src/common.c

   1 /*
   2  * Copyright (C) 2011-2012 Julien Desfossez
   3  *
   4  * This program is free software; you can redistribute it and/or modify
   5  * it under the terms of the GNU General Public License Version 2 as
   6  * published by the Free Software Foundation;
   7  *
   8  * This program is distributed in the hope that it will be useful,
   9  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  10  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  11  * GNU General Public License for more details.
  12  *
  13  * You should have received a copy of the GNU General Public License along
  14  * with this program; if not, write to the Free Software Foundation, Inc.,
  15  * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
  16  */
  17
  18 #include <babeltrace/ctf/events.h>
  19 #include <stdlib.h>
  20 #include <linux/unistd.h>
  21 #include <string.h>
  22 #include "common.h"
  23
  24 uint64_t get_cpu_id(const struct bt_ctf_event *event)
  25 {
  26         const struct bt_definition *scope;
  27         uint64_t cpu_id;
  28
  29         scope = bt_ctf_get_top_level_scope(event, BT_STREAM_PACKET_CONTEXT);
  30         cpu_id = bt_ctf_get_uint64(bt_ctf_get_field(event, scope, "cpu_id"));
  31         if (bt_ctf_field_get_error()) {
  32                 fprintf(stderr, "[error] get cpu_id\n");
  33                 return -1ULL;
  34         }
  35
  36         return cpu_id;
  37 }
  38
  39 uint64_t get_context_tid(const struct bt_ctf_event *event)
  40 {
  41         const struct bt_definition *scope;
  42         uint64_t tid;
  43
  44         scope = bt_ctf_get_top_level_scope(event, BT_STREAM_EVENT_CONTEXT);
  45         tid = bt_ctf_get_int64(bt_ctf_get_field(event,
  46                                 scope, "_tid"));
  47         if (bt_ctf_field_get_error()) {
  48                 fprintf(stderr, "Missing tid context info\n");
  49                 return -1ULL;
  50         }
  51
  52         return tid;
  53 }
  54
  55 uint64_t get_context_pid(const struct bt_ctf_event *event)
  56 {
  57         const struct bt_definition *scope;
  58         uint64_t pid;
  59
  60         scope = bt_ctf_get_top_level_scope(event, BT_STREAM_EVENT_CONTEXT);
  61         pid = bt_ctf_get_int64(bt_ctf_get_field(event,
  62                                 scope, "_pid"));
  63         if (bt_ctf_field_get_error()) {
  64                 fprintf(stderr, "Missing pid context info\n");
  65                 return -1ULL;
  66         }
  67
  68         return pid;
  69 }
  70
  71 uint64_t get_context_ppid(const struct bt_ctf_event *event)
  72 {
  73         const struct bt_definition *scope;
  74         uint64_t ppid;
  75
  76         scope = bt_ctf_get_top_level_scope(event, BT_STREAM_EVENT_CONTEXT);
  77         ppid = bt_ctf_get_int64(bt_ctf_get_field(event,
  78                                 scope, "_ppid"));
  79         if (bt_ctf_field_get_error()) {
  80                 fprintf(stderr, "Missing ppid context info\n");
  81                 return -1ULL;
  82         }
  83
  84         return ppid;
  85 }
  86
  87 uint64_t get_context_vtid(const struct bt_ctf_event *event)
  88 {
  89         const struct definition *scope;
  90         uint64_t vtid;
  91
  92         scope = bt_ctf_get_top_level_scope(event, BT_STREAM_EVENT_CONTEXT);
  93         vtid = bt_ctf_get_int64(bt_ctf_get_field(event,
  94                                 scope, "_vtid"));
  95         if (bt_ctf_field_get_error()) {
  96                 return -1ULL;
  97         }
  98
  99         return vtid;
 100 }
 101
 102 uint64_t get_context_vpid(const struct bt_ctf_event *event)
 103 {
 104         const struct definition *scope;
 105         uint64_t vpid;
 106
 107         scope = bt_ctf_get_top_level_scope(event, BT_STREAM_EVENT_CONTEXT);
 108         vpid = bt_ctf_get_int64(bt_ctf_get_field(event,
 109                                 scope, "_vpid"));
 110         if (bt_ctf_field_get_error()) {
 111                 return -1ULL;
 112         }
 113
 114         return vpid;
 115 }
 116
 117 uint64_t get_context_vppid(const struct bt_ctf_event *event)
 118 {
 119         const struct definition *scope;
 120         uint64_t vppid;
 121
 122         scope = bt_ctf_get_top_level_scope(event, BT_STREAM_EVENT_CONTEXT);
