102 lines
3.7 KiB
C
102 lines
3.7 KiB
C
#if 0
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/*─────────────────────────────────────────────────────────────────╗
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│ To the extent possible under law, Justine Tunney has waived │
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│ all copyright and related or neighboring rights to this file, │
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│ as it is written in the following disclaimers: │
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│ • http://unlicense.org/ │
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│ • http://creativecommons.org/publicdomain/zero/1.0/ │
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╚─────────────────────────────────────────────────────────────────*/
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#endif
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#include "libc/calls/calls.h"
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#include "libc/calls/hefty/spawn.h"
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#include "libc/calls/struct/stat.h"
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#include "libc/log/check.h"
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#include "libc/macros.h"
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#include "libc/runtime/gc.h"
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#include "libc/runtime/runtime.h"
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#include "libc/stdio/stdio.h"
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#include "libc/str/str.h"
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#include "libc/sysv/consts/auxv.h"
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#include "libc/sysv/consts/clock.h"
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#include "libc/sysv/consts/fileno.h"
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#include "libc/sysv/consts/madv.h"
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#include "libc/sysv/consts/map.h"
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#include "libc/sysv/consts/o.h"
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#include "libc/sysv/consts/prot.h"
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#include "libc/time/time.h"
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#include "libc/x/x.h"
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/**
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* @fileoverview Overcommit tutorial.
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* You can allocate memory like a central banker prints money.
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*/
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/* #define kHugeAmount (10LU * 1024LU * 1024LU * 1024LU * 1024LU) */
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#define kHugeAmount (1LU * 1024LU * 1024LU * 1024LU)
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int copyfile2(const char *frompath, const char *topath, bool dontoverwrite) {
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struct stat st;
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ssize_t transferred;
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int rc, fromfd, tofd;
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int64_t inoffset, outoffset;
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rc = -1;
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if ((fromfd = open(frompath, O_RDONLY | O_DIRECT, 0)) != -1) {
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if (fstat(fromfd, &st) != -1 &&
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(tofd =
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open(topath,
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O_WRONLY | O_CREAT | O_DIRECT | (dontoverwrite ? O_EXCL : 0),
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st.st_mode & 0777)) != -1) {
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inoffset = 0;
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outoffset = 0;
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while (st.st_size &&
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(transferred = copy_file_range(fromfd, &inoffset, tofd, &outoffset,
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st.st_size, 0)) != -1) {
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st.st_size -= transferred;
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}
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if (!st.st_size) rc = 0;
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rc |= close(tofd);
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}
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rc |= close(fromfd);
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}
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return rc;
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}
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int main(int argc, char *argv[]) {
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int fd, pid;
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size_t size;
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long double t1, t2;
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const char *core, *core2, *core3;
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volatile unsigned char *mem;
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size = ROUNDUP(kHugeAmount, PAGESIZE);
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core = gc(xasprintf("%s.%s", getauxval(AT_EXECFN), "core"));
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core2 = gc(xasprintf("%s.%s", getauxval(AT_EXECFN), "core2"));
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core3 = gc(xasprintf("%s.%s", getauxval(AT_EXECFN), "core3"));
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CHECK_NE(-1, (fd = open(core, O_RDWR | O_CREAT | O_TRUNC | O_CLOEXEC, 0600)));
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CHECK_NE(-1, ftruncate(fd, size));
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CHECK_NE(MAP_FAILED,
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(mem = mmap(NULL, size, PROT_READ | PROT_WRITE, MAP_SHARED, fd, 0)));
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strcpy(&mem[0], "hello\n\n\n\n\n\n\n\n\n\n");
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strcpy(&mem[kHugeAmount / 2], "hello\n\n\n\n\n\n\n\n\n\n");
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CHECK_NE(-1, munmap(mem, size));
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CHECK_NE(-1,
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(pid = spawnve(
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0, (int[3]){STDIN_FILENO, STDOUT_FILENO, STDERR_FILENO},
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"o/examples/stat.com",
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(char *const[]){"o/examples/stat.com", core, NULL}, environ)));
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CHECK_NE(-1, waitpid(pid, NULL, 0));
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CHECK_NE(-1, close(fd));
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t1 = dtime(CLOCK_REALTIME);
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CHECK_NE(-1, copyfile(core, core2, false));
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t2 = dtime(CLOCK_REALTIME);
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printf("%.6Lf\n", t2 - t1);
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t1 = dtime(CLOCK_REALTIME);
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CHECK_NE(-1, copyfile2(core, core3, false));
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t2 = dtime(CLOCK_REALTIME);
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printf("%.6Lf\n", t2 - t1);
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/* CHECK_NE(-1, unlink(core)); */
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return 0;
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}
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