gint shadow_main(gint argc, gchar* argv[]) {
/* check the compiled GLib version */
if (!GLIB_CHECK_VERSION(2, 32, 0)) {
g_printerr("** GLib version 2.32.0 or above is required but Shadow was compiled against version %u.%u.%u\n",
(guint)GLIB_MAJOR_VERSION, (guint)GLIB_MINOR_VERSION, (guint)GLIB_MICRO_VERSION);
return -1;
}
if(GLIB_MAJOR_VERSION == 2 && GLIB_MINOR_VERSION == 40) {
g_printerr("** You compiled against GLib version %u.%u.%u, which has bugs known to break Shadow. Please update to a newer version of GLib.\n",
(guint)GLIB_MAJOR_VERSION, (guint)GLIB_MINOR_VERSION, (guint)GLIB_MICRO_VERSION);
return -1;
}
/* check the that run-time GLib matches the compiled version */
const gchar* mismatch = glib_check_version(GLIB_MAJOR_VERSION, GLIB_MINOR_VERSION, GLIB_MICRO_VERSION);
if(mismatch) {
g_printerr("** The version of the run-time GLib library (%u.%u.%u) is not compatible with the version against which Shadow was compiled (%u.%u.%u). GLib message: '%s'\n",
glib_major_version, glib_minor_version, glib_micro_version,
(guint)GLIB_MAJOR_VERSION, (guint)GLIB_MINOR_VERSION, (guint)GLIB_MICRO_VERSION,
mismatch);
return -1;
}
/* setup configuration - this fails and aborts if invalid */
gchar* cmds = g_strjoinv(" ", argv);
gchar** cmdv = g_strsplit(cmds, " ", 0);
Configuration* config = configuration_new(argc, cmdv);
g_free(cmds);
g_strfreev(cmdv);
if(!config) {
/* incorrect options given */
return -1;
} else if(config->printSoftwareVersion) {
g_printerr("%s running GLib v%u.%u.%u and IGraph v%s\n%s\n",
SHADOW_VERSION_STRING,
(guint)GLIB_MAJOR_VERSION, (guint)GLIB_MINOR_VERSION, (guint)GLIB_MICRO_VERSION,
#if defined(IGRAPH_VERSION)
IGRAPH_VERSION,
#else
"(n/a)",
#endif
SHADOW_INFO_STRING);
configuration_free(config);
return 0;
}
/* check environment for LD_PRELOAD */
gchar** envlist = g_get_environ();
gboolean preloadSuccess = _main_checkPreloadEnvironment(envlist);
g_strfreev(envlist);
gboolean respawned = g_getenv("SHADOW_SPAWNED") != NULL ? TRUE : FALSE;
if(respawned) {
/* if shadow already respawned once and LD_PRELOAD still isnt correct,
* then the user will need to provide the correct path */
if(!preloadSuccess) {
g_printerr("** Environment Check Failed: LD_PRELOAD does not contain an absolute path to "INTERPOSELIBSTR"\n");
return -1;
}
/* NOTE: we ignore valgrind and preload options during the respawn */
} else {
/* if preload is not set, or the user added a preload library,
* or we are going to run valgrind, we need to respawn */
if(config->preloads || config->runValgrind || !preloadSuccess) {
gchar** envlist = _main_getSpawnEnviroment(config->preloads, config->runValgrind);
gchar* cmds = g_strjoinv(" ", argv);
gchar** cmdv = g_strsplit(cmds, " ", 0);
GError* error = NULL;
gint exitStatus = 0;
gboolean spawnSuccess = config->runValgrind ?