 123         vppid = bt_ctf_get_int64(bt_ctf_get_field(event,
 124                                 scope, "_vppid"));
 125         if (bt_ctf_field_get_error()) {
 126                 return -1ULL;
 127         }
 128
 129         return vppid;
 130 }
 131
 132 char *get_context_comm(const struct bt_ctf_event *event)
 133 {
 134         const struct bt_definition *scope;
 135         char *comm;
 136
 137         scope = bt_ctf_get_top_level_scope(event, BT_STREAM_EVENT_CONTEXT);
 138         comm = bt_ctf_get_char_array(bt_ctf_get_field(event,
 139                                 scope, "_procname"));
 140         if (bt_ctf_field_get_error()) {
 141                 fprintf(stderr, "Missing comm context info\n");
 142                 return NULL;
 143         }
 144
 145         return comm;
 146 }
 147
 148 char *get_context_hostname(const struct bt_ctf_event *event)
 149 {
 150         const struct definition *scope;
 151         char *hostname;
 152
 153         scope = bt_ctf_get_top_level_scope(event, BT_STREAM_EVENT_CONTEXT);
 154         hostname = bt_ctf_get_char_array(bt_ctf_get_field(event,
 155                                 scope, "_hostname"));
 156         if (bt_ctf_field_get_error()) {
 157                 return NULL;
 158         }
 159
 160         return hostname;
 161 }
 162
 163 /*
 164  * To get the parent process, put the pid in the tid field
 165  * because the parent process gets pid = tid
 166  */
 167 struct processtop *find_process_tid(struct lttngtop *ctx, int tid, char *comm)
 168 {
 169         struct processtop *tmp;
 170
 171         tmp = g_hash_table_lookup(ctx->process_hash_table,
 172                         (gconstpointer) (unsigned long) tid);
 173
 174         return tmp;
 175 }
 176
 177 struct processtop* add_proc(struct lttngtop *ctx, int tid, char *comm,
 178                 unsigned long timestamp)
 179 {
 180         struct processtop *newproc;
 181
 182         /* if the PID already exists, we just rename the process */
 183         /* FIXME : need to integrate with clone/fork/exit to be accurate */
 184         newproc = find_process_tid(ctx, tid, comm);
 185
 186         if (!newproc) {
 187                 newproc = g_new0(struct processtop, 1);
 188                 newproc->tid = tid;
 189                 newproc->birth = timestamp;
 190                 newproc->process_files_table = g_ptr_array_new();
 191                 newproc->files_history = NULL;
 192                 newproc->totalfileread = 0;
 193                 newproc->totalfilewrite = 0;
 194                 newproc->fileread = 0;
 195                 newproc->filewrite = 0;
 196                 newproc->syscall_info = NULL;
 197                 newproc->threadparent = NULL;
 198                 newproc->threads = g_ptr_array_new();
 199                 newproc->perf = g_hash_table_new(g_str_hash, g_str_equal);
 200                 g_ptr_array_add(ctx->process_table, newproc);
 201                 g_hash_table_insert(ctx->process_hash_table,
 202                                 (gpointer) (unsigned long) tid, newproc);
 203
 204                 ctx->nbnewthreads++;
 205                 ctx->nbthreads++;
 206         }
 207         newproc->comm = strdup(comm);
 208
 209         return newproc;
 210 }
 211
 212 struct processtop* update_proc(struct processtop* proc, int pid, int tid,
 213                 int ppid, int vpid, int vtid, int vppid, char *comm, char *hostname)
 214 {
 215         if (proc) {
 216                 proc->pid = pid;
 217                 proc->tid = tid;
 218                 proc->ppid = ppid;
 219                 proc->vpid = vpid;
 220                 proc->vtid = vtid;
 221                 proc->vppid = vppid;
 222                 if (strcmp(proc->comm, comm) != 0) {
 223                         free(proc->comm);
 224                         proc->comm = strdup(comm);
 225                 }
 226                 if (hostname) {
 227                         if (proc->hostname && strcmp(proc->hostname, hostname) != 0) {
 228                                 free(proc->hostname);
 229                         }
 230                         proc->hostname = strdup(hostname);
 231                 }
 232         }
 233         return proc;
 234 }
 235
 236 /*
 237  * This function just sets the time of death of a process.
