Merge pull request 'Red-black tree' (#5) from Chewing_Bever/libvieter:red-black-tree into dev

Reviewed-on: vieter-v/libvieter#5

.clangd

@@ -0,0 +1,2 @@
+CompileFlags:
+  Add: -ferror-limit=0

.woodpecker/lint.yml

@@ -0,0 +1,16 @@
+variables:
+  &image 'git.rustybever.be/chewing_bever/c-devop:alpine3.17'
+
+branches:
+  exclude: [ main ]
+platform: linux/amd64
+
+pipeline:
+  lint:
+    image: *image
+    pull: true
+    commands:
+      - make lint
+      - make objs CFLAGS='-Werror -fsyntax-only'
+    when:
+      event: [push, pull_request]

.woodpecker/test-mem.yml

@@ -0,0 +1,20 @@
+variables:
+  &image 'git.rustybever.be/chewing_bever/c-devop:alpine3.17'
+
+branches:
+  exclude: [ main ]
+platform: linux/amd64
+
+depends_on:
+  - test
+
+pipeline:
+  test:
+    image: *image
+    pull: true
+    commands:
+      - make test-mem
+      - make clean
+      - make test-mem CFLAGS='-O3 -Werror -Wall'
+    when:
+      event: [push, pull_request]

.woodpecker/test.yml

@@ -0,0 +1,22 @@
+variables:
+  &image 'git.rustybever.be/chewing_bever/c-devop:alpine3.17'
+
+matrix:
+  PLATFORM:
+    - 'linux/amd64'
+    - 'linux/arm64'
+
+branches:
+  exclude: [ main ]
+platform: ${PLATFORM}
+
+pipeline:
+  build-and-test:
+    image: *image
+    pull: true
+    commands:
+      - make test
+      - make clean
+      - make test CFLAGS='-O3 -Werror -Wall'
+    when:
+      event: [push, pull_request]

LICENSE

@@ -0,0 +1,674 @@
+                    GNU GENERAL PUBLIC LICENSE
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+combined work, and to convey the resulting work.  The terms of this
+License will continue to apply to the part which is the covered work,
+but the special requirements of the GNU Affero General Public License,
+section 13, concerning interaction through a network will apply to the
+combination as such.
+
+  14. Revised Versions of this License.
+
+  The Free Software Foundation may publish revised and/or new versions of
+the GNU General Public License from time to time.  Such new versions will
+be similar in spirit to the present version, but may differ in detail to
+address new problems or concerns.
+
+  Each version is given a distinguishing version number.  If the
+Program specifies that a certain numbered version of the GNU General
+Public License "or any later version" applies to it, you have the
+option of following the terms and conditions either of that numbered
+version or of any later version published by the Free Software
+Foundation.  If the Program does not specify a version number of the
+GNU General Public License, you may choose any version ever published
+by the Free Software Foundation.
+
+  If the Program specifies that a proxy can decide which future
+versions of the GNU General Public License can be used, that proxy's
+public statement of acceptance of a version permanently authorizes you
+to choose that version for the Program.
+
+  Later license versions may give you additional or different
+permissions.  However, no additional obligations are imposed on any
+author or copyright holder as a result of your choosing to follow a
+later version.
+
+  15. Disclaimer of Warranty.
+
+  THERE IS NO WARRANTY FOR THE PROGRAM, TO THE EXTENT PERMITTED BY
+APPLICABLE LAW.  EXCEPT WHEN OTHERWISE STATED IN WRITING THE COPYRIGHT
+HOLDERS AND/OR OTHER PARTIES PROVIDE THE PROGRAM "AS IS" WITHOUT WARRANTY
+OF ANY KIND, EITHER EXPRESSED OR IMPLIED, INCLUDING, BUT NOT LIMITED TO,
+THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
+PURPOSE.  THE ENTIRE RISK AS TO THE QUALITY AND PERFORMANCE OF THE PROGRAM
+IS WITH YOU.  SHOULD THE PROGRAM PROVE DEFECTIVE, YOU ASSUME THE COST OF
+ALL NECESSARY SERVICING, REPAIR OR CORRECTION.
+
+  16. Limitation of Liability.
+
+  IN NO EVENT UNLESS REQUIRED BY APPLICABLE LAW OR AGREED TO IN WRITING
+WILL ANY COPYRIGHT HOLDER, OR ANY OTHER PARTY WHO MODIFIES AND/OR CONVEYS
+THE PROGRAM AS PERMITTED ABOVE, BE LIABLE TO YOU FOR DAMAGES, INCLUDING ANY
+GENERAL, SPECIAL, INCIDENTAL OR CONSEQUENTIAL DAMAGES ARISING OUT OF THE
+USE OR INABILITY TO USE THE PROGRAM (INCLUDING BUT NOT LIMITED TO LOSS OF
+DATA OR DATA BEING RENDERED INACCURATE OR LOSSES SUSTAINED BY YOU OR THIRD
+PARTIES OR A FAILURE OF THE PROGRAM TO OPERATE WITH ANY OTHER PROGRAMS),
+EVEN IF SUCH HOLDER OR OTHER PARTY HAS BEEN ADVISED OF THE POSSIBILITY OF
+SUCH DAMAGES.
+
+  17. Interpretation of Sections 15 and 16.
+
+  If the disclaimer of warranty and limitation of liability provided
+above cannot be given local legal effect according to their terms,
+reviewing courts shall apply local law that most closely approximates
+an absolute waiver of all civil liability in connection with the
+Program, unless a warranty or assumption of liability accompanies a
+copy of the Program in return for a fee.
+
+                     END OF TERMS AND CONDITIONS
+
+            How to Apply These Terms to Your New Programs
+
+  If you develop a new program, and you want it to be of the greatest
+possible use to the public, the best way to achieve this is to make it
+free software which everyone can redistribute and change under these terms.
+
+  To do so, attach the following notices to the program.  It is safest
+to attach them to the start of each source file to most effectively
+state the exclusion of warranty; and each file should have at least
+the "copyright" line and a pointer to where the full notice is found.
+
+    <one line to give the program's name and a brief idea of what it does.>
+    Copyright (C) <year>  <name of author>
+
+    This program is free software: you can redistribute it and/or modify
+    it under the terms of the GNU General Public License as published by
+    the Free Software Foundation, either version 3 of the License, or
+    (at your option) any later version.
+
+    This program is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU General Public License for more details.
+
+    You should have received a copy of the GNU General Public License
+    along with this program.  If not, see <https://www.gnu.org/licenses/>.
+
+Also add information on how to contact you by electronic and paper mail.
+
+  If the program does terminal interaction, make it output a short
+notice like this when it starts in an interactive mode:
+
+    <program>  Copyright (C) <year>  <name of author>
+    This program comes with ABSOLUTELY NO WARRANTY; for details type `show w'.
+    This is free software, and you are welcome to redistribute it
+    under certain conditions; type `show c' for details.
+
+The hypothetical commands `show w' and `show c' should show the appropriate
+parts of the General Public License.  Of course, your program's commands
+might be different; for a GUI interface, you would use an "about box".
+
+  You should also get your employer (if you work as a programmer) or school,
+if any, to sign a "copyright disclaimer" for the program, if necessary.
+For more information on this, and how to apply and follow the GNU GPL, see
+<https://www.gnu.org/licenses/>.
+
+  The GNU General Public License does not permit incorporating your program
+into proprietary programs.  If your program is a subroutine library, you
+may consider it more useful to permit linking proprietary applications with
+the library.  If this is what you want to do, use the GNU Lesser General
+Public License instead of this License.  But first, please read
+<https://www.gnu.org/licenses/why-not-lgpl.html>.

Makefile

@@ -8,8 +8,10 @@ SRC_DIR ?= src
 TEST_DIR ?= test
 INC_DIRS ?= include
 
+LIB := $(BUILD_DIR)/$(LIB_FILENAME)
+
 SRCS != find '$(SRC_DIR)' -iname '*.c'
-SRCS_H != find $(INC_DIRS) -iname '*.h'
+SRCS_H != find $(INC_DIRS) '$(SRC_DIR)' -iname '*.h'
 SRCS_TEST != find '$(TEST_DIR)' -iname '*.c'
 
 OBJS := $(SRCS:%=$(BUILD_DIR)/%.o)
@@ -17,6 +19,8 @@ OBJS_TEST := $(SRCS_TEST:%=$(BUILD_DIR)/%.o)
 DEPS := $(SRCS:%=$(BUILD_DIR)/%.d) $(SRCS_TEST:%=$(BUILD_DIR)/%.d)
 
 BINS_TEST := $(OBJS_TEST:%.c.o=%)
+TARGETS_TEST := $(BINS_TEST:%=test-%)
+TARGETS_MEM_TEST := $(BINS_TEST:%=test-mem-%)
 
 INC_FLAGS := $(addprefix -I,$(INC_DIRS))
 
@@ -25,41 +29,59 @@ INC_FLAGS := $(addprefix -I,$(INC_DIRS))
 #  object file is also recompiled if only a header is changed.
 # -MP: generate a dummy target for every header file (according to the  docs it
 #  prevents some errors when removing header files)
-CFLAGS ?= -MMD -MP -Wall -Werror -Wextra
-CFLAGS += $(INC_FLAGS)
+CFLAGS ?= -MMD -MP -g
+VIETERCFLAGS := $(INC_FLAGS) $(CFLAGS) -Wall -Wextra
 
