2 files changed, 160 insertions, 0 deletions
diff --git a/test/test_timer.c b/test/test_timer.c
new file mode 100644
index 0000000..341b4f3
--- /dev/null
+++ b/test/test_timer.c
@@ -0,0 +1,158 @@
+/*
+  Copyright 2020 David Robillard <http://drobilla.net>
+
+  Permission to use, copy, modify, and/or distribute this software for any
+  purpose with or without fee is hereby granted, provided that the above
+  copyright notice and this permission notice appear in all copies.
+
+  THIS SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+  WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+  MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+  ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+  WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+  ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+  OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+*/
+
+/*
+  Tests that update events are received and than redisplays they trigger happen
+  immediately in the same event loop iteration.
+*/
+
+#undef NDEBUG
+
+#include "test_utils.h"
+
+#include "pugl/pugl.h"
+#include "pugl/pugl_stub.h"
+
+#include <assert.h>
+#include <math.h>
+#include <stdbool.h>
+#include <stddef.h>
+
+#ifdef __APPLE__
+static const double timeout = 1 / 60.0;
+#else
+static const double timeout = -1.0;
+#endif
+
+#ifdef _WIN32
+// Windows SetTimer has a maximum resolution of 10ms
+static const double tolerance = 0.011;
+#else
+static const double tolerance = 0.002;
+#endif
+
+static const uintptr_t timerId     = 1u;
+static const double    timerPeriod = 1 / 60.0;
+
+typedef enum {
+	START,
+	EXPOSED,
+} State;
+
+typedef struct {
+	PuglTestOptions opts;
+	PuglWorld*      world;
+	PuglView*       view;
+	size_t          numAlarms;
+	State           state;
+} PuglTest;
+
+static PuglStatus
+onEvent(PuglView* view, const PuglEvent* event)
+{
+	PuglTest* test = (PuglTest*)puglGetHandle(view);
+
+	if (test->opts.verbose) {
+		printEvent(event, "Event: ", true);
+	}
+
+	switch (event->type) {
+	case PUGL_EXPOSE:
+		test->state = EXPOSED;
+		break;
+
+	case PUGL_TIMER:
+		assert(event->timer.id == timerId);
+		++test->numAlarms;
+		break;
+
+	default:
+		break;
+	}
+
+	return PUGL_SUCCESS;
+}
+
+static double
+roundPeriod(const double period)
+{
+	return floor(period * 1000.0) / 1000.0; // Round down to milliseconds
+}
+
+int
+main(int argc, char** argv)
+{
+	PuglTest app = {puglParseTestOptions(&argc, &argv),
+	                puglNewWorld(PUGL_PROGRAM, 0),
+	                NULL,
+	                0,
+	                START};
+
+	// Set up view
+	app.view = puglNewView(app.world);
+	puglSetClassName(app.world, "Pugl Test");
+	puglSetBackend(app.view, puglStubBackend());
+	puglSetHandle(app.view, &app);
+	puglSetEventFunc(app.view, onEvent);
+
+	// Create and show window
+	assert(!puglCreateWindow(app.view, "Pugl Test"));
+	assert(!puglShowWindow(app.view));
+	while (app.state != EXPOSED) {
+		assert(!puglUpdate(app.world, timeout));
+	}
+
+	// Register a timer with a longer period first
+	assert(!puglStartTimer(app.view, timerId, timerPeriod * 2.0));
+
+	// Replace it with the one we want (to ensure timers are replaced)
+	assert(!puglStartTimer(app.view, timerId, timerPeriod));
+
+	const double startTime = puglGetTime(app.world);
+
+	puglUpdate(app.world, 1.0);
+
+	// Calculate the actual period of the timer
+	const double endTime        = puglGetTime(app.world);
+	const double duration       = endTime - startTime;
+	const double expectedPeriod = roundPeriod(timerPeriod);
+	const double actualPeriod   = roundPeriod(duration / (double)app.numAlarms);
+	const double difference     = fabs(actualPeriod - expectedPeriod);
+
+	if (difference > tolerance) {
+		fprintf(stderr,
+		        "error: Period not within %f of %f\n",
+		        tolerance,
+		        expectedPeriod);
+		fprintf(stderr, "note: Actual period %f\n", actualPeriod);
+	}
+
+	assert(difference <= tolerance);
+
+	// Deregister timer and tick once to synchronize
+	assert(!puglStopTimer(app.view, timerId));
+	puglUpdate(app.world, 0.0);
+
+	// Update for a half second and check that we receive no more alarms
+	app.numAlarms = 0;
+	puglUpdate(app.world, 0.5);
+	assert(app.numAlarms == 0);
+
+	puglFreeView(app.view);
+	puglFreeWorld(app.world);
+
+	return 0;
+}
diff --git a/test/test_utils.h b/test/test_utils.h
index 3e62714..cef94dd 100644
--- a/test/test_utils.h
+++ b/test/test_utils.h
@@ -126,6 +126,8 @@ printEvent(const PuglEvent* event, const char* prefix, const bool verbose)
 		             prefix,
 		             event->client.data1,
 		             event->client.data2);
+	case PUGL_TIMER:
+		return PRINT("%sTimer %" PRIuPTR "\n", prefix, event->timer.id);
 	default:
 		break;
 	}