Additional debugging

.gitignore

@@ -9,3 +9,5 @@ docs/
 examples/
 internal_docs
 build.sh
+libctru/source/util/rbtree/test/*.o
+libctru/source/util/rbtree/test/rbtree_test

libctru/include/3ds/util/rbtree.h

@@ -4,6 +4,12 @@
  */
 #pragma once
 
+#ifdef _3DS
+#include <3ds/synchronization.h>
+#else
+#include <pthread.h>
+#endif
+#include <stdbool.h>
 #include <stdint.h>
 #include <stddef.h>
 
@@ -21,16 +27,23 @@ typedef int  (*rbtree_node_comparator_t)(const rbtree_node_t *lhs,
 /// An rbtree node.
 struct rbtree_node
 {
+  uint32_t      prefix[32];   ///< Guard prefix.
+  char          nodeTag[4];   ///< Node tag.
   uintptr_t     parent_color; ///< Parent color.
   rbtree_node_t *child[2];    ///< Node children.
+  rbtree_t      *tree;        ///< Owning tree.
+  uint32_t      *suffix[32];  ///< Guard suffix.
 };
 
 /// An rbtree.
 struct rbtree
 {
+  char                     treeTag[4]; ///< Tree tag.
   rbtree_node_t            *root;      ///< Root node.
   rbtree_node_comparator_t comparator; ///< Node comparator.
   size_t                   size;       ///< Size.
+  LightLock                lock;       ///< Tree mutex.
+  bool                     busy;       ///< Busy flag.
 };
 
 #ifdef __cplusplus

libctru/source/allocator/linear.cpp

@@ -7,11 +7,13 @@ extern "C"
 
 #include "mem_pool.h"
 #include "addrmap.h"
+#include "lock.h"
 
 extern u32 __ctru_linear_heap;
 extern u32 __ctru_linear_heap_size;
 
 static MemPool sLinearPool;
+static LightLock sLock = 1;
 
 static bool linearInit()
 {
@@ -42,6 +44,7 @@ void* linearMemAlign(size_t size, size_t alignment)
 		return nullptr;
 
 	// Initialize the pool if it is not ready
+	LockGuard guard(sLock);
 	if (!sLinearPool.Ready() && !linearInit())
 		return nullptr;
 
@@ -56,7 +59,9 @@ void* linearMemAlign(size_t size, size_t alignment)
 		sLinearPool.Deallocate(chunk);
 		return nullptr;
 	}
-	if (rbtree_insert(&sAddrMap, &node->node));
+	if (rbtree_insert(&sAddrMap, &node->node) != &node->node)
+		svcBreak(USERBREAK_PANIC);
+
 	return chunk.addr;
 }
 
@@ -73,12 +78,14 @@ void* linearRealloc(void* mem, size_t size)
 
 size_t linearGetSize(void* mem)
 {
+	LockGuard guard(sLock);
 	auto node = getNode(mem);
 	return node ? node->chunk.size : 0;
 }
 
 void linearFree(void* mem)
 {
+	LockGuard guard(sLock);
 	auto node = getNode(mem);
 	if (!node) return;
 
@@ -91,5 +98,6 @@ void linearFree(void* mem)
 
 u32 linearSpaceFree()
 {
+	LockGuard guard(sLock);
 	return sLinearPool.GetFreeSpace();
 }

libctru/source/allocator/lock.h

@@ -0,0 +1,23 @@
+#pragma once
+
+extern "C"
+{
+	#include <3ds/synchronization.h>
+}
+
+class LockGuard
+{
+public:
+	~LockGuard()
+	{
+		LightLock_Unlock(&lock);
+	}
+
+	LockGuard(LightLock &lock) : lock(lock)
+	{
+		LightLock_Lock(&lock);
+	}
+
+private:
+	LightLock &lock;
+};

libctru/source/allocator/mappable.cpp

@@ -7,8 +7,10 @@ extern "C"
 
 #include "mem_pool.h"
 #include "addrmap.h"
+#include "lock.h"
 
 static MemPool sMappablePool;
+static LightLock sLock = 1;
 
 static bool mappableInit()
 {
@@ -25,6 +27,7 @@ static bool mappableInit()
 void* mappableAlloc(size_t size)
 {
 	// Initialize the pool if it is not ready
+	LockGuard guard(sLock);
 	if (!sMappablePool.Ready() && !mappableInit())
 		return nullptr;
 
