Test world stop while other thread in deep recursion in gctest (pthreads)

* tests/gctest.c [GC_PTHREADS]: Add TODO item.
* tests/gctest.c [GC_PTHREADS] (do_gcollect,
collect_from_other_thread): New function.
* tests/gctest.c [GC_PTHREADS] (MAX_GCOLLECT_THREADS): New macro.
* tests/gctest.c [GC_PTHREADS] (gcollect_threads_cnt): New variable.
* tests/gctest.c [GC_PTHREADS] (ints): If up<0 and low>-up then
increment gcollect_threads_cnt atomically and call
collect_from_other_thread() instead of GC_gcollect_and_unmap unless
gcollect_threads_cnt exceeds limit (MAX_GCOLLECT_THREADS).

1 files changed, 38 insertions, 0 deletions

diff --git a/tests/gctest.c b/tests/gctest.c
index ff7cd066..bf9da87a 100644
--- a/tests/gctest.c
+++ b/tests/gctest.c
@@ -461,10 +461,48 @@ sexpr reverse(sexpr x)
     return reverse1(x, nil);
 }
 
+#ifdef GC_PTHREADS
+  /* TODO: Implement for Win32 */
+
+  void *do_gcollect(void *arg)
+  {
+    if (print_stats)
+      GC_log_printf("Collect from a standalone thread\n");
+    GC_gcollect();
+    return arg;
+  }
+
+  void collect_from_other_thread(void)
+  {
+    pthread_t t;
+    int code = pthread_create(&t, NULL, do_gcollect, NULL /* arg */);
+
+    if (code != 0) {
+      GC_printf("gcollect thread creation failed, errno= %d\n", code);
+      FAIL;
+    }
+    code = pthread_join(t, NULL);
+    if (code != 0) {
+      GC_printf("gcollect thread join failed, errno= %d\n", code);
+      FAIL;
+    }
+  }
+
+# define MAX_GCOLLECT_THREADS ((NTHREADS+2)/3)
+  volatile AO_t gcollect_threads_cnt = 0;
+#endif /* GC_PTHREADS */
+
 sexpr ints(int low, int up)
 {
     if (up < 0 ? low > -up : low > up) {
         if (up < 0) {
+#           ifdef GC_PTHREADS
+                if (AO_fetch_and_add1(&gcollect_threads_cnt) + 1
+                        <= MAX_GCOLLECT_THREADS) {
+                    collect_from_other_thread();
+                    return nil;
+                }
+#           endif
             GC_gcollect_and_unmap();
         }
         return nil;