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