Dynamic heap memory allocator library written in C.
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Full memory allocation API: Includes
xd_malloc(),xd_calloc(),xd_realloc(), andxd_free(). -
Thread-safe operations: Safe to use in multi-threaded environments.
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Small metadata overhead: Each memory block contains a small header (8 or 16 bytes based on the architecture) used for efficient allocation and deallocation.
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Dynamic free list: Tracks free memory blocks using a doubly-linked list with pointers embedded directly in the free blocks (no additional memory overhead).
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Efficient memory reuse: Minimizes fragmentation by splitting blocks larger than the requested size and coalescing adjacent free blocks in constant time O(1).
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Page-aligned arenas: Acquires memory from the OS in 4 KB chunks to reduce system call overhead.
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Isolated memory arenas: Separates each memory arena with protective boundaries (fenceposts) to prevent cross-arena corruption.
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Heap corruption detection: Detects external heap break (
brk) change and disables the allocator to avoid undefined behavior. -
8-byte alignment: Ensures memory blocks are always aligned to 8-bytes for compatibility.
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Configurable allocation policy: Uses first-fit by default, supports best-fit by defining the macro
XD_USE_BEST_FIT. -
Architecture support: Works on both 32-bit and 64-bit systems.
The allocator has been tested and verified to work correctly on both 32-bit and 64-bit systems. The repository includes automated test cases, and additional manual tests have also been performed to ensure reliability.
The screenshot below shows a successful test run using:
make run_tests
Suggestions, improvements, and bug reports are welcome!
Feel free to open an issue or submit a pull request.
This project is released under the MIT License. See LICENSE for details.