From ced3b0e070da1a8de9faf5bb38735d53cfe99079 Mon Sep 17 00:00:00 2001
From: Daniel Micay <danielmicay@gmail.com>
Date: Wed, 5 Dec 2018 03:27:09 -0500
Subject: [PATCH] support Android malloc_usable_size

---
 h_malloc.c | 12 ++++++------
 h_malloc.h |  8 +++++++-
 2 files changed, 13 insertions(+), 7 deletions(-)

diff --git a/h_malloc.c b/h_malloc.c
index fdc0e92..d065c71 100644
--- a/h_malloc.c
+++ b/h_malloc.c
@@ -511,12 +511,12 @@ static inline void *allocate_small(size_t requested_size) {
     return p;
 }
 
-static size_t slab_size_class(void *p) {
-    size_t offset = (char *)p - (char *)ro.slab_region_start;
+static size_t slab_size_class(const void *p) {
+    size_t offset = (const char *)p - (const char *)ro.slab_region_start;
     return offset / REAL_CLASS_REGION_SIZE;
 }
 
-static size_t slab_usable_size(void *p) {
+static size_t slab_usable_size(const void *p) {
     return size_classes[slab_size_class(p)];
 }
 
@@ -742,7 +742,7 @@ static void regions_quarantine_deallocate_pages(void *p, size_t size, size_t gua
     }
 }
 
-static size_t hash_page(void *p) {
+static size_t hash_page(const void *p) {
     uintptr_t u = (uintptr_t)p >> PAGE_SHIFT;
     size_t sum = u;
     sum = (sum << 7) - sum + (u >> 16);
@@ -814,7 +814,7 @@ static int regions_insert(void *p, size_t size, size_t guard_size) {
     return 0;
 }
 
-static struct region_metadata *regions_find(void *p) {
+static struct region_metadata *regions_find(const void *p) {
     struct region_allocator *ra = ro.region_allocator;
 
     size_t mask = ra->total - 1;
@@ -1363,7 +1363,7 @@ EXPORT void h_free_sized(void *p, size_t expected_size) {
     thread_seal_metadata();
 }
 
-EXPORT size_t h_malloc_usable_size(void *p) {
+EXPORT size_t h_malloc_usable_size(H_MALLOC_USABLE_SIZE_CONST void *p) {
     if (p == NULL) {
         return 0;
     }
diff --git a/h_malloc.h b/h_malloc.h
index e59875f..697f33e 100644
--- a/h_malloc.h
+++ b/h_malloc.h
@@ -47,8 +47,14 @@ void h_free(void *ptr);
 // POSIX
 int h_posix_memalign(void **memptr, size_t alignment, size_t size);
 
+#ifdef __ANDROID__
+#define H_MALLOC_USABLE_SIZE_CONST const
+#else
+#define H_MALLOC_USABLE_SIZE_CONST
+#endif
+
 // glibc extensions
-size_t h_malloc_usable_size(void *ptr);
+size_t h_malloc_usable_size(H_MALLOC_USABLE_SIZE_CONST void *ptr);
 int h_mallopt(int param, int value);
 int h_malloc_trim(size_t pad);
 void h_malloc_stats(void);