From 2d75df22efe25d4e50a6f1cc117f3258829316db Mon Sep 17 00:00:00 2001
From: "Sven M. Hallberg" <pesco@khjk.org>
Date: Sun, 9 Feb 2020 18:06:28 +0100
Subject: [PATCH] add a dumb but working implementation of h_arena_realloc()
---
src/allocator.c | 29 +++++++++++++++++++++++++++++
src/allocator.h | 1 +
src/parsers/bind.c | 3 +--
3 files changed, 31 insertions(+), 2 deletions(-)
diff --git a/src/allocator.c b/src/allocator.c
index 2ff5caca..93c94e1d 100644
--- a/src/allocator.c
+++ b/src/allocator.c
@@ -267,3 +267,32 @@ void h_allocator_stats(HArena *arena, HArenaStats *stats) {
stats->arena_li_malloc_bytes = arena->arena_li_malloc_bytes;
#endif
}
+
+void* h_arena_realloc(HArena *arena, void* ptr, size_t n) {
+ struct arena_link *link;
+ void* ret;
+ size_t ncopy;
+
+ // XXX this is really wasteful, but maybe better than nothing?
+ //
+ // first, we walk the blocks to find our ptr. since we don't know how large
+ // the original allocation was, we must always make a new one and copy as
+ // much data from the old block as there could have been.
+
+ for (link = arena->head; link; link = link->next) {
+ if (ptr >= (void *)link->rest && ptr <= (void *)link->rest + link->used)
+ break; /* found it */
+ }
+ assert(link != NULL);
+
+ ncopy = (void *)link->rest + link->used - ptr;
+ if (n < ncopy)
+ ncopy = n;
+
+ ret = h_arena_malloc_noinit(arena, n);
+ assert(ret != NULL);
+ memcpy(ret, ptr, ncopy);
+ h_arena_free(arena, ptr);
+
+ return ret;
+}
diff --git a/src/allocator.h b/src/allocator.h
index 06d1e6f5..8ebde723 100644
--- a/src/allocator.h
+++ b/src/allocator.h
@@ -55,6 +55,7 @@ HArena *h_new_arena(HAllocator* allocator, size_t block_size); // pass 0 for def
void* h_arena_malloc_noinit(HArena *arena, size_t count) ATTR_MALLOC(2);
void* h_arena_malloc(HArena *arena, size_t count) ATTR_MALLOC(2);
+void* h_arena_realloc(HArena *arena, void* ptr, size_t count);
void h_arena_free(HArena *arena, void* ptr); // For future expansion, with alternate memory managers.
void h_delete_arena(HArena *arena);
void h_arena_set_except(HArena *arena, jmp_buf *except);
diff --git a/src/parsers/bind.c b/src/parsers/bind.c
index 87f42330..eac49744 100644
--- a/src/parsers/bind.c
+++ b/src/parsers/bind.c
@@ -21,8 +21,7 @@ static void *aa_alloc(HAllocator *allocator, size_t size)
static void *aa_realloc(HAllocator *allocator, void *ptr, size_t size)
{
HArena *arena = ((ArenaAllocator *)allocator)->arena;
- assert(((void)"XXX need realloc for arena allocator", 0));
- return NULL;
+ return h_arena_realloc(arena, ptr, size);
}
static void aa_free(HAllocator *allocator, void *ptr)
--
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