 238  * When we rotate the cputime we remove it from the process list.
 239  */
 240 void death_proc(struct lttngtop *ctx, int tid, char *comm,
 241                 unsigned long timestamp)
 242 {
 243         struct processtop *tmp;
 244         tmp = find_process_tid(ctx, tid, comm);
 245
 246         g_hash_table_remove(ctx->process_hash_table,
 247                         (gpointer) (unsigned long) tid);
 248         if (tmp && strcmp(tmp->comm, comm) == 0) {
 249                 tmp->death = timestamp;
 250                 ctx->nbdeadthreads++;
 251                 ctx->nbthreads--;
 252         }
 253 }
 254
 255 struct processtop* get_proc(struct lttngtop *ctx, int tid, char *comm,
 256                 unsigned long timestamp)
 257 {
 258         struct processtop *tmp;
 259         tmp = find_process_tid(ctx, tid, comm);
 260         if (tmp && strcmp(tmp->comm, comm) == 0)
 261                 return tmp;
 262         return add_proc(ctx, tid, comm, timestamp);
 263 }
 264
 265 struct processtop *get_proc_pid(struct lttngtop *ctx, int tid, int pid,
 266                 unsigned long timestamp)
 267 {
 268         struct processtop *tmp;
 269         tmp = find_process_tid(ctx, tid, NULL);
 270         if (tmp && tmp->pid == pid)
 271                 return tmp;
 272         return add_proc(ctx, tid, "Unknown", timestamp);
 273 }
 274
 275 void add_thread(struct processtop *parent, struct processtop *thread)
 276 {
 277         gint i;
 278         struct processtop *tmp;
 279
 280         if (!parent)
 281                 return;
 282
 283         for (i = 0; i < parent->threads->len; i++) {
 284                 tmp = g_ptr_array_index(parent->threads, i);
 285                 if (tmp == thread)
 286                         return;
 287         }
 288         g_ptr_array_add(parent->threads, thread);
 289 }
 290
 291 struct cputime* add_cpu(int cpu)
 292 {
 293         struct cputime *newcpu;
 294
 295         newcpu = g_new0(struct cputime, 1);
 296         newcpu->id = cpu;
 297         newcpu->current_task = NULL;
 298         newcpu->perf = g_hash_table_new(g_str_hash, g_str_equal);
 299
 300         g_ptr_array_add(lttngtop.cpu_table, newcpu);
 301
 302         return newcpu;
 303 }
 304 struct cputime* get_cpu(int cpu)
 305 {
 306         gint i;
 307         struct cputime *tmp;
 308
 309         for (i = 0; i < lttngtop.cpu_table->len; i++) {
 310                 tmp = g_ptr_array_index(lttngtop.cpu_table, i);
 311                 if (tmp->id == cpu)
 312                         return tmp;
 313         }
 314
 315         return add_cpu(cpu);
 316 }
 317
 318 /*
 319  * At the end of a sampling period, we need to display the cpu time for each
 320  * process and to reset it to zero for the next period
 321  */
 322 void rotate_cputime(unsigned long end)
 323 {
 324         gint i;
 325         struct cputime *tmp;
 326         unsigned long elapsed;
 327
 328         for (i = 0; i < lttngtop.cpu_table->len; i++) {
 329                 tmp = g_ptr_array_index(lttngtop.cpu_table, i);
 330                 elapsed = end - tmp->task_start;
 331                 if (tmp->current_task) {
 332                         tmp->current_task->totalcpunsec += elapsed;
 333                         tmp->current_task->threadstotalcpunsec += elapsed;
 334                         if (tmp->current_task->pid != tmp->current_task->tid &&
 335                                         tmp->current_task->threadparent) {
 336                                 tmp->current_task->threadparent->threadstotalcpunsec += elapsed;
 337                         }
 338                 }
 339                 tmp->task_start = end;
 340         }
 341 }
 342
 343 void reset_perf_counter(gpointer key, gpointer value, gpointer user_data)
 344 {
 345         ((struct perfcounter*) value)->count = 0;
 346 }
 347
 348 void copy_perf_counter(gpointer key, gpointer value, gpointer new_table)
 349 {
 350         struct perfcounter *newperf;
 351
 352         newperf = g_new0(struct perfcounter, 1);
 353         newperf->count = ((struct perfcounter *) value)->count;
 354         newperf->visible = ((struct perfcounter *) value)->visible;