@@ -45,12 +48,14 @@ void* mappableAlloc(size_t size)
 
 size_t mappableGetSize(void* mem)
 {
+	LockGuard guard(sLock);
 	auto node = getNode(mem);
 	return node ? node->chunk.size : 0;
 }
 
 void mappableFree(void* mem)
 {
+	LockGuard guard(sLock);
 	auto node = getNode(mem);
 	if (!node) return;
 
@@ -63,5 +68,6 @@ void mappableFree(void* mem)
 
 u32 mappableSpaceFree()
 {
+	LockGuard guard(sLock);
 	return sMappablePool.GetFreeSpace();
 }

libctru/source/allocator/vram.cpp

@@ -7,8 +7,10 @@ extern "C"
 
 #include "mem_pool.h"
 #include "addrmap.h"
+#include "lock.h"
 
 static MemPool sVramPool;
+static LightLock sLock = 1;
 
 static bool vramInit()
 {
@@ -39,6 +41,7 @@ void* vramMemAlign(size_t size, size_t alignment)
 		return nullptr;
 
 	// Initialize the pool if it is not ready
+	LockGuard guard(sLock);
 	if (!sVramPool.Ready() && !vramInit())
 		return nullptr;
 
@@ -70,12 +73,14 @@ void* vramRealloc(void* mem, size_t size)
 
 size_t vramGetSize(void* mem)
 {
+	LockGuard guard(sLock);
 	auto node = getNode(mem);
 	return node ? node->chunk.size : 0;
 }
 
 void vramFree(void* mem)
 {
+	LockGuard guard(sLock);
 	auto node = getNode(mem);
 	if (!node) return;
 
@@ -88,5 +93,6 @@ void vramFree(void* mem)
 
 u32 vramSpaceFree()
 {
+	LockGuard guard(sLock);
 	return sVramPool.GetFreeSpace();
 }

