add ZONE_USE_MMAP

1 files changed, 42 insertions, 11 deletions

diff --git a/zone.h b/zone.h
index c2e033e..bce6796 100644
--- a/zone.h
+++ b/zone.h
@@ -3,8 +3,6 @@
 
 #include <stdint.h>
 
-#define ZONE_FRAME_CAPACITY_DEFAULT 1024
-
 typedef struct ZoneFrame ZoneFrame;
 struct ZoneFrame {
 	ZoneFrame *prev, *next;
@@ -33,17 +31,50 @@ char *zn_strdup(Zone *z, const char *s);
 
 #ifdef ZONE_IMPL
 
-#include <stdlib.h>
 #include <stdio.h>
 #include <string.h>
+
 #include "zone.h"
 
-static ZoneFrame *zn_new_frame(size_t capacity) {
-	ZoneFrame *zf = malloc(sizeof *zf + capacity * sizeof(uintptr_t));
-	if (!zf) {
-		fprintf(stderr, "failed to allocate memory zone frame\n");
-		abort();
+#if defined(ZONE_USE_MMAP)
+
+	#include <sys/mman.h>
+	#include <unistd.h>
+
+	#define ZONE_CAPACITY ((sysconf(_SC_PAGE_SIZE) * 2 - sizeof(ZoneFrame))/sizeof(uintptr_t))
+	static ZoneFrame *zn_zf_allocate(size_t capacity) {
+		ZoneFrame *zf = mmap(NULL, sizeof *zf + capacity * sizeof(uintptr_t), PROT_READ | PROT_WRITE, MAP_ANONYMOUS | MAP_PRIVATE, -1, 0);
+		if (!zf) {
+			fprintf(stderr, "failed to allocate memory zone frame\n");
+			abort();
+		}
+		return zf;
+	}
+	static void zn_zf_free(ZoneFrame *zf) {
+		munmap(zf, sizeof *zf + zf->capacity * sizeof(uintptr_t));
+	}
+
+#else
+
+	#include <stdlib.h>
+
+	#define ZONE_CAPACITY 1024
+	static ZoneFrame *zn_zf_allocate(size_t capacity) {
+		ZoneFrame *zf = malloc(sizeof *zf + capacity * sizeof(uintptr_t));
+		if (!zf) {
+			fprintf(stderr, "failed to allocate memory zone frame\n");
+			abort();
+		}
+		return zf;
 	}
+	static void zn_zf_free(ZoneFrame *zf) {
+		free(zf);
+	}
+
+#endif
+
+static ZoneFrame *zn_zf_new(size_t capacity) {
+	ZoneFrame *zf = zn_zf_allocate(capacity);
 	zf->prev = NULL;
 	zf->next = NULL;
 	zf->length = 0;
@@ -65,9 +96,9 @@ void *zn_zf_alloc(Zone *z, ZoneFrame **zfo, size_t n) {
 		}
 	}
 	if (!zf) {
-		size_t cap = ZONE_FRAME_CAPACITY_DEFAULT;
+		size_t cap = ZONE_CAPACITY;
 		while (wordsz >= cap) cap <<= 1; 
-		zf = zn_new_frame(cap);
+		zf = zn_zf_new(cap);
 		zf->prev = z->tail;
 		if (z->tail) z->tail->next = zf;
 		z->tail = zf;
@@ -99,7 +130,7 @@ void zn_free(Zone *z) {
 	t = z->tail;
 	while (t) {
 		p = t->prev;
-		free(t);
+		zn_zf_free(t);
 		t = p;
 	}
 }