commit 392c55fd882f4efabf9cca102e87d3bec883e81a
Author: rhuibertsjr <rhuibertsjr@gmail.com>
Date:   Tue Apr 30 20:04:44 2024 +0200

    Added: Initial project layout

diff --git a/.gitignore b/.gitignore
new file mode 100644
index 0000000..d163863
--- /dev/null
+++ b/.gitignore
@@ -0,0 +1 @@
+build/
\ No newline at end of file
diff --git a/build.sh b/build.sh
new file mode 100644
index 0000000..31e42bf
--- /dev/null
+++ b/build.sh
@@ -0,0 +1,21 @@
+#!/bin/bash
+
+# Creating lay-out
+cd "$(dirname "$0")"
+
+mkdir -p build/
+
+cd build/
+
+# Building flags
+CFLAGS="-g -Wall -Wextra -O0 --std=gnu99"
+LDFLAGS="-lc -pthread"
+
+# Building executable...
+echo -e "\nBuilding posix-threading-synchronisation research..."
+
+time gcc -x c $CFLAGS $DEFINES ../src/main.c -o ./gazoo_test_environment $LDFLAGS
+
+echo ""
+
+cd ..
diff --git a/src/arena.c b/src/arena.c
new file mode 100644
index 0000000..edc7a29
--- /dev/null
+++ b/src/arena.c
@@ -0,0 +1,91 @@
+internal Arena *
+arena_initialize(u64 size, b8 growable)
+{
+  Arena *result = 0;
+  void *backing_buffer = platform_memory_reserve(size);
+
+  if (backing_buffer != NULL)
+  {
+    platform_memory_commit(backing_buffer, ARENA_INITIAL_COMMIT_SIZE);
+
+    result = (Arena*) backing_buffer;
+    result->backing_buffer = backing_buffer;
+    result->current = result;
+
+    // rhjr: immutable arena header
+    result->base_pos =
+      memory_align_power_of_two(sizeof(Arena), ARENA_DEFAULT_ALIGNMENT);
+    result->offset = result->base_pos;
+
+    result->growable = growable;
+    result->size = size;
+  }
+
+  // rhjr: arenas should be instantiated early on in the programs lifetime, that
+  //       is why this assertion will also be used in production.
+  ASSERT(result != 0);
+  return result;
+}
+
+internal Arena *
+arena_initialize_default()
+{
+  Arena *result = arena_initialize(ARENA_DEFAULT_RESERVE_SIZE, 1);
+  return result;
+}
+
+internal void *
+arena_allocate(Arena *arena, u64 size)
+{
+  Arena *current = arena->current;
+  u64 pos_mem =
+    memory_align_power_of_two(current->offset, ARENA_DEFAULT_ALIGNMENT);
+  u64 pos_new = current->offset + size;
+
+  if (current->size < pos_new && current->growable)
+  {
+    Arena *new_memory_bock;
+
+    if (size > ARENA_DEFAULT_RESERVE_SIZE)
+    {
+      // rhjr: TODO add support for allocations larger then a single page, in a
+      //       single allocation call.
