+#if FILE_BACKED_MALLOC
+#include <stdlib.h>
+#include <sys/mman.h>
+typedef struct mmap_data_s
+{
+ size_t len;
+}
+mmap_data_t;
+static void *mmap_malloc(size_t size)
+{
+ char vabuf[MAX_OSPATH + 1];
+ char *tmpdir = getenv("TEMP");
+ mmap_data_t *data;
+ int fd;
+ size += sizeof(mmap_data_t); // waste block
+ dpsnprintf(vabuf, sizeof(vabuf), "%s/darkplaces.XXXXXX", tmpdir ? tmpdir : "/tmp");
+ fd = mkstemp(vabuf);
+ if(fd < 0)
+ return NULL;
+ ftruncate(fd, size);
+ data = (unsigned char *) mmap(NULL, size, PROT_READ | PROT_WRITE, MAP_SHARED | MAP_NORESERVE, fd, 0);
+ close(fd);
+ unlink(vabuf);
+ if(!data)
+ return NULL;
+ data->len = size;
+ return (void *) (data + 1);
+}
+static void mmap_free(void *mem)
+{
+ mmap_data_t *data;
+ if(!mem)
+ return;
+ data = ((mmap_data_t *) mem) - 1;
+ munmap(data, data->len);
+}
+#define malloc mmap_malloc
+#define free mmap_free
+#endif
+