From 39b006b493530582d32559ecc1f074785f413cce Mon Sep 17 00:00:00 2001
From: Justin Ethier <justin.ethier@gmail.com>
Date: Thu, 13 Aug 2020 18:04:04 -0400
Subject: [PATCH] Make multiple SCM calls

---
 examples/call-scm-from-c/full-with-gc.scm | 30 ++++++++++++-----------
 examples/call-scm-from-c/full.c           | 12 ++++++---
 2 files changed, 25 insertions(+), 17 deletions(-)

diff --git a/examples/call-scm-from-c/full-with-gc.scm b/examples/call-scm-from-c/full-with-gc.scm
index e9dec313..5bce8b42 100644
--- a/examples/call-scm-from-c/full-with-gc.scm
+++ b/examples/call-scm-from-c/full-with-gc.scm
@@ -7,36 +7,38 @@
 
 (define lock (make-mutex))
 (define *done* #f)
-(define *dummy signal-done) ;; Hack to prevent optimizing out signal-done
+(define *dummy* signal-done) ;; Hack to prevent optimizing out signal-done
+(define *dummy2* sum-numbers) ;; Hack to prevent optimizing out signal-done
 
 (define-c start-c-thread
   "(void *data, int argc, closure _, object k)"
   "start_c_thread(data); 
    return_closcall1(data, k, boolean_t); ")
 
-;; TODO: this does not work right now, it crashes because we are not setup for GC!
+(define (sum-numbers)
+ (let ((result 0))
+  (for-each
+    (lambda (n)
+      (set! result (+ result n)))
+    (iota 1000))
+  (lambda X
+    (list result 'result #(result)))))
+
+;(define (print-result
 
 ;; Signal (wait) that it is done, this is called from C
 (define (signal-done) ; obj)
- (let ((result 0)
-       (obj #t))
-  (for-each
-    (lambda (n)
-      (set! result (+ result n))
-    )
-    (iota 1000))
-
-  (write `(Called from C result is ,result set *done* to ,obj))
+ (let ((obj #t))
+  (write `(Called from C set *done* to ,obj))
   (newline)
   (mutex-lock! lock)
   (set! *done* obj)
-  (mutex-unlock! lock)
-  (list list result '#())))
+  (mutex-unlock! lock)))
 
 ;; More efficient to use a condition var here to signal ready,
 ;; but this is just an example
 (define (wait)
-  (thread-sleep! 1)
+  (thread-sleep! 0.1)
   (mutex-lock! lock)
   (define done *done*)
   (mutex-unlock! lock)
diff --git a/examples/call-scm-from-c/full.c b/examples/call-scm-from-c/full.c
index a6790ce2..e9607112 100644
--- a/examples/call-scm-from-c/full.c
+++ b/examples/call-scm-from-c/full.c
@@ -9,6 +9,7 @@
  * that we wish to call into.
  */
 extern object __glo_signal_91done;
+extern object __glo_sum_91numbers;
 
 gc_thread_data local;
 
@@ -23,11 +24,17 @@ void *Cyc_init_thread(object thread_and_thunk);
  */
 void *c_thread(void *parent_thd)
 {
+  object obj;
   printf("Hello from C thread\n");
-  sleep(1);
   printf("C calling into SCM\n");
 
-  object obj = scm_call_with_gc(parent_thd, __glo_signal_91done, boolean_t);
+  obj = scm_call_with_gc(parent_thd, __glo_sum_91numbers, boolean_t);
+
+  printf("C received: ");
+  Cyc_write(NULL, obj, stdout);
+  printf("\n");
+
+  obj = scm_call_with_gc(parent_thd, __glo_signal_91done, boolean_t);
 
   printf("C received: ");
   Cyc_write(NULL, obj, stdout);
@@ -67,7 +74,6 @@ void after_call_scm(gc_thread_data *thd, int argc, object k, object result)
   int i;
   printf("after call scm %p result %p\n", &i, result);
 
-
   mclosure0(clo, cleanup_and_return);
   object buf[1]; buf[0] = result;
   GC(thd, &clo, buf, 1);