cosmopolitan/libc/runtime/mapanon.c
Justine Tunney 933411ba99 Improve synchronization
- Fix bugs in kDos2Errno definition
- malloc() should now be thread safe
- Fix bug in rollup.com header generator
- Fix open(O_APPEND) on the New Technology
- Fix select() on the New Technology and test it
- Work towards refactoring i/o for thread safety
- Socket reads and writes on NT now poll for signals
- Work towards i/o completion ports on the New Technology
- Make read() and write() intermittently check for signals
- Blinkenlights keyboard i/o so much better on NT w/ poll()
- You can now poll() files and sockets at the same time on NT
- Fix bug in appendr() that manifests with dlmalloc footers off
2022-04-15 15:31:55 -07:00

66 lines
3 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 2020 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/bits/weaken.h"
#include "libc/calls/calls.h"
#include "libc/errno.h"
#include "libc/nexgen32e/bsr.h"
#include "libc/runtime/runtime.h"
#include "libc/sysv/consts/map.h"
#include "libc/sysv/consts/prot.h"
#include "libc/sysv/errfuns.h"
/**
* Helper function for allocating anonymous mapping.
*
* This function is equivalent to:
*
* mmap(NULL, mapsize, PROT_READ | PROT_WRITE,
* MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);
*
* If mmap() fails, possibly because the parent process did this:
*
* if (!vfork()) {
* setrlimit(RLIMIT_AS, &(struct rlimit){maxbytes, maxbytes});
* execv(prog, (char *const[]){prog, 0});
* }
* wait(0);
*
* Then this function will call:
*
* __oom_hook(size);
*
* If it's linked. The LIBC_TESTLIB library provides an implementation,
* which can be installed as follows:
*
* int main() {
* InstallQuotaHandlers();
* // ...
* }
*
* That is performed automatically for unit test executables.
*/
noasan void *mapanon(size_t size) {
/* asan runtime depends on this function */
void *m;
m = mmap(0, size, PROT_READ | PROT_WRITE, MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);
if (m == MAP_FAILED && weaken(__oom_hook)) {
weaken(__oom_hook)(size);
}
return m;
}