commit 90dfaca10eee546284a69d183b03b35e7cd6ccee Author: Kevin Alavik Date: Sun Jun 1 23:58:58 2025 +0200 init diff --git a/.gitignore b/.gitignore new file mode 100644 index 0000000..b812448 --- /dev/null +++ b/.gitignore @@ -0,0 +1,8 @@ +* + +!.gitignore +!LICENSE +!examples/ +!examples/arena.c +!examples/arena.cpp +!arena.h \ No newline at end of file diff --git a/LICENSE b/LICENSE new file mode 100644 index 0000000..38a7c2f --- /dev/null +++ b/LICENSE @@ -0,0 +1,201 @@ + Apache License + Version 2.0, January 2004 + http://www.apache.org/licenses/ + + TERMS AND CONDITIONS FOR USE, REPRODUCTION, AND DISTRIBUTION + + 1. Definitions. + + "License" shall mean the terms and conditions for use, reproduction, + and distribution as defined by Sections 1 through 9 of this document. + + "Licensor" shall mean the copyright owner or entity authorized by + the copyright owner that is granting the License. + + "Legal Entity" shall mean the union of the acting entity and all + other entities that control, are controlled by, or are under common + control with that entity. For the purposes of this definition, + "control" means (i) the power, direct or indirect, to cause the + direction or management of such entity, whether by contract or + otherwise, or (ii) ownership of fifty percent (50%) or more of the + outstanding shares, or (iii) beneficial ownership of such entity. + + "You" (or "Your") shall mean an individual or Legal Entity + exercising permissions granted by this License. + + "Source" form shall mean the preferred form for making modifications, + including but not limited to software source code, documentation + source, and configuration files. + + "Object" form shall mean any form resulting from mechanical + transformation or translation of a Source form, including but + not limited to compiled object code, generated documentation, + and conversions to other media types. + + "Work" shall mean the work of authorship, whether in Source or + Object form, made available under the License, as indicated by a + copyright notice that is included in or attached to the work + (an example is provided in the Appendix below). + + "Derivative Works" shall mean any work, whether in Source or Object + form, that is based on (or derived from) the Work and for which the + editorial revisions, annotations, elaborations, or other modifications + represent, as a whole, an original work of authorship. For the purposes + of this License, Derivative Works shall not include works that remain + separable from, or merely link (or bind by name) to the interfaces of, + the Work and Derivative Works thereof. + + "Contribution" shall mean any work of authorship, including + the original version of the Work and any modifications or additions + to that Work or Derivative Works thereof, that is intentionally + submitted to Licensor for inclusion in the Work by the copyright owner + or by an individual or Legal Entity authorized to submit on behalf of + the copyright owner. For the purposes of this definition, "submitted" + means any form of electronic, verbal, or written communication sent + to the Licensor or its representatives, including but not limited to + communication on electronic mailing lists, source code control systems, + and issue tracking systems that are managed by, or on behalf of, the + Licensor for the purpose of discussing and improving the Work, but + excluding communication that is conspicuously marked or otherwise + designated in writing by the copyright owner as "Not a Contribution." + + "Contributor" shall mean Licensor and any individual or Legal Entity + on behalf of whom a Contribution has been received by Licensor and + subsequently incorporated within the Work. + + 2. Grant of Copyright License. Subject to the terms and conditions of + this License, each Contributor hereby grants to You a perpetual, + worldwide, non-exclusive, no-charge, royalty-free, irrevocable + copyright license to reproduce, prepare Derivative Works of, + publicly display, publicly perform, sublicense, and distribute the + Work and such Derivative Works in Source or Object form. + + 3. Grant of Patent License. Subject to the terms and conditions of + this License, each Contributor hereby grants to You a perpetual, + worldwide, non-exclusive, no-charge, royalty-free, irrevocable + (except as stated in this section) patent license to make, have made, + use, offer to sell, sell, import, and otherwise transfer the Work, + where such license applies only to those patent claims licensable + by such Contributor that are necessarily infringed by their + Contribution(s) alone or by combination of