mirrors/cosmopolitan
1
0
Fork 0
mirror of https://github.com/jart/cosmopolitan.git synced 2025-07-20 17:40:30 +00:00
Code Issues Projects Releases Packages Wiki Activity Actions

Get rid of kmalloc()

Browse source 
This changes *NSYNC to allocate waiters on the stack so our locks don't
need to depend on dynamic memory. This make our runtiem simpler, and it
also fixes bugs with thread cancellation support.
This commit is contained in:
Justine Tunney 2023-09-11 21:34:53 -07:00
parent 77a7873057
commit a359de7893
No known key found for this signature in database
GPG key ID: BE714B4575D6E328
57 changed files with 405 additions and 472 deletions
Download patch file Download diff file Expand all files Collapse all files

22
third_party/nsync/mu_semaphore_sem.c vendored
View file

@ -1,5 +1,5 @@
/*-*- mode:c;indent-tabs-mode:nil;c-basic-offset:2;tab-width:8;coding:utf-8 -*-│
│vi: set net ft=c ts=2 sts=2 sw=2 fenc=utf-8 :vi│
/*-*- mode:c;indent-tabs-mode:t;c-basic-offset:8;tab-width:8;coding:utf-8 -*-│
│vi: set et ft=c ts=8 tw=8 fenc=utf-8 :vi│
╞══════════════════════════════════════════════════════════════════════════════╡
│ Copyright 2022 Justine Alexandra Roberts Tunney │
│ │
@ -25,6 +25,7 @@
#include "libc/intrin/strace.internal.h"
#include "libc/str/str.h"
#include "libc/sysv/consts/f.h"
#include "libc/sysv/consts/fd.h"
#include "third_party/nsync/mu_semaphore.h"
#include "third_party/nsync/time.h"
// clang-format off
@ -44,14 +45,19 @@ static nsync_semaphore *sem_big_enough_for_sem = (nsync_semaphore *) (uintptr_t)
/* Initialize *s; the initial value is 0. */
void nsync_mu_semaphore_init_sem (nsync_semaphore *s) {
int newfd;
struct sem *f = (struct sem *) s;
f->id = 0;
ASSERT (!sys_sem_init (0, &f->id));
STRACE ("sem_init(0, [%ld]) → 0", f->id);
ASSERT ((newfd = __sys_fcntl (f->id, F_DUPFD_CLOEXEC, 100)) != -1);
ASSERT (!sys_sem_destroy (f->id));
f->id = newfd;
ASSERT (__sys_fcntl (f->id, F_SETFD, FD_CLOEXEC) == 0); // ouch
}
/* Releases system resources associated with *s. */
void nsync_mu_semaphore_destroy_sem (nsync_semaphore *s) {
int rc;
struct sem *f = (struct sem *) s;
ASSERT (!(rc = sys_sem_destroy (f->id)));
STRACE ("sem_destroy(%ld) → %d", rc);
}
/* Wait until the count of *s exceeds 0, and decrement it. */
@ -60,9 +66,7 @@ errno_t nsync_mu_semaphore_p_sem (nsync_semaphore *s) {
errno_t result;
struct sem *f = (struct sem *) s;
e = errno;
BEGIN_CANCELLATION_POINT;
rc = sys_sem_wait (f->id);
END_CANCELLATION_POINT;
STRACE ("sem_wait(%ld) → %d% m", f->id, rc);
if (!rc) {
result = 0;
@ -82,9 +86,7 @@ errno_t nsync_mu_semaphore_p_with_deadline_sem (nsync_semaphore *s, nsync_time a
errno_t result;
struct sem *f = (struct sem *) s;
e = errno;
BEGIN_CANCELLATION_POINT;
rc = sys_sem_timedwait (f->id, &abs_deadline);
END_CANCELLATION_POINT;
STRACE ("sem_timedwait(%ld, %s) → %d% m", f->id,
DescribeTimespec(0, &abs_deadline), rc);
if (!rc) {