[06/13] libfrog: add missing per-thread variable error handling

Commit Message

Darrick J. Wong Sept. 6, 2019, 3:36 a.m. UTC

From: Darrick J. Wong <[e-mail]>

Add missing return value checks for everything that the per-thread
variable code calls.

Signed-off-by: Darrick J. Wong <[e-mail]>
---
 libfrog/ptvar.c |   17 +++++++++++++++--
 1 file changed, 15 insertions(+), 2 deletions(-)

Patch

diff --git a/libfrog/ptvar.c b/libfrog/ptvar.c
index 6cb58208..55324b71 100644
--- a/libfrog/ptvar.c
+++ b/libfrog/ptvar.c
@@ -44,8 +44,12 @@  ptvar_alloc(
 	int		ret;
 
 #ifdef _SC_LEVEL1_DCACHE_LINESIZE
+	long		l1_dcache;
+
 	/* Try to prevent cache pingpong by aligning to cacheline size. */
-	size = max(size, sysconf(_SC_LEVEL1_DCACHE_LINESIZE));
+	l1_dcache = sysconf(_SC_LEVEL1_DCACHE_LINESIZE);
+	if (l1_dcache > 0)
+		size = roundup(size, l1_dcache);
 #endif
 
 	ptv = malloc(PTVAR_SIZE(nr, size));
@@ -88,17 +92,26 @@  ptvar_get(
 	int		*retp)
 {
 	void		*p;
+	int		ret;
 
 	p = pthread_getspecific(ptv->key);
 	if (!p) {
 		pthread_mutex_lock(&ptv->lock);
 		assert(ptv->nr_used < ptv->nr_counters);
 		p = &ptv->data[(ptv->nr_used++) * ptv->data_size];
-		pthread_setspecific(ptv->key, p);
+		ret = pthread_setspecific(ptv->key, p);
+		if (ret)
+			goto out_unlock;
 		pthread_mutex_unlock(&ptv->lock);
 	}
 	*retp = 0;
 	return p;
+
+out_unlock:
+	ptv->nr_used--;
+	pthread_mutex_unlock(&ptv->lock);
+	*retp = ret;
+	return NULL;
 }
 
 /* Iterate all of the per-thread variables. */