_main_spawnShadowWithValgrind(cmdv, envlist, &exitStatus, &error) :
_main_spawnShadow(cmdv, envlist, &exitStatus, &error);
g_free(cmds);
g_strfreev(cmdv);
g_strfreev(envlist);
if(!spawnSuccess) {
g_printerr("** Error %i while re-spawning shadow process: %s\n", error->code, error->message);
return -1;
}
/* child was run */
return (exitStatus == 0) ? 0 : -1;
}
}
utility_assert(preloadSuccess);
/* tell the preaload lib we are ready for action */
extern void interposer_setShadowIsLoaded();
interposer_setShadowIsLoaded();
/* allocate and initialize our main simulation driver */
gint returnCode = 0;
shadowMaster = master_new(config);
if(shadowMaster) {
/* run the simulation */
returnCode = master_run(shadowMaster);
/* cleanup */
master_free(shadowMaster);
shadowMaster = NULL;
}
configuration_free(config);
g_printerr("** shadow returning code %i (%s)\n", returnCode, (returnCode == 0) ? "success" : "error");
return returnCode;
}
static gint _main_helper(Options* options) {
/* start off with some status messages */
#if defined(IGRAPH_VERSION)
gint igraphMajor = -1, igraphMinor = -1, igraphPatch = -1;
igraph_version(NULL, &igraphMajor, &igraphMinor, &igraphPatch);
gchar* startupStr = g_strdup_printf("Starting %s with GLib v%u.%u.%u and IGraph v%i.%i.%i",
SHADOW_VERSION_STRING,
(guint)GLIB_MAJOR_VERSION, (guint)GLIB_MINOR_VERSION, (guint)GLIB_MICRO_VERSION,
igraphMajor, igraphMinor, igraphPatch);
#else
gchar* startupStr = g_strdup_printf("Starting %s with GLib v%u.%u.%u (IGraph version not available)",
SHADOW_VERSION_STRING,
(guint)GLIB_MAJOR_VERSION, (guint)GLIB_MINOR_VERSION, (guint)GLIB_MICRO_VERSION);
#endif
message("%s", startupStr);
/* avoid logging the message to stderr twice (only log if this is not a relaunch) */
if(g_getenv("SHADOW_SPAWNED") == NULL) {
g_printerr("** %s\n", startupStr);
}
g_free(startupStr);
message(SHADOW_INFO_STRING);
message("logging current startup arguments and environment");
gchar** envlist = g_get_environ();
gchar** arglist = g_strsplit(options_getArgumentString(options), " ", 0);
_main_logEnvironment(arglist, envlist);
g_strfreev(arglist);
g_strfreev(envlist);
/* check if we still need to setup our required environment and relaunch */
if(g_getenv("SHADOW_SPAWNED") == NULL) {
message("shadow will automatically adjust environment and relaunch");
message("loading shadow configuration file");
/* we need to relaunch.
* first lets load the config file to help us setup the environment */
const GString* fileName = options_getInputXMLFilename(options);
if(!fileName) {
return EXIT_FAILURE;
}
GString* file = utility_getFileContents(fileName->str);
if(!file) {
critical("unable to read config file contents");
return EXIT_FAILURE;
}
Configuration* config = configuration_new(options, file);
g_string_free(file, TRUE);
file = NULL;
if(!config) {
critical("there was a problem parsing the Shadow config file, and we can't run without it");
return EXIT_FAILURE;
}
message("shadow configuration file loaded, parsed, and passed validation");
/* now start to set up the environment */
gchar** envlist = g_get_environ();
GString* commandBuffer = g_string_new(options_getArgumentString(options));
if(!envlist || !commandBuffer) {
critical("there was a problem loading existing environment");
configuration_free(config);
return EXIT_FAILURE;
}
message("setting up LD_PRELOAD environment");
/* compute the proper LD_PRELOAD value, extract the shadow preload file and
* set it as a command line argument if needed */
gchar* preloadArgValue = NULL;
{
/* before we restart, we should:
* -set the shadow preload lib as a command line arg
* -make sure it does not exist in LD_PRELOAD, but otherwise leave LD_PRELOAD in place
* we need to search for our preload lib. our order of preference follows.
*/
/* 1. existing "--preload=" option value */
if(_main_isValidPathToPreloadLib(options_getPreloadString(options))) {
preloadArgValue = g_strdup(options_getPreloadString(options));
}
/* 2. the 'preload' attribute value of the 'shadow' element in shadow.config.xml */
/* we only need to search if we haven't already found a valid path */
if(!preloadArgValue) {
ConfigurationShadowElement* element = configuration_getShadowElement(config);
if(element && element->preloadPath.isSet) {
gchar* path = element->preloadPath.string->str;
if(_main_isValidPathToPreloadLib(path)) {
preloadArgValue = g_strdup(path);
}
}
}
/* 3. the LD_PRELOAD value */
GString* preloadEnvValueBuffer = NULL;