libctru/source/crc32c.c

@@ -0,0 +1,81 @@
+#include "crc32c.h"
+
+static const uint32_t crc32cTable[] =
+{
+	0x00000000, 0xF26B8303, 0xE13B70F7, 0x1350F3F4,
+	0xC79A971F, 0x35F1141C, 0x26A1E7E8, 0xD4CA64EB,
+	0x8AD958CF, 0x78B2DBCC, 0x6BE22838, 0x9989AB3B,
+	0x4D43CFD0, 0xBF284CD3, 0xAC78BF27, 0x5E133C24,
+	0x105EC76F, 0xE235446C, 0xF165B798, 0x030E349B,
+	0xD7C45070, 0x25AFD373, 0x36FF2087, 0xC494A384,
+	0x9A879FA0, 0x68EC1CA3, 0x7BBCEF57, 0x89D76C54,
+	0x5D1D08BF, 0xAF768BBC, 0xBC267848, 0x4E4DFB4B,
+	0x20BD8EDE, 0xD2D60DDD, 0xC186FE29, 0x33ED7D2A,
+	0xE72719C1, 0x154C9AC2, 0x061C6936, 0xF477EA35,
+	0xAA64D611, 0x580F5512, 0x4B5FA6E6, 0xB93425E5,
+	0x6DFE410E, 0x9F95C20D, 0x8CC531F9, 0x7EAEB2FA,
+	0x30E349B1, 0xC288CAB2, 0xD1D83946, 0x23B3BA45,
+	0xF779DEAE, 0x05125DAD, 0x1642AE59, 0xE4292D5A,
+	0xBA3A117E, 0x4851927D, 0x5B016189, 0xA96AE28A,
+	0x7DA08661, 0x8FCB0562, 0x9C9BF696, 0x6EF07595,
+	0x417B1DBC, 0xB3109EBF, 0xA0406D4B, 0x522BEE48,
+	0x86E18AA3, 0x748A09A0, 0x67DAFA54, 0x95B17957,
+	0xCBA24573, 0x39C9C670, 0x2A993584, 0xD8F2B687,
+	0x0C38D26C, 0xFE53516F, 0xED03A29B, 0x1F682198,
+	0x5125DAD3, 0xA34E59D0, 0xB01EAA24, 0x42752927,
+	0x96BF4DCC, 0x64D4CECF, 0x77843D3B, 0x85EFBE38,
+	0xDBFC821C, 0x2997011F, 0x3AC7F2EB, 0xC8AC71E8,
+	0x1C661503, 0xEE0D9600, 0xFD5D65F4, 0x0F36E6F7,
+	0x61C69362, 0x93AD1061, 0x80FDE395, 0x72966096,
+	0xA65C047D, 0x5437877E, 0x4767748A, 0xB50CF789,
+	0xEB1FCBAD, 0x197448AE, 0x0A24BB5A, 0xF84F3859,
+	0x2C855CB2, 0xDEEEDFB1, 0xCDBE2C45, 0x3FD5AF46,
+	0x7198540D, 0x83F3D70E, 0x90A324FA, 0x62C8A7F9,
+	0xB602C312, 0x44694011, 0x5739B3E5, 0xA55230E6,
+	0xFB410CC2, 0x092A8FC1, 0x1A7A7C35, 0xE811FF36,
+	0x3CDB9BDD, 0xCEB018DE, 0xDDE0EB2A, 0x2F8B6829,
+	0x82F63B78, 0x709DB87B, 0x63CD4B8F, 0x91A6C88C,
+	0x456CAC67, 0xB7072F64, 0xA457DC90, 0x563C5F93,
+	0x082F63B7, 0xFA44E0B4, 0xE9141340, 0x1B7F9043,
+	0xCFB5F4A8, 0x3DDE77AB, 0x2E8E845F, 0xDCE5075C,
+	0x92A8FC17, 0x60C37F14, 0x73938CE0, 0x81F80FE3,
+	0x55326B08, 0xA759E80B, 0xB4091BFF, 0x466298FC,
+	0x1871A4D8, 0xEA1A27DB, 0xF94AD42F, 0x0B21572C,
+	0xDFEB33C7, 0x2D80B0C4, 0x3ED04330, 0xCCBBC033,
+	0xA24BB5A6, 0x502036A5, 0x4370C551, 0xB11B4652,
+	0x65D122B9, 0x97BAA1BA, 0x84EA524E, 0x7681D14D,
+	0x2892ED69, 0xDAF96E6A, 0xC9A99D9E, 0x3BC21E9D,
+	0xEF087A76, 0x1D63F975, 0x0E330A81, 0xFC588982,
+	0xB21572C9, 0x407EF1CA, 0x532E023E, 0xA145813D,
+	0x758FE5D6, 0x87E466D5, 0x94B49521, 0x66DF1622,
+	0x38CC2A06, 0xCAA7A905, 0xD9F75AF1, 0x2B9CD9F2,
+	0xFF56BD19, 0x0D3D3E1A, 0x1E6DCDEE, 0xEC064EED,
+	0xC38D26C4, 0x31E6A5C7, 0x22B65633, 0xD0DDD530,
+	0x0417B1DB, 0xF67C32D8, 0xE52CC12C, 0x1747422F,
+	0x49547E0B, 0xBB3FFD08, 0xA86F0EFC, 0x5A048DFF,
+	0x8ECEE914, 0x7CA56A17, 0x6FF599E3, 0x9D9E1AE0,
+	0xD3D3E1AB, 0x21B862A8, 0x32E8915C, 0xC083125F,
+	0x144976B4, 0xE622F5B7, 0xF5720643, 0x07198540,
+	0x590AB964, 0xAB613A67, 0xB831C993, 0x4A5A4A90,
+	0x9E902E7B, 0x6CFBAD78, 0x7FAB5E8C, 0x8DC0DD8F,
+	0xE330A81A, 0x115B2B19, 0x020BD8ED, 0xF0605BEE,
+	0x24AA3F05, 0xD6C1BC06, 0xC5914FF2, 0x37FACCF1,
+	0x69E9F0D5, 0x9B8273D6, 0x88D28022, 0x7AB90321,
+	0xAE7367CA, 0x5C18E4C9, 0x4F48173D, 0xBD23943E,
+	0xF36E6F75, 0x0105EC76, 0x12551F82, 0xE03E9C81,
+	0x34F4F86A, 0xC69F7B69, 0xD5CF889D, 0x27A40B9E,
+	0x79B737BA, 0x8BDCB4B9, 0x988C474D, 0x6AE7C44E,
+	0xBE2DA0A5, 0x4C4623A6, 0x5F16D052, 0xAD7D5351
+};
+
+uint32_t crc32c(const void *buffer, size_t size, uint32_t crc)
+{
+	const uint8_t *ptr = (const uint8_t*)buffer;
+
+	crc ^= ~(uint32_t)0;
+
+	for(size_t i = 0; i < size; ++i)
+		crc = crc32cTable[(crc ^ ptr[i]) & 0xFF] ^ (crc >> 8);
+
+	return ~crc;
+}

libctru/source/crc32c.h

@@ -0,0 +1,6 @@
+#pragma once
+
+#include <stddef.h>
+#include <stdint.h>
+
+uint32_t crc32c(const void *buffer, size_t size, uint32_t crc);

libctru/source/util/rbtree/rbtree_clear.c

@@ -5,25 +5,28 @@ void
 rbtree_clear(rbtree_t                 *tree,
              rbtree_node_destructor_t destructor)
 {
+  rbtree_set_busy(tree);
+  rbtree_validate(tree);
+
   rbtree_node_t *node = tree->root;
 