 .PHONY: all
 all: vieter
 
 
 # =====COMPILATION=====
+# Utility used by the CI to lint
+.PHONY: objs
+objs: $(OBJS)
+
 .PHONY: vieter
-vieter: $(BUILD_DIR)/$(LIB_FILENAME)
-$(BUILD_DIR)/$(LIB_FILENAME): $(OBJS)
+vieter: $(LIB)
+$(LIB): $(OBJS)
 	ar -rcs $@ $(OBJS)
 
 $(BUILD_DIR)/$(SRC_DIR)/%.c.o: $(SRC_DIR)/%.c
 	mkdir -p $(dir $@)
-	$(CC) $(CFLAGS) -c $< -o $@
+	$(CC) $(VIETERCFLAGS) -c $< -o $@
 
 
 # =====TESTING=====
 .PHONY: test
-test: build-test
-	@ $(foreach bin,$(BINS_TEST),./$(bin);)
+test: $(TARGETS_TEST)
+
+.PHONY: test-mem
+test-mem: $(TARGETS_MEM_TEST)
+
+.PHONY: $(TARGETS_TEST)
+$(TARGETS_TEST): test-%: %
+	./$^
+
+.PHONY: $(TARGETS_MEM_TEST)
+$(TARGETS_MEM_TEST): test-mem-%: %
+	valgrind --tool=memcheck --error-exitcode=1 --track-origins=yes --leak-check=full ./$^
 
 .PHONY: build-test
 build-test: $(BINS_TEST)
 
-# For simplicity, we link every object file to each of the test files. This
-# might be changed later if this starts to become too slow.
-$(BINS_TEST): %: %.c.o $(OBJS)
-	$(CC) $^ -o $@
+$(BINS_TEST): %: %.c.o $(LIB)
+	$(CC) \
+		$^ -o $@
 
-# Each test includes the test directory, which contains the acutest header file
+# Along with the include directory, each test includes $(TEST_DIR) (which
+# contains the acutest.h header file), and the src directory of the module it's
+# testing. This allows tests to access internal methods, which aren't publicly
+# exposed.
 $(BUILD_DIR)/$(TEST_DIR)/%.c.o: $(TEST_DIR)/%.c
 	mkdir -p $(dir $@)
-	$(CC) $(CFLAGS) -I$(TEST_DIR) -c $< -o $@
+	$(CC) $(VIETERCFLAGS) -I$(TEST_DIR) \
+		-I$(dir $(@:$(BUILD_DIR)/$(TEST_DIR)/%=$(SRC_DIR)/%)) \
+		-c $< -o $@
 
 # =====MAINTENANCE=====
 .PHONY: lint

README.md

@@ -1,15 +1,12 @@
 # libvieter
 
-This library powers part of Vieter, most noteably the sections that can easily
+This library powers part of Vieter, most notably the sections that can easily
 be implemented in C (or just parts I want to implement in C because it's fun).
 
-The goal of this library is to be completely self-contained, meaning any
-required data structures have to be implemented as well. It can only depend on
-the C standard libraries.
+The goal of this library is to be as self-contained as possible; data
+structures should be implemented manually if possible.
 
-Currently it contains the following:
-
-* Cron expression parser & next time calculator
+See the [source code](src) for the list of modules.
 
 ## Development
 
@@ -18,16 +15,55 @@ Currently it contains the following:
 Everything is handled by the provided Makefile. To compile the static library,
 simply run `make`.
 
+### Project structure
+
+Each module has its own subdirectory inside `src`, e.g. `src/cron`. This
+directory contains the actual implementation of a module, along with any
+internally used header files. Each internal function should be defined in a
+header file, as to make testing these possible.
+
+Each module should also have its own header file inside the `include`
+directory. This header file defines the public API that the library exposes for
+this specific module.
+
+Any code in a module may only import internal headers from that module, along
+with any of the public API header files. Modules should not depend on each
+other's internal implementationns.
+
+Each module should contain a README describing its contents.
+
+All file names, function names... (even internals) should follow snake case
+convention and have a prefix unique to that module, starting with `vieter_`.
+For example, the `cron` modules uses the `vieter_cron_` prefix for everything.
+
+Header files should only import what they explicitely need. If some function is
+only used in a .c file, the import should be placed in the .c file instead.
+
 ### Testing
 
 This library uses [Acutest](https://github.com/mity/acutest) for its tests.
 Tests should be placed in the `test` subdirectory, further divided into
-directories that correspond those in `src`. Test files should begin with
+directories that correspond to those in `src`. Test files should begin with
 `test_`, and their format should follow the expected format for Acutest.
 
+Each `test_` is compiled separately into a binary, linked with libvieter. A
+test file can import any of the public API header files, along with any header
+files defined in its respective module. This allows testing internal functions.
+
 To run the tests, simply run `make test`. If you wish to only run a specific
 test binary, you can find them in `build/test`.
 
+The name of tests in the `TEST_LIST` variable should be prefixed with the
+module they're testing. This makes it much easier to distinguish the output of
+tests in the CLI. For example:
+
+```c
+TEST_LIST = {
+    {"cron illegal parts", test_illegal_parts},
+    {NULL, NULL}
+};
+```
+
 ### `compile_commands.json`
 
 Clangd requires a `compile_commands.json` to function properly. You can

include/vieter_cron.h

@@ -1,7 +1,6 @@
 #ifndef VIETER_CRON
 #define VIETER_CRON
 
-#include <stdbool.h>
 #include <stdint.h>
 #include <stdlib.h>
 #include <string.h>
@@ -35,18 +34,38 @@ typedef struct vieter_cron_simple_time {
   int minute;
 } vieter_cron_simple_time;
 
-vieter_cron_expression *ce_init();
+/*
+ * Allocate and initialize a new empty cron expression.
+ */
+vieter_cron_expression *vieter_cron_expr_init();
 
+/*
+ * Deallocate a cron expression.
+ */
 void vieter_cron_expr_free(vieter_cron_expression *ce);
 
+/*
+ * Given a cron expression and a reference time, calculate the next time after
+ * the reference time that this expression matches.
+ */
 void vieter_cron_expr_next(vieter_cron_simple_time *out,
                            vieter_cron_expression *ce,
                            vieter_cron_simple_time *ref);
 
+/*
+ * Convencience wrapper around vieter_cron_expr_next that uses the current time
+ * as the reference time.
+ */
 void vieter_cron_expr_next_from_now(vieter_cron_simple_time *out,
                                     vieter_cron_expression *ce);
 
-enum vieter_cron_parse_error vieter_cron_expr_parse(vieter_cron_expression *out,
+/*
+ * Try to parse a string into a cron expression. Note that the cron expression
+ * is updated in-place, meaning it can contain invalid information if the
+ * function returns an error. The cron expression should only be used if the
+ * function succeeded.
+ */
+vieter_cron_parse_error vieter_cron_expr_parse(vieter_cron_expression *out,
                                                const char *expression);
 
 #endif

include/vieter_heap.h

@@ -0,0 +1,62 @@
+#ifndef VIETER_HEAP
+#define VIETER_HEAP
+
+#include <stdint.h>
+
+typedef struct vieter_heap vieter_heap;
+
+typedef enum vieter_heap_error {
+  vieter_heap_ok = 0,
+  vieter_heap_empty = 1
+} vieter_heap_error;
+
+/*
+ * Allocate and initialize an empty heap.
+ */
+vieter_heap *vieter_heap_init();
+
+/*
+ * Deallocate a heap.
+ */
+void vieter_heap_free(vieter_heap *heap);
+
+/*
+ * Return how many elements are currently in the heap.
+ */
+uint64_t vieter_heap_size(vieter_heap *heap);
+
+/*
+ * Insert a new value into the heap.
+ */
+vieter_heap_error vieter_heap_insert(vieter_heap *heap, uint64_t key,
+                                     void *data);
+
+/*
+ * Remove the smallest element from the heap.
+ */
+vieter_heap_error vieter_heap_pop(void **out, vieter_heap *heap);
+
+/*
+ * Get the smallest element in the heap without removing it.
+ */
+vieter_heap_error vieter_heap_peek(void **out, vieter_heap *heap);
+
+/*
+ * Acquire a read lock on the heap. Return value is the result of
+ * pthread_rwlock_rdlock.
+ */
+int vieter_heap_rlock(vieter_heap *heap);
+
+/*
+ * Acquire a write lock on the heap. Return value is the result of
+ * pthread_rwlock_wrlock.
+ */
+int vieter_heap_wlock(vieter_heap *heap);
+
+/*
+ * Unlock the lock after having acquired it. Return value is the result of
+ * pthread_rwlock_unlock.
+ */
+int vieter_heap_unlock(vieter_heap *heap);
+
+#endif

