From 6f7ce4063f8fb991e6fefddc8d77f3aa105d8efc Mon Sep 17 00:00:00 2001
From: Rodrigo Arias <rodrigo.arias@bsc.es>
Date: Fri, 10 Nov 2023 15:27:55 +0100
Subject: [PATCH] Enable all models if the require key is missing

Allows programs to update to a new libovni library without breaking the
instrumentation. Only until the first call to ovni_thread_require() the
models are enabled on demand.
---
 src/emu/model.c                  |  7 +++---
 src/rt/ovni.c                    | 42 ++++++++++++--------------------
 test/emu/common/instr.h          |  1 +
 test/emu/nosv/multiple-segment.c |  1 +
 4 files changed, 21 insertions(+), 30 deletions(-)

diff --git a/src/emu/model.c b/src/emu/model.c
index 90db93e..ba82912 100644
--- a/src/emu/model.c
+++ b/src/emu/model.c
@@ -198,14 +198,13 @@ model_version_probe(struct model_spec *spec, struct emu *emu)
 			return -1;
 		}
 
-		/* The ovni.require key is mandatory */
 		JSON_Object *require = json_object_dotget_object(t->meta, "ovni.require");
 		if (require == NULL) {
-			err("missing 'ovni.require' key in metadata");
-			return -1;
+			warn("missing 'ovni.require' key, enabling all models");
+			enable = 1;
+			break;
 		}
 
-		/* But not all threads need to have this model */
 		const char *req_version = json_object_get_string(require, spec->name);
 		if (req_version == NULL)
 			continue;
diff --git a/src/rt/ovni.c b/src/rt/ovni.c
index 42924de..65b06e7 100644
--- a/src/rt/ovni.c
+++ b/src/rt/ovni.c
@@ -464,29 +464,6 @@ thread_metadata_store(void)
 		die("failed to write thread metadata");
 }
 
-static void
-thread_require_unsafe(const char *model, const char *version)
-{
-	int parsedver[3];
-	if (version_parse(version, parsedver) != 0)
-		die("failed to parse provided version \"%s\"", version);
-
-	/* Store into metadata */
-	JSON_Object *meta = json_value_get_object(rthread.meta);
-
-	if (meta == NULL)
-		die("json_value_get_object failed");
-
-	char dotpath[128];
-	if (snprintf(dotpath, 128, "ovni.require.%s", model) >= 128)
-		die("model name too long");
-
-	/* TODO: What if is already set? */
-
-	if (json_object_dotset_string(meta, dotpath, version) != 0)
-		die("json_object_dotset_string failed");
-}
-
 void
 ovni_thread_require(const char *model, const char *version)
 {
@@ -507,7 +484,22 @@ ovni_thread_require(const char *model, const char *version)
 	if (version == NULL)
 		die("version string is NULL");
 
-	thread_require_unsafe(model, version);
+	int parsedver[3];
+	if (version_parse(version, parsedver) != 0)
+		die("failed to parse provided version \"%s\"", version);
+
+	/* Store into metadata */
+	JSON_Object *meta = json_value_get_object(rthread.meta);
+
+	if (meta == NULL)
+		die("json_value_get_object failed");
+
+	char dotpath[128];
+	if (snprintf(dotpath, 128, "ovni.require.%s", model) >= 128)
+		die("model name too long");
+
+	if (json_object_dotset_string(meta, dotpath, version) != 0)
+		die("json_object_dotset_string failed");
 }
 
 static void
@@ -526,8 +518,6 @@ thread_metadata_populate(void)
 
 	if (json_object_dotset_string(meta, "ovni.lib.commit", OVNI_GIT_COMMIT) != 0)
 		die("json_object_dotset_string failed");
-
-	thread_require_unsafe("ovni", "1.0.0");
 }
 
 static void
diff --git a/test/emu/common/instr.h b/test/emu/common/instr.h
index 7701a6e..37c05c8 100644
--- a/test/emu/common/instr.h
+++ b/test/emu/common/instr.h
@@ -111,6 +111,7 @@ instr_start(int rank, int nranks)
 	dbg("thread %d has cpu %d (ncpus=%d)",
 			get_tid(), curcpu, nranks);
 
+	instr_require("ovni");
 	instr_thread_execute(curcpu, -1, 0);
 }
 
diff --git a/test/emu/nosv/multiple-segment.c b/test/emu/nosv/multiple-segment.c
index 2b721be..4c597c4 100644
--- a/test/emu/nosv/multiple-segment.c
+++ b/test/emu/nosv/multiple-segment.c
@@ -46,6 +46,7 @@ main(void)
 	int lcpu = rank % N;
 
 	ovni_thread_init(get_tid());
+	instr_require("ovni");
 	instr_nosv_init();
 	instr_thread_execute(lcpu, -1, 0);