/* we always search the env variable and remove existing Shadow preload libs */
if(g_environ_getenv(envlist, "LD_PRELOAD") != NULL) {
gchar** tokens = g_strsplit(g_environ_getenv(envlist, "LD_PRELOAD"), ":", 0);
for(gint i = 0; tokens[i] != NULL; i++) {
/* each token in the env variable should be an absolute path */
if(_main_isValidPathToPreloadLib(tokens[i])) {
/* found a valid path, only save it if we don't have one yet (from options or config) */
if(!preloadArgValue) {
preloadArgValue = g_strdup(tokens[i]);
}
} else {
/* maintain non-shadow entries */
if(preloadEnvValueBuffer) {
g_string_append_printf(preloadEnvValueBuffer, ":%s", tokens[i]);
} else {
preloadEnvValueBuffer = g_string_new(tokens[i]);
}
}
}
g_strfreev(tokens);
}
/* 4. the 'environment' attribute of the 'shadow' configuration element in shadow.config.xml */
/* always go through the 'environment' attribute of the 'shadow' element to pull in any keys defined there */
{
ConfigurationShadowElement* element = configuration_getShadowElement(config);
if(element && element->environment.isSet) {
/* entries are split by ';' */
gchar** envTokens = g_strsplit(element->environment.string->str, ";", 0);
for(gint i = 0; envTokens[i] != NULL; i++) {
/* each env entry is key=value, get 2 tokens max */
gchar** items = g_strsplit(envTokens[i], "=", 2);
gchar* key = items[0];
gchar* value = items[1];
if(key != NULL && value != NULL) {
/* check if the key is LD_PRELOAD */
if(!g_ascii_strncasecmp(key, "LD_PRELOAD", 10)) {
gchar** preloadTokens = g_strsplit(value, ":", 0);
for(gint j = 0; preloadTokens[j] != NULL; j++) {
/* each token in the env variable should be an absolute path */
if(_main_isValidPathToPreloadLib(preloadTokens[j])) {
/* found a valid path, only save it if we don't have one yet (from options or config) */
if(!preloadArgValue) {
preloadArgValue = g_strdup(preloadTokens[j]);
}
} else {
/* maintain non-shadow entries */
if(preloadEnvValueBuffer) {
g_string_append_printf(preloadEnvValueBuffer, ":%s", preloadTokens[j]);
} else {
preloadEnvValueBuffer = g_string_new(preloadTokens[j]);
}
}
}
g_strfreev(preloadTokens);
} else {
/* set the key=value pair, but don't overwrite any existing settings */
envlist = g_environ_setenv(envlist, key, value, 0);
}
}
g_strfreev(items);
}
g_strfreev(envTokens);
}
}
/* save away the non-shadow preload libs */
if(preloadEnvValueBuffer) {
envlist = g_environ_setenv(envlist, "LD_PRELOAD", preloadEnvValueBuffer->str, 1);
g_string_free(preloadEnvValueBuffer, TRUE);
preloadEnvValueBuffer = NULL;
} else {
envlist = g_environ_unsetenv(envlist, "LD_PRELOAD");
}
/* 5. as a last hope, try looking in RPATH since shadow is built with one */
/* we only need to search if we haven't already found a valid path */
if(!preloadArgValue) {
gchar* rpathStr = _main_getRPath();
if(rpathStr != NULL) {
gchar** tokens = g_strsplit(rpathStr, ":", 0);
for(gint i = 0; tokens[i] != NULL; i++) {
GString* candidateBuffer = g_string_new(NULL);
/* rpath specifies directories, so look inside */
g_string_printf(candidateBuffer, "%s/%s", tokens[i], INTERPOSELIBSTR);
gchar* candidate = g_string_free(candidateBuffer, FALSE);
if(_main_isValidPathToPreloadLib(candidate)) {
preloadArgValue = candidate;
break;
} else {
g_free(candidate);
}
}
g_strfreev(tokens);
}
g_free(rpathStr);
}
/* if we still didn't find our preload lib, that is a user error */
if(!preloadArgValue) {
critical("can't find path to %s, did you specify an absolute path to an existing readable file?", INTERPOSELIBSTR);
configuration_free(config);
return EXIT_FAILURE;
}
/* now that we found the correct path to the preload lib, first remove any possibly
* incomplete path that might exist in the command line args, and then replace it
* with the path that we found and verified is correct. */
{
/* first remove all preload options */
gchar** tokens = g_strsplit(commandBuffer->str, " ", 0);
g_string_free(commandBuffer, TRUE);
commandBuffer = NULL;
for(gint i = 0; tokens[i] != NULL; i++) {
/* use -1 to search the entire string */
if(!g_ascii_strncasecmp(tokens[i], "--preload=", 10)) {
/* skip this key=value string */
} else if(!g_ascii_strncasecmp(tokens[i], "-p", 2)) {
/* skip this key, and also the next arg which is the value */
i++;
} else {
if(commandBuffer) {
g_string_append_printf(commandBuffer, " %s", tokens[i]);
} else {
commandBuffer = g_string_new(tokens[i]);
}
}
}
g_strfreev(tokens);
/* now add back in the preload option */