include/vieter_tree.h

@@ -0,0 +1,70 @@
+#ifndef VIETER_TREE
+#define VIETER_TREE
+
+#include <stdint.h>
+#include <stdlib.h>
+
+typedef struct vieter_tree vieter_tree;
+
+typedef enum vieter_tree_error {
+  vieter_tree_ok = 0,
+  vieter_tree_already_present = 1,
+  vieter_tree_not_present = 2,
+  vieter_tree_iterator_done = 3
+} vieter_tree_error;
+
+/*
+ * Allocate and initialize a new red-black binary tree.
+ */
+vieter_tree *vieter_tree_init();
+
+/*
+ * Deallocate a red-black binary tree.
+ */
+void vieter_tree_free(vieter_tree *tree);
+
+/*
+ * Insert a new entry into the tree.
+ */
+vieter_tree_error vieter_tree_insert(vieter_tree *tree, uint64_t key,
+                                     void *data);
+
+/*
+ * Look for an entry in the tree.
+ */
+vieter_tree_error vieter_tree_search(void **out, vieter_tree *tree,
+                                     uint64_t key);
+
+/*
+ * Remove a given entry from the tree.
+ */
+vieter_tree_error vieter_tree_remove(void **out, vieter_tree *tree,
+                                     uint64_t key);
+
+/*
+ * Return how many entries are currently in the tree.
+ */
+uint64_t vieter_tree_size(vieter_tree *tree);
+
+/*
+ * An iterator that can be used to traverse a tree in-order.
+ */
+typedef struct vieter_tree_iterator vieter_tree_iterator;
+
+/*
+ * Allocate and initialize a new iterator from the given tree.
+ */
+vieter_tree_iterator *vieter_tree_iterator_from(vieter_tree *tree);
+
+/*
+ * Free an iterator.
+ */
+void vieter_tree_iterator_free(vieter_tree_iterator **ptp);
+
+/*
+ * Return the iterator's next element.
+ */
+vieter_tree_error vieter_tree_iterator_next(void **out,
+                                            vieter_tree_iterator *iter);
+
+#endif

src/cron/vieter_cron_parse.c

@@ -1,4 +1,8 @@
-#include "vieter_cron.h"
+#include "vieter_cron_parse.h"
+#include <stdbool.h>
+#include <stdlib.h>
+#include <string.h>
+#include <time.h>
 
 // This prefix is needed to properly compile
 const uint8_t parse_month_days[] = {31, 28, 31, 30, 31, 30,

src/cron/vieter_cron_parse.h

@@ -0,0 +1,11 @@
+#ifndef VIETER_CRON_PARSE
+#define VIETER_CRON_PARSE
+
+#include "vieter_cron.h"
+
+vieter_cron_parse_error vieter_cron_expr_parse_range(uint64_t *out, char *s,
+                                                     uint8_t min, uint8_t max);
+
+vieter_cron_parse_error vieter_cron_expr_parse_part(uint64_t *out, char *s,
+                                                    uint8_t min, uint8_t max);
+#endif

src/heap/README.md

@@ -0,0 +1,33 @@
+This min-heap implementation is a pretty standard binomial heap.
+
+## Representation in memory
+
+A heap consists of one or more binomial trees, each with a different order `k`
+and `2^k` total nodes. This heap can contain `2^64 - 1` elements at most, which
+is far more than your memory can contain, but it's still fun to mention.
+
+A tree does not have its own memory structure; a node that's the root of a
+binomial tree is simply called the tree.
+
+Each node has the following layout:
+
+```c
+typedef struct vieter_heap_node {
+    uint64_t key;
+    void *data;
+    struct vieter_heap_node *largest_order;
+    union {
+      struct vieter_heap_node *next_tree;
+      struct vieter_heap_node *next_largest_order;
+    } ptr;
+    uint8_t order;
+} vieter_heap_node;
+```
+
+Each node has a pointer to its child with the largest order (if the node's
+order is `0`, this pointer will be NULL). Each non-root node has a pointer to
+its sibling with the next-highest order. These pointers allow the children of a
+binomial tree to be recombined into a new tree, once their root has been
+pop'ed.
+
+Roots point to the binomial tree in the heap with the next largest order.

src/heap/vieter_heap.c

@@ -0,0 +1,96 @@
+#include "vieter_heap_internal.h"
+
+#include <stdlib.h>
+
+vieter_heap *vieter_heap_init() {
+  vieter_heap *heap = calloc(1, sizeof(vieter_heap));
+
+  pthread_rwlock_init(&heap->lock, NULL);
+
+  return heap;
+}
+
+uint64_t vieter_heap_size(vieter_heap *heap) {
+  uint64_t size = 0;
+  vieter_heap_node *tree = heap->tree;
+
+  while (tree != NULL) {
+    size |= (uint64_t)1 << tree->order;
+
+    tree = tree->ptr.next_tree;
+  }
+
+  return size;
+}
+
+void vieter_heap_free(vieter_heap *heap) {
+  vieter_heap_node *tree = heap->tree;
+  vieter_heap_node *next;
+
+  while (tree != NULL) {
+    next = tree->ptr.next_tree;
+    vieter_heap_tree_free(tree);
+    tree = next;
+  }
+
+  free(heap);
+}
+
+vieter_heap_error vieter_heap_insert(vieter_heap *heap, uint64_t key,
+                                     void *data) {
+  vieter_heap_node *new_tree = vieter_heap_node_init();
+  new_tree->key = key;
+  new_tree->data = data;
+  new_tree->order = 0;
+
+  if (heap->tree == NULL) {
+    heap->tree = new_tree;
+  } else {
+    heap->tree = vieter_heap_tree_merge(heap->tree, new_tree);
+  }
+
+  return vieter_heap_ok;
+}
+
+vieter_heap_error vieter_heap_pop(void **out, vieter_heap *heap) {
+  if (heap->tree == NULL) {
+    return vieter_heap_empty;
+  }
+
+  heap->tree = vieter_heap_tree_pop(out, heap->tree);
+
+  return vieter_heap_ok;
+}
+
+vieter_heap_error vieter_heap_peek(void **out, vieter_heap *heap) {
+  if (heap->tree == NULL) {
+    return vieter_heap_empty;
+  }
+
+  vieter_heap_node *tree = heap->tree;
+  uint64_t smallest_key = tree->key;
+  *out = tree->data;
+
+  while (tree->ptr.next_tree != NULL) {
+    tree = tree->ptr.next_tree;
+
+    if (tree->key < smallest_key) {
+      smallest_key = tree->key;
+      *out = tree->data;
+    }
+  }
+
+  return vieter_heap_ok;
+}
+
+int vieter_heap_rlock(vieter_heap *heap) {
+  return pthread_rwlock_rdlock(&heap->lock);
+}
+
+int vieter_heap_wlock(vieter_heap *heap) {
+  return pthread_rwlock_wrlock(&heap->lock);
+}
+
+int vieter_heap_unlock(vieter_heap *heap) {
+  return pthread_rwlock_unlock(&heap->lock);
+}

src/heap/vieter_heap_internal.h

@@ -0,0 +1,8 @@
+#include "vieter_heap.h"
+#include "vieter_heap_tree.h"
+#include <pthread.h>
+
+struct vieter_heap {
+  vieter_heap_node *tree;
+  pthread_rwlock_t lock;
+};

src/heap/vieter_heap_tree.c

@@ -0,0 +1,192 @@
+#include "vieter_heap_tree.h"
+
+vieter_heap_node *vieter_heap_node_init() {
+  return calloc(1, sizeof(vieter_heap_node));
+}
+
+void vieter_heap_node_free(vieter_heap_node *node) { free(node); }
+
+void vieter_heap_tree_free(vieter_heap_node *root) {
+  if (root->order == 0) {
+    goto end;
+  }
+
+  uint64_t size = 1;
+  vieter_heap_node **stack =
+      malloc(((uint64_t)1 << root->order) * sizeof(vieter_heap_node *));
+  stack[0] = root->largest_order;
+
+  vieter_heap_node *node;
+
+  while (size > 0) {
+    node = stack[size - 1];
+    size--;
+
+    if (node->largest_order != NULL) {
+      stack[size] = node->largest_order;
+      size++;
+    }
+
+    if (node->ptr.next_largest_order != NULL) {
+      stack[size] = node->ptr.next_largest_order;
+      size++;
+    }
+
+    vieter_heap_node_free(node);
+  }
+
+  free(stack);
+
+end:
+  vieter_heap_node_free(root);
+}
+
+vieter_heap_node *vieter_heap_tree_merge_same_order(vieter_heap_node *root_a,
+                                                    vieter_heap_node *root_b) {
+  vieter_heap_node *root, *child;
+
+  if (root_a->key <= root_b->key) {
+    root = root_a;
+    child = root_b;
+  } else {
+    root = root_b;
+    child = root_a;
+  }
+
+  child->ptr.next_largest_order = root->largest_order;
+  root->largest_order = child;
+
+  root->order++;
+
+  return root;
+}
+
+vieter_heap_node *vieter_heap_tree_merge(vieter_heap_node *target_tree,
+                                         vieter_heap_node *other_tree) {
+  vieter_heap_node *out = target_tree;
+
+  vieter_heap_node *next_other_tree, *next_target_tree;
+  vieter_heap_node *previous_target_tree = NULL;
+
+  while (target_tree != NULL && other_tree != NULL) {
+    if (target_tree->order == other_tree->order) {
+      next_other_tree = other_tree->ptr.next_tree;
+      next_target_tree = target_tree->ptr.next_tree;
+
+      target_tree = vieter_heap_tree_merge_same_order(target_tree, other_tree);
+
+      target_tree->ptr.next_tree = next_target_tree;
+
+      // If this merge produces a binomial tree whose size is already in
+      // target, it will be the next target. Therefore, we can  merge target's
+      // trees until we no longer have a duplicate depth.
+      while (next_target_tree != NULL &&
+             next_target_tree->order == target_tree->order) {
+        next_target_tree = next_target_tree->ptr.next_tree;
+        target_tree = vieter_heap_tree_merge_same_order(
+            target_tree, target_tree->ptr.next_tree);
+        target_tree->ptr.next_tree = next_target_tree;
+      }
+
+      if (previous_target_tree != NULL) {
+        previous_target_tree->ptr.next_tree = target_tree;
+      } else {
+        out = target_tree;
+      }
+
+      other_tree = next_other_tree;
+    } else if (target_tree->order > other_tree->order) {
+      next_other_tree = other_tree->ptr.next_tree;
+
+      if (previous_target_tree == NULL) {
+        previous_target_tree = other_tree;
+        out = other_tree;
+      } else {
+        previous_target_tree->ptr.next_tree = other_tree;
+
+        // This single missing line right here broke this entire function for
+        // nearly a week.
+        previous_target_tree = other_tree;
+      }
+
+      other_tree->ptr.next_tree = target_tree;
+      other_tree = next_other_tree;
+    } else {
+      if (previous_target_tree == NULL) {
+        out = target_tree;
+      }
+
+      previous_target_tree = target_tree;
+      target_tree = target_tree->ptr.next_tree;
+    }
+  }
+
+  // Append final part of tree to target
+  if (target_tree == NULL) {
+    previous_target_tree->ptr.next_tree = other_tree;
+  }
+
+  return out;
+}
+
+vieter_heap_node *vieter_heap_tree_pop(void **out, vieter_heap_node *tree) {
+  vieter_heap_node *tree_before_smallest = NULL;
+  vieter_heap_node *previous_tree = NULL;
+  vieter_heap_node *original_root = tree;
+
+  uint64_t smallest_key = tree->key;
+
+  while (tree->ptr.next_tree != NULL) {
+    previous_tree = tree;
+    tree = tree->ptr.next_tree;
+
+    if (tree->key < smallest_key) {
+      smallest_key = tree->key;
+      tree_before_smallest = previous_tree;
+    }
+  }
+
+  vieter_heap_node *tree_to_pop;
+
+  if (tree_before_smallest != NULL) {
+    tree_to_pop = tree_before_smallest->ptr.next_tree;
+    tree_before_smallest->ptr.next_tree = tree_to_pop->ptr.next_tree;
+  } else {
+    tree_to_pop = original_root;
+    original_root = original_root->ptr.next_tree;
+  }
+
+  *out = tree_to_pop->data;
+
+  if (tree_to_pop->order == 0) {
+    vieter_heap_tree_free(tree_to_pop);
+
+    return original_root;
+  }
+
+  // Each child has a pointer to its sibling with the next largest order. If we
+  // want to convert this list of children into their own tree, these pointers
+  // have to be reversed.
+  previous_tree = tree_to_pop->largest_order;
+  vieter_heap_node_free(tree_to_pop);
+
+  tree = previous_tree->ptr.next_largest_order;
+  previous_tree->ptr.next_tree = NULL;
+
+  vieter_heap_node *next_tree;
+
+  while (tree != NULL) {
+    next_tree = tree->ptr.next_largest_order;
+    tree->ptr.next_tree = previous_tree;
+
+    previous_tree = tree;
+    tree = next_tree;
+  }
+
+  // original_root is zero if the heap only contained a single tree.
+  if (original_root != NULL) {
+    return vieter_heap_tree_merge(original_root, previous_tree);
+  } else {
+    return previous_tree;
+  }
+}