-  while(tree->root != NULL)
+  while(tree->root)
   {
-    while(node->child[LEFT] != NULL)
+    while(node->child[LEFT])
       node = node->child[LEFT];
 
-    if(node->child[RIGHT] != NULL)
+    if(node->child[RIGHT])
       node = node->child[RIGHT];
     else
     {
       rbtree_node_t *parent = get_parent(node);
 
-      if(parent == NULL)
+      if(!parent)
         tree->root = NULL;
       else
         parent->child[node != parent->child[LEFT]] = NULL;
 
-      if(destructor != NULL)
+      if(destructor)
         (*destructor)(node);
 
       node = parent;
@@ -31,4 +34,7 @@ rbtree_clear(rbtree_t                 *tree,
   }
 
   tree->size = 0;
+
+  rbtree_validate(tree);
+  rbtree_clear_busy(tree);
 }

libctru/source/util/rbtree/rbtree_empty.c

@@ -1,7 +1,14 @@
 #include <3ds/util/rbtree.h>
+#include "rbtree_internal.h"
 
 int
 rbtree_empty(const rbtree_t *tree)
 {
-  return tree->root == NULL;
+  rbtree_set_busy((rbtree_t*)tree);
+  rbtree_validate(tree);
+
+  bool empty = !tree->root;
+
+  rbtree_clear_busy((rbtree_t*)tree);
+  return empty;
 }

libctru/source/util/rbtree/rbtree_find.c

@@ -5,10 +5,13 @@ rbtree_node_t*
 rbtree_find(const rbtree_t      *tree,
             const rbtree_node_t *node)
 {
+  rbtree_set_busy((rbtree_t*)tree);
+  rbtree_validate(tree);
+
   rbtree_node_t *tmp  = tree->root;
   rbtree_node_t *save = NULL;
 
-  while(tmp != NULL)
+  while(tmp)
   {
     int rc = (*tree->comparator)(node, tmp);
     if(rc < 0)
@@ -26,5 +29,8 @@ rbtree_find(const rbtree_t      *tree,
     }
   }
 
+  rbtree_validate(tree);
+  rbtree_clear_busy((rbtree_t*)tree);
+
   return save;
 }

libctru/source/util/rbtree/rbtree_init.c

@@ -1,10 +1,19 @@
 #include <3ds/util/rbtree.h>
+#include "rbtree_internal.h"
 
 void
 rbtree_init(rbtree_t                 *tree,
             rbtree_node_comparator_t comparator)
 {
+  tree->treeTag[3] = 'T';
+  tree->treeTag[2] = 'R';
+  tree->treeTag[1] = 'E';
+  tree->treeTag[0] = 'E';
   tree->root       = NULL;
   tree->comparator = comparator;
   tree->size       = 0;
+  tree->busy       = false;
+  LightLock_Init(&tree->lock);
+
+  rbtree_validate(tree);
 }

libctru/source/util/rbtree/rbtree_insert.c

@@ -6,12 +6,30 @@ do_insert(rbtree_t      *tree,
           rbtree_node_t *node,
           int           multi)
 {
+  rbtree_set_busy(tree);
+  rbtree_validate(tree);
+
+  for(size_t i = 0; i < 32; ++i)
+  {
+    node->prefix[i] = 0;
+    node->suffix[i] = 0;
+  }
+
+  node->nodeTag[3]   = 'N';
+  node->nodeTag[2]   = 'O';
+  node->nodeTag[1]   = 'D';
+  node->nodeTag[0]   = 'E';
+  node->parent_color = 0;
+  node->child[LEFT]  = NULL;
+  node->child[RIGHT] = NULL;
+  node->tree         = tree;
+
   rbtree_node_t *original = node;
   rbtree_node_t **tmp     = &tree->root;
   rbtree_node_t *parent   = NULL;
   rbtree_node_t *save     = NULL;
 
