mirror of
https://github.com/jart/cosmopolitan.git
synced 2025-02-01 03:53:33 +00:00
791f79fcb3
- We now serialize the file descriptor table when spawning / executing processes on Windows. This means you can now inherit more stuff than just standard i/o. It's needed by bash, which duplicates the console to file descriptor #255. We also now do a better job serializing the environment variables, so you're less likely to encounter E2BIG when using your bash shell. We also no longer coerce environ to uppercase - execve() on Windows now remotely controls its parent process to make them spawn a replacement for itself. Then it'll be able to terminate immediately once the spawn succeeds, without having to linger around for the lifetime as a shell process for proxying the exit code. When process worker thread running in the parent sees the child die, it's given a handle to the new child, to replace it in the process table. - execve() and posix_spawn() on Windows will now provide CreateProcess an explicit handle list. This allows us to remove handle locks which enables better fork/spawn concurrency, with seriously correct thread safety. Other codebases like Go use the same technique. On the other hand fork() still favors the conventional WIN32 inheritence approach which can be a little bit messy, but is *controlled* by guaranteeing perfectly clean slates at both the spawning and execution boundaries - sigset_t is now 64 bits. Having it be 128 bits was a mistake because there's no reason to use that and it's only supported by FreeBSD. By using the system word size, signal mask manipulation on Windows goes very fast. Furthermore @asyncsignalsafe funcs have been rewritten on Windows to take advantage of signal masking, now that it's much more pleasant to use. - All the overlapped i/o code on Windows has been rewritten for pretty good signal and cancelation safety. We're now able to ensure overlap data structures are cleaned up so long as you don't longjmp() out of out of a signal handler that interrupted an i/o operation. Latencies are also improved thanks to the removal of lots of "busy wait" code. Waits should be optimal for everything except poll(), which shall be the last and final demon we slay in the win32 i/o horror show. - getrusage() on Windows is now able to report RUSAGE_CHILDREN as well as RUSAGE_SELF, thanks to aggregation in the process manager thread.
66 lines
3.6 KiB
C
66 lines
3.6 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/sysv/consts/clock.h"
|
|
#include "libc/calls/struct/rusage.h"
|
|
#include "libc/calls/struct/timespec.h"
|
|
#include "libc/calls/struct/timeval.h"
|
|
#include "libc/errno.h"
|
|
#include "libc/sysv/consts/rusage.h"
|
|
#include "libc/time/time.h"
|
|
|
|
/**
|
|
* Returns sum of CPU time consumed by current process since birth.
|
|
*
|
|
* This function provides a basic idea of how computationally expensive
|
|
* your program is, in terms of both the userspace and kernel processor
|
|
* resources it's hitherto consumed. Here's an example of how you might
|
|
* display this information:
|
|
*
|
|
* printf("consumed %g seconds of cpu time\n",
|
|
* (double)clock() / CLOCKS_PER_SEC);
|
|
*
|
|
* This function offers at best microsecond accuracy on all supported
|
|
* platforms. Please note the reported values might be a bit chunkier
|
|
* depending on the kernel scheduler sampling interval see `CLK_TCK`.
|
|
*
|
|
* @return units of CPU time consumed, where each unit's time length
|
|
* should be `1./CLOCKS_PER_SEC` seconds; Cosmopolitan currently
|
|
* returns the unit count in microseconds, i.e. `CLOCKS_PER_SEC`
|
|
* is hard-coded as 1000000. On failure this returns -1 / errno.
|
|
* @raise ENOSYS should be returned currently if run on Bare Metal
|
|
* @see clock_gettime() which polyfills this on Linux and BSDs
|
|
* @see getrusage() which polyfills this on XNU and NT
|
|
*/
|
|
int64_t clock(void) {
|
|
int e;
|
|
struct rusage ru;
|
|
struct timespec ts;
|
|
e = errno;
|
|
if (clock_gettime(CLOCK_PROCESS_CPUTIME_ID, &ts)) {
|
|
errno = e;
|
|
if (getrusage(RUSAGE_SELF, &ru) != -1) {
|
|
ts = timeval_totimespec(timeval_add(ru.ru_utime, ru.ru_stime));
|
|
} else {
|
|
return -1;
|
|
}
|
|
}
|
|
// convert nanoseconds to microseconds w/ ceil rounding
|
|
// this would need roughly ~7,019,309 years to overflow
|
|
return ts.tv_sec * 1000000 + (ts.tv_nsec + 999) / 1000;
|
|
}
|