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2556097a98d2bc4f876c07db6f642f0cb1ac8186
MaxScale/server/core/load_utils.c
VilhoRaatikka fd11e6a7f5 Session-specific logging. Added functions 
void session_enable_log(SESSION* ses, logfile_id_t id)
and
void session_disable_log(SESSION* ses, logfile_id_t id)

Which switch specific log type on/off if the log type in question is not generally enabled.

Each thread carries a thread-specific struct log_info_t which includes members for current session id and bitfield for enabled log types for the current session. That information is checked before actual log write functions are called.

Each file where session-specific logging is used, must include the following exports:

/** Defined in log_manager.cc */
extern int            lm_enabled_logfiles_bitmask;
extern size_t         log_ses_count[];
extern __thread log_info_t tls_log_info;
2014-11-19 00:08:59 +02:00

395 lines
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/*
* This file is distributed as part of the MariaDB Corporation MaxScale. It is free
* software: you can redistribute it and/or modify it under the terms of the
* GNU General Public License as published by the Free Software Foundation,
* version 2.
*
* This program is distributed in the hope that it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
* FOR A PARTICULAR PURPOSE. See the GNU General Public License for more
* details.
*
* You should have received a copy of the GNU General Public License along with
* this program; if not, write to the Free Software Foundation, Inc., 51
* Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
*
* Copyright MariaDB Corporation Ab 2013-2014
*/
/**
* @file load_utils.c Utility functions to aid the loading of dynamic
* modules into the gateway
*
* @verbatim
* Revision History
*
* Date Who Description
* 13/06/13 Mark Riddoch Initial implementation
* 14/06/13 Mark Riddoch Updated to add call to ModuleInit if one is
* defined in the loaded module.
* Also updated to call fixed GetModuleObject
* 02/06/14 Mark Riddoch Addition of module info
*
* @endverbatim
*/
#include <sys/param.h>
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <string.h>
#include <dlfcn.h>
#include <modules.h>
#include <modinfo.h>
#include <skygw_utils.h>
#include <log_manager.h>
/** Defined in log_manager.cc */
extern int lm_enabled_logfiles_bitmask;
extern size_t log_ses_count[];
extern __thread log_info_t tls_log_info;
static MODULES *registered = NULL;
static MODULES *find_module(const char *module);
static void register_module(const char *module,
const char *type,
void *dlhandle,
char *version,
void *modobj,
MODULE_INFO *info);
static void unregister_module(const char *module);
char* get_maxscale_home(void)
{
char* home = getenv("MAXSCALE_HOME");
if (home == NULL)
{
home = "/usr/local/skysql/MaxScale";
}
return home;
}
/**
* Load the dynamic library related to a gateway module. The routine
* will look for library files in the current directory,
* $MAXSCALE_HOME/modules and /usr/local/skysql/MaxScale/modules.
*
* @param module Name of the module to load
* @param type Type of module, used purely for registration
* @return The module specific entry point structure or NULL
*/
void *
load_module(const char *module, const char *type)
{
char *home, *version;
char fname[MAXPATHLEN+1];
void *dlhandle, *sym;
char *(*ver)();
void *(*ep)(), *modobj;
MODULES *mod;
MODULE_INFO *mod_info = NULL;
if ((mod = find_module(module)) == NULL)
{
/*<
* The module is not already loaded
*
* Search of the shared object.
*/
snprintf(fname,MAXPATHLEN+1, "./lib%s.so", module);
if (access(fname, F_OK) == -1)
{
home = get_maxscale_home ();
snprintf(fname, MAXPATHLEN+1,"%s/modules/lib%s.so", home, module);
if (access(fname, F_OK) == -1)
{
LOGIF(LE, (skygw_log_write_flush(
LOGFILE_ERROR,
"Error : Unable to find library for "
"module: %s.",
module)));
return NULL;
}
}
if ((dlhandle = dlopen(fname, RTLD_NOW|RTLD_LOCAL)) == NULL)
{
LOGIF(LE, (skygw_log_write_flush(
LOGFILE_ERROR,
"Error : Unable to load library for module: "
"%s\n\n\t\t %s."
"\n\n",
module,
dlerror())));
return NULL;
}
if ((sym = dlsym(dlhandle, "version")) == NULL)
{
LOGIF(LE, (skygw_log_write_flush(
LOGFILE_ERROR,
"Error : Version interface not supported by "
"module: %s\n\t\t\t %s.",
module,
dlerror())));
dlclose(dlhandle);
return NULL;
}
ver = sym;
version = ver();
/*
* If the module has a ModuleInit function cal it now.
*/
if ((sym = dlsym(dlhandle, "ModuleInit")) != NULL)
{
void (*ModuleInit)() = sym;
ModuleInit();
}
if ((sym = dlsym(dlhandle, "info")) != NULL)
{
int fatal = 0;
mod_info = sym;
if (strcmp(type, MODULE_PROTOCOL) == 0
&& mod_info->modapi != MODULE_API_PROTOCOL)
{
LOGIF(LE, (skygw_log_write_flush(
LOGFILE_ERROR,
"Module '%s' does not implement "
"the protocol API.\n",
module)));
fatal = 1;
}
if (strcmp(type, MODULE_ROUTER) == 0