g_string_append_printf(commandBuffer, " --preload=%s", preloadArgValue);
}
}
message("setting up LD_STATIC_TLS_EXTRA environment");
/* compute the proper TLS size we need for dlmopen()ing all of the plugins,
* but only do this if the user didn't manually specify a size */
if(g_environ_getenv(envlist, "LD_STATIC_TLS_EXTRA") == NULL) {
gchar* staticTLSValue = _main_getStaticTLSValue(options, config, preloadArgValue);
envlist = g_environ_setenv(envlist, "LD_STATIC_TLS_EXTRA", staticTLSValue, 0);
message("we need %s total bytes of static TLS storage", staticTLSValue);
g_free(staticTLSValue);
}
/* cleanup unused string */
if(preloadArgValue) {
g_free(preloadArgValue);
preloadArgValue = NULL;
}
/* are we running valgrind */
if(options_doRunValgrind(options)) {
message("setting up environment for valgrind");
/* make glib friendlier to valgrind */
envlist = g_environ_setenv(envlist, "G_DEBUG", "gc-friendly", 0);
envlist = g_environ_setenv(envlist, "G_SLICE", "always-malloc", 0);
/* add the valgrind command and some default options */
g_string_prepend(commandBuffer,
"valgrind --leak-check=full --show-reachable=yes --track-origins=yes --trace-children=yes --log-file=shadow-valgrind-%p.log --error-limit=no ");
} else {
/* The following can be used to add internal GLib memory validation that
* will abort the program if it finds an error. This is only useful outside
* of the valgrind context, as otherwise valgrind will complain about
* the implementation of the GLib validator.
* e.g. $ G_SLICE=debug-blocks shadow --file
*
* envlist = g_environ_setenv(envlist, "G_SLICE", "debug-blocks", 0);
*/
}
/* keep track that we are relaunching shadow */
envlist = g_environ_setenv(envlist, "SHADOW_SPAWNED", "TRUE", 1);
gchar* command = g_string_free(commandBuffer, FALSE);
gchar** arglist = g_strsplit(command, " ", 0);
g_free(command);
configuration_free(config);
message("environment was updated; shadow is relaunching now with new environment");
Logger* logger = logger_getDefault();
if(logger) {
logger_setDefault(NULL);
logger_unref(logger);
}
/* execvpe only returns if there is an error, otherwise the current process
* image is replaced with a new process */
gint returnValue = execvpe(arglist[0], arglist, envlist);
/* cleanup */
if(envlist) {
g_strfreev(envlist);
}
if(arglist) {
g_strfreev(arglist);
}
critical("** Error %i while re-launching shadow process: %s", returnValue, g_strerror(returnValue));
return EXIT_FAILURE;
}
/* we dont need to relaunch, so we can run the simulation */
/* make sure we have initialized static tls */
if(!_main_verifyStaticTLS()) {
critical("** Shadow Setup Check Failed: LD_STATIC_TLS_EXTRA does not contain a nonzero value");
return EXIT_FAILURE;
}
/* make sure we have the shadow preload lib */
if(!_main_isValidPathToPreloadLib(options_getPreloadString(options))) {
critical("** Shadow Setup Check Failed: cannot find absolute path to "INTERPOSELIBSTR"");
return EXIT_FAILURE;
}
/* now load the preload library into shadow's namespace */
if(!_main_loadShadowPreload(options)) {
critical("** Shadow Setup Check Failed: unable to load preload library");
return EXIT_FAILURE;
}
/* tell the preload lib we are ready for action */
extern int interposer_setShadowIsLoaded(int);
int interposerResult = interposer_setShadowIsLoaded(1);
if(interposerResult != 0) {
/* it was not intercepted, meaning our preload library is not set up properly */
critical("** Shadow Setup Check Failed: preload library is not correctly interposing functions");
return EXIT_FAILURE;
}
message("startup checks passed, we are ready to start simulation");
/* pause for debugger attachment if the option is set */
if(options_doRunDebug(options)) {
gint pid = (gint)getpid();
message("Pausing with SIGTSTP to enable debugger attachment (pid %i)", pid);
g_printerr("** Pausing with SIGTSTP to enable debugger attachment (pid %i)\n", pid);
raise(SIGTSTP);
message("Resuming now");
}
/* allocate and initialize our main simulation driver */
gint returnCode = 0;
shadowMaster = master_new(options);
message("log message buffering is enabled for efficiency");
logger_setEnableBuffering(logger_getDefault(), TRUE);
if(shadowMaster) {
/* run the simulation */
returnCode = master_run(shadowMaster);
/* cleanup */
master_free(shadowMaster);
shadowMaster = NULL;
}
message("%s simulation was shut down cleanly, returning code %i", SHADOW_VERSION_STRING, returnCode);
return returnCode;
}