src/heap/vieter_heap_tree.h

@@ -0,0 +1,54 @@
+#ifndef VIETER_HEAP_TREE
+#define VIETER_HEAP_TREE
+
+#include <stdint.h>
+#include <stdlib.h>
+
+typedef struct vieter_heap_node {
+  uint64_t key;
+  void *data;
+  struct vieter_heap_node *largest_order;
+  union {
+    // Roots point to next tree in the heap, other nodes point to their first
+    // neighbour.
+    struct vieter_heap_node *next_tree;
+    struct vieter_heap_node *next_largest_order;
+  } ptr;
+  uint8_t order;
+} vieter_heap_node;
+
+/*
+ * Allocate and initialize a heap node object.
+ */
+vieter_heap_node *vieter_heap_node_init();
+
+/*
+ * Deallocate a node object.
+ */
+void vieter_heap_node_free(vieter_heap_node *node);
+
+/*
+ * Deallocate a node's entire structure.
+ */
+void vieter_heap_tree_free(vieter_heap_node *root);
+
+/*
+ * Given the roots of the smallest trees in two heaps, merge them into a single
+ * large heap.
+ */
+vieter_heap_node *vieter_heap_tree_merge(vieter_heap_node *root_a,
+                                         vieter_heap_node *root_b);
+
+/*
+ * Given the roots of two trees of the same order, merge them into a heap of one
+ * order larger.
+ */
+vieter_heap_node *vieter_heap_tree_merge_same_order(vieter_heap_node *root_a,
+                                                    vieter_heap_node *root_b);
+
+/*
+ * Remove the smallest element from the given heap.
+ */
+vieter_heap_node *vieter_heap_tree_pop(void **out, vieter_heap_node *root);
+
+#endif

src/tree/vieter_tree.c

@@ -0,0 +1,116 @@
+#include "vieter_tree_balancing.h"
+#include "vieter_tree_internal.h"
+
+vieter_tree *vieter_tree_init() { return calloc(1, sizeof(vieter_tree)); }
+
+uint64_t vieter_tree_size(vieter_tree *tree) { return tree->size; }
+
+vieter_tree_error vieter_tree_insert(vieter_tree *tree, uint64_t key,
+                                     void *data) {
+  if (tree->size == 0) {
+    tree->root = vieter_tree_node_init();
+    tree->root->key = key;
+    tree->root->data = data;
+    vieter_tree_node_set(tree->root, vieter_tree_node_black, true);
+    tree->size = 1;
+
+    return vieter_tree_ok;
+  }
+
+  vieter_tree_error res = vieter_tree_node_insert(tree->root, key, data);
+
+  if (res != vieter_tree_ok) {
+    return res;
+  }
+
+  tree->size++;
+
+  return vieter_tree_ok;
+}
+
+vieter_tree_error vieter_tree_search(void **out, vieter_tree *tree,
+                                     uint64_t key) {
+  if (tree->size == 0) {
+    return vieter_tree_not_present;
+  }
+
+  return vieter_tree_node_search(out, tree->root, key);
+}
+
+vieter_tree_error vieter_tree_remove(void **out, vieter_tree *tree,
+                                     uint64_t key) {
+  if (tree->size == 0) {
+    return vieter_tree_not_present;
+  }
+
+  vieter_tree_error res = vieter_tree_node_remove(out, &tree->root, key);
+
+  if (res != vieter_tree_ok) {
+    return res;
+  }
+
+  tree->size--;
+
+  return vieter_tree_ok;
+}
+
+void vieter_tree_free(vieter_tree *tree) {
+  if (tree->size == 0) {
+    goto end;
+  }
+
+  uint64_t capacity = 4;
+  uint64_t size = 1;
+  vieter_tree_node **stack = malloc(capacity * sizeof(vieter_tree_node *));
+  stack[0] = tree->root;
+
+  vieter_tree_node *node;
+
+  while (size > 0) {
+    node = stack[size - 1];
+    size--;
+
+    if (size + 2 > capacity) {
+      capacity *= 2;
+      stack = realloc(stack, capacity * sizeof(vieter_tree_node *));
+    }
+
+    if (node->children[0] != NULL) {
+      stack[size] = node->children[0];
+      size++;
+    }
+
+    if (node->children[1] != NULL) {
+      stack[size] = node->children[1];
+      size++;
+    }
+
+    vieter_tree_node_free(node);
+  }
+
+  free(stack);
+
+end:
+  free(tree);
+}
+
+bool vieter_tree_validate(vieter_tree *tree) {
+  if (tree->size == 0) {
+    return true;
+  }
+
+  // DFS to get expected black nodes
+  uint64_t expected_black_nodes = 0;
+  vieter_tree_node *node = tree->root;
+
+  while (node != NULL) {
+    if (vieter_tree_node_get(node, vieter_tree_node_black)) {
+      expected_black_nodes++;
+    }
+
+    node = node->children[0];
+  }
+
+  return vieter_tree_node_get(tree->root, vieter_tree_node_black) &&
+         vieter_tree_node_validate(tree->root, 0, expected_black_nodes);
+}