-  while(*tmp != NULL)
+  while(*tmp)
   {
     int cmp = (*(tree->comparator))(node, *tmp);
     parent  = *tmp;
@@ -29,8 +47,20 @@ do_insert(rbtree_t      *tree,
     }
   }
 
-  if(save != NULL)
+  if(save)
   {
+    node->nodeTag[3]   = 'D';
+    node->nodeTag[2]   = 'O';
+    node->nodeTag[1]   = 'N';
+    node->nodeTag[0]   = 'E';
+    node->parent_color = 0;
+    node->child[LEFT]  = NULL;
+    node->child[RIGHT] = NULL;
+    node->tree         = NULL;
+
+    rbtree_validate(tree);
+    rbtree_clear_busy(tree);
+
     return save;
   }
 
@@ -78,6 +108,9 @@ do_insert(rbtree_t      *tree,
 
   tree->size += 1;
 
+  rbtree_validate(tree);
+  rbtree_clear_busy(tree);
+
   return original;
 }
 

libctru/source/util/rbtree/rbtree_internal.h

@@ -1,4 +1,5 @@
 #pragma once
+#include "3ds/util/rbtree.h"
 
 #define LEFT  0
 #define RIGHT 1
@@ -28,7 +29,7 @@ set_red(rbtree_node_t *node)
 static inline rbtree_color_t
 get_color(const rbtree_node_t *node)
 {
-  if(node == NULL)
+  if(!node)
     return BLACK;
   return (rbtree_color_t)(node->parent_color & COLOR_MASK);
 }
@@ -58,7 +59,19 @@ set_parent(rbtree_node_t       *node,
   node->parent_color = (get_color(node)) | ((uintptr_t)parent);
 }
 
+void
+rbtree_set_busy(rbtree_t *tree);
+
+void
+rbtree_clear_busy(rbtree_t *tree);
+
 void
 rbtree_rotate(rbtree_t      *tree,
               rbtree_node_t *node,
               int           left);
+
+void
+rbtree_validate(const rbtree_t *tree);
+
+void
+rbtree_node_validate(const rbtree_t *tree, const rbtree_node_t *node, size_t *all, size_t *black, size_t *depth);

libctru/source/util/rbtree/rbtree_iterator.c

@@ -7,16 +7,16 @@ do_iterate(const rbtree_node_t *node,
 {
   rbtree_node_t *it = (rbtree_node_t*)node;
 
-  if(it->child[next] != NULL)
+  if(it->child[next])
   {
     it = it->child[next];
-    while(it->child[!next] != NULL)
+    while(it->child[!next])
       it = it->child[!next];
   }
   else
   {
     rbtree_node_t *parent = get_parent(node);
-    while(parent != NULL && it == parent->child[next])
+    while(parent && it == parent->child[next])
     {
       it = parent;
       parent = get_parent(it);

libctru/source/util/rbtree/rbtree_minmax.c

@@ -5,33 +5,32 @@ static inline rbtree_node_t*
 do_minmax(const rbtree_t *tree,
           int            max)
 {
+  rbtree_set_busy((rbtree_t*)tree);
+  rbtree_validate(tree);
+
   rbtree_node_t *node = tree->root;
 
-  if(node == NULL)
+  if(!node)
+  {
+    rbtree_clear_busy((rbtree_t*)tree);
     return NULL;
+  }
 
-  while(node->child[max] != NULL)
+  while(node->child[max])
     node = node->child[max];
 
+  rbtree_clear_busy((rbtree_t*)tree);
   return node;
 }
 
 rbtree_node_t*
 rbtree_min(const rbtree_t *tree)
 {
-  rbtree_node_t *node;
+  return do_minmax(tree, LEFT);
-
-  node = do_minmax(tree, LEFT);
-
-  return node;
 }
 
 rbtree_node_t*
 rbtree_max(const rbtree_t *tree)
 {
-  rbtree_node_t *node;
+  return do_minmax(tree, RIGHT);
-
-  node = do_minmax(tree, RIGHT);
-
-  return node;
 }

libctru/source/util/rbtree/rbtree_remove.c

@@ -1,4 +1,5 @@
 #include <3ds/util/rbtree.h>
+#include <3ds/svc.h>
 #include "rbtree_internal.h"
 