 355         newperf->sort = ((struct perfcounter *) value)->sort;
 356         g_hash_table_insert((GHashTable *) new_table, strdup(key), newperf);
 357 }
 358
 359 void copy_process_table(gpointer key, gpointer value, gpointer new_table)
 360 {
 361         g_hash_table_insert((GHashTable *) new_table, key, value);
 362 }
 363
 364 void rotate_perfcounter() {
 365         int i;
 366         struct processtop *tmp;
 367         for (i = 0; i < lttngtop.process_table->len; i++) {
 368                 tmp = g_ptr_array_index(lttngtop.process_table, i);
 369                 g_hash_table_foreach(tmp->perf, reset_perf_counter, NULL);
 370         }
 371 }
 372
 373 void cleanup_processtop()
 374 {
 375         gint i, j;
 376         struct processtop *tmp;
 377         struct files *tmpf; /* a temporary file */
 378
 379         for (i = 0; i < lttngtop.process_table->len; i++) {
 380                 tmp = g_ptr_array_index(lttngtop.process_table, i);
 381                 tmp->totalcpunsec = 0;
 382                 tmp->threadstotalcpunsec = 0;
 383                 tmp->fileread = 0;
 384                 tmp->filewrite = 0;
 385
 386                 for (j = 0; j < tmp->process_files_table->len; j++) {
 387                         tmpf = g_ptr_array_index(tmp->process_files_table, j);
 388                         if (tmpf != NULL) {
 389                                 tmpf->read = 0;
 390                                 tmpf->write = 0;
 391
 392                                 if (tmpf->flag == __NR_close)
 393                                         g_ptr_array_index(
 394                                                 tmp->process_files_table, j
 395                                         ) = NULL;
 396                         }
 397                 }
 398         }
 399 }
 400
 401 void reset_global_counters()
 402 {
 403         lttngtop.nbnewproc = 0;
 404         lttngtop.nbdeadproc = 0;
 405         lttngtop.nbnewthreads = 0;
 406         lttngtop.nbdeadthreads = 0;
 407         lttngtop.nbnewfiles = 0;
 408         lttngtop.nbclosedfiles = 0;
 409 }
 410
 411 void copy_global_counters(struct lttngtop *dst)
 412 {
 413         dst->nbproc = lttngtop.nbproc;
 414         dst->nbnewproc = lttngtop.nbnewproc;
 415         dst->nbdeadproc = lttngtop.nbdeadproc;
 416         dst->nbthreads = lttngtop.nbthreads;
 417         dst->nbnewthreads = lttngtop.nbnewthreads;
 418         dst->nbdeadthreads = lttngtop.nbdeadthreads;
 419         dst->nbfiles = lttngtop.nbfiles;
 420         dst->nbnewfiles = lttngtop.nbnewfiles;
 421         dst->nbclosedfiles = lttngtop.nbclosedfiles;
 422         reset_global_counters();
 423 }
 424
 425 struct lttngtop* get_copy_lttngtop(unsigned long start, unsigned long end)
 426 {
 427         gint i, j;
 428         unsigned long time;
 429         struct lttngtop *dst;
 430         struct processtop *tmp, *tmp2, *new;
 431         struct cputime *tmpcpu, *newcpu;
 432         struct files *tmpfile, *newfile;
 433
 434         dst = g_new0(struct lttngtop, 1);
 435         dst->start = start;
 436         dst->end = end;
 437         copy_global_counters(dst);
 438         dst->process_table = g_ptr_array_new();
 439         dst->files_table = g_ptr_array_new();
 440         dst->cpu_table = g_ptr_array_new();
 441         dst->process_hash_table = g_hash_table_new(g_direct_hash, g_direct_equal);
 442         g_hash_table_foreach(lttngtop.process_hash_table, copy_process_table,
 443                         dst->process_hash_table);
 444
 445         rotate_cputime(end);
 446
 447         for (i = 0; i < lttngtop.process_table->len; i++) {
 448                 tmp = g_ptr_array_index(lttngtop.process_table, i);
 449                 new = g_new0(struct processtop, 1);
 450
 451                 memcpy(new, tmp, sizeof(struct processtop));
 452                 new->threads = g_ptr_array_new();
 453                 new->comm = strdup(tmp->comm);
 454                 new->process_files_table = g_ptr_array_new();
 455                 new->files_history = tmp->files_history;
 456                 new->perf = g_hash_table_new(g_str_hash, g_str_equal);
 457                 g_hash_table_foreach(tmp->perf, copy_perf_counter, new->perf);