src/tree/vieter_tree_balancing.c

@@ -0,0 +1,289 @@
+#include "vieter_tree_balancing.h"
+#include <string.h>
+
+bool vieter_tree_node_validate(vieter_tree_node *node,
+                               uint64_t passed_black_nodes,
+                               uint64_t expected_black_nodes) {
+  // Path to NULL children should contain the same amount of black nodes
+  if (node == NULL) {
+    return passed_black_nodes == expected_black_nodes;
+  }
+
+  if (vieter_tree_node_get(node, vieter_tree_node_black)) {
+    passed_black_nodes++;
+  }
+
+  // Either the node itself is black, or its children are both either NULL or
+  // black.
+  bool correctly_colored_children =
+      vieter_tree_node_get(node, vieter_tree_node_black) ||
+      ((node->children[0] == NULL ||
+        vieter_tree_node_get(node->children[0], vieter_tree_node_black)) &&
+       (node->children[1] == NULL ||
+        vieter_tree_node_get(node->children[1], vieter_tree_node_black)));
+  bool right_child_flag_set =
+      node->parent == NULL ||
+      (vieter_tree_node_get(node, vieter_tree_node_right) ==
+       (node->parent->children[1] == node));
+
+  return correctly_colored_children && right_child_flag_set &&
+         vieter_tree_node_validate(node->children[0], passed_black_nodes,
+                                   expected_black_nodes) &&
+         vieter_tree_node_validate(node->children[1], passed_black_nodes,
+                                   expected_black_nodes);
+}
+
+/*
+ * This function should be rewritten to use tree rotations instead.
+ */
+vieter_tree_node *vieter_tree_node_balance(vieter_tree_node *node) {
+  vieter_tree_node *parent = node->parent;
+  vieter_tree_node *grand_parent = parent->parent;
+  vieter_tree_node *root = grand_parent;
+  vieter_tree_node *children[2];
+  vieter_tree_node *grand_children[4];
+
+  uint64_t key_root = root->key;
+  void *data_root = root->data;
+
+  if (vieter_tree_node_get(node, vieter_tree_node_right)) {
+    children[0] = parent;
+    children[1] = node;
+
+    if (vieter_tree_node_get(parent, vieter_tree_node_right)) {
+      root->key = parent->key;
+      root->data = parent->data;
+
+      parent->key = key_root;
+      parent->data = data_root;
+
+      grand_children[0] = grand_parent->children[0];
+      grand_children[1] = parent->children[0];
+      grand_children[2] = node->children[0];
+      grand_children[3] = node->children[1];
+    } else {
+      root->key = node->key;
+      root->data = node->data;
+
+      node->key = key_root;
+      node->data = data_root;
+
+      grand_children[0] = parent->children[0];
+      grand_children[1] = node->children[0];
+      grand_children[2] = node->children[1];
+      grand_children[3] = grand_parent->children[1];
+    }
+  } else {
+    children[0] = node;
+    children[1] = parent;
+
+    if (vieter_tree_node_get(parent, vieter_tree_node_right)) {
+      root->key = node->key;
+      root->data = node->data;
+
+      node->key = key_root;
+      node->data = data_root;
+
+      grand_children[0] = grand_parent->children[0];
+      grand_children[1] = node->children[0];
+      grand_children[2] = node->children[1];
+      grand_children[3] = parent->children[1];
+    } else {
+      root->key = parent->key;
+      root->data = parent->data;
+
+      parent->key = key_root;
+      parent->data = data_root;
+
+      grand_children[0] = node->children[0];
+      grand_children[1] = node->children[1];
+      grand_children[2] = parent->children[1];
+      grand_children[3] = grand_parent->children[1];
+    }
+  }
+
+  vieter_tree_node_set(
+      root, vieter_tree_node_right,
+      vieter_tree_node_get(grand_parent, vieter_tree_node_right));
+
+  vieter_tree_node_set(children[0], vieter_tree_node_black, true);
+  vieter_tree_node_set(children[1], vieter_tree_node_black, true);
+
+  vieter_tree_node_set(root, vieter_tree_node_black, false);
+
+  vieter_tree_node_set_children(children[0], grand_children);
+  vieter_tree_node_set_children(children[1], grand_children + 2);
+  vieter_tree_node_set_children(root, children);
+
+  return root;
+}
+
+void vieter_tree_node_balance_after_insert(vieter_tree_node *node) {
+  while (!vieter_tree_node_get(node, vieter_tree_node_black) &&
+         node->parent != NULL &&
+         !vieter_tree_node_get(node->parent, vieter_tree_node_black)) {
+    node = vieter_tree_node_balance(node);
+  }
+
+  // The root must always be black
+  if (node->parent == NULL) {
+    vieter_tree_node_set(node, vieter_tree_node_black, true);
+  }
+}
+
+vieter_tree_node *vieter_tree_node_rotate(vieter_tree_node *old_root,
+                                          bool dir) {
+  vieter_tree_node *new_root = old_root->children[1 - dir];
+
+  if (old_root->parent != NULL) {
+    vieter_tree_node_set_child(
+        old_root->parent, new_root,
+        vieter_tree_node_get(old_root, vieter_tree_node_right));
+  } else {
+    new_root->parent = NULL;
+  }
+
+  // Right rotation
+  if (dir) {
+    vieter_tree_node_set_child(old_root, new_root->children[1], false);
+    vieter_tree_node_set_child(new_root, old_root, true);
+  }
+  // Left rotation
+  else {
+    vieter_tree_node_set_child(old_root, new_root->children[0], true);
+    vieter_tree_node_set_child(new_root, old_root, false);
+  }
+
+  return new_root;
+}
+
+/*
+ * This function is currently implemented by very literally following the
+ * Wikipedia pseudocode. It's honestly not too bad, and I couldn't be bothered
+ * to properly research how to implement red-black removal (how is this so hard
+ * to find?)
+ *
+ * https://en.wikipedia.org/wiki/Red%E2%80%93black_tree#Removal_of_a_black_non-root_leaf
+ */
+vieter_tree_node *vieter_tree_node_remove_balanced(vieter_tree_node *node) {
+  vieter_tree_node *out;
+
+  if (node->parent == NULL) {
+    out = node->children[0] != NULL ? node->children[0] : node->children[1];
+
+    vieter_tree_node_free(node);
+
+    // This only happens when the root was the only element in the tree
+    if (out == NULL)
+      return out;
+
+    vieter_tree_node_set(out, vieter_tree_node_black, true);
+    out->parent = NULL;
+
+    return out;
+  }
+
+  // A red node can only have 0 or 2 children. The node we receive only has
+  // one child at most, so we know if it's red that it doesn't have any
+  // children. A black node that has a single (right) child can be replaced by
+  // this child, granted it becomes black as well. Either way, the node can be
+  // replaced by its right child (even if it's NULL).
+  if (!vieter_tree_node_get(node, vieter_tree_node_black) ||
+      node->children[1] != NULL) {
+    out = node->children[1];
+
+    vieter_tree_node_set_child(
+        node->parent, node->children[1],
+        vieter_tree_node_get(node, vieter_tree_node_right));
+
+    if (node->children[1] != NULL)
+      vieter_tree_node_set(node->children[1], vieter_tree_node_black, true);
+
+    vieter_tree_node_free(node);
+
+    return out;
+  }
+
+  // The complicated case is when we want to remove a black leaf
+  // https://en.wikipedia.org/wiki/Red%E2%80%93black_tree#Removal_of_a_black_non-root_leaf
+
+  out = node;
+  vieter_tree_node *parent = node->parent;
+  vieter_tree_node *sibling, *close_nephew, *distant_nephew;
+  bool dir = vieter_tree_node_get(node, vieter_tree_node_right);
+  parent->children[dir] = NULL;
+
+  vieter_tree_node_free(node);
+
+  goto start;
+
+  do {
+    dir = vieter_tree_node_get(node, vieter_tree_node_right);
+
+  start:
+    sibling = parent->children[1 - dir];
+    distant_nephew = sibling->children[1 - dir];
+    close_nephew = sibling->children[dir];
+
+    if (!vieter_tree_node_get(sibling, vieter_tree_node_black))
+      goto case3;
+
+    if (distant_nephew != NULL &&
+        !vieter_tree_node_get(distant_nephew, vieter_tree_node_black))
+      goto case6;
+
+    if (close_nephew != NULL &&
+        !vieter_tree_node_get(close_nephew, vieter_tree_node_black))
+      goto case5;
+
+    if (!vieter_tree_node_get(parent, vieter_tree_node_black))
+      goto case4;
+
+    // Case 2
+    vieter_tree_node_set(sibling, vieter_tree_node_black, false);
+    node = parent;
+    out = node;
+  } while ((parent = node->parent) != NULL);
+
+  // Case 1
+  return out;
+
+case3:
+  out = vieter_tree_node_rotate(parent, dir);
+  vieter_tree_node_set(parent, vieter_tree_node_black, false);
+  vieter_tree_node_set(sibling, vieter_tree_node_black, true);
+  sibling = close_nephew;
+  distant_nephew = sibling->children[1 - dir];
+
+  if (distant_nephew != NULL &&
+      !vieter_tree_node_get(distant_nephew, vieter_tree_node_black))
+    goto case6;
+
+  close_nephew = sibling->children[dir];
+
+  if (close_nephew != NULL &&
+      !vieter_tree_node_get(close_nephew, vieter_tree_node_black))
+    goto case5;
+
+case4:
+  vieter_tree_node_set(sibling, vieter_tree_node_black, false);
+  vieter_tree_node_set(parent, vieter_tree_node_black, true);
+
+  return out;
+
+case5:
+  vieter_tree_node_rotate(sibling, 1 - dir);
+  vieter_tree_node_set(sibling, vieter_tree_node_black, false);
+  vieter_tree_node_set(close_nephew, vieter_tree_node_black, true);
+  distant_nephew = sibling;
+  sibling = close_nephew;
+
+case6:
+  out = vieter_tree_node_rotate(parent, dir);
+  vieter_tree_node_set(sibling, vieter_tree_node_black,
+                       vieter_tree_node_get(parent, vieter_tree_node_black));
+  vieter_tree_node_set(parent, vieter_tree_node_black, true);
+  vieter_tree_node_set(distant_nephew, vieter_tree_node_black, true);
+
+  return out;
+}

