tools/perf/util/thread.c

   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 int thread__init_map_groups(struct thread *thread, struct machine *machine)
  14 {
  15         struct thread *leader;
  16         pid_t pid = thread->pid_;
  17
  18         if (pid == thread->tid || pid == -1) {
  19                 thread->mg = map_groups__new(machine);
  20         } else {
  21                 leader = __machine__findnew_thread(machine, pid, pid);
  22                 if (leader)
  23                         thread->mg = map_groups__get(leader->mg);
  24         }
  25
  26         return thread->mg ? 0 : -1;
  27 }
  28
  29 struct thread *thread__new(pid_t pid, pid_t tid)
  30 {
  31         char *comm_str;
  32         struct comm *comm;
  33         struct thread *thread = zalloc(sizeof(*thread));
  34
  35         if (thread != NULL) {
  36                 thread->pid_ = pid;
  37                 thread->tid = tid;
  38                 thread->ppid = -1;
  39                 thread->cpu = -1;
  40                 INIT_LIST_HEAD(&thread->comm_list);
  41
  42                 if (unwind__prepare_access(thread) < 0)
  43                         goto err_thread;
  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, 0);
  57                 RB_CLEAR_NODE(&thread->rb_node);
  58         }
  59
  60         return thread;
  61
  62 err_thread:
  63         free(thread);
  64         return NULL;
  65 }
  66
  67 void 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
  88 struct thread *thread__get(struct thread *thread)
  89 {
  90         if (thread)
  91                 atomic_inc(&thread->refcnt);
  92         return thread;
  93 }
  94
  95 void thread__put(struct thread *thread)
  96 {
  97         if (thread && atomic_dec_and_test(&thread->refcnt)) {
  98                 list_del_init(&thread->node);
  99                 thread__delete(thread);
 100         }
 101 }
 102
 103 struct comm *thread__comm(const struct thread *thread)
 104 {
 105         if (list_empty(&thread->comm_list))
 106                 return NULL;
 107
 108         return list_first_entry(&thread->comm_list, struct comm, list);
 109 }
 110
 111 struct comm *thread__exec_comm(const struct thread *thread)
 112 {
 113         struct comm *comm, *last = NULL, *second_last = NULL;
 114
 115         list_for_each_entry(comm, &thread->comm_list, list) {
 116                 if (comm->exec)
 117                         return comm;
 118                 second_last = last;
 119                 last = comm;
 120         }
 121
 122         /*
 123          * 'last' with no start time might be the parent's comm of a synthesized
 124          * thread (created by processing a synthesized fork event). For a main
 125          * thread, that is very probably wrong. Prefer a later comm to avoid
 126          * that case.
 127          */
 128         if (second_last && !last->start && thread->pid_ == thread->tid)
 129                 return second_last;
 130
 131         return last;
 132 }
 133
 134 int __thread__set_comm(struct thread *thread, const char *str, u64 timestamp,
 135                        bool exec)
 136 {
 137         struct comm *new, *curr = thread__comm(thread);
 138         int err;
 139
 140         /* Override the default :tid entry */
 141         if (!thread->comm_set) {
 142                 err = comm__override(curr, str, timestamp, exec);
 143                 if (err)
 144                         return err;
 145         } else {
 146                 new = comm__new(str, timestamp, exec);
 147                 if (!new)
 148                         return -ENOMEM;
 149                 list_add(&new->list, &thread->comm_list);
 150
 151                 if (exec)
 152                         unwind__flush_access(thread);
 153         }
 154
 155         thread->comm_set = true;
 156
 157         return 0;
 158 }
 159
 160 const char *thread__comm_str(const struct thread *thread)
 161 {
 162         const struct comm *comm = thread__comm(thread);
 163
 164         if (!comm)
 165                 return NULL;
 166
 167         return comm__str(comm);
 168 }
 169
 170 /* CHECKME: it should probably better return the max comm len from its comm list */
 171 int thread__comm_len(struct thread *thread)
 172 {
 173         if (!thread->comm_len) {
 174                 const char *comm = thread__comm_str(thread);
 175                 if (!comm)
 176                         return 0;
 177                 thread->comm_len = strlen(comm);
 178         }
 179
 180         return thread->comm_len;
 181 }
 182
 183 size_t thread__fprintf(struct thread *thread, FILE *fp)
 184 {
 185         return fprintf(fp, "Thread %d %s\n", thread->tid, thread__comm_str(thread)) +
 186                map_groups__fprintf(thread->mg, fp);
 187 }
 188
 189 void thread__insert_map(struct thread *thread, struct map *map)
 190 {
 191         map_groups__fixup_overlappings(thread->mg, map, stderr);
 192         map_groups__insert(thread->mg, map);
 193 }
 194
 195 static int thread__clone_map_groups(struct thread *thread,
 196                                     struct thread *parent)
 197 {
 198         int i;
 199
 200         /* This is new thread, we share map groups for process. */
 201         if (thread->pid_ == parent->pid_)
 202                 return 0;
 203
 204         if (thread->mg == parent->mg) {
 205                 pr_debug("broken map groups on thread %d/%d parent %d/%d\n",
 206                          thread->pid_, thread->tid, parent->pid_, parent->tid);
 207                 return 0;
 208         }
 209
 210         /* But this one is new process, copy maps. */
 211         for (i = 0; i < MAP__NR_TYPES; ++i)
 212                 if (map_groups__clone(thread->mg, parent->mg, i) < 0)
 213                         return -ENOMEM;
 214
 215         return 0;
 216 }
 217
 218 int thread__fork(struct thread *thread, struct thread *parent, u64 timestamp)
 219 {
 220         int err;
 221
 222         if (parent->comm_set) {
 223                 const char *comm = thread__comm_str(parent);
 224                 if (!comm)
 225                         return -ENOMEM;
 226                 err = thread__set_comm(thread, comm, timestamp);
 227                 if (err)
 228                         return err;
 229         }
 230
 231         thread->ppid = parent->tid;
 232         return thread__clone_map_groups(thread, parent);
 233 }
 234
 235 void thread__find_cpumode_addr_location(struct thread *thread,
 236                                         enum map_type type, u64 addr,
 237                                         struct addr_location *al)
 238 {
 239         size_t i;
 240         const u8 cpumodes[] = {
 241                 PERF_RECORD_MISC_USER,
 242                 PERF_RECORD_MISC_KERNEL,
 243                 PERF_RECORD_MISC_GUEST_USER,
 244                 PERF_RECORD_MISC_GUEST_KERNEL
 245         };
 246
 247         for (i = 0; i < ARRAY_SIZE(cpumodes); i++) {
 248                 thread__find_addr_location(thread, cpumodes[i], type, addr, al);
 249                 if (al->map)
 250                         break;
 251         }
 252 }