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

@@ -23,11 +23,11 @@
  * 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.
+ * Copyright 2018 Joyent, Inc.
  */
 
 #include "lint.h"
 #include "thr_uberdata.h"
 #include <pthread.h>

@@ -558,11 +558,11 @@
         return (ulwp);
 }
 
 int
 _thrp_create(void *stk, size_t stksize, void *(*func)(void *), void *arg,
-    long flags, thread_t *new_thread, size_t guardsize)
+    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;

@@ -713,10 +713,13 @@
                 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);
 }

@@ -723,11 +726,12 @@
 
 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));
+        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

@@ -2396,10 +2400,91 @@
 __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.