src/tree/vieter_tree_balancing.h

@@ -0,0 +1,46 @@
+#ifndef VIETER_TREE_BALANCING
+#define VIETER_TREE_BALANCING
+
+#include "vieter_tree_node.h"
+
+/*
+ * Check whether the given tree is a valid red-black tree.
+ *
+ * @param node root of the (sub)tree
+ * @param passed_black_nodes how many black nodes the recursion has already seen
+ * at this point. This should be initialized as 0 for the topmost call.
+ * @param expected_black_nodes the correct amount of black nodes to expect when
+ * a NULL child is encountered.
+ * @return true if the tree is valid, false otherwise
+ */
+bool vieter_tree_node_validate(vieter_tree_node *node,
+                               uint64_t passed_black_nodes,
+                               uint64_t expected_black_nodes);
+
+/*
+ * Balance a path of 3 nodes into a complete binary tree, with a red root and
+ * black children.
+ */
+vieter_tree_node *vieter_tree_node_balance(vieter_tree_node *node);
+
+/*
+ * Ensure the tree remains a valid red-black tree after having inserting the
+ * node.
+ */
+void vieter_tree_node_balance_after_insert(vieter_tree_node *node);
+
+/*
+ * Remove the given node, ensuring the tree remains a valid red-black tree.
+ *
+ * @param node node to remove. This should have at most a single child. If node
+ * isn't the root, this should be the right child, otherwise it can be either.
+ * @return root of the subtree that this function operated on. This can
+ * sometimes be the new root of the entire tree.
+ */
+vieter_tree_node *vieter_tree_node_remove_balanced(vieter_tree_node *node);
+
+/*
+ * Perform a tree rotation of the subtree with the given root.
+ */
+vieter_tree_node *vieter_tree_node_rotate(vieter_tree_node *old_root, bool dir);
+#endif

src/tree/vieter_tree_internal.h

@@ -0,0 +1,22 @@
+#include "vieter_tree.h"
+#include "vieter_tree_node.h"
+
+#include <stdbool.h>
+
+struct vieter_tree {
+  uint64_t size;
+  vieter_tree_node *root;
+};
+
+/*
+ * Inspect whether the tree is still a valid red-black-tree.
+ *
+ * @return true if valid, false otherwise.
+ */
+bool vieter_tree_validate(vieter_tree *tree);
+
+struct vieter_tree_iterator {
+  vieter_tree_node *current_node;
+  bool started;
+  bool done;
+};

src/tree/vieter_tree_iterator.c

@@ -0,0 +1,49 @@
+#include "vieter_tree.h"
+#include "vieter_tree_internal.h"
+
+vieter_tree_iterator *vieter_tree_iterator_from(vieter_tree *tree) {
+  vieter_tree_iterator *iter = calloc(1, sizeof(vieter_tree_iterator));
+
+  // An empty tree's iterator will be done immediately
+  if (tree->size == 0) {
+    iter->started = true;
+    iter->done = true;
+
+    return iter;
+  }
+
+  iter->current_node = tree->root;
+
+  return iter;
+}
+
+vieter_tree_error vieter_tree_iterator_next(void **out,
+                                            vieter_tree_iterator *iter) {
+  if (iter->done) {
+    return vieter_tree_iterator_done;
+  }
+
+  if (!iter->started) {
+    while (iter->current_node->children[0] != NULL) {
+      iter->current_node = iter->current_node->children[0];
+    }
+
+    iter->started = true;
+  }
+
+  *out = iter->current_node->data;
+
+  iter->current_node = vieter_tree_node_next(iter->current_node);
+
+  if (iter->current_node == NULL) {
+    iter->done = true;
+  }
+
+  return vieter_tree_ok;
+}
+
+void vieter_tree_iterator_free(vieter_tree_iterator **ptp) {
+  free(*ptp);
+
+  *ptp = NULL;
+}

src/tree/vieter_tree_node.c

@@ -0,0 +1,171 @@
+#include "vieter_tree_node.h"
+#include "vieter_tree_balancing.h"
+
+#include <string.h>
+
+vieter_tree_node *vieter_tree_node_init() {
+  return calloc(1, sizeof(vieter_tree_node));
+}
+
+void vieter_tree_node_free(vieter_tree_node *node) { free(node); }
+
+void vieter_tree_node_add_child(vieter_tree_node *parent, uint64_t key,
+                                vieter_tree_node *child) {
+  if (parent == NULL) {
+    return;
+  }
+
+  bool side = key > parent->key;
+  parent->children[side] = child;
+
+  if (child != NULL) {
+    child->parent = parent;
+    vieter_tree_node_set(child, vieter_tree_node_right, side);
+  }
+}
+
+void vieter_tree_node_set_children(vieter_tree_node *parent,
+                                   vieter_tree_node **children) {
+  memcpy(parent->children, children, 2 * sizeof(vieter_tree_node *));
+
+  for (uint8_t i = 0; i < 2; i++) {
+    if (parent->children[i] != NULL) {
+      parent->children[i]->parent = parent;
+      vieter_tree_node_set(parent->children[i], vieter_tree_node_right, i);
+    }
+  }
+}
+
+void vieter_tree_node_set_child(vieter_tree_node *parent,
+                                vieter_tree_node *child, bool right) {
+  parent->children[right] = child;
+
+  if (child != NULL) {
+    child->parent = parent;
+    vieter_tree_node_set(child, vieter_tree_node_right, right);
+  }
+}
+
+vieter_tree_error vieter_tree_node_insert(vieter_tree_node *root, uint64_t key,
+                                          void *data) {
+  vieter_tree_node *node = root;
+  vieter_tree_node *parent = root;
+
+  while (node != NULL) {
+    if (node->key == key) {
+      return vieter_tree_already_present;
+    }
+
+    parent = node;
+    node = node->children[key > parent->key];
+  }
+
+  vieter_tree_node *new_node = vieter_tree_node_init();
+  new_node->key = key;
+  new_node->data = data;
+
+  vieter_tree_node_add_child(parent, key, new_node);
+  vieter_tree_node_balance_after_insert(new_node);
+
+  return vieter_tree_ok;
+}
+
+vieter_tree_error vieter_tree_node_search_node(vieter_tree_node **out,
+                                               vieter_tree_node *root,
+                                               uint64_t key) {
+  vieter_tree_node *node = root;
+
+  while (node != NULL) {
+    if (node->key == key) {
+      *out = node;
+
+      return vieter_tree_ok;
+    }
+
+    node = node->children[key > node->key];
+  }
+
+  return vieter_tree_not_present;
+}
+
+vieter_tree_error vieter_tree_node_search(void **out, vieter_tree_node *root,
+                                          uint64_t key) {
+  vieter_tree_node *target;
+  vieter_tree_error res = vieter_tree_node_search_node(&target, root, key);
+
+  if (res != vieter_tree_ok) {
+    return res;
+  }
+
+  *out = target->data;
+
+  return vieter_tree_ok;
+}
+
+vieter_tree_error
+vieter_tree_node_remove(void **out, vieter_tree_node **root_ptr, uint64_t key) {
+  vieter_tree_node *target;
+  vieter_tree_error res = vieter_tree_node_search_node(&target, *root_ptr, key);
+
+  if (res != vieter_tree_ok) {
+    return res;
+  }
+
+  *out = target->data;
+  vieter_tree_node *possible_new_root;
+
+  if (target->children[0] != NULL && target->children[1] != NULL) {
+    vieter_tree_node *replacement = target->children[1];
+
+    while (replacement->children[0] != NULL) {
+      replacement = replacement->children[0];
+    }
+
+    target->key = replacement->key;
+    target->data = replacement->data;
+
+    possible_new_root = vieter_tree_node_remove_balanced(replacement);
+  } else {
+    possible_new_root = vieter_tree_node_remove_balanced(target);
+  }
+
+  if (possible_new_root == NULL) {
+    *root_ptr = NULL;
+  } else if (possible_new_root->parent == NULL) {
+    *root_ptr = possible_new_root;
+  }
+
+  return vieter_tree_ok;
+}
+
+void vieter_tree_node_set(vieter_tree_node *node, vieter_tree_node_flag flag,
+                          bool set) {
+  if (set) {
+    node->flags |= flag;
+  } else {
+    node->flags &= ~flag;
+  }
+}
+
+bool vieter_tree_node_get(vieter_tree_node *node, vieter_tree_node_flag flag) {
+  return (node->flags & flag) != 0;
+}
+
+vieter_tree_node *vieter_tree_node_next(vieter_tree_node *node) {
+  if (node->children[1] != NULL) {
+    node = node->children[1];
+
+    while (node->children[0] != NULL) {
+      node = node->children[0];
+    }
+
+    return node;
+  }
+
+  while (node->parent != NULL &&
+         vieter_tree_node_get(node, vieter_tree_node_right)) {
+    node = node->parent;
+  }
+
+  return node->parent;
+}