+      ASSERT(0);
+    }
+    else
+    {
+      new_memory_bock = arena_initialize_default();
+
+      if (new_memory_bock)
+      {
+        sll_stack_push(arena->current, new_memory_bock, prev);
+
+        current = new_memory_bock;
+
+        pos_mem =
+          memory_align_power_of_two(current->offset, ARENA_DEFAULT_ALIGNMENT);
+        pos_new = current->offset + size;
+      }
+
+    }
+
+  }
+
+  void *memory = (void*)((u64) current->backing_buffer + pos_mem);
+  arena->offset = pos_new;
+
+  platform_memory_commit(memory, size);
+  memset(memory, 0, size);
+
+  return memory;
+}
+
+internal void
+arena_release(Arena *arena)
+{
+  for (Arena *node = arena->current, *prev = 0; node != 0; node = prev)
+  {
+    prev = node->prev;
+    platform_memory_release(node, node->size);
+  }
+}
diff --git a/src/arena.h b/src/arena.h
new file mode 100644
index 0000000..d09a304
--- /dev/null
+++ b/src/arena.h
@@ -0,0 +1,40 @@
+#ifndef ARENA_H
+#define ARENA_H
+
+#define ARENA_INITIAL_COMMIT_SIZE sizeof(struct Arena)
+#define ARENA_DEFAULT_ALIGNMENT   8
+
+#ifndef ARENA_DEFAULT_RESERVE_SIZE
+#  define ARENA_DEFAULT_RESERVE_SIZE KB(4)
+#endif // ARENA_DEFAULT_RESERVE_SIZE
+
+typedef struct Arena Arena;
+struct Arena {
+  struct Arena *current;
+  struct Arena *prev;
+  u64 *backing_buffer;
+  u64 base_pos;
+  u64 offset;
+  u64 size;
+  b8 growable;
+};
+
+STATIC_ASSERT(ARENA_INITIAL_COMMIT_SIZE <= ARENA_DEFAULT_RESERVE_SIZE,
+              arena_default_allocation_size);
+
+//= rhjr: arenas
+
+internal Arena * arena_initialize(u64 size, b8 growable);
+internal Arena * arena_initialize_default();
+
+internal void *  arena_allocate(Arena *arena, u64 size);
+
+#define arena_push_array(arena, type, count) \
+  (type*) arena_allocate((arena), sizeof(type) * (count))
+
+#define arena_push(arena, type) \
+  (type*) arena_allocate((arena), sizeof(type))
+
+internal void arena_release(Arena *arena);
+
+#endif // ARENA_H
diff --git a/src/base.h b/src/base.h
new file mode 100644
index 0000000..4956525
--- /dev/null
+++ b/src/base.h
@@ -0,0 +1,49 @@
+#ifndef BASE_H
+#define BASE_H
+
+#include <stdio.h>
+#include <stdint.h>
+#include <stdlib.h>
+#include <string.h>
+
+#define internal static
+
+typedef uint8_t  u8;
+typedef uint16_t u16;
+typedef uint32_t u32;
+typedef uint64_t u64;
+
+typedef int8_t  i8;
+typedef int16_t i16;
+typedef int32_t i32;
+typedef int64_t i64;
+
+typedef uint8_t  b8;
+typedef uint8_t  b16;
+typedef uint8_t  b32;
+typedef uint8_t  b64;
+
+#define KB(b) ((b) << 10)
+#define MB(b) ((b) << 20)
+
+#define Glue_(A,B) A##B
+#define Glue(A,B) Glue_(A,B)
+
+#define STATEMENT(S) do{ S } while(0)
+#define ASSERT(c) STATEMENT( if (!(c)){ (*(volatile int*)0 = 0); } )
+#define STATIC_ASSERT(c,l) typedef u8 Glue(l,__LINE__) [(c)?1:-1]
+
+//= rhjr: linkedlist helpers
+
+#define sll_stack_push(f,n,next) ((n)->next=(f), (f)=(n))
+
+//= rhjr: memory helpers
+
+#define memory_align_power_of_two(x,b)     (((x) + (b) - 1)&(~((b) - 1)))
+
+#define memory_zero(s,z)       memset((s), 0, (z))
+#define memory_zero_struct(s)  memory_zero((s), sizeof(*(s)))
+
+#define memory_copy(dst, src, length) memmove((dst), (src), (length))
+
+#endif // BASE_H
diff --git a/src/linux_platform.c b/src/linux_platform.c
new file mode 100644
index 0000000..a3a1635
--- /dev/null
+++ b/src/linux_platform.c
@@ -0,0 +1,32 @@
+
+internal void *
+platform_memory_reserve(u64 size)
+{
