Add a skeleton of a heap profiler extracted from Mono

tools/extheapshot.c

@@ -0,0 +1,144 @@
+/*
+ * This is a butchered version of the Mono log profiler; most features have
+ * been removed, except for some features needed for heap analysis of niecza
+ * which have been added.  Changes by sorear.
+ */
+
+/*
+ * proflog.c: mono log profiler
+ *
+ * Author:
+ *   Paolo Molaro (lupus@ximian.com)
+ *
+ * Copyright 2010 Novell, Inc (http://www.novell.com)
+ * Copyright 2011 Xamarin Inc (http://www.xamarin.com)
+ */
+
+#include <mono/metadata/profiler.h>
+#include <mono/metadata/threads.h>
+#include <mono/metadata/mono-gc.h>
+#include <mono/metadata/debug-helpers.h>
+
+#include <time.h>
+#include <stdlib.h>
+#include <stdio.h>
+
+/*#include <string.h>
+#include <assert.h>
+#include <unistd.h>
+#include <fcntl.h>
+#include <errno.h>*/
+
+struct _MonoProfiler {
+};
+
+static int do_heap_shot = 0;
+
+/* For linux compile with:
+ * gcc -fPIC -shared -o libmono-profiler-log.so proflog.c utils.c -Wall -g -lz `pkg-config --cflags --libs mono-2`
+ * gcc -o mprof-report decode.c utils.c -Wall -g -lz -lrt -lpthread `pkg-config --cflags mono-2`
+ *
+ * For osx compile with:
+ * gcc -m32 -Dmono_free=free shared -o libmono-profiler-log.dylib proflog.c utils.c -Wall -g -lz `pkg-config --cflags mono-2` -undefined suppress -flat_namespace
+ * gcc -m32 -o mprof-report decode.c utils.c -Wall -g -lz -lrt -lpthread `pkg-config --cflags mono-2`
+ *
+ * Install with:
+ * sudo cp mprof-report /usr/local/bin
+ * sudo cp libmono-profiler-log.so /usr/local/lib
+ * sudo ldconfig
+ */
+
+static int
+gc_reference (MonoObject *obj, MonoClass *klass, uintptr_t size, uintptr_t num, MonoObject **refs, uintptr_t *offsets, void *data)
+{
+	printf ("obj: %p, klass: %s, refs: %d, size: %d\n", obj, mono_class_get_name(klass), (int)num, (int)size);
+	return 0;
+}
+
+static unsigned int hs_mode_s = 0;
+static unsigned int hs_mode_gc = 0;
+static unsigned int gc_count = 0;
+static unsigned int last_gc_gen_started = -1;
+static time_t last_hs_time = 0;
+
+static void
+heap_walk (MonoProfiler *profiler)
+{
+	int do_walk = 0;
+	time_t now = time(0);
+	if (!do_heap_shot)
+		return;
+	if (hs_mode_s && (now - last_hs_time) >= hs_mode_s)
+		do_walk = 1;
+	else if (hs_mode_gc && (gc_count % hs_mode_gc) == 0)
+		do_walk = 1;
+	else if (!hs_mode_s && !hs_mode_gc && last_gc_gen_started == mono_gc_max_generation ())
+		do_walk = 1;
+
+	if (!do_walk)
+		return;
+
+	printf("Heap shot started...\n");
+	mono_gc_walk_heap (0, gc_reference, NULL);
+	last_hs_time = now;
+	printf("Heap shot ends.\n");
+}
+
+static void
+gc_event (MonoProfiler *profiler, MonoGCEvent ev, int generation) {
+	/* to deal with nested gen1 after gen0 started */
+	if (ev == MONO_GC_EVENT_START) {
+		last_gc_gen_started = generation;
+		if (generation == mono_gc_max_generation ())
+			gc_count++;
+	}
+	if (ev == MONO_GC_EVENT_PRE_START_WORLD)
+		heap_walk (profiler);
+	//printf ("gc event %d for generation %d\n", ev, generation);
+}
+
+static void
+gc_handle (MonoProfiler *prof, int op, int type, uintptr_t handle, MonoObject *obj) {
+}
+
+static void
+gc_roots (MonoProfiler *prof, int num, void **objects, int *root_types, uintptr_t *extra_info)
+{
+	int i;
+	for (i = 0; i < num; ++i) {
+		printf("root: %p t=%d ei=%d\n", objects[i], root_types[i], (int)extra_info[i]);
+	}
+}
+
+/* 
+ * declaration to silence the compiler: this is the entry point that
+ * mono will load from the shared library and call.
+ */
+extern void
+mono_profiler_startup (const char *desc);
+
+static void
+log_shutdown (MonoProfiler *prof)
+{
+}
+
+static void
+gc_resize (MonoProfiler *profiler, int64_t new_size) {
+}
+
+void
+mono_profiler_startup (const char *desc)
+{
+	int events = MONO_PROFILE_GC|MONO_PROFILE_GC_MOVES|
+	    MONO_PROFILE_GC_ROOTS;
+
+	do_heap_shot = 1;
+	hs_mode_s = 10;
+
+	mono_profiler_install (NULL, log_shutdown);
+	mono_profiler_install_gc (gc_event, gc_resize);
+	mono_profiler_install_gc_roots (gc_handle, gc_roots);
+
+	mono_profiler_set_events (events);
+}
+