[PATCH 6/7] core: simplify callers of alloc_insert_rcu

[Eric Wong <e@80x24.org>]

From: Eric Wong <mwrap-perl@80x24.org>

We can actually handle all RCU locking/unlocking inside
alloc_insert_rcu to simplify callers.
---
 mwrap_core.h | 60 +++++++++++++++++++---------------------------------
 1 file changed, 22 insertions(+), 38 deletions(-)

diff --git a/mwrap_core.h b/mwrap_core.h
index 3161243..b014f5d 100644
--- a/mwrap_core.h
+++ b/mwrap_core.h
@@ -319,11 +319,6 @@ again:
 	return l;
 }
 
-static void update_stats_rcu_unlock(const struct src_loc *l)
-{
-	if (caa_likely(l)) rcu_read_unlock();
-}
-
 static const COP *mwp_curcop(void)
 {
 #if MWRAP_PERL
@@ -506,17 +501,20 @@ void free(void *p)
 }
 
 static void
-alloc_insert_rcu(struct src_loc *l, struct alloc_hdr *h, size_t size,
-		void *real, size_t generation)
+alloc_insert_rcu(struct src_loc *sl, struct alloc_hdr *h, size_t size,
+		void *real)
 {
 	h->size = size;
 	h->real = real;
+	size_t gen = 0;
+	struct src_loc *l = update_stats_rcu_lock(&gen, size, sl);
 	h->as.live.loc = l;
-	h->as.live.gen = generation;
+	h->as.live.gen = gen;
 	if (l) {
 		pthread_mutex_t *mtx = src_loc_mutex_lock(l);
 		cds_list_add_rcu(&h->anode, &l->allocs);
 		CHECK(int, 0, pthread_mutex_unlock(mtx));
+		rcu_read_unlock();
 	}
 }
 
@@ -564,10 +562,7 @@ mwrap_memalign(void **pp, size_t alignment, size_t size, struct src_loc *sl)
 		if (!ptr_is_aligned(p, alignment))
 			p = ptr_align(p, alignment);
 		struct alloc_hdr *h = ptr2hdr(p);
-		size_t gen = 0;
-		struct src_loc *l = update_stats_rcu_lock(&gen, size, sl);
-		alloc_insert_rcu(l, h, size, real, gen);
-		update_stats_rcu_unlock(l);
+		alloc_insert_rcu(sl, h, size, real);
 		*pp = p;
 	}
 
@@ -649,15 +644,11 @@ void *malloc(size_t size)
 
 	void *p = real_malloc(asize);
 	if (p) {
-		size_t gen = 0;
 		SRC_LOC_BT(bt);
 		struct alloc_hdr *h = p;
-		struct src_loc *l = update_stats_rcu_lock(&gen, size, &bt.sl);
-		alloc_insert_rcu(l, h, size, h, gen);
-		update_stats_rcu_unlock(l);
-		p = hdr2ptr(h);
+		alloc_insert_rcu(&bt.sl, h, size, h);
+		return hdr2ptr(h);
 	}
-	if (p) return p;
 enomem:
 	errno = ENOMEM;
 	return 0;
@@ -673,12 +664,9 @@ void *calloc(size_t nmemb, size_t size)
 		goto enomem;
 	void *p = real_malloc(asize);
 	if (p) {
-		size_t gen = 0;
 		struct alloc_hdr *h = p;
 		SRC_LOC_BT(bt);
-		struct src_loc *l = update_stats_rcu_lock(&gen, size, &bt.sl);
-		alloc_insert_rcu(l, h, size, h, gen);
-		update_stats_rcu_unlock(l);
+		alloc_insert_rcu(&bt.sl, h, size, h);
 		return memset(hdr2ptr(h), 0, size);
 	}
 enomem:
@@ -694,28 +682,24 @@ void *realloc(void *ptr, size_t size)
 		free(ptr);
 		return 0;
 	}
-	if (__builtin_add_overflow(size, sizeof(struct alloc_hdr), &asize)) {
-		errno = ENOMEM;
-		return 0;
-	}
+	if (__builtin_add_overflow(size, sizeof(struct alloc_hdr), &asize))
+		goto enomem;
 	void *p = real_malloc(asize);
 	if (p) {
-		size_t gen = 0;
 		struct alloc_hdr *h = p;
 		SRC_LOC_BT(bt);
-		struct src_loc *l = update_stats_rcu_lock(&gen, size, &bt.sl);
-		alloc_insert_rcu(l, h, size, h, gen);
-		update_stats_rcu_unlock(l);
+		alloc_insert_rcu(&bt.sl, h, size, h);
 		p = hdr2ptr(h);
+		if (ptr) {
+			struct alloc_hdr *old = ptr2hdr(ptr);
+			memcpy(p, ptr, old->size < size ? old->size : size);
+			free(ptr);
+		}
+		return p;
 	}
-
-	if (ptr && p) {
-		struct alloc_hdr *old = ptr2hdr(ptr);
-		memcpy(p, ptr, old->size < size ? old->size : size);
-		free(ptr);
-	}
-	if (caa_unlikely(!p)) errno = ENOMEM;
-	return p;
+enomem:
+	errno = ENOMEM;
+	return 0;
 }
 
 struct dump_arg {