mirror of
https://github.com/jart/cosmopolitan.git
synced 2025-01-31 19:43:32 +00:00
e522aa3a07
- ASAN memory morgue is now lockless - Make C11 atomics header more portable - Rewrote pthread keys support to be lockless - Simplify Python's unicode table unpacking code - Make crash report write(2) closer to being atomic - Make it possible to strace/ftrace a single thread - ASAN now checks nul-terminated strings fast and properly - Windows fork() now restores TLS memory of calling thread
55 lines
2.9 KiB
C
55 lines
2.9 KiB
C
/*-*- 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│
|
|
╞══════════════════════════════════════════════════════════════════════════════╡
|
|
│ Copyright 2021 Justine Alexandra Roberts Tunney │
|
|
│ │
|
|
│ Permission to use, copy, modify, and/or distribute this software for │
|
|
│ any purpose with or without fee is hereby granted, provided that the │
|
|
│ above copyright notice and this permission notice appear in all copies. │
|
|
│ │
|
|
│ THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL │
|
|
│ WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED │
|
|
│ WARRANTIES OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE │
|
|
│ AUTHOR BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL │
|
|
│ DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR │
|
|
│ PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER │
|
|
│ TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR │
|
|
│ PERFORMANCE OF THIS SOFTWARE. │
|
|
╚─────────────────────────────────────────────────────────────────────────────*/
|
|
#include "libc/intrin/atomic.h"
|
|
#include "libc/intrin/kmalloc.h"
|
|
#include "libc/runtime/internal.h"
|
|
#include "libc/x/x.h"
|
|
#include "third_party/zlib/zlib.h"
|
|
|
|
/**
|
|
* Inflates data once atomically, e.g.
|
|
*
|
|
* void *GetData(void) {
|
|
* static _Atomic(void *) ptr;
|
|
* static const unsigned char rodata[] = {...};
|
|
* return xload(&ptr, rodata, 112, 1024);
|
|
* }
|
|
*
|
|
* The above is an example of how this helper may be used to have lazy
|
|
* loading of big infrequently accessed image data.
|
|
*
|
|
* @param a points to your static pointer holder
|
|
* @param p is read-only data compressed using raw deflate
|
|
* @param n is byte length of deflated data
|
|
* @param m is byte length of inflated data
|
|
* @return pointer to inflated data
|
|
* @threadsafe
|
|
*/
|
|
void *xload(_Atomic(void *) * a, const void *p, size_t n, size_t m) {
|
|
void *r, *z;
|
|
if ((r = atomic_load_explicit(a, memory_order_acquire))) return r;
|
|
if (!(r = kmalloc(m))) return 0;
|
|
if (__inflate(r, m, p, n)) return 0;
|
|
z = 0;
|
|
if (!atomic_compare_exchange_strong_explicit(a, &z, r, memory_order_release,
|
|
memory_order_relaxed)) {
|
|
r = z;
|
|
}
|
|
return r;
|
|
}
|