src/tree/vieter_tree_node.h

@@ -0,0 +1,94 @@
+#ifndef VIETER_TREE_NODE
+#define VIETER_TREE_NODE
+
+#include "vieter_tree.h"
+#include <stdbool.h>
+#include <stdint.h>
+
+typedef enum vieter_tree_node_flag {
+  vieter_tree_node_black = ((uint8_t)1) << 0,
+  // This flag is used to index the children array. If this flag isn't set,
+  // it'll evaluate to false, or index 0 in the children array.
+  vieter_tree_node_right = ((uint8_t)1) << 1
+} vieter_tree_node_flag;
+
+typedef struct vieter_tree_node {
+  uint64_t key;
+  void *data;
+  struct vieter_tree_node *parent;
+  struct vieter_tree_node *children[2];
+  uint8_t flags;
+} vieter_tree_node;
+
+/*
+ * Allocate a new node.
+ */
+vieter_tree_node *vieter_tree_node_init();
+
+/*
+ * Free an allocated node.
+ */
+void vieter_tree_node_free(vieter_tree_node *node);
+
+/*
+ * Insert a new key into the given tree.
+ */
+vieter_tree_error vieter_tree_node_insert(vieter_tree_node *root, uint64_t key,
+                                          void *data);
+
+/*
+ * Return the node representing the requested value.
+ */
+vieter_tree_error vieter_tree_node_search_node(vieter_tree_node **out,
+                                               vieter_tree_node *root,
+                                               uint64_t key);
+
+/*
+ * Search for the data represented by the given key.
+ */
+vieter_tree_error vieter_tree_node_search(void **out, vieter_tree_node *root,
+                                          uint64_t key);
+
+/*
+ * Remove the data associated with the given key.
+ */
+vieter_tree_error
+vieter_tree_node_remove(void **out, vieter_tree_node **root_ptr, uint64_t key);
+
+/*
+ * Set a node's bit flag to the given value.
+ */
+void vieter_tree_node_set(vieter_tree_node *node, vieter_tree_node_flag flag,
+                          bool value);
+
+/*
+ * Get whether a node's bit flag is set.
+ */
+bool vieter_tree_node_get(vieter_tree_node *node, vieter_tree_node_flag flag);
+
+/*
+ * Add a new child to the parent, replacing either its left or right child,
+ * depending on the key values.
+ */
+void vieter_tree_node_add_child(vieter_tree_node *parent, uint64_t key,
+                                vieter_tree_node *child);
+
+/*
+ * Replace a node's children array.
+ */
+void vieter_tree_node_set_children(vieter_tree_node *parent,
+                                   vieter_tree_node **children);
+
+/*
+ * Set a node's left or right child to the given node.
+ */
+void vieter_tree_node_set_child(vieter_tree_node *parent,
+                                vieter_tree_node *child, bool right);
+
+/*
+ * Return the in-order successor of the given node, or NULL if it's the last
+ * node in the tree.
+ */
+vieter_tree_node *vieter_tree_node_next(vieter_tree_node *node);
+
+#endif

test/cron/test_parse.c

@@ -1,7 +1,7 @@
 #include "acutest.h"
 #include "vieter_cron.h"
 
-void test_not_allowed() {
+void test_illegal_expressions() {
     char *expressions[] = {
         "4 *-7",
         "4 *-7/4",
@@ -33,6 +33,6 @@ void test_not_allowed() {
 }
 
 TEST_LIST = {
-    {"not_allowed", test_not_allowed},
+    {"cron illegal expressions", test_illegal_expressions},
     {NULL, NULL}
 };

test/cron/test_parse_part.c

@@ -0,0 +1,43 @@
+#include "acutest.h"
+#include "vieter_cron_parse.h"
+
+struct parse_test {
+    char *part;
+    uint8_t min;
+    uint8_t max;
+};
+
+void test_illegal_parts() {
+    struct parse_test parts[] = {
+        { "*-7", 0, 23 },
+        { "*-7/4", 0, 23 },
+        { "7/*", 0, 23 },
+        { "/5", 0, 23 },
+        { "4~6", 0, 23 },
+        { "5/2-5", 0, 23 },
+        { "1/2/3", 0, 23 },
+        { "*5", 0, 59 },
+        { "x", 0, 59 },
+        { NULL, 0, 0 }
+    };
+
+    int i = 0;
+    uint64_t out;
+    char *s;
+
+    while (parts[i].part != NULL) {
+        // Function modifies string in-place
+        s = strdup(parts[i].part);
+
+        TEST_CHECK_(vieter_cron_expr_parse_part(&out, s, parts[i].min, parts[i].max) != vieter_cron_parse_ok, "%s (%i - %i)", parts[i].part, parts[i].min, parts[i].max);
+
+        free(s);
+
+        i++;
+    }
+}
+
+TEST_LIST = {
+    {"cron illegal parts", test_illegal_parts},
+    {NULL, NULL}
+};

test/heap/test_heap.c

@@ -0,0 +1,187 @@
+#include "acutest.h"
+#include "vieter_heap_internal.h"
+#include <stdlib.h>
+
+#define TEST_SIZE(heap, size) \
+    TEST_CHECK(vieter_heap_size(heap) == size); \
+    TEST_MSG("Size: %zu, expected: %lu", vieter_heap_size(heap), (uint64_t)size)
+
+void test_init() {
+    vieter_heap *heap = vieter_heap_init();
+    TEST_CHECK(heap != NULL);
+    TEST_SIZE(heap, 0);
+    vieter_heap_free(heap);
+}
+
+void count_nodes(uint64_t *counter, vieter_heap_node *root) {
+    (*counter)++;
+
+    if (root->largest_order != NULL) {
+        count_nodes(counter, root->largest_order);
+    }
+
+    // This will also traverse the various trees
+    if (root->ptr.next_largest_order != NULL) {
+        count_nodes(counter, root->ptr.next_largest_order);
+    }
+}
+
+uint64_t count_nodes_heap(vieter_heap *heap) {
+    uint64_t counter = 0;
+
+    if (heap->tree != NULL) {
+        count_nodes(&counter, heap->tree);
+    }
+
+    return counter;
+}
+
+void test_insert() {
+    vieter_heap *heap = vieter_heap_init();
+    TEST_SIZE(heap, 0);
+
+    void *data;
+
+    for (uint64_t i = 50; i > 0; i--) {
+        vieter_heap_insert(heap, i, (void *)i);
+        TEST_SIZE(heap, (uint64_t)51 - i);
+        TEST_CHECK(count_nodes_heap(heap) == (uint64_t)51 - i);
+
+        data = 0;
+
+        TEST_CHECK(vieter_heap_peek(&data, heap) == vieter_heap_ok);
+        TEST_CHECK_(data == (void *)i, "%lX == %lX", (uint64_t)data, i);
+    }
+
+    vieter_heap_free(heap);
+}
+
+void test_insert_random() {
+    srand(1);
+
+    vieter_heap *heap = vieter_heap_init();
+    TEST_SIZE(heap, 0);
+
+    uint64_t num = rand();
+    uint64_t smallest = num;
+
+    void *data = NULL;
+
+    for (uint64_t i = 0; i < 5000; i++) {
+        vieter_heap_insert(heap, num, (void *)num);
+        TEST_SIZE(heap, i + 1);
+        TEST_CHECK(count_nodes_heap(heap) == (uint64_t)i + 1);
+
+        if (num < smallest) {
+            smallest = num;
+        }
+
+        TEST_CHECK(vieter_heap_peek(&data, heap) == vieter_heap_ok);
+        TEST_CHECK(data == (void *)smallest);
+
+        data = NULL;
+
+        num = rand();
+    }
+
+    vieter_heap_free(heap);
+}
+
+void test_pop() {
+    const uint64_t n = 500;
+
+    vieter_heap *heap = vieter_heap_init();
+    TEST_SIZE(heap, 0);
+
+    void *data;
+
+    for (uint64_t i = n; i > 0; i--) {
+        vieter_heap_insert(heap, i, (void *)i);
+        TEST_SIZE(heap, (uint64_t)n + 1 - i);
+        TEST_CHECK(count_nodes_heap(heap) == (uint64_t)n + 1 - i);
+
+        TEST_CHECK(vieter_heap_peek(&data, heap) == vieter_heap_ok);
+        TEST_CHECK(data == (void*)i);
+    }
+
+    data = NULL;
+
+    for (uint64_t i = 1; i <= n; i++) {
+        TEST_CHECK(vieter_heap_pop(&data, heap) == vieter_heap_ok);
+        TEST_CHECK(data == (void*)i);
+        TEST_SIZE(heap, (uint64_t)n - i);
+    }
+
+    vieter_heap_free(heap);
+}
+
+int uint64_t_compare(const void *a, const void *b) {
+    if ((*(uint64_t *)a) < (*(uint64_t *)b)) {
+        return -1;
+    } else if ((*(uint64_t *)a) > (*(uint64_t *)b)) {
+        return 1;
+    } else {
+        return 0;
+    }
+}
+
+void test_pop_random() {
+    const uint64_t n = 500;
+
+    srand(0);
+
+    vieter_heap *heap = vieter_heap_init();
+
+    uint64_t *numbers = malloc(n * sizeof(uint64_t));
+    uint64_t num;
+
+    for (uint64_t i = 0; i < n; i++) {
+        num = rand();
+        vieter_heap_insert(heap, num, (void *)num);
+        TEST_SIZE(heap, i + 1);
+        TEST_CHECK(count_nodes_heap(heap) == i + 1);
+
+        numbers[i] = num;
+    }
+
+
+    qsort(numbers, n, sizeof(uint64_t), uint64_t_compare);
+
+    void *data = NULL;
+
+    for (uint64_t i = 0; i < n; i++) {
+        TEST_CHECK(vieter_heap_peek(&data, heap) == vieter_heap_ok);
+        TEST_CHECK_(data == (void *)numbers[i], "peek %lx == %lx", (uint64_t)data, numbers[i]);
+
+        data = NULL;
+
+        TEST_CHECK(vieter_heap_pop(&data, heap) == vieter_heap_ok);
+        TEST_CHECK_(data == (void *)numbers[i], "pop %lx == %lx", (uint64_t)data, numbers[i]);
+        TEST_SIZE(heap, n - i - 1);
+        TEST_CHECK(count_nodes_heap(heap) == n - i - 1);
+
+        // Assure each size is also a valid heap after inserting
+        vieter_heap_insert(heap, numbers[i], (void *)numbers[i]);
+        TEST_SIZE(heap, n - i);
+        TEST_CHECK(count_nodes_heap(heap) == n - i);
+
+        data = NULL;
+
+        TEST_CHECK(vieter_heap_pop(&data, heap) == vieter_heap_ok);
+        TEST_CHECK_(data == (void *)numbers[i], "pop %lx == %lx", (uint64_t)data, numbers[i]);
+        TEST_SIZE(heap, n - i - 1);
+        TEST_CHECK(count_nodes_heap(heap) == n - i - 1);
+    }
+
+    vieter_heap_free(heap);
+    free(numbers);
+}
+
+TEST_LIST = {
+    {"heap init", test_init},
+    {"heap insert", test_insert},
+    {"heap insert random", test_insert_random},
+    {"heap pop", test_pop},
+    {"heap pop random", test_pop_random},
+    {NULL, NULL}
+};

