1 files changed, 171 insertions, 0 deletions
diff --git a/src/bumpptr_alloc_always_align.c b/src/bumpptr_alloc_always_align.c
new file mode 100644
index 0000000..6cb82df
--- /dev/null
+++ b/src/bumpptr_alloc_always_align.c
@@ -0,0 +1,171 @@
+#include <assert.h>
+#include <errno.h>
+#include <stddef.h> /* NULL, size_t */
+#include <stdint.h> /* uintptr_t */
+#include <stdio.h> /* uintptr_t */
+#include <unistd.h> /* sysconf(_SC_PAGESIZE) */
+#include <string.h> /* memset */
+#include <sys/mman.h> /* memset */
+
+#define MIN_ALIGNMENT 16
+
+#ifndef MEMSIZE
+#define MEMSIZE 1024*4*1024*1024l
+#endif
+
+#define unlikely(x)     __builtin_expect((x),0)
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+__thread void* mem_start = NULL;
+__thread uintptr_t mem_end = 0;
+__thread uintptr_t ptr = 0;
+
+inline void* bump_up(size_t size, size_t align) {
+	assert(align % 2 == 0);
+
+	if (unlikely(mem_start == NULL)) {
+		mem_start = mmap(NULL, MEMSIZE, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0);
+		if(mem_start == MAP_FAILED) {
+			perror("mmap");
+			return NULL;
+		}
+		ptr = (uintptr_t)mem_start;
+		mem_end = ptr + MEMSIZE;
+	}
+
+	// align ptr;
+	uintptr_t aligned = (ptr + align - 1) & ~(align - 1);
+
+	uintptr_t new_ptr = aligned + size;
+	if (new_ptr > mem_end)
+		return NULL;
+	else {
+		ptr = new_ptr;
+		return (void*)aligned;
+	}
+}
+
+void* malloc(size_t size) {
+	return bump_up(size, MIN_ALIGNMENT);
+}
+
+void free(__attribute__ ((unused)) void* ptr) {
+}
+
+void* realloc(void* ptr, size_t size) {
+	if(ptr == NULL)
+		return malloc(size);
+
+	void* new_ptr = bump_up(size, MIN_ALIGNMENT);
+	// this may copies to much
+	memcpy(new_ptr, ptr, size);
+	return new_ptr;
+}
+
+void* memalign(size_t alignment, size_t size) {
+	return bump_up(size, alignment);
+}
+
+int posix_memalign(void **memptr, size_t alignment, size_t size)
+{
+	void *out;
+
+	if(memptr == NULL) {
+		return 22;
+	}
+
+	if((alignment % sizeof(void*)) != 0) {
+		return 22;
+	}
+
+	/* if not power of two */
+	if(!((alignment != 0) && !(alignment & (alignment - 1)))) {
+		return 22;
+	}
+
+	if(size == 0) {
+		*memptr = NULL;
+		return 0;
+	}
+
+	out = bump_up(size, alignment);
+	if(out == NULL) {
+		return 12;
+	}
+
+	*memptr = out;
+	return 0;
+}
+
+void* calloc(size_t nmemb, size_t size)
+{
+	void *out;
+	size_t fullsize = nmemb * size;
+
+	if((size != 0) && ((fullsize / size) != nmemb)) {
+		return NULL;
+	}
+	
+	out = bump_up(fullsize, MIN_ALIGNMENT);
+	if(out == NULL) {
+		return NULL;
+	}
+
+	memset(out, 0, fullsize);
+	return out;
+}
+
+void* valloc(size_t size)
+{
+	long ret = sysconf(_SC_PAGESIZE);
+	if(ret == -1) {
+		return NULL;
+	}
+
+	return memalign(ret, size);
+}
+
+void* pvalloc(size_t size)
+{
+	size_t ps, rem, allocsize;
+
+	long ret = sysconf(_SC_PAGESIZE);
+	if(ret == -1) {
+		return NULL;
+	}
+
+	ps = ret;
+	rem = size % ps;
+	allocsize = size;
+	if(rem != 0) {
+		allocsize = ps + (size - rem);
+	}
+
+	return memalign(ps, allocsize);
+}
+
+void* aligned_alloc(size_t alignment, size_t size)
+{
+	if(alignment > size) {
+		return NULL;
+	}
+
+	if((size % alignment) != 0) {
+		return NULL;
+	}
+
+	return memalign(alignment, size);
+}
+
+int malloc_stats() {
+	fprintf(stderr, "Bump pointer allocator by muhq\n");
+	fprintf(stderr, "Memsize: %zu, start address: %p, bump pointer %p\n", MEMSIZE, mem_start, ptr);
+	return 0;
+}
+
+#ifdef __cplusplus
+}
+#endif