1/* Start thread. Mach version.
2 Copyright (C) 2000-2022 Free Software Foundation, Inc.
3 This file is part of the GNU C Library.
4
5 The GNU C Library is free software; you can redistribute it and/or
6 modify it under the terms of the GNU Lesser General Public
7 License as published by the Free Software Foundation; either
8 version 2.1 of the License, or (at your option) any later version.
9
10 The GNU C Library is distributed in the hope that it will be useful,
11 but WITHOUT ANY WARRANTY; without even the implied warranty of
12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
13 Lesser General Public License for more details.
14
15 You should have received a copy of the GNU Lesser General Public
16 License along with the GNU C Library; if not, see
17 <https://www.gnu.org/licenses/>. */
18
19#include <assert.h>
20#include <errno.h>
21#include <string.h>
22
23#include <mach.h>
24
25#include <pt-internal.h>
26
27/* Prepare a wakeup message. */
28static error_t
29create_wakeupmsg (struct __pthread *thread)
30{
31 kern_return_t err;
32
33 /* Build wakeup message. */
34 thread->wakeupmsg.msgh_bits = MACH_MSGH_BITS (MACH_MSG_TYPE_COPY_SEND, 0);
35 thread->wakeupmsg.msgh_size = 0;
36
37 err = __mach_port_allocate (__mach_task_self (), MACH_PORT_RIGHT_RECEIVE,
38 &thread->wakeupmsg.msgh_remote_port);
39 if (err)
40 return EAGAIN;
41
42 thread->wakeupmsg.msgh_local_port = MACH_PORT_NULL;
43 thread->wakeupmsg.msgh_seqno = 0;
44 thread->wakeupmsg.msgh_id = 0;
45
46 err = __mach_port_insert_right (__mach_task_self (),
47 thread->wakeupmsg.msgh_remote_port,
48 thread->wakeupmsg.msgh_remote_port,
49 MACH_MSG_TYPE_MAKE_SEND);
50 if (err)
51 {
52 __mach_port_destroy (__mach_task_self (),
53 thread->wakeupmsg.msgh_remote_port);
54 return EAGAIN;
55 }
56
57 /* No need to queue more than one wakeup message on this port. */
58 __mach_port_set_qlimit (__mach_task_self (),
59 thread->wakeupmsg.msgh_remote_port, 1);
60
61 return 0;
62}
63
64/* Allocate any resouces for THREAD. The new kernel thread should not
65 be eligible to be scheduled. */
66int
67__pthread_thread_alloc (struct __pthread *thread)
68{
69 static int do_create;
70 error_t err;
71
72 err = create_wakeupmsg (thread);
73 if (err)
74 return err;
75
76 if (!do_create)
77 {
78 assert (__pthread_total == 0);
79 thread->kernel_thread = __mach_thread_self ();
80 do_create = 1;
81 }
82 else
83 {
84 err = __thread_create (__mach_task_self (), &thread->kernel_thread);
85 if (err)
86 {
87 __mach_port_destroy (__mach_task_self (),
88 thread->wakeupmsg.msgh_remote_port);
89 return EAGAIN;
90 }
91 }
92
93 return 0;
94}
95

source code of glibc/sysdeps/mach/htl/pt-thread-alloc.c