 static void
@@ -51,31 +52,55 @@ recolor(rbtree_t      *tree,
     }
   }
 
-  if(node != NULL)
+  if(node)
     set_black(node);
 }
 
+static bool
+in_tree(const rbtree_t      *tree,
+        const rbtree_node_t *node)
+{
+  if(tree->root == node)
+    return true;
+
+  const rbtree_node_t *parent = get_parent(node);
+  while(parent)
+  {
+    if(tree->root == parent)
+      return true;
+
+    parent = get_parent(parent);
+  }
+
+  return false;
+}
+
 rbtree_node_t*
 rbtree_remove(rbtree_t                 *tree,
               rbtree_node_t            *node,
               rbtree_node_destructor_t destructor)
 {
+  rbtree_set_busy(tree);
+  if(!in_tree(tree, node))
+    svcBreak(USERBREAK_PANIC);
+  rbtree_validate(tree);
+
   rbtree_color_t color;
   rbtree_node_t  *child, *parent, *original = node;
   rbtree_node_t  *next;
 
   next = rbtree_node_next(node);
 
-  if(node->child[LEFT] != NULL && node->child[RIGHT] != NULL)
+  if(node->child[LEFT] && node->child[RIGHT])
   {
     rbtree_node_t *old = node;
 
     node = node->child[RIGHT];
-    while(node->child[LEFT] != NULL)
+    while(node->child[LEFT])
       node = node->child[LEFT];
 
     parent = get_parent(old);
-    if(parent != NULL)
+    if(parent)
     {
       if(parent->child[LEFT] == old)
         parent->child[LEFT] = node;
@@ -93,7 +118,7 @@ rbtree_remove(rbtree_t                 *tree,
       parent = node;
     else
     {
-      if(child != NULL)
+      if(child)
         set_parent(child, parent);
       parent->child[LEFT] = child;
 
@@ -107,7 +132,7 @@ rbtree_remove(rbtree_t                 *tree,
   }
   else
   {
-    if(node->child[LEFT] == NULL)
+    if(!node->child[LEFT])
       child = node->child[RIGHT];
     else
       child = node->child[LEFT];
@@ -115,9 +140,9 @@ rbtree_remove(rbtree_t                 *tree,
     parent = get_parent(node);
     color  = get_color(node);
 
-    if(child != NULL)
+    if(child)
       set_parent(child, parent);
-    if(parent != NULL)
+    if(parent)
     {
       if(parent->child[LEFT] == node)
         parent->child[LEFT] = child;
@@ -131,10 +156,22 @@ rbtree_remove(rbtree_t                 *tree,
   if(color == BLACK)
     recolor(tree, parent, child);
 
-  if(destructor != NULL)
+  original->nodeTag[3]   = 'D';
+  original->nodeTag[2]   = 'O';
+  original->nodeTag[1]   = 'N';
+  original->nodeTag[0]   = 'E';
+  original->parent_color = 0;
+  original->child[LEFT]  = NULL;
+  original->child[RIGHT] = NULL;
+  original->tree         = NULL;
+
+  if(destructor)
     (*destructor)(original);
 
   tree->size -= 1;
 
+  rbtree_validate(tree);
+  rbtree_clear_busy(tree);
+
   return next;
 }

libctru/source/util/rbtree/rbtree_rotate.c

@@ -10,12 +10,12 @@ rbtree_rotate(rbtree_t      *tree,
   rbtree_node_t *parent = get_parent(node);
 
   node->child[left] = tmp->child[!left];
-  if(tmp->child[!left] != NULL)
+  if(tmp->child[!left])
     set_parent(tmp->child[!left], node);
 
   tmp->child[!left] = node;
   set_parent(tmp, parent);
-  if(parent != NULL)
+  if(parent)
   {
     if(node == parent->child[!left])
       parent->child[!left] = tmp;

libctru/source/util/rbtree/rbtree_size.c

@@ -1,7 +1,14 @@
 #include <3ds/util/rbtree.h>
+#include "rbtree_internal.h"
 
 size_t
 rbtree_size(const rbtree_t *tree)
 {
-  return tree->size;
+  rbtree_set_busy((rbtree_t*)tree);
+  rbtree_validate(tree);
+
+  size_t size = tree->size;
+
+  rbtree_clear_busy((rbtree_t*)tree);
+  return size;
 }

