From cdd75e3b0d1e668bc498f18f0ea8353f9f955114 Mon Sep 17 00:00:00 2001 From: Stephane Eranian Date: Thu, 13 Oct 2016 03:59:35 -0700 Subject: [PATCH] perf jit: Improve error messages from JVMTI This patch improves the usefulness of error messages generated by the JVMTI interfac.e This can help identify the root cause of a problem by printing the actual error code. The patch adds a new helper function called print_error(). Signed-off-by: Stephane Eranian Cc: Anton Blanchard Cc: Jiri Olsa Cc: Namhyung Kim Cc: Nilay Vaish Cc: Peter Zijlstra Link: http://lkml.kernel.org/r/1476356383-30100-2-git-send-email-eranian@google.com [ Handle failure to convert numeric error to a string in print_error() ] Signed-off-by: Arnaldo Carvalho de Melo --- tools/perf/jvmti/libjvmti.c | 39 +++++++++++++++++++++++++++++---------- 1 file changed, 29 insertions(+), 10 deletions(-) diff --git a/tools/perf/jvmti/libjvmti.c b/tools/perf/jvmti/libjvmti.c index ac12e4b..5612641 100644 --- a/tools/perf/jvmti/libjvmti.c +++ b/tools/perf/jvmti/libjvmti.c @@ -12,6 +12,19 @@ static int has_line_numbers; void *jvmti_agent; +static void print_error(jvmtiEnv *jvmti, const char *msg, jvmtiError ret) +{ + char *err_msg = NULL; + jvmtiError err; + err = (*jvmti)->GetErrorName(jvmti, ret, &err_msg); + if (err == JVMTI_ERROR_NONE) { + warnx("%s failed with %s", msg, err_msg); + (*jvmti)->Deallocate(jvmti, (unsigned char *)err_msg); + } else { + warnx("%s failed with an unknown error %d", msg, ret); + } +} + static jvmtiError do_get_line_numbers(jvmtiEnv *jvmti, void *pc, jmethodID m, jint bci, jvmti_line_info_t *tab, jint *nr) @@ -22,8 +35,10 @@ do_get_line_numbers(jvmtiEnv *jvmti, void *pc, jmethodID m, jint bci, jvmtiError ret; ret = (*jvmti)->GetLineNumberTable(jvmti, m, &nr_lines, &loc_tab); - if (ret != JVMTI_ERROR_NONE) + if (ret != JVMTI_ERROR_NONE) { + print_error(jvmti, "GetLineNumberTable", ret); return ret; + } for (i = 0; i < nr_lines; i++) { if (loc_tab[i].start_location < bci) { @@ -71,6 +86,8 @@ get_line_numbers(jvmtiEnv *jvmti, const void *compile_info, jvmti_line_info_t ** /* free what was allocated for nothing */ (*jvmti)->Deallocate(jvmti, (unsigned char *)lne); nr_total += (int)nr; + } else { + print_error(jvmti, "GetLineNumberTable", ret); } } } @@ -130,7 +147,7 @@ compiled_method_load_cb(jvmtiEnv *jvmti, ret = (*jvmti)->GetMethodDeclaringClass(jvmti, method, &decl_class); if (ret != JVMTI_ERROR_NONE) { - warnx("jvmti: cannot get declaring class"); + print_error(jvmti, "GetMethodDeclaringClass", ret); return; } @@ -144,21 +161,21 @@ compiled_method_load_cb(jvmtiEnv *jvmti, ret = (*jvmti)->GetSourceFileName(jvmti, decl_class, &file_name); if (ret != JVMTI_ERROR_NONE) { - warnx("jvmti: cannot get source filename ret=%d", ret); + print_error(jvmti, "GetSourceFileName", ret); goto error; } ret = (*jvmti)->GetClassSignature(jvmti, decl_class, &class_sign, NULL); if (ret != JVMTI_ERROR_NONE) { - warnx("jvmti: getclassignature failed"); + print_error(jvmti, "GetClassSignature", ret); goto error; } ret = (*jvmti)->GetMethodName(jvmti, method, &func_name, &func_sign, NULL); if (ret != JVMTI_ERROR_NONE) { - warnx("jvmti: failed getmethodname"); + print_error(jvmti, "GetMethodName", ret); goto error; } @@ -253,7 +270,7 @@ Agent_OnLoad(JavaVM *jvm, char *options, void *reserved __unused) ret = (*jvmti)->AddCapabilities(jvmti, &caps1); if (ret != JVMTI_ERROR_NONE) { - warnx("jvmti: acquire compiled_method capability failed"); + print_error(jvmti, "AddCapabilities", ret); return -1; } ret = (*jvmti)->GetJLocationFormat(jvmti, &format); @@ -264,7 +281,9 @@ Agent_OnLoad(JavaVM *jvm, char *options, void *reserved __unused) ret = (*jvmti)->AddCapabilities(jvmti, &caps1); if (ret == JVMTI_ERROR_NONE) has_line_numbers = 1; - } + } else if (ret != JVMTI_ERROR_NONE) + print_error(jvmti, "GetJLocationFormat", ret); + memset(&cb, 0, sizeof(cb)); @@ -273,21 +292,21 @@ Agent_OnLoad(JavaVM *jvm, char *options, void *reserved __unused) ret = (*jvmti)->SetEventCallbacks(jvmti, &cb, sizeof(cb)); if (ret != JVMTI_ERROR_NONE) { - warnx("jvmti: cannot set event callbacks"); + print_error(jvmti, "SetEventCallbacks", ret); return -1; } ret = (*jvmti)->SetEventNotificationMode(jvmti, JVMTI_ENABLE, JVMTI_EVENT_COMPILED_METHOD_LOAD, NULL); if (ret != JVMTI_ERROR_NONE) { - warnx("jvmti: setnotification failed for method_load"); + print_error(jvmti, "SetEventNotificationMode(METHOD_LOAD)", ret); return -1; } ret = (*jvmti)->SetEventNotificationMode(jvmti, JVMTI_ENABLE, JVMTI_EVENT_DYNAMIC_CODE_GENERATED, NULL); if (ret != JVMTI_ERROR_NONE) { - warnx("jvmti: setnotification failed on code_generated"); + print_error(jvmti, "SetEventNotificationMode(CODE_GENERATED)", ret); return -1; } return 0; -- 2.7.4