improve bumpptr_alloc

Return always 16 Byte aligned blocks and mmap the whole available
memory reported by free -t per thread.

1 files changed, 13 insertions, 2 deletions

diff --git a/src/bumpptr_alloc.c b/src/bumpptr_alloc.c
index 2690809..576dc40 100644
--- a/src/bumpptr_alloc.c
+++ b/src/bumpptr_alloc.c
@@ -6,7 +6,11 @@
 #include <string.h> /* memset */
 #include <sys/mman.h> /* memset */
 
+#define MIN_ALIGNMENT 16
+
+#ifndef MEMSIZE
 #define MEMSIZE 1024*4*1024*1024l
+#endif
 
 #ifdef __cplusplus
 extern "C" {
@@ -27,6 +31,12 @@ void* malloc(size_t size) {
 		ptr = (uintptr_t)mem_start;
 	}
 
+	// align ptr;
+	if (ptr % MIN_ALIGNMENT != 0) {
+		size_t mask = MIN_ALIGNMENT -1;
+		ptr = (ptr + mask) & ~mask;
+	}
+
 	void* ret = (void*)ptr;
 	ptr += size;
 	return ret;
@@ -49,8 +59,9 @@ void* realloc(void* ptr, size_t size) {
 }
 
 void* memalign(size_t alignment, size_t size) {
-	// bump ptr to alignment and malloc
-	ptr = (ptr + (alignment - 1)) & -alignment;
+	// align ptr to alignment and malloc
+	size_t mask = alignment - 1;
+	ptr = (ptr + mask) & ~mask;
 	return malloc(size);
 }