libctru/source/util/rbtree/rbtree_validate.c

@@ -0,0 +1,164 @@
+#include "rbtree_internal.h"
+
+#include <3ds/svc.h>
+
+#include <stdlib.h>
+
+#define panic() do { \
+  svcBreak(USERBREAK_PANIC); \
+  abort(); \
+} while(0)
+
+void
+rbtree_validate(const rbtree_t *tree)
+{
+  if(!tree)
+    panic();
+
+  // root node must be black
+  if(!is_black(tree->root))
+    panic();
+
+  // root node's parent must be null
+  if(tree->root)
+  {
+    if(get_parent(tree->root))
+      panic();
+  }
+
+  // validate subtree starting at root node
+  size_t size = 0;
+  rbtree_node_validate(tree, tree->root, &size, NULL, NULL);
+
+  // make sure we are tracking the correct number of nodes
+  if(size != tree->size)
+    panic();
+}
+
+void
+rbtree_node_validate(const rbtree_t *tree, const rbtree_node_t *node, size_t *size, size_t *black, size_t *depth)
+{
+  if(!node) // implies is_black
+  {
+    if(black)
+      *black = 1;
+
+    if(depth)
+      *depth = 1;
+
+    return;
+  }
+
+  for(size_t i = 0; i < 32; ++i)
+  {
+    if(node->prefix[i])
+      panic();
+
+    if(node->suffix[i])
+      panic();
+  }
+
+  rbtree_node_t *parent = get_parent(node);
+  if(!parent)
+  {
+    // only the root node can have a null parent
+    if(node != tree->root)
+      panic();
+  }
+  else
+  {
+    // make sure this node is a child of its parent
+    if(parent->child[LEFT] != node && parent->child[RIGHT] != node)
+      panic();
+
+    // if the parent is red, this node must be black
+    if(is_red(parent) && !is_black(node))
+      panic();
+  }
+
+  if(is_red(node))
+  {
+    // if this node is red, both children must be black
+    if(!is_black(node->child[LEFT]))
+      panic();
+
+    if(!is_black(node->child[RIGHT]))
+      panic();
+  }
+
+  if(node->child[LEFT])
+  {
+    // this node must be >= left child
+    if((*(tree->comparator))(node, node->child[LEFT]) < 0)
+      panic();
+  }
+
+  if(node->child[RIGHT])
+  {
+    // this node must be <= right child
+    if((*(tree->comparator))(node, node->child[RIGHT]) > 0)
+      panic();
+  }
+
+  // validate subtree at left child
+  size_t left_size = 0;
+  size_t left_black = 0;
+  size_t left_depth = 0;
+  rbtree_node_validate(tree, node->child[LEFT], &left_size, &left_black, &left_depth);
+
+  // validate subtree at right child
+  size_t right_size = 0;
+  size_t right_black = 0;
+  size_t right_depth = 0;
+  rbtree_node_validate(tree, node->child[RIGHT], &right_size, &right_black, &right_depth);
+
+  // size is left+right subtrees plus self
+  if(size)
+    *size = left_size + right_size + 1;
+
+  // all possible paths to leaf nodes must have the same number of black nodes along the path
+  if(left_black != right_black)
+    panic();
+
+  if(black)
+    *black = left_black + (is_black(node) ? 1 : 0);
+
+  // depth of one subtree must not exceed 2x depth of the other subtree
+  if(left_depth < right_depth)
+  {
+    if(right_depth - left_depth > left_depth)
+      panic();
+  }
+  else if(left_depth - right_depth > right_depth)
+    panic();
+
+  if(depth)
+  {
+    if(left_depth > right_depth)
+      *depth = left_depth + 1;
+    else
+      *depth = right_depth + 1;
+  }
+}
+
+void
+rbtree_set_busy(rbtree_t *tree)
+{
+  LightLock_Lock(&tree->lock);
+  if(tree->busy)
+    panic();
+
+  tree->busy = true;
+  LightLock_Unlock(&tree->lock);
+}
+
+void
+rbtree_clear_busy(rbtree_t *tree)
+{
+  LightLock_Lock(&tree->lock);
+  if(!tree->busy)
+    panic();
+
+  tree->busy = false;
+  LightLock_Unlock(&tree->lock);
+}

