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-rw-r--r--src/bumpptr_alloc.c151
1 files changed, 151 insertions, 0 deletions
diff --git a/src/bumpptr_alloc.c b/src/bumpptr_alloc.c
new file mode 100644
index 0000000..fc8f77e
--- /dev/null
+++ b/src/bumpptr_alloc.c
@@ -0,0 +1,151 @@
+#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 MEMSIZE 1024*4*1024*1024l
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+__thread void* mem_start = NULL;
+__thread void* mem_end = NULL;
+
+__thread uintptr_t ptr = 0;
+__thread uintptr_t last_freed_ptr = 0;
+
+void* malloc(size_t size) {
+ if(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;
+ }
+
+ void* ret = (void*)ptr;
+ ptr += size;
+ return ret;
+}
+
+void free(void* ptr) {
+}
+
+void* realloc(void* ptr, size_t size) {
+ if(ptr == NULL)
+ return malloc(size);
+
+ if(size == 0)
+ return NULL;
+
+ void* new_ptr = malloc(size);
+ // this may copies to much
+ memcpy(new_ptr, ptr, size);
+ return new_ptr;
+}
+
+void* memalign(size_t alignment, size_t size) {
+ // bump ptr to alignment and malloc
+ ptr = (ptr + (alignment - 1)) & -alignment;
+ return malloc(size);
+}
+
+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 = memalign(alignment, size);
+ 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 = malloc(fullsize);
+ 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);
+}
+
+#ifdef __cplusplus
+}
+#endif