+  void* result = mmap(0, size, PROT_NONE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0);
+  return result;
+}
+
+#define PAGE_SIZE sysconf(_SC_PAGESIZE)
+
+internal b8
+platform_memory_commit(void *ptr, u64 size)
+{
+  void *page_aligned_ptr =
+    (void *)(((uintptr_t)ptr + PAGE_SIZE - 1) & ~(PAGE_SIZE - 1));
+  mprotect(page_aligned_ptr, size, PROT_READ|PROT_WRITE);
+  return 1;
+
+}
+
+internal void
+platform_memory_decommit(void *ptr, u64 size)
+{
+  madvise(ptr, size, MADV_DONTNEED);
+  mprotect(ptr, size, PROT_NONE);
+}
+
+internal void
+platform_memory_release(void *ptr, u64 size)
+{
+  munmap(ptr, size);
+}
diff --git a/src/linux_platform.h b/src/linux_platform.h
new file mode 100644
index 0000000..b6a5ceb
--- /dev/null
+++ b/src/linux_platform.h
@@ -0,0 +1,22 @@
+#ifndef LINUX_PLATFORM_H
+#define LINUX_PLATFORM_H
+
+#include <sys/mman.h>
+#include <sys/stat.h>
+
+#include <unistd.h>
+#include <fcntl.h>
+
+//= rhjr: multi-threading
+
+#include <pthread.h>
+#include <sys/syscall.h>
+
+//= rhjr: platform memory management
+
+internal void * platform_memory_reserve(u64 size);
+internal b8     platform_memory_commit(void *ptr, u64 size);
+internal void   platform_memory_decommit(void *ptr, u64 size);
+internal void   platform_memory_release(void *ptr, u64 size);
+
+#endif // LINUX_PLATFORM_H
diff --git a/src/main.c b/src/main.c
new file mode 100644
index 0000000..c273634
--- /dev/null
+++ b/src/main.c
@@ -0,0 +1,22 @@
+#include "base.h"
+#include "arena.h"
+#include "linux_platform.h"
+#include "string.h"
+
+#include "arena.c"
+#include "linux_platform.c"
+#include "string.c"
+
+int
+main(void)
+{
+  Arena *arena = arena_initialize_default();
+
+  /* lifetime of objects */
+  String8 string = str8_lit("Hello world");
+
+  print_str8(string);
+
+  arena_release(arena);
+  return 0;
+}
diff --git a/src/string.c b/src/string.c
new file mode 100644
index 0000000..ca9e06e
--- /dev/null
+++ b/src/string.c
@@ -0,0 +1,20 @@
+internal String8
+str8_initialize(u8 *cstring, u64 length)
+{
+  String8 result = { cstring, length };
+  return result;
+}
+
+internal String8
+str8_range(u8 *first, u8 *opl) {
+  String8 result = { first, (u64)(opl - first) };
+  return result;
+}
+
+internal String8
+str8_from_cstring(u8 *cstring) {
+  u8 *ptr = cstring;
+  for (;*ptr != 0; ptr += 1);
+  String8 result = str8_range(cstring, ptr);
+  return result;
+}
diff --git a/src/string.h b/src/string.h
new file mode 100644
index 0000000..a336377
--- /dev/null
+++ b/src/string.h
@@ -0,0 +1,23 @@
+#ifndef STRING_H
+#define STRING_H 1
+
+typedef struct String8 String8;
+struct String8
+{
+  u8 *str;
+  u64 length;
+};
+
+internal String8 str8_initialize(u8 *cstring, u64 length);
+#define str8_lit(cstring)                                                      \
+  str8_initialize((u8*)(cstring), sizeof(cstring) - 1)
+
+#define str8_lit_comp(cstring)                                                 \
+  {(u8*)(cstring), sizeof(cstring) - 1}
+
+//= rhjr: helper macros
+
+#define print_str8(str8)                                                       \
+  printf("%.*s\n", (i32) str8.length, str8.str)
+
+#endif // STRING_H
diff --git a/start.sh b/start.sh
new file mode 100644
index 0000000..60b4fc8
--- /dev/null
+++ b/start.sh
@@ -0,0 +1,15 @@
+#!/bin/bash
+
+cd "$(dirname "$0")"
+mkdir -p build/
+
+cd build/
+
+# Running executable
+echo ""
+
+./gazoo_test_environment
+
+echo ""
+
+cd ..