test/testshm: Fix synchronization of msgput/msgwait IPC functions.

* test/testshm.h():
  Move (APR_INLINE) common msgput/msgwait() functions there.

* test/testshm.h(msgput, msgwait):
  Use atomics (cas) to prevent producer and consumer from writing to
  the same box.

* testshm.c, testshmconsumer.c, testshmproducer.c:
  Use common helpers.


Merges r1902267 from trunk.
Merges r1908004 from 1.8.x.
Submitted by: ylavic


git-svn-id: https://svn.apache.org/repos/asf/apr/apr/branches/1.7.x@1908005 13f79535-47bb-0310-9956-ffa450edef68

1 files changed, 53 insertions, 3 deletions

diff --git a/test/testshm.h b/test/testshm.h
index 5b24a9d42..4d4f0c5db 100644
--- a/test/testshm.h
+++ b/test/testshm.h
@@ -17,17 +17,67 @@
 #ifndef TESTSHM_H
 #define TESTSHM_H
 
+#include "apr.h"
+#include "apr_time.h"
+#include "apr_atomic.h"
+#include "apr_strings.h"
+
+#include <assert.h>
+
 typedef struct mbox {
     char msg[1024]; 
-    int msgavail; 
+    apr_uint32_t msgavail; 
 } mbox;
 mbox *boxes;
 
 #define N_BOXES 10
+#define N_MESSAGES 100
 #define SHARED_SIZE (apr_size_t)(N_BOXES * sizeof(mbox))
 #define SHARED_FILENAME "data/apr.testshm.shm"
-#define N_MESSAGES 100
 #define MSG "Sending a message"
 
-#endif
+#if APR_HAS_SHARED_MEMORY
 
+static APR_INLINE
+int msgwait(const char *msg, int count, int duration, int sleep_ms)
+{
+    int recvd = 0, i;
+    apr_time_t start = apr_time_now();
+    apr_interval_time_t sleep_duration = apr_time_from_sec(duration);
+    apr_interval_time_t sleep_delay = apr_time_from_msec(sleep_ms);
+    while (apr_time_now() - start < sleep_duration) {
+        for (i = 0; i < N_BOXES; i++) {
+            if (apr_atomic_cas32(&boxes[i].msgavail, 0, 1) == 1) {
+                if (msg) {
+                    assert(strcmp(boxes[i].msg, msg) == 0);
+                }
+                *boxes[i].msg = '\0';
+                if (++recvd == count) {
+                    return recvd;
+                }
+            }
+        }
+        apr_sleep(sleep_delay);
+    }
+    return recvd;
+}
+
+static APR_INLINE
+int msgput(const char *msg, int boxnum)
+{
+    if (apr_atomic_cas32(&boxes[boxnum].msgavail, -1, 0) != 0) {
+        return 0;
+    }
+    if (msg) {
+        apr_cpystrn(boxes[boxnum].msg, msg, sizeof(boxes[boxnum].msg));
+    }
+    else {
+        *boxes[boxnum].msg = '\0';
+    }
+    apr_atomic_set32(&boxes[boxnum].msgavail, 1);
+    return 1;
+}
+
+#endif /* APR_HAS_SHARED_MEMORY */
+
+#endif