8158 Want named threads API
9857 proc manpages should have LIBRARY section

*** 23,33 ****
   * Copyright (c) 1999, 2010, Oracle and/or its affiliates. All rights reserved.
   * Copyright (c) 2016 by Delphix. All rights reserved.
   * Copyright (c) 2017 by The MathWorks, Inc. All rights reserved.
   */
  /*
!  * Copyright 2016 Joyent, Inc.
   */
  
  #include "lint.h"
  #include "thr_uberdata.h"
  #include <pthread.h>
--- 23,33 ----
   * Copyright (c) 1999, 2010, Oracle and/or its affiliates. All rights reserved.
   * Copyright (c) 2016 by Delphix. All rights reserved.
   * Copyright (c) 2017 by The MathWorks, Inc. All rights reserved.
   */
  /*
!  * Copyright 2018 Joyent, Inc.
   */
  
  #include "lint.h"
  #include "thr_uberdata.h"
  #include <pthread.h>
*** 558,568 ****
          return (ulwp);
  }
  
  int
  _thrp_create(void *stk, size_t stksize, void *(*func)(void *), void *arg,
!     long flags, thread_t *new_thread, size_t guardsize)
  {
          ulwp_t *self = curthread;
          uberdata_t *udp = self->ul_uberdata;
          ucontext_t uc;
          uint_t lwp_flags;
--- 558,568 ----
          return (ulwp);
  }
  
  int
  _thrp_create(void *stk, size_t stksize, void *(*func)(void *), void *arg,
!     long flags, thread_t *new_thread, size_t guardsize, const char *name)
  {
          ulwp_t *self = curthread;
          uberdata_t *udp = self->ul_uberdata;
          ucontext_t uc;
          uint_t lwp_flags;
*** 713,722 ****
--- 713,725 ----
                  tdb_event(TD_CREATE, udp);
          }
  
          exit_critical(self);
  
+         if (name != NULL)
+                 (void) pthread_setname_np(tid, name);
+ 
          if (!(flags & THR_SUSPENDED))
                  (void) _thrp_continue(tid, TSTP_REGULAR);
  
          return (0);
  }
*** 723,733 ****
  
  int
  thr_create(void *stk, size_t stksize, void *(*func)(void *), void *arg,
      long flags, thread_t *new_thread)
  {
!         return (_thrp_create(stk, stksize, func, arg, flags, new_thread, 0));
  }
  
  /*
   * A special cancellation cleanup hook for DCE.
   * cleanuphndlr, when it is not NULL, will contain a callback
--- 726,737 ----
  
  int
  thr_create(void *stk, size_t stksize, void *(*func)(void *), void *arg,
      long flags, thread_t *new_thread)
  {
!         return (_thrp_create(stk, stksize, func, arg, flags, new_thread, 0,
!             NULL));
  }
  
  /*
   * A special cancellation cleanup hook for DCE.
   * cleanuphndlr, when it is not NULL, will contain a callback
*** 2396,2405 ****
--- 2400,2490 ----
  __nthreads(void)
  {
          return (curthread->ul_uberdata->nthreads);
  }
  
+ /* "/proc/self/lwp/%u/lwpname" w/o stdio */
+ static void
+ lwpname_path(pthread_t tid, char *buf, size_t bufsize)
+ {
+         (void) strlcpy(buf, "/proc/self/lwp/", bufsize);
+         ultos((uint64_t)tid, 10, buf + strlen(buf));
+         (void) strlcat(buf, "/lwpname", bufsize);
+ }
+ 
+ #pragma weak pthread_setname_np = thr_setname
+ int
+ thr_setname(pthread_t tid, const char *name)
+ {
+         extern ssize_t __write(int, const void *, size_t);
+         char path[PATH_MAX];
+         int saved_errno;
+         size_t len;
+         ssize_t n;
+         int fd;
+ 
+         if (name == NULL)
+                 name = "";
+ 
+         len = strlen(name) + 1;
+         if (len > THREAD_NAME_MAX)
+                 return (ERANGE);
+ 
+         lwpname_path(tid, path, sizeof (path));
+ 
+         if ((fd = __open(path, O_WRONLY, 0)) < 0) {
+                 if (errno == ENOENT)
+                         errno = ESRCH;
+                 return (errno);
+         }
+ 
+         n = __write(fd, name, len);
+         saved_errno = errno;
+         (void) __close(fd);
+ 
+         if (n < 0)
+                 return (saved_errno);
+         if (n != len)
+                 return (EFAULT);
+         return (0);
+ }
+ 
+ #pragma weak pthread_getname_np = thr_getname
+ int
+ thr_getname(pthread_t tid, char *buf, size_t bufsize)
+ {
+         extern ssize_t __read(int, void *, size_t);
+         char name[THREAD_NAME_MAX];
+         char path[PATH_MAX];
+         int saved_errno;
+         ssize_t n;
+         int fd;
+ 
+         if (buf == NULL)
+                 return (EINVAL);
+ 
+         lwpname_path(tid, path, sizeof (path));
+ 
+         if ((fd = __open(path, O_RDONLY, 0)) < 0) {
+                 if (errno == ENOENT)
+                         errno = ESRCH;
+                 return (errno);
+         }
+ 
+         n = __read(fd, name, sizeof (name));
+         saved_errno = errno;
+         (void) __close(fd);
+ 
+         if (n < 0)
+                 return (saved_errno);
+         if (n != sizeof (name))
+                 return (EFAULT);
+         if (strlcpy(buf, name, bufsize) >= bufsize)
+                 return (ERANGE);
+         return (0);
+ }
+ 
  /*
   * XXX
   * The remainder of this file implements the private interfaces to java for
   * garbage collection.  It is no longer used, at least by java 1.2.
   * It can all go away once all old JVMs have disappeared.