 458
 459                 /* compute the stream speed */
 460                 if (end - start != 0) {
 461                         time = (end - start) / NSEC_PER_SEC;
 462                         new->fileread = new->fileread/(time);
 463                         new->filewrite = new->filewrite/(time);
 464                 }
 465
 466                 for (j = 0; j < tmp->process_files_table->len; j++) {
 467                         tmpfile = g_ptr_array_index(tmp->process_files_table, j);
 468
 469                         newfile = malloc(sizeof(struct files));
 470
 471                         if (tmpfile != NULL) {
 472                                 memcpy(newfile, tmpfile, sizeof(struct files));
 473                                 newfile->name = strdup(tmpfile->name);
 474                                 newfile->ref = new;
 475                                 g_ptr_array_add(new->process_files_table,
 476                                                 newfile);
 477                                 g_ptr_array_add(dst->files_table, newfile);
 478                         } else {
 479                                 g_ptr_array_add(new->process_files_table, NULL);
 480                                 g_ptr_array_add(dst->files_table, NULL);
 481                         }
 482                         /*
 483                          * if the process died during the last period, we remove all
 484                          * files associated with if after the copy
 485                          */
 486                         if (tmp->death > 0 && tmp->death < end) {
 487                                 /* FIXME : close the files before */
 488                                 g_ptr_array_remove(tmp->process_files_table, tmpfile);
 489                                 g_free(tmpfile);
 490                         }
 491                 }
 492                 g_ptr_array_add(dst->process_table, new);
 493
 494                 /*
 495                  * if the process died during the last period, we remove it from
 496                  * the current process list after the copy
 497                  */
 498                 if (tmp->death > 0 && tmp->death < end) {
 499                         g_ptr_array_remove(lttngtop.process_table, tmp);
 500                         /* FIXME : TRUE does not mean clears the object in it */
 501                         g_ptr_array_free(tmp->threads, TRUE);
 502                         free(tmp->comm);
 503                         g_ptr_array_free(tmp->process_files_table, TRUE);
 504                         /* FIXME : clear elements */
 505                         g_hash_table_destroy(tmp->perf);
 506                         g_free(tmp);
 507                 }
 508         }
 509         rotate_perfcounter();
 510
 511         for (i = 0; i < lttngtop.cpu_table->len; i++) {
 512                 tmpcpu = g_ptr_array_index(lttngtop.cpu_table, i);
 513                 newcpu = g_new0(struct cputime, 1);
 514                 memcpy(newcpu, tmpcpu, sizeof(struct cputime));
 515                 newcpu->perf = g_hash_table_new(g_str_hash, g_str_equal);
 516                 g_hash_table_foreach(tmpcpu->perf, copy_perf_counter, newcpu->perf);
 517                 /*
 518                  * note : we don't care about the current process pointer in the copy
 519                  * so the reference is invalid after the memcpy
 520                  */
 521                 g_ptr_array_add(dst->cpu_table, newcpu);
 522         }
 523         /* FIXME : better algo */
 524         /* create the threads index if required */
 525         for (i = 0; i < dst->process_table->len; i++) {
 526                 tmp = g_ptr_array_index(dst->process_table, i);
 527                 if (tmp->pid == tmp->tid) {
 528                         for (j = 0; j < dst->process_table->len; j++) {
 529                                 tmp2 = g_ptr_array_index(dst->process_table, j);
 530                                 if (tmp2->pid == tmp->pid) {
 531                                         tmp2->threadparent = tmp;
 532                                         g_ptr_array_add(tmp->threads, tmp2);
