Fix default impl of apr_atomic_xchg32, and add a test case for it

git-svn-id: http://svn.apache.org/repos/asf/apr/apr/trunk@64642 13f79535-47bb-0310-9956-ffa450edef68

2 files changed, 14 insertions, 1 deletions

diff --git a/atomic/unix/apr_atomic.c b/atomic/unix/apr_atomic.c
index 97bbb669d..16912b968 100644
--- a/atomic/unix/apr_atomic.c
+++ b/atomic/unix/apr_atomic.c
@@ -306,7 +306,7 @@ apr_uint32_t apr_atomic_xchg32(volatile apr_uint32_t *mem, apr_uint32_t val)
         prev = *mem;
         *mem = val;
         apr_thread_mutex_unlock(lock);
-        return val;
+        return prev;
     }
     return *mem;
 #else
diff --git a/test/testatomic.c b/test/testatomic.c
index 6603b6517..2ad4a743b 100644
--- a/test/testatomic.c
+++ b/test/testatomic.c
@@ -184,6 +184,19 @@ static apr_status_t check_basic_atomics32(void)
     }
     printf("OK\n");
 
+    printf("%-60s", "testing apr_atomic_xchg32");
+    apr_atomic_set32(&y32, 100);
+    oldval = apr_atomic_xchg32(&y32, 50);
+    if (oldval != 100) {
+        fprintf(stderr, "Failed\noldval =%d should be 100\n", oldval);
+        return APR_EGENERAL;
+    }
+    if (y32 != 50) {
+        fprintf(stderr, "Failed\nnewval =%d should be 50\n", oldval);
+        return APR_EGENERAL;
+    }
+    printf("OK\n");
+
     printf("%-60s", "testing apr_atomic_cas32");
     oldval = apr_atomic_cas32(&casval, 12, 0);
     if (oldval != 0) {