Improve const correctness in the repo

src/arena.c

@@ -343,7 +343,8 @@ arena_extent_alloc_large(
 }
 
 void
-arena_extent_dalloc_large_prep(tsdn_t *tsdn, arena_t *arena, edata_t *edata) {
+arena_extent_dalloc_large_prep(tsdn_t *tsdn, arena_t *arena,
+    const edata_t *edata) {
 	if (config_stats) {
 		arena_large_dalloc_stats_update(
 		    tsdn, arena, edata_usize_get(edata));
@@ -352,7 +353,7 @@ arena_extent_dalloc_large_prep(tsdn_t *tsdn, arena_t *arena, edata_t *edata) {
 
 void
 arena_extent_ralloc_large_shrink(
-    tsdn_t *tsdn, arena_t *arena, edata_t *edata, size_t oldusize) {
+    tsdn_t *tsdn, arena_t *arena, const edata_t *edata, size_t oldusize) {
 	size_t usize = edata_usize_get(edata);
 
 	if (config_stats) {
@@ -362,7 +363,7 @@ arena_extent_ralloc_large_shrink(
 
 void
 arena_extent_ralloc_large_expand(
-    tsdn_t *tsdn, arena_t *arena, edata_t *edata, size_t oldusize) {
+    tsdn_t *tsdn, arena_t *arena, const edata_t *edata, size_t oldusize) {
 	size_t usize = edata_usize_get(edata);
 
 	if (config_stats) {
@@ -1662,7 +1663,7 @@ arena_ralloc(tsdn_t *tsdn, arena_t *arena, void *ptr, size_t oldsize,
 }
 
 ehooks_t *
-arena_get_ehooks(arena_t *arena) {
+arena_get_ehooks(const arena_t *arena) {
 	return base_ehooks_get(arena->base);
 }
 
@@ -1685,7 +1686,7 @@ arena_set_extent_hooks(
 }
 
 dss_prec_t
-arena_dss_prec_get(arena_t *arena) {
+arena_dss_prec_get(const arena_t *arena) {
 	return (dss_prec_t)atomic_load_u(&arena->dss_prec, ATOMIC_ACQUIRE);
 }
 
@@ -1699,8 +1700,9 @@ arena_dss_prec_set(arena_t *arena, dss_prec_t dss_prec) {
 }
 
 void
-arena_name_get(arena_t *arena, char *name) {
-	char *end = (char *)memchr((void *)arena->name, '\0', ARENA_NAME_LEN);
+arena_name_get(const arena_t *arena, char *name) {
+	const char *end = (const char *)memchr(
+	    arena->name, '\0', ARENA_NAME_LEN);
 	assert(end != NULL);
 	size_t len = (uintptr_t)end - (uintptr_t)arena->name + 1;
 	assert(len > 0 && len <= ARENA_NAME_LEN);
@@ -1751,7 +1753,7 @@ arena_retain_grow_limit_get_set(
 }
 
 unsigned
-arena_nthreads_get(arena_t *arena, bool internal) {
+arena_nthreads_get(const arena_t *arena, bool internal) {
 	return atomic_load_u(&arena->nthreads[internal], ATOMIC_RELAXED);
 }
 

src/base.c

@@ -112,7 +112,7 @@ label_done:
 }
 
 static inline bool
-base_edata_is_reused(edata_t *edata) {
+base_edata_is_reused(const edata_t *edata) {
 	/*
 	 * Borrow the guarded bit to indicate if the extent is a recycled one,
 	 * i.e. the ones returned to base for reuse; currently only tcache bin
@@ -133,8 +133,8 @@ base_edata_init(
 }
 
 static size_t
-base_get_num_blocks(base_t *base, bool with_new_block) {
-	base_block_t *b = base->blocks;
+base_get_num_blocks(const base_t *base, bool with_new_block) {
+	const base_block_t *b = base->blocks;
 	assert(b != NULL);
 
 	size_t n_blocks = with_new_block ? 2 : 1;

src/eset.c

@@ -32,17 +32,17 @@ eset_init(eset_t *eset, extent_state_t state) {
 }
 
 size_t
-eset_npages_get(eset_t *eset) {
+eset_npages_get(const eset_t *eset) {
 	return atomic_load_zu(&eset->npages, ATOMIC_RELAXED);
 }
 
 size_t
-eset_nextents_get(eset_t *eset, pszind_t pind) {
+eset_nextents_get(const eset_t *eset, pszind_t pind) {
 	return atomic_load_zu(&eset->bin_stats[pind].nextents, ATOMIC_RELAXED);
 }
 
 size_t
-eset_nbytes_get(eset_t *eset, pszind_t pind) {
+eset_nbytes_get(const eset_t *eset, pszind_t pind) {
 	return atomic_load_zu(&eset->bin_stats[pind].nbytes, ATOMIC_RELAXED);
 }
 

src/pa_extra.c

@@ -73,12 +73,12 @@ pa_shard_postfork_child(tsdn_t *tsdn, pa_shard_t *shard) {
 }
 
 size_t
-pa_shard_nactive(pa_shard_t *shard) {
+pa_shard_nactive(const pa_shard_t *shard) {
 	return atomic_load_zu(&shard->nactive, ATOMIC_RELAXED);
 }
 
 size_t
-pa_shard_ndirty(pa_shard_t *shard) {
+pa_shard_ndirty(const pa_shard_t *shard) {
 	size_t ndirty = ecache_npages_get(&shard->pac.ecache_dirty);
 	if (shard->ever_used_hpa) {
 		ndirty += psset_ndirty(&shard->hpa_shard.psset);
@@ -87,13 +87,13 @@ pa_shard_ndirty(pa_shard_t *shard) {
 }
 
 size_t
-pa_shard_nmuzzy(pa_shard_t *shard) {
+pa_shard_nmuzzy(const pa_shard_t *shard) {
 	return ecache_npages_get(&shard->pac.ecache_muzzy);
 }
 
 void
 pa_shard_basic_stats_merge(
-    pa_shard_t *shard, size_t *nactive, size_t *ndirty, size_t *nmuzzy) {
+    const pa_shard_t *shard, size_t *nactive, size_t *ndirty, size_t *nmuzzy) {
 	*nactive += pa_shard_nactive(shard);
 	*ndirty += pa_shard_ndirty(shard);
 	*nmuzzy += pa_shard_nmuzzy(shard);