&& mod_info->modapi != MODULE_API_ROUTER)
{
LOGIF(LE, (skygw_log_write_flush(
LOGFILE_ERROR,
"Module '%s' does not implement "
"the router API.\n",
module)));
fatal = 1;
}
if (strcmp(type, MODULE_MONITOR) == 0
&& mod_info->modapi != MODULE_API_MONITOR)
{
LOGIF(LE, (skygw_log_write_flush(
LOGFILE_ERROR,
"Module '%s' does not implement "
"the monitor API.\n",
module)));
fatal = 1;
}
if (strcmp(type, MODULE_FILTER) == 0
&& mod_info->modapi != MODULE_API_FILTER)
{
LOGIF(LE, (skygw_log_write_flush(
LOGFILE_ERROR,
"Module '%s' does not implement "
"the filter API.\n",
module)));
fatal = 1;
}
if (fatal)
{
dlclose(dlhandle);
return NULL;
}
}
if ((sym = dlsym(dlhandle, "GetModuleObject")) == NULL)
{
LOGIF(LE, (skygw_log_write_flush(
LOGFILE_ERROR,
"Error : Expected entry point interface missing "
"from module: %s\n\t\t\t %s.",
module,
dlerror())));
dlclose(dlhandle);
return NULL;
}
ep = sym;
modobj = ep();
LOGIF(LM, (skygw_log_write_flush(
LOGFILE_MESSAGE,
"Loaded module %s: %s from %s",
module,
version,
fname)));
register_module(module, type, dlhandle, version, modobj, mod_info);
}
else
{
/*
* The module is already loaded, get the entry points again and
* return a reference to the already loaded module.
*/
modobj = mod->modobj;
}
return modobj;
}
/**
* Unload a module.
*
* No errors are returned since it is not clear that much can be done
* to fix issues relating to unloading modules.
*
* @param module The name of the module
*/
void
unload_module(const char *module)
{
MODULES *mod = find_module(module);
void *handle;
if (!mod)
return;
handle = mod->handle;
unregister_module(module);
dlclose(handle);
}
/**
* Find a module that has been previously loaded and return the handle for that
* library
*
* @param module The name of the module
* @return The module handle or NULL if it was not found
*/
static MODULES *
find_module(const char *module)
{
MODULES *mod = registered;
while (mod)
if (strcmp(mod->module, module) == 0)
return mod;
else
mod = mod->next;
return NULL;
}
/**
* Register a newly loaded module. The registration allows for single copies
* to be loaded and cached entry point information to be return.
*
* @param module The name of the module loaded
* @param type The type of the module loaded
* @param dlhandle The handle returned by dlopen
* @param version The version string returned by the module
* @param modobj The module object
* @param mod_info The module information
*/
static void
register_module(const char *module, const char *type, void *dlhandle, char *version, void *modobj, MODULE_INFO *mod_info)
{
MODULES *mod;
if ((mod = malloc(sizeof(MODULES))) == NULL)
return;
mod->module = strdup(module);
mod->type = strdup(type);
mod->handle = dlhandle;
mod->version = strdup(version);
mod->modobj = modobj;
mod->next = registered;
mod->info = mod_info;
registered = mod;
}
/**
* Unregister a module
*
* @param module The name of the module to remove
*/
static void
unregister_module(const char *module)
{
MODULES *mod = find_module(module);
MODULES *ptr;
if (!mod)
return; // Module not found
if (registered == mod)
registered = mod->next;
else
{
ptr = registered;
while (ptr && ptr->next != mod)
ptr = ptr->next;
}
/*<
* The module is now not in the linked list and all
* memory related to it can be freed
*/
free(mod->module);
free(mod->type);
free(mod->version);
free(mod);
}
/**
* Print Modules
*
* Diagnostic routine to display all the loaded modules
*/
void
printModules()
{
MODULES *ptr = registered;
printf("%-15s | %-11s | Version\n", "Module Name", "Module Type");
printf("-----------------------------------------------------\n");
while (ptr)
{
printf("%-15s | %-11s | %s\n", ptr->module, ptr->type, ptr->version);
ptr = ptr->next;
}
}
/**
* Print Modules to a DCB
*
* Diagnostic routine to display all the loaded modules
*/
void
dprintAllModules(DCB *dcb)
{
MODULES *ptr = registered;
dcb_printf(dcb, "Modules.\n");
dcb_printf(dcb, "----------------+-------------+---------+-------+-------------------------\n");
dcb_printf(dcb, "%-15s | %-11s | Version | API | Status\n", "Module Name", "Module Type");
dcb_printf(dcb, "----------------+-------------+---------+-------+-------------------------\n");
while (ptr)
{
dcb_printf(dcb, "%-15s | %-11s | %-7s ", ptr->module, ptr->type, ptr->version);
if (ptr->info)
dcb_printf(dcb, "| %d.%d.%d | %s",
ptr->info->api_version.major,
ptr->info->api_version.minor,
ptr->info->api_version.patch,
ptr->info->status == MODULE_IN_DEVELOPMENT
? "In Development"
: (ptr->info->status == MODULE_ALPHA_RELEASE
? "Alpha"
: (ptr->info->status == MODULE_BETA_RELEASE
? "Beta"
: (ptr->info->status == MODULE_GA
? "GA"
: (ptr->info->status == MODULE_EXPERIMENTAL
? "Experimental" : "Unknown")))));
dcb_printf(dcb, "\n");
ptr = ptr->next;
}
dcb_printf(dcb, "----------------+-------------+---------+-------+-------------------------\n\n");
}
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