src/jdk.hotspot.agent/linux/native/libsaproc/ps_proc.c

*** 26,35 ****
--- 26,36 ----
  #include <stdlib.h>
  #include <string.h>
  #include <signal.h>
  #include <errno.h>
  #include <elf.h>
+ #include <dirent.h>
  #include <sys/types.h>
  #include <sys/wait.h>
  #include <sys/ptrace.h>
  #include <sys/uio.h>
  #include "libproc_impl.h"
*** 372,382 ****
    .get_lwp_regs= process_get_lwp_regs
  };
  
  // attach to the process. One and only one exposed stuff
  JNIEXPORT struct ps_prochandle* JNICALL
! Pgrab(pid_t pid, char* err_buf, size_t err_buf_len) {
    struct ps_prochandle* ph = NULL;
    thread_info* thr = NULL;
  
    if ( (ph = (struct ps_prochandle*) calloc(1, sizeof(struct ps_prochandle))) == NULL) {
       snprintf(err_buf, err_buf_len, "can't allocate memory for ps_prochandle");
--- 373,383 ----
    .get_lwp_regs= process_get_lwp_regs
  };
  
  // attach to the process. One and only one exposed stuff
  JNIEXPORT struct ps_prochandle* JNICALL
! Pgrab(pid_t pid, char* err_buf, size_t err_buf_len, bool is_in_container) {
    struct ps_prochandle* ph = NULL;
    thread_info* thr = NULL;
  
    if ( (ph = (struct ps_prochandle*) calloc(1, sizeof(struct ps_prochandle))) == NULL) {
       snprintf(err_buf, err_buf_len, "can't allocate memory for ps_prochandle");
*** 399,409 ****
--- 400,431 ----
    // as the symbols in the pthread library will be used to figure out
    // the list of threads within the same process.
    read_lib_info(ph);
  
    // read thread info
+   if (is_in_container) {
+     char taskpath[PATH_MAX];
+     DIR *dirp;
+     struct dirent *entry;
+ 
+     snprintf(taskpath, PATH_MAX, "/proc/%d/task", ph->pid);
+     dirp = opendir(taskpath);
+     int lwp_id;
+     while ((entry = readdir(dirp)) != NULL) {
+       if (*entry->d_name == '.') {
+         continue;
+       }
+       lwp_id = atoi(entry->d_name);
+       if (lwp_id == ph->pid) {
+         continue;
+       }
+       add_new_thread(ph, -1, lwp_id);
+     }
+     closedir(dirp);
+   } else {
      read_thread_info(ph, add_new_thread);
+   }
  
    // attach to the threads
    thr = ph->threads;
    while (thr) {
       // don't attach to the main thread again