linux/tools/perf/util/thread.c
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   1#include "../perf.h"
   2#include <stdlib.h>
   3#include <stdio.h>
   4#include <string.h>
   5#include "session.h"
   6#include "thread.h"
   7#include "thread-stack.h"
   8#include "util.h"
   9#include "debug.h"
  10#include "comm.h"
  11#include "unwind.h"
  12
  13#include <api/fs/fs.h>
  14
  15int thread__init_map_groups(struct thread *thread, struct machine *machine)
  16{
  17        struct thread *leader;
  18        pid_t pid = thread->pid_;
  19
  20        if (pid == thread->tid || pid == -1) {
  21                thread->mg = map_groups__new(machine);
  22        } else {
  23                leader = __machine__findnew_thread(machine, pid, pid);
  24                if (leader) {
  25                        thread->mg = map_groups__get(leader->mg);
  26                        thread__put(leader);
  27                }
  28        }
  29
  30        return thread->mg ? 0 : -1;
  31}
  32
  33struct thread *thread__new(pid_t pid, pid_t tid)
  34{
  35        char *comm_str;
  36        struct comm *comm;
  37        struct thread *thread = zalloc(sizeof(*thread));
  38
  39        if (thread != NULL) {
  40                thread->pid_ = pid;
  41                thread->tid = tid;
  42                thread->ppid = -1;
  43                thread->cpu = -1;
  44                INIT_LIST_HEAD(&thread->comm_list);
  45
  46                comm_str = malloc(32);
  47                if (!comm_str)
  48                        goto err_thread;
  49
  50                snprintf(comm_str, 32, ":%d", tid);
  51                comm = comm__new(comm_str, 0, false);
  52                free(comm_str);
  53                if (!comm)
  54                        goto err_thread;
  55
  56                list_add(&comm->list, &thread->comm_list);
  57                atomic_set(&thread->refcnt, 1);
  58                RB_CLEAR_NODE(&thread->rb_node);
  59        }
  60
  61        return thread;
  62
  63err_thread:
  64        free(thread);
  65        return NULL;
  66}
  67
  68void thread__delete(struct thread *thread)
  69{
  70        struct comm *comm, *tmp;
  71
  72        BUG_ON(!RB_EMPTY_NODE(&thread->rb_node));
  73
  74        thread_stack__free(thread);
  75
  76        if (thread->mg) {
  77                map_groups__put(thread->mg);
  78                thread->mg = NULL;
  79        }
  80        list_for_each_entry_safe(comm, tmp, &thread->comm_list, list) {
  81                list_del(&comm->list);
  82                comm__free(comm);
  83        }
  84        unwind__finish_access(thread);
  85
  86        free(thread);
  87}
  88
  89struct thread *thread__get(struct thread *thread)
  90{
  91        if (thread)
  92                atomic_inc(&thread->refcnt);
  93        return thread;
  94}
  95
  96void thread__put(struct thread *thread)
  97{
  98        if (thread && atomic_dec_and_test(&thread->refcnt)) {
  99                /*
 100                 * Remove it from the dead_threads list, as last reference
 101                 * is gone.
 102                 */
 103                list_del_init(&thread->node);
 104                thread__delete(thread);
 105        }
 106}
 107
 108struct comm *thread__comm(const struct thread *thread)
 109{
 110        if (list_empty(&thread->comm_list))
 111                return NULL;
 112
 113        return list_first_entry(&thread->comm_list, struct comm, list);
 114}
 115
 116struct comm *thread__exec_comm(const struct thread *thread)
 117{
 118        struct comm *comm, *last = NULL;
 119
 120        list_for_each_entry(comm, &thread->comm_list, list) {
 121                if (comm->exec)
 122                        return comm;
 123                last = comm;
 124        }
 125
 126        return last;
 127}
 128
 129int __thread__set_comm(struct thread *thread, const char *str, u64 timestamp,
 130                       bool exec)
 131{
 132        struct comm *new, *curr = thread__comm(thread);
 133        int err;
 134
 135        /* Override the default :tid entry */
 136        if (!thread->comm_set) {
 137                err = comm__override(curr, str, timestamp, exec);
 138                if (err)
 139                        return err;
 140        } else {
 141                new = comm__new(str, timestamp, exec);
 142                if (!new)
 143                        return -ENOMEM;
 144                list_add(&new->list, &thread->comm_list);
 145
 146                if (exec)
 147                        unwind__flush_access(thread);
 148        }
 149
 150        thread->comm_set = true;
 151
 152        return 0;
 153}
 154
 155int thread__set_comm_from_proc(struct thread *thread)
 156{
 157        char path[64];
 158        char *comm = NULL;
 159        size_t sz;
 160        int err = -1;
 161
 162        if (!(snprintf(path, sizeof(path), "%d/task/%d/comm",
 163                       thread->pid_, thread->tid) >= (int)sizeof(path)) &&