libctru/source/util/rbtree/test/Makefile

@@ -0,0 +1,28 @@
+CFILES   := $(wildcard ../*.c)
+CXXFILES := $(wildcard *.cpp)
+
+OFILES   := $(patsubst ../%,%,$(CFILES:.c=.c.o))
+OXXFILES := $(CXXFILES:.cpp=.cpp.o)
+
+CPPFLAGS := -Wall -g -I../../../../include -O2 \
+            -D"LightLock=pthread_mutex_t" \
+            -D"LightLock_Init(x)=pthread_mutex_init(x, NULL)" \
+            -D"LightLock_Lock(x)=pthread_mutex_lock(x)" \
+            -D"LightLock_Unlock(x)=pthread_mutex_unlock(x)"
+
+CFLAGS   := $(CPPFLAGS)
+CXXFLAGS := $(CPPFLAGS) -std=c++11
+
+all: rbtree_test
+
+rbtree_test: $(OFILES) $(OXXFILES)
+	$(CXX) -o $@ $^ $(LDFLAGS)
+
+$(OFILES): %.c.o: ../%.c
+	$(CC) -o $@ -c $< $(CFLAGS)
+
+$(OXXFILES): %.cpp.o: %.cpp
+	$(CXX) -o $@ -c $< $(CXXFLAGS)
+
+clean:
+	$(RM) rbtree_test $(OFILES) $(OXXFILES)

libctru/source/util/rbtree/test/main.cpp

@@ -0,0 +1,130 @@
+extern "C"
+{
+#include <3ds/svc.h>
+#include <3ds/util/rbtree.h>
+#include "../rbtree_internal.h"
+}
+
+#include <cstddef>
+#include <cstdint>
+#include <cstdio>
+#include <functional>
+#include <limits>
+#include <random>
+#include <vector>
+
+namespace
+{
+struct IntNode
+{
+  IntNode(int value) : value(value)
+  {}
+
+  const int value;
+  rbtree_node_t node;
+};
+
+IntNode *getIntNode(rbtree_node_t *node)
+{
+  return rbtree_item(node, IntNode, node);
+}
+
+const IntNode *getIntNode(const rbtree_node_t *node)
+{
+  return rbtree_item(node, IntNode, node);
+}
+
+void IntNodeDestructor(rbtree_node_t *node)
+{
+  delete getIntNode(node);
+}
+
+int IntNodeComparator(const rbtree_node_t *lhs, const rbtree_node_t *rhs)
+{
+  auto left = getIntNode(lhs)->value;
+  auto right = getIntNode(rhs)->value;
+
+  if(left < right)
+    return -1;
+  if(right < left)
+    return 1;
+  return 0;
+}
+
+#if 0
+void printNode(const rbtree_node_t *node, int indent)
+{
+  if(!node)
+  {
+    std::printf("%*s(nil) black\n", indent, "");
+    return;
+  }
+
+  std::printf("%*s%d %s\n", indent, "", getIntNode(node)->value, is_black(node) ? "black" : "red");
+
+  printNode(node->child[LEFT], indent + 2);
+  printNode(node->child[RIGHT], indent + 2);
+}
+
+void printTree(const rbtree_t *tree)
+{
+  std::printf("==========\n");
+  printNode(tree->root, 0);
+}
+#endif
+}
+
+void svcBreak(UserBreakType breakReason)
+{
+  std::abort();
+}
+
+int main(int argc, char *argv[])
+{
+  std::default_random_engine eng;
+
+  {
+    std::random_device rand;
+    std::random_device::result_type seedBuffer[32];
+    for(auto &d : seedBuffer)
+      d = rand();
+
+    std::seed_seq seed(std::begin(seedBuffer), std::end(seedBuffer));
+    eng.seed(seed);
+  }
+
+  auto dist = std::bind(std::uniform_int_distribution<int>(std::numeric_limits<int>::min(), std::numeric_limits<int>::max()), std::ref(eng));
+  auto remove = std::bind(std::uniform_int_distribution<std::size_t>(0, 100), std::ref(eng));
+
+  rbtree_t tree;
+  rbtree_init(&tree, IntNodeComparator);
+
+  for(std::size_t chance = 0; chance <= 100; chance += 25)
+  {
+    std::printf("Chance %zu\n", chance);
+
+    std::vector<IntNode*> nodes;
+    for(std::size_t i = 0; i < 10000; ++i)
+    {
+      auto node = new IntNode(dist());
+      if(rbtree_insert(&tree, &node->node) != &node->node)
+        delete node;
+      else
+        nodes.emplace_back(node);
+
+      // remove random node
+      if(remove() <= chance)
+      {
+        auto it = std::begin(nodes) + (eng() % nodes.size());
+        rbtree_remove(&tree, &(*it)->node, IntNodeDestructor);
+        nodes.erase(it);
+      }
+
+//      printTree(&tree);
+    }
+  }
+
+  std::printf("Ended with %zu nodes in tree\n", rbtree_size(&tree));
+
+  rbtree_clear(&tree, IntNodeDestructor);
+}