their Contribution(s) + with the Work to which such Contribution(s) was submitted. If You + institute patent litigation against any entity (including a + cross-claim or counterclaim in a lawsuit) alleging that the Work + or a Contribution incorporated within the Work constitutes direct + or contributory patent infringement, then any patent licenses + granted to You under this License for that Work shall terminate + as of the date such litigation is filed. + + 4. Redistribution. You may reproduce and distribute copies of the + Work or Derivative Works thereof in any medium, with or without + modifications, and in Source or Object form, provided that You + meet the following conditions: + + (a) You must give any other recipients of the Work or + Derivative Works a copy of this License; and + + (b) You must cause any modified files to carry prominent notices + stating that You changed the files; and + + (c) You must retain, in the Source form of any Derivative Works + that You distribute, all copyright, patent, trademark, and + attribution notices from the Source form of the Work, + excluding those notices that do not pertain to any part of + the Derivative Works; and + + (d) If the Work includes a "NOTICE" text file as part of its + distribution, then any Derivative Works that You distribute must + include a readable copy of the attribution notices contained + within such NOTICE file, excluding those notices that do not + pertain to any part of the Derivative Works, in at least one + of the following places: within a NOTICE text file distributed + as part of the Derivative Works; within the Source form or + documentation, if provided along with the Derivative Works; or, + within a display generated by the Derivative Works, if and + wherever such third-party notices normally appear. The contents + of the NOTICE file are for informational purposes only and + do not modify the License. You may add Your own attribution + notices within Derivative Works that You distribute, alongside + or as an addendum to the NOTICE text from the Work, provided + that such additional attribution notices cannot be construed + as modifying the License. + + You may add Your own copyright statement to Your modifications and + may provide additional or different license terms and conditions + for use, reproduction, or distribution of Your modifications, or + for any such Derivative Works as a whole, provided Your use, + reproduction, and distribution of the Work otherwise complies with + the conditions stated in this License. + + 5. Submission of Contributions. Unless You explicitly state otherwise, + any Contribution intentionally submitted for inclusion in the Work + by You to the Licensor shall be under the terms and conditions of + this License, without any additional terms or conditions. + Notwithstanding the above, nothing herein shall supersede or modify + the terms of any separate license agreement you may have executed + with Licensor regarding such Contributions. + + 6. Trademarks. This License does not grant permission to use the trade + names, trademarks, service marks, or product names of the Licensor, + except as required for reasonable and customary use in describing the + origin of the Work and reproducing the content of the NOTICE file. + + 7. Disclaimer of Warranty. Unless required by applicable law or + agreed to in writing, Licensor provides the Work (and each + Contributor provides its Contributions) on an "AS IS" BASIS, + WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or + implied, including, without limitation, any warranties or conditions + of TITLE, NON-INFRINGEMENT, MERCHANTABILITY, or FITNESS FOR A + PARTICULAR PURPOSE. You are solely responsible for determining the + appropriateness of using or redistributing the Work and assume any + risks associated with Your exercise of permissions under this License. + + 8. Limitation of Liability. In no event and under no legal theory, + whether in tort (including negligence), contract, or otherwise, + unless required by applicable law (such as deliberate and grossly + negligent acts) or agreed to in writing, shall any Contributor be + liable to You for damages, including any direct, indirect, special, + incidental, or consequential damages of any character arising as a + result of this License or out of the use or inability to use the + Work (including but not limited to damages for loss of goodwill, + work stoppage, computer failure or malfunction, or any and all + other commercial damages or losses), even if such Contributor + has been advised of the possibility of such damages. + + 9. Accepting Warranty