 164            procfs__read_str(path, &comm, &sz) == 0) {
 165                comm[sz - 1] = '\0';
 166                err = thread__set_comm(thread, comm, 0);
 167        }
 168
 169        return err;
 170}
 171
 172const char *thread__comm_str(const struct thread *thread)
 173{
 174        const struct comm *comm = thread__comm(thread);
 175
 176        if (!comm)
 177                return NULL;
 178
 179        return comm__str(comm);
 180}
 181
 182/* CHECKME: it should probably better return the max comm len from its comm list */
 183int thread__comm_len(struct thread *thread)
 184{
 185        if (!thread->comm_len) {
 186                const char *comm = thread__comm_str(thread);
 187                if (!comm)
 188                        return 0;
 189                thread->comm_len = strlen(comm);
 190        }
 191
 192        return thread->comm_len;
 193}
 194
 195size_t thread__fprintf(struct thread *thread, FILE *fp)
 196{
 197        return fprintf(fp, "Thread %d %s\n", thread->tid, thread__comm_str(thread)) +
 198               map_groups__fprintf(thread->mg, fp);
 199}
 200
 201int thread__insert_map(struct thread *thread, struct map *map)
 202{
 203        int ret;
 204
 205        ret = unwind__prepare_access(thread, map, NULL);
 206        if (ret)
 207                return ret;
 208
 209        map_groups__fixup_overlappings(thread->mg, map, stderr);
 210        map_groups__insert(thread->mg, map);
 211
 212        return 0;
 213}
 214
 215static int __thread__prepare_access(struct thread *thread)
 216{
 217        bool initialized = false;
 218        int i, err = 0;
 219
 220        for (i = 0; i < MAP__NR_TYPES; ++i) {
 221                struct maps *maps = &thread->mg->maps[i];
 222                struct map *map;
 223
 224                pthread_rwlock_rdlock(&maps->lock);
 225
 226                for (map = maps__first(maps); map; map = map__next(map)) {
 227                        err = unwind__prepare_access(thread, map, &initialized);
 228                        if (err || initialized)
 229                                break;
 230                }
 231
 232                pthread_rwlock_unlock(&maps->lock);
 233        }
 234
 235        return err;
 236}
 237
 238static int thread__prepare_access(struct thread *thread)
 239{
 240        int err = 0;
 241
 242        if (symbol_conf.use_callchain)
 243                err = __thread__prepare_access(thread);
 244
 245        return err;
 246}
 247
 248static int thread__clone_map_groups(struct thread *thread,
 249                                    struct thread *parent)
 250{
 251        int i;
 252
 253        /* This is new thread, we share map groups for process. */
 254        if (thread->pid_ == parent->pid_)
 255                return thread__prepare_access(thread);
 256
 257        if (thread->mg == parent->mg) {
 258                pr_debug("broken map groups on thread %d/%d parent %d/%d\n",
 259                         thread->pid_, thread->tid, parent->pid_, parent->tid);
 260                return 0;
 261        }
 262
 263        /* But this one is new process, copy maps. */
 264        for (i = 0; i < MAP__NR_TYPES; ++i)
 265                if (map_groups__clone(thread, parent->mg, i) < 0)
 266                        return -ENOMEM;
 267
 268        return 0;
 269}
 270
 271int thread__fork(struct thread *thread, struct thread *parent, u64 timestamp)
 272{
 273        int err;
 274
 275        if (parent->comm_set) {
 276                const char *comm = thread__comm_str(parent);
 277                if (!comm)
 278                        return -ENOMEM;
 279                err = thread__set_comm(thread, comm, timestamp);
 280                if (err)
 281                        return err;
 282        }
 283
 284        thread->ppid = parent->tid;
 285        return thread__clone_map_groups(thread, parent);
 286}
 287
 288void thread__find_cpumode_addr_location(struct thread *thread,
 289                                        enum map_type type, u64 addr,
 290                                        struct addr_location *al)
 291{
 292        size_t i;
 293        const u8 cpumodes[] = {
 294                PERF_RECORD_MISC_USER,
 295                PERF_RECORD_MISC_KERNEL,
 296                PERF_RECORD_MISC_GUEST_USER,
 297                PERF_RECORD_MISC_GUEST_KERNEL
 298        };
 299
 300        for (i = 0; i < ARRAY_SIZE(cpumodes); i++) {
 301                thread__find_addr_location(thread, cpumodes[i], type, addr, al);
 302                if (al->map)
 303                        break;
 304        }
 305}
 306
 307struct thread *thread__main_thread(struct machine *machine, struct thread *thread)
 308{
 309        if (thread->pid_ == thread->tid)
 310                return thread__get(thread);
 311
 312        if (thread->pid_ == -1)
 313                return NULL;
 314
 315        return machine__find_thread(machine, thread->pid_, thread->pid_);
 316}
 317