SUCCESS;
+}
+
 /* Scaffolding
  *
  * Run all the test cases, output if they passed or failed.
@@ -169,7 +206,8 @@ static rt_test_fixture *_test_fixtures[] = {TEST_FIXTURE_LIST};
 static rt_test_case _test_cases[] = {TEST_CASE(RelPtrTest),
                                      TEST_CASE(NegRelPtrTest),
                                      TEST_CASE_FIXTURE(PushRenderList, render_list_fixture),
-                                     TEST_CASE_FIXTURE(PushLongRenderList, render_list_fixture)};
+                                     TEST_CASE_FIXTURE(PushLongRenderList, render_list_fixture),
+                                     TEST_CASE(HashTableBasics)};
 
 int main() {
     int out = 0;