 533                                 }
 534                         }
 535                 }
 536         }
 537
 538         //  update_global_stats(dst);
 539         cleanup_processtop();
 540
 541         return dst;
 542 }
 543
 544
 545 enum bt_cb_ret handle_statedump_process_state(struct bt_ctf_event *call_data,
 546                 void *private_data)
 547 {
 548         const struct bt_definition *scope;
 549         struct processtop *proc;
 550         unsigned long timestamp;
 551         int64_t pid, tid, ppid, vtid, vpid, vppid;
 552         char *procname;
 553
 554         timestamp = bt_ctf_get_timestamp(call_data);
 555         if (timestamp == -1ULL)
 556                 goto error;
 557
 558         scope = bt_ctf_get_top_level_scope(call_data,
 559                          BT_EVENT_FIELDS);
 560         pid = bt_ctf_get_int64(bt_ctf_get_field(call_data,
 561                              scope, "_pid"));
 562         if (bt_ctf_field_get_error()) {
 563                 fprintf(stderr, "Missing pid context info\n");
 564                 goto error;
 565         }
 566         ppid = bt_ctf_get_int64(bt_ctf_get_field(call_data,
 567                                 scope, "_ppid"));
 568         if (bt_ctf_field_get_error()) {
 569                 fprintf(stderr, "Missing ppid context info\n");
 570                 goto error;
 571         }
 572         tid = bt_ctf_get_int64(bt_ctf_get_field(call_data,
 573                                 scope, "_tid"));
 574         if (bt_ctf_field_get_error()) {
 575                 fprintf(stderr, "Missing tid context info\n");
 576                 goto error;
 577         }
 578         vtid = bt_ctf_get_int64(bt_ctf_get_field(call_data,
 579                                 scope, "_vtid"));
 580         if (bt_ctf_field_get_error()) {
 581                 fprintf(stderr, "Missing vtid context info\n");
 582                 goto error;
 583         }
 584         vpid = bt_ctf_get_int64(bt_ctf_get_field(call_data,
 585                                 scope, "_vpid"));
 586         if (bt_ctf_field_get_error()) {
 587                 fprintf(stderr, "Missing vpid context info\n");
 588                 goto error;
 589         }
 590         vppid = bt_ctf_get_int64(bt_ctf_get_field(call_data,
 591                                 scope, "_vppid"));
 592         if (bt_ctf_field_get_error()) {
 593                 fprintf(stderr, "Missing vppid context info\n");
 594                 goto error;
 595         }
 596
 597         scope = bt_ctf_get_top_level_scope(call_data,
 598                         BT_EVENT_FIELDS);
 599         procname = bt_ctf_get_char_array(bt_ctf_get_field(call_data,
 600                                 scope, "_name"));
 601         if (bt_ctf_field_get_error()) {
 602                 fprintf(stderr, "Missing process name context info\n");
 603                 goto error;
 604         }
 605
 606         proc = find_process_tid(&lttngtop, tid, procname);
 607         if (proc == NULL)
 608                 proc = add_proc(&lttngtop, tid, procname, timestamp);
 609         update_proc(proc, pid, tid, ppid, vpid, vtid, vppid, procname, NULL);
 610
 611         if (proc) {
 612                 free(proc->comm);
 613                 proc->comm = strdup(procname);
 614                 proc->pid = pid;
 615         }
 616
 617         return BT_CB_OK;
 618
 619 error:
 620         return BT_CB_ERROR_STOP;
 621 }
 622
 623 struct tm format_timestamp(uint64_t timestamp)
 624 {
 625         struct tm tm;
 626         uint64_t ts_sec = 0, ts_nsec;
 627         time_t time_s;
 628
 629         ts_nsec = timestamp;
 630         ts_sec += ts_nsec / NSEC_PER_SEC;
 631         ts_nsec = ts_nsec % NSEC_PER_SEC;
 632
 633         time_s = (time_t) ts_sec;
 634
 635         localtime_r(&time_s, &tm);
 636
 637         return tm;
 638 }
 639
 640 int *lookup_tid_list(int tid)
 641 {
 642         return g_hash_table_lookup(tid_list, (gpointer) &tid);
 643 }
 644
 645 char *lookup_hostname_list(const char *hostname)
 646 {
 647         if (!hostname)
 648                 return NULL;
 649
 650         return g_hash_table_lookup(hostname_list, (gpointer) hostname);
 651 }