test/heap/test_merge.c

@@ -0,0 +1,28 @@
+#include "acutest.h"
+#include "vieter_heap.h"
+#include "vieter_heap_tree.h"
+#include <stdlib.h>
+
+void test_merge_same_order() {
+    vieter_heap_node *root_a = vieter_heap_node_init();
+    root_a->key = 1;
+    root_a->order = 0;
+
+    vieter_heap_node *root_b = vieter_heap_node_init();
+    root_b->key = 2;
+    root_b->order = 0;
+
+    vieter_heap_node *merged = vieter_heap_tree_merge_same_order(root_a, root_b);
+
+    TEST_CHECK(merged == root_a);
+    TEST_CHECK(merged->key == 1);
+    TEST_CHECK(merged->largest_order == root_b);
+    TEST_CHECK(merged->ptr.next_largest_order == NULL);
+
+    vieter_heap_tree_free(merged);
+}
+
+TEST_LIST = {
+    {"heap merge same order", test_merge_same_order},
+    {NULL, NULL}
+};

test/tree/test_balancing.c

@@ -0,0 +1,71 @@
+#include "acutest.h"
+#include "vieter_tree_internal.h"
+#include "vieter_tree_node.h"
+#include "vieter_tree_balancing.h"
+
+// This uses the examples from wikipedia
+// https://en.wikipedia.org/wiki/Tree_rotation
+
+void test_rotate_right() {
+    vieter_tree_node *a = vieter_tree_node_init();
+    vieter_tree_node *b = vieter_tree_node_init();
+    vieter_tree_node *p = vieter_tree_node_init();
+
+    vieter_tree_node_set_child(p, a, false);
+    vieter_tree_node_set_child(p, b, true);
+
+    vieter_tree_node *c = vieter_tree_node_init();
+    vieter_tree_node *q = vieter_tree_node_init();
+
+    vieter_tree_node_set_child(q, p, false);
+    vieter_tree_node_set_child(q, c, true);
+
+    vieter_tree_node *new_root = vieter_tree_node_rotate(q, true);
+
+    TEST_CHECK(new_root == p);
+    TEST_CHECK(new_root->children[0] == a);
+    TEST_CHECK(new_root->children[1] == q);
+    TEST_CHECK(new_root->children[1]->children[0] == b);
+    TEST_CHECK(new_root->children[1]->children[1] == c);
+
+    vieter_tree_node_free(a);
+    vieter_tree_node_free(b);
+    vieter_tree_node_free(p);
+    vieter_tree_node_free(c);
+    vieter_tree_node_free(q);
+}
+
+void test_rotate_left() {
+    vieter_tree_node *b = vieter_tree_node_init();
+    vieter_tree_node *c = vieter_tree_node_init();
+    vieter_tree_node *q = vieter_tree_node_init();
+
+    vieter_tree_node_set_child(q, b, false);
+    vieter_tree_node_set_child(q, c, true);
+
+    vieter_tree_node *a = vieter_tree_node_init();
+    vieter_tree_node *p = vieter_tree_node_init();
+
+    vieter_tree_node_set_child(p, a, false);
+    vieter_tree_node_set_child(p, q, true);
+
+    vieter_tree_node *new_root = vieter_tree_node_rotate(p, false);
+
+    TEST_CHECK(new_root == q);
+    TEST_CHECK(new_root->children[0] == p);
+    TEST_CHECK(new_root->children[1] == c);
+    TEST_CHECK(new_root->children[0]->children[0] == a);
+    TEST_CHECK(new_root->children[0]->children[1] == b);
+
+    vieter_tree_node_free(a);
+    vieter_tree_node_free(b);
+    vieter_tree_node_free(p);
+    vieter_tree_node_free(c);
+    vieter_tree_node_free(q);
+}
+
+TEST_LIST = {
+    {"tree rotate right", test_rotate_right},
+    {"tree rotate left", test_rotate_left},
+    {NULL, NULL}
+};

test/tree/test_tree.c

@@ -0,0 +1,72 @@
+#include "acutest.h"
+#include "vieter_tree_internal.h"
+
+#define TEST_SIZE(tree, size) \
+    TEST_CHECK(vieter_tree_size(tree) == size); \
+    TEST_MSG("Size: %zu", vieter_tree_size(tree))
+
+void test_init() {
+    vieter_tree *tree = vieter_tree_init();
+    TEST_CHECK(tree != NULL);
+    TEST_SIZE(tree, 0);
+    vieter_tree_free(tree);
+}
+
+void test_insert() {
+    vieter_tree *tree = vieter_tree_init();
+
+    for (uint64_t i = 0; i < 250; i++) {
+        TEST_CHECK(vieter_tree_insert(tree, i, (void *)i) == vieter_tree_ok);
+        TEST_SIZE(tree, i + 1);
+        TEST_CHECK(vieter_tree_validate(tree));
+    }
+
+    vieter_tree_iterator *iter = vieter_tree_iterator_from(tree);
+
+    void *out = NULL;
+
+    for (uint64_t i = 0; i < 250; i++) {
+        TEST_CHECK(vieter_tree_search(&out, tree, i) == vieter_tree_ok);
+        TEST_CHECK(out == (void *)i);
+        TEST_CHECK(vieter_tree_insert(tree, i, NULL) == vieter_tree_already_present);
+        TEST_CHECK(vieter_tree_search(&out, tree, i) == vieter_tree_ok);
+
+        out = NULL;
+
+        TEST_CHECK(vieter_tree_iterator_next(&out, iter) == vieter_tree_ok);
+        TEST_CHECK(out == (void *)i);
+    }
+
+    TEST_CHECK(vieter_tree_iterator_next(&out, iter) == vieter_tree_iterator_done);
+
+    vieter_tree_iterator_free(&iter);
+    vieter_tree_free(tree);
+}
+
+void test_remove() {
+    vieter_tree *tree = vieter_tree_init();
+
+    for (uint64_t i = 0; i < 250; i++) {
+        TEST_CHECK(vieter_tree_insert(tree, i, NULL) == vieter_tree_ok);
+        TEST_CHECK(vieter_tree_validate(tree));
+    }
+
+    void *out;
+
+    for (uint64_t i = 0; i < 250; i++) {
+        TEST_CHECK(vieter_tree_search(&out, tree, i) == vieter_tree_ok);
+        TEST_CHECK(vieter_tree_remove(&out, tree, i) == vieter_tree_ok);
+        TEST_CHECK(vieter_tree_validate(tree));
+        TEST_CHECK(vieter_tree_search(&out, tree, i) == vieter_tree_not_present);
+        TEST_SIZE(tree, 250 - i - 1);
+    }
+
+    vieter_tree_free(tree);
+}
+
+TEST_LIST = {
+    {"tree init", test_init},
+    {"tree insert", test_insert},
+    {"tree remove", test_remove},
+    {NULL, NULL}
+};

test/tree/test_tree_random.c

@@ -0,0 +1,59 @@
+#include "acutest.h"
+#include "vieter_tree_internal.h"
+
+#define TEST_SIZE(tree, size) \
+    TEST_CHECK(vieter_tree_size(tree) == size); \
+    TEST_MSG("Size: %zu", vieter_tree_size(tree))
+
+int uint64_t_compare(const void *a, const void *b) {
+    if ((*(uint64_t *)a) < (*(uint64_t *)b)) {
+        return -1;
+    } else if ((*(uint64_t *)a) > (*(uint64_t *)b)) {
+        return 1;
+    } else {
+        return 0;
+    }
+}
+
+void test_insert_random() {
+    const uint64_t n = 1000;
+    srand(0);
+
+    vieter_tree *tree = vieter_tree_init();
+
+    uint64_t *numbers = malloc(n * sizeof(uint64_t));
+    uint64_t num;
+    void *out = NULL;
+
+    for (uint64_t i = 0; i < n; i++) {
+        num = rand();
+        vieter_tree_insert(tree, num, (void *)num);
+        TEST_SIZE(tree, i + 1);
+        TEST_CHECK(vieter_tree_validate(tree));
+        TEST_CHECK(vieter_tree_search(&out, tree, num) == vieter_tree_ok);
+        TEST_CHECK(out == (void *)num);
+
+        out = NULL;
+
+        numbers[i] = num;
+    }
+
+    qsort(numbers, n, sizeof(uint64_t), uint64_t_compare);
+
+    vieter_tree_iterator *iter = vieter_tree_iterator_from(tree);
+    out = NULL;
+
+    for (uint64_t i = 0; i < n; i++) {
+        TEST_CHECK(vieter_tree_iterator_next(&out, iter) == vieter_tree_ok);
+        TEST_CHECK(out == (void *)numbers[i]);
+    }
+
+    free(numbers);
+    vieter_tree_iterator_free(&iter);
+    vieter_tree_free(tree);
+}
+
+TEST_LIST = {
+    {"tree insert random", test_insert_random},
+    {NULL, NULL}
+};