or Additional Liability. While redistributing + the Work or Derivative Works thereof, You may choose to offer, + and charge a fee for, acceptance of support, warranty, indemnity, + or other liability obligations and/or rights consistent with this + License. However, in accepting such obligations, You may act only + on Your own behalf and on Your sole responsibility, not on behalf + of any other Contributor, and only if You agree to indemnify, + defend, and hold each Contributor harmless for any liability + incurred by, or claims asserted against, such Contributor by reason + of your accepting any such warranty or additional liability. + + END OF TERMS AND CONDITIONS + + APPENDIX: How to apply the Apache License to your work. + + To apply the Apache License to your work, attach the following + boilerplate notice, with the fields enclosed by brackets "[]" + replaced with your own identifying information. (Don't include + the brackets!) The text should be enclosed in the appropriate + comment syntax for the file format. We also recommend that a + file or class name and description of purpose be included on the + same "printed page" as the copyright notice for easier + identification within third-party archives. + + Copyright 2025 Piraterna + + Licensed under the Apache License, Version 2.0 (the "License"); + you may not use this file except in compliance with the License. + You may obtain a copy of the License at + + http://www.apache.org/licenses/LICENSE-2.0 + + Unless required by applicable law or agreed to in writing, software + distributed under the License is distributed on an "AS IS" BASIS, + WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. + See the License for the specific language governing permissions and + limitations under the License. diff --git a/arena.h b/arena.h new file mode 100644 index 0000000..9d6c996 --- /dev/null +++ b/arena.h @@ -0,0 +1,397 @@ +/* + * ============================================================================ + * arena.h - Minimal, Portable Freestanding Arena Allocator + * ============================================================================ + * + * Overview: + * This header provides a simple, drop-in arena allocator suitable for + * freestanding or embedded environments where standard malloc/free may not + * be available or desirable. It supports both dynamic memory allocation and + * a static buffer fallback for environments without dynamic memory. + * + * Features: + * - Dynamic arena allocation (default): allocates arena memory via + * configurable malloc/free macros. + * - Static arena allocation (#define ARENA_NOALLOC): uses fixed-size + * static buffer specified by #define ARENA_SIZE. + * - Optional thread safety with user-defined ARENA_LOCK() / ARENA_UNLOCK(). + * - Simple API: init, alloc, alloc_aligned, reset, destroy, and error reporting. + * - No individual free calls; only whole-arena reset or destroy. + * - Optional namespace support for C++ via ARENA_NAMESPACE. + * + * Usage Examples: + * ------------- + * // 1. Dynamic arena allocation (default mode): + * #define ARENA_IMPLEMENTATION + * #include "arena.h" + * + * arena_t *a = arena_init(4096); // Create 4KB arena + * if (!a) { puts(arena_error(NULL)); exit(1); } + * + * void *p = arena_alloc(a, 128); // Allocate 128 bytes + * if (!p) { puts(arena_error(a)); } + * + * arena_reset(a); // Reset arena for reuse + * + * arena_destroy(a); // Free arena memory + * + * // 2. Static arena (no malloc/free): + * #define ARENA_NOALLOC + * #define ARENA_SIZE 8192 + * #define ARENA_IMPLEMENTATION + * #include "arena.h" + * + * arena_t *a = arena_init(); // No size needed + * if (!a) { puts(arena_error(NULL)); exit(1); } + * + * void *p = arena_alloc(a, 128); + * if (!p) { puts(arena_error(a)); } + * + * arena_reset(a); // Reset arena for reuse + * // No destroy needed for static arena + * + * // 3. Thread safety (example with pthread mutex): + * #define ARENA_LOCK() pthread_mutex_lock(&lock) + * #define ARENA_UNLOCK() pthread_mutex_unlock(&lock) + * pthread_mutex_t lock = PTHREAD_MUTEX_INITIALIZER; + * + * Notes: + * ------ + * - Only whole-arena reset or destroy; no per-allocation free. + * - arena_alloc_aligned() provides aligned allocations (alignment must be + * power of two). + * - arena_error() returns last error message for debugging. + * - Configurable allocation functions via ARENA_MALLOC/ARENA_FREE macros. + * - Compatible with C and C++ (with optional namespace support). + * + * License: + * -------- + * Apache License 2.0 (see LICENSE file or + * https://www.apache.org/licenses/LICENSE-2.0) + * + * ============================================================================ + */ + +#ifndef ARENA_H +#define ARENA_H + +#ifdef __cplusplus +extern "C" +{ +#endif + + /* ============================================================================ + * Arena Structure + * ============================================================================ + */ + typedef struct arena_t + { + unsigned char *data; /* Pointer to arena memory */ + unsigned long capacity; /* Total size in bytes */ + unsigned long pos; /* Current offset / allocation position */ + const char *error; /* Last error string (per arena) */ + } arena_t; + +/* ============================================================================ + * Function Prefixing + * ============================================================================ + */ +#ifdef ARENA_NAMESPACE +#define _ARENA_PREFIX(name) name +#else +#define _ARENA_PREFIX(name) arena_##name +#endif + +/* ============================================================================ + * Thread-Safety Hooks (optional) + * ============================================================================ + */ +#ifndef ARENA_LOCK +#define ARENA_LOCK() +#endif + +#ifndef ARENA_UNLOCK +#define ARENA_UNLOCK() +#endif + +/* ============================================================================ + * Allocation Hooks (unless NOALLOC is defined) + * ============================================================================ + */ +#ifndef ARENA_NOALLOC +#ifndef ARENA_MALLOC + extern void *_arena_alloc(unsigned long); +#define ARENA_MALLOC(size) _arena_alloc(size) +#endif + +#ifndef ARENA_FREE + extern void _arena_free(void *); +#define ARENA_FREE(ptr) _arena_free(ptr) +#endif +#endif /* ARENA_NOALLOC */ + +/* ============================================================================ + * Function Declarations + * ============================================================================ + */ +#ifdef ARENA_NOALLOC + arena_t *_ARENA_PREFIX(init)(void); /* No size needed */ +#else + arena_t *_ARENA_PREFIX(init)(int size); +#endif + void *_ARENA_PREFIX(alloc)(arena_t *arena, int size); + void *_ARENA_PREFIX(alloc_aligned)(arena_t *arena, int size, int alignment); + void _ARENA_PREFIX(reset)(arena_t *arena); +#ifndef ARENA_NOALLOC + void _ARENA_PREFIX(destroy)(arena_t *arena); +#endif + const char *_ARENA_PREFIX(error)(arena_t *arena); +#ifdef __cplusplus +} /* extern "C" */ + +#ifdef ARENA_NAMESPACE +namespace arena +{ + using ::alloc; + using ::alloc_aligned; + using ::arena_t; + using ::error; + using ::init; + using ::reset; +#ifndef ARENA_NOALLOC + using ::destroy; +#endif +} +#endif /* ARENA_NAMESPACE */ +#endif /* __cplusplus */ + +#ifdef ARENA_IMPLEMENTATION + +/* ============================================================================ + * Internal default error string when arena pointer is NULL + * ============================================================================ + */ +static const char *_arena_error_global = "no error"; + +/* ============================================================================ + * arena_error - returns the last error string for the arena, or global if NULL + * ============================================================================ + */ +const char *_ARENA_PREFIX(error)(arena_t *arena) +{ + if (arena) + return arena->error ? arena->error : "no error"; + return _arena_error_global; +} + +/* ============================================================================ + * Static Arena (if NOALLOC is enabled) + * ============================================================================ + */ +#ifdef ARENA_NOALLOC +#ifndef ARENA_SIZE +#error "ARENA_SIZE must be defined when using ARENA_NOALLOC" +#endif + +static unsigned char _arena_static_data[ARENA_SIZE]; +static arena_t _arena_static = {_arena_static_data, ARENA_SIZE, 0, NULL}; +static int _arena_static_used = 0; +#endif + +/* ============================================================================ + * arena_init + * ============================================================================ + */ +#ifdef ARENA_NOALLOC +arena_t *_ARENA_PREFIX(init)(void) +{ + ARENA_LOCK(); + + if (_arena_static_used) + { + _arena_static.error = "static arena already used"; + ARENA_UNLOCK(); + return NULL; + } + + _arena_static.pos = 0; + _arena_static.error = "no error"; + _arena_static_used = 1; + + ARENA_UNLOCK(); + return &_arena_static; +} +#else +arena_t *_ARENA_PREFIX(init)(int size) +{ + ARENA_LOCK(); + + arena_t *arena = (arena_t *)ARENA_MALLOC(sizeof(arena_t)); + if (!arena) + { + _arena_error_global = "out of memory (arena struct)"; + ARENA_UNLOCK(); + return NULL; + } + + arena->data = (unsigned char *)ARENA_MALLOC(size); + if (!arena->data) + { + ARENA_FREE(arena); + _arena_error_global = "out of memory (arena data)"; + ARENA_UNLOCK(); + return NULL; + } + + arena->capacity = size; + arena->pos = 0; + arena->error = "no error"; + + ARENA_UNLOCK(); + return arena; +} +#endif + +/* ============================================================================ + * arena_alloc + * Allocates memory without alignment guarantees. + * ============================================================================ + */ +void *_ARENA_PREFIX(alloc)(arena_t *arena, int size) +{ + if (!arena) + { + _arena_error_global = "null arena"; + return NULL; + } + + if (size <= 0) + { + arena->error = "invalid allocation size"; + return NULL; + } + + ARENA_LOCK(); + + if (arena->pos + (unsigned long)size > arena->capacity) + { + arena->error = "arena overflow"; + ARENA_UNLOCK(); + return NULL; + } + + void *ptr = arena->data + arena->pos; + arena->pos += size; + arena->error = "no error"; + + ARENA_UNLOCK(); + return ptr; +} + +/* ============================================================================ + * arena_alloc_aligned + * Allocates memory with specified alignment (must be power of two). + * ============================================================================ + */ +void *_ARENA_PREFIX(alloc_aligned)(arena_t *arena, int size, int alignment) +{ + if (!arena) + { + _arena_error_global = "null arena"; + return NULL; + } + + if (size <= 0) + { + arena->error = "invalid allocation size"; + return NULL; + } + + if (alignment <= 0 || (alignment & (alignment - 1)) != 0) + { + arena->error = "alignment must be power of two"; + return NULL; + } + + ARENA_LOCK(); + + unsigned long current_addr = (unsigned long)(arena->data + arena->pos); + unsigned long offset = (alignment - (current_addr % alignment)) % alignment; + unsigned long new_pos = arena->pos + offset; + + if (new_pos + (unsigned long)size > arena->capacity) + { + arena->error = "arena overflow (aligned)"; + ARENA_UNLOCK(); + return NULL; + } + + void *ptr = arena->data + new_pos; + arena->pos = new_pos + size; + arena->error = "no error"; + + ARENA_UNLOCK(); + return ptr; +} + +/* ============================================================================ + * arena_reset - resets arena to reuse memory (pos = 0) + * ============================================================================ + */ +void _ARENA_PREFIX(reset)(arena_t *arena) +{ + if (!arena) + return; + + ARENA_LOCK(); + + arena->pos = 0; + arena->error = "no error"; + + ARENA_UNLOCK(); +} + +/* ============================================================================ + * arena_destroy - frees arena memory (only for dynamic arena) + * ============================================================================ + */ +#ifndef ARENA_NOALLOC +void _ARENA_PREFIX(destroy)(arena_t *arena) +{ + if (!arena) + return; + + ARENA_LOCK(); + + ARENA_FREE(arena->data); + ARENA_FREE(arena); + _arena_error_global = "no error"; + + ARENA_UNLOCK(); +} +#endif + +/* ============================================================================ + * arena_used - returns number of bytes currently allocated (internal) + * ============================================================================ + */ +static inline unsigned long _ARENA_PREFIX(used)(arena_t *arena) +{ + if (!arena) + return 0; + return arena->pos; +} + +/* ============================================================================ + * arena_capacity - returns total capacity of arena (internal) + * ============================================================================ + */ +static inline unsigned long _ARENA_PREFIX(capacity)(arena_t *arena) +{ + if (!arena) + return 0; + return arena->capacity; +} + +#endif /* ARENA_IMPLEMENTATION */ +#endif /* ARENA_H */ diff --git a/examples/arena.c b/examples/arena.c new file mode 100644 index 0000000..cb6e85c --- /dev/null +++ b/examples/arena.c @@ -0,0 +1,33 @@ +#include +#include +#include + +#define ARENA_IMPLEMENTATION +#define ARENA_NOALLOC +#define ARENA_SIZE 1024 + +pthread_mutex_t lock = PTHREAD_MUTEX_INITIALIZER; +#define ARENA_LOCK() pthread_mutex_lock(&lock) +#define ARENA_UNLOCK() pthread_mutex_unlock(&lock) + +#include "../arena.h" + +int main(void) +{ + arena_t *arena = arena_init(); + if (!arena) + { + fprintf(stderr, "Arena init error: %s\n", arena_error(NULL)); + return 1; + } + + // Example: allocate 128 bytes (no alignment grantees) + void *p = arena_alloc(arena, 128); + if (!p) + { + fprintf(stderr, "Arena alloc error: %s\n", arena_error(arena)); + return 1; + } + printf("Allocated 128 bytes at %p\n", p); + return 0; +}