sysprof: fix a message with stop without run

The function `misc.sysprof.stop()` reports that profiler is
already running:

| $ ./src/luajit -e 'print(misc.sysprof.stop())'
| nil     profiler is running already     22

The patch splits error code `PROFILE_ERRRUN` to a two separate
error codes `PROFILE_ERRISRUN` and `PROFILE_ERRNOTRUN` to handle
both in `sysprof_error()` and fixes aforementioned problem.

Follows up tarantool/tarantool#781

src/lib_misc.c

@@ -288,7 +288,7 @@ static int sysprof_error(lua_State *L, int status, const char *err_details)
       lua_pushinteger(L, EINVAL);
       return 3;
 #if LJ_HASSYSPROF
-    case PROFILE_ERRRUN:
+    case PROFILE_ERRISRUN:
       lua_pushnil(L);
       lua_pushstring(L, err2msg(LJ_ERR_PROF_ISRUNNING));
       if (err_details) {
@@ -298,6 +298,11 @@ static int sysprof_error(lua_State *L, int status, const char *err_details)
       }
       lua_pushinteger(L, EINVAL);
       return 3;
+    case PROFILE_ERRNOTRUN:
+      lua_pushnil(L);
+      lua_pushstring(L, err2msg(LJ_ERR_PROF_NOTRUNNING));
+      lua_pushinteger(L, EINVAL);
+      return 3;
     case PROFILE_ERRIO:
       return luaL_fileresult(L, 0, NULL);
 #endif
@@ -415,7 +420,7 @@ LJLIB_CF(misc_memprof_start)
       lua_pushinteger(L, EINVAL);
       return 3;
 #if LJ_HASMEMPROF
-    case PROFILE_ERRRUN:
+    case PROFILE_ERRISRUN:
       lua_pushnil(L);
       lua_pushstring(L, err2msg(LJ_ERR_PROF_ISRUNNING));
       lua_pushinteger(L, EINVAL);
@@ -444,7 +449,7 @@ LJLIB_CF(misc_memprof_stop)
       lua_pushinteger(L, EINVAL);
       return 3;
 #if LJ_HASMEMPROF
-    case PROFILE_ERRRUN:
+    case PROFILE_ERRNOTRUN:
       lua_pushnil(L);
       lua_pushstring(L, err2msg(LJ_ERR_PROF_NOTRUNNING));
       lua_pushinteger(L, EINVAL);

src/lj_memprof.c

@@ -262,7 +262,7 @@ int lj_memprof_start(struct lua_State *L, const struct lj_memprof_options *opt)
   if (mp->state != MPS_IDLE) {
     /* Clean up resources. Ignore possible errors. */
     opt->on_stop(opt->ctx, opt->buf);
-    return PROFILE_ERRRUN;
+    return PROFILE_ERRISRUN;
   }
 
   /* Discard possible old errno. */
@@ -319,7 +319,7 @@ int lj_memprof_stop(struct lua_State *L)
   }
 
   if (mp->state != MPS_PROFILE)
-    return PROFILE_ERRRUN;
+    return PROFILE_ERRNOTRUN;
 
   if (mp->g != G(L))
     return PROFILE_ERRUSE;

src/lj_sysprof.c

@@ -359,7 +359,7 @@ static int sysprof_validate(struct sysprof *sp,
 
     case SPS_PROFILE:
     case SPS_HALT:
-      return PROFILE_ERRRUN;
+      return PROFILE_ERRISRUN;
 
     default:
       lj_assertX(0, "bad sysprof profiler state");
@@ -494,7 +494,7 @@ int lj_sysprof_stop(lua_State *L)
   struct lj_wbuf *out = &sp->out;
 
   if (SPS_IDLE == sp->state)
-    return PROFILE_ERRRUN;
+    return PROFILE_ERRNOTRUN;
   else if (G(L) != g)
     return PROFILE_ERRUSE;
 

src/lmisclib.h

@@ -138,9 +138,10 @@ struct luam_Sysprof_Options {
 
 #define PROFILE_SUCCESS 0
 #define PROFILE_ERRUSE  1
-#define PROFILE_ERRRUN  2
+#define PROFILE_ERRISRUN  2
 #define PROFILE_ERRMEM  3
 #define PROFILE_ERRIO   4
+#define PROFILE_ERRNOTRUN 5
 
 LUAMISC_API int luaM_sysprof_set_writer(luam_Sysprof_writer writer);
 

test/tarantool-tests/profilers/misclib-sysprof-lapi.test.lua

@@ -10,7 +10,7 @@ local test = tap.test("misclib-sysprof-lapi"):skipcond({
   ["Disabled due to #10803"] = os.getenv("LUAJIT_TEST_USE_VALGRIND"),
 })
 
-test:plan(33)
+test:plan(34)
 
 jit.off()
 -- XXX: Run JIT tuning functions in a safe frame to avoid errors
@@ -98,7 +98,8 @@ assert(res, err)
 
 -- Not running.
 res, err, errno = misc.sysprof.stop()
-test:ok(res == nil and err, "result status and error with not running")
+test:is(res, nil, "result status with not running")
+test:ok(err:match("profiler is not running"), "error with not running")
 test:ok(type(errno) == "number", "errno with not running")
 
 -- Bad path.