ncurses 5.7 - patch 20090718

[ncurses.git] / test / rain.c

diff --git a/test/rain.c b/test/rain.c
index 3f6c39fc8f19a066e52b4e5f871c4e62b7949203..f4a5e7f332ea9265e5a21f776eb2ca8d8d03c35d 100644 (file)
--- a/test/rain.c
+++ b/test/rain.c
@@ -26,7 +26,7 @@
  * authorization.                                                           *
  ****************************************************************************/
 /*
- * $Id: rain.c,v 1.26 2008/03/09 00:17:09 tom Exp $
+ * $Id: rain.c,v 1.34 2008/05/24 23:34:34 tom Exp $
  */
 #include <test.priv.h>
 
@@ -38,7 +38,8 @@
 
 WANT_USE_WINDOW();
 
-#define MAX_DROP 5
+#define MAX_THREADS    10
+#define MAX_DROP       5
 
 struct DATA;
 
@@ -47,12 +48,24 @@ typedef void (*DrawPart) (struct DATA *);
 typedef struct DATA {
     int y, x;
 #ifdef USE_PTHREADS
-    pthread_t thread;
     DrawPart func;
     int state;
 #endif
 } DATA;
 
+#ifdef USE_PTHREADS
+pthread_cond_t cond_next_drop;
+pthread_mutex_t mutex_next_drop;
+static int used_threads;
+
+typedef struct {
+    pthread_t myself;
+    long counter;
+} STATS;
+
+static STATS drop_threads[MAX_THREADS];
+#endif
+
 static void
 onsig(int n GCC_UNUSED)
 {
@@ -147,12 +160,11 @@ part6(DATA * drop)
 static void
 napsome(void)
 {
-    refresh();
     napms(60);
 }
 
 /*
- * This runs inside the mutex.
+ * This runs inside the use_window() mutex.
  */
 static int
 really_draw(WINDOW *win, void *arg)
@@ -162,6 +174,7 @@ really_draw(WINDOW *win, void *arg)
     (void) win;
     next_j(data->state);
     data->func(data);
+    refresh();
     return OK;
 }
 
@@ -174,40 +187,116 @@ draw_part(void (*func) (DATA *), int state, DATA * data)
     napsome();
 }
 
+/*
+ * Tell the threads that one of them can start work on a new raindrop.
+ * They may all be busy if we're sending requests too rapidly.
+ */
+static int
+put_next_drop(void)
+{
+    pthread_cond_signal(&cond_next_drop);
+    pthread_mutex_unlock(&mutex_next_drop);
+
+    return 0;
+}
+
+/*
+ * Wait until we're assigned the task of drawing a new raindrop.
+ */
+static int
+get_next_drop(void)
+{
+    pthread_mutex_lock(&mutex_next_drop);
+    pthread_cond_wait(&cond_next_drop, &mutex_next_drop);
+
+    return TRUE;
+}
+
 static void *
 draw_drop(void *arg)
 {
     DATA mydata;
+    int mystats;
+
+    /*
+     * Find myself in the list of threads so we can count the number of loops.
+     */
+    for (mystats = 0; mystats < MAX_THREADS; ++mystats) {
+       if (drop_threads[mystats].myself == pthread_self())
+           break;
+    }
+
+    do {
+       if (mystats < MAX_THREADS)
+           drop_threads[mystats].counter++;
 
-    mydata = *(DATA *) arg;    /* make a copy of caller's data */
+       /*
+        * Make a copy of caller's data.  We're cheating for the cases after
+        * the first loop since we still have a pointer into the main thread
+        * to the data which it uses for setting up this thread (but it has
+        * been modified to use different coordinates).
+        */
+       mydata = *(DATA *) arg;
 
-    draw_part(part1, 0, &mydata);
-    draw_part(part2, 1, &mydata);
-    draw_part(part3, 2, &mydata);
-    draw_part(part4, 3, &mydata);
-    draw_part(part5, 4, &mydata);
-    draw_part(part6, 0, &mydata);
+       draw_part(part1, 0, &mydata);
+       draw_part(part2, 1, &mydata);
+       draw_part(part3, 2, &mydata);
+       draw_part(part4, 3, &mydata);
+       draw_part(part5, 4, &mydata);
+       draw_part(part6, 0, &mydata);
+    } while (get_next_drop());
 
     return NULL;
 }
+
+/*
+ * The description of pthread_create() is misleading, since it implies that
+ * threads will exit cleanly after their function returns.
+ * 
+ * Since they do not (and the number of threads is limited by system
+ * resources), make a limited number of threads, and signal any that are
+ * waiting when we want a thread past that limit.
+ */
+static int
+start_drop(DATA * data)
+{
+    int rc;
+
+    if (!used_threads) {
+       /* mutex and condition for signalling thread */
+       pthread_mutex_init(&mutex_next_drop, NULL);
+       pthread_cond_init(&cond_next_drop, NULL);
+    }
+
+    if (used_threads < MAX_THREADS) {
+       rc = pthread_create(&(drop_threads[used_threads].myself),
+                           NULL,
+                           draw_drop,
+                           data);
+       ++used_threads;
+    } else {
+       rc = put_next_drop();
+    }
+    return rc;
+}
 #endif
 
 static int
 get_input(void)
 {
-    int ch;
-    ch = USING_WINDOW(stdscr, wgetch);
-    return ch;
+    return USING_WINDOW(stdscr, wgetch);
 }
 
 int
 main(int argc GCC_UNUSED,
      char *argv[]GCC_UNUSED)
 {
+    bool done = FALSE;
     DATA drop;
+#ifndef USE_PTHREADS
     DATA last[MAX_DROP];
+#endif
     int j = 0;
-    bool done = FALSE;
 
     setlocale(LC_ALL, "");
 
@@ -229,20 +318,21 @@ main(int argc GCC_UNUSED,
     curs_set(0);
     timeout(0);
 
+#ifndef USE_PTHREADS
     for (j = MAX_DROP; --j >= 0;) {
        last[j].x = random_x();
        last[j].y = random_y();
     }
+    j = 0;
+#endif
 
     while (!done) {
        drop.x = random_x();
        drop.y = random_y();
 
 #ifdef USE_PTHREADS
-       if (pthread_create(&(drop.thread), NULL, draw_drop, &drop)) {
+       if (start_drop(&drop) != 0) {
            beep();
-           done = TRUE;
-           continue;
        }
 #else
        /*
@@ -287,5 +377,10 @@ main(int argc GCC_UNUSED,
     }
     curs_set(1);
     endwin();
+#ifdef USE_PTHREADS
+    printf("Counts per thread:\n");
+    for (j = 0; j < MAX_THREADS; ++j)
+       printf("  %d:%ld\n", j, drop_threads[j].counter);
+#endif
     ExitProgram(EXIT_SUCCESS);
 }