Initial import

2025-08-07 02:10:27 +00:00 · 2020-06-15 07:18:57 -07:00 · 2020-06-15 07:18:57 -07:00 · c91b3c5006
commit c91b3c5006
14915 changed files with 590219 additions and 0 deletions
--- a/examples/bigmem.c
+++ b/examples/bigmem.c
@ -0,0 +1,101 @@
+#if 0
+/*─────────────────────────────────────────────────────────────────╗
+│ To the extent possible under law, Justine Tunney has waived      │
+│ all copyright and related or neighboring rights to this file,    │
+│ as it is written in the following disclaimers:                   │
+│   • http://unlicense.org/                                        │
+│   • http://creativecommons.org/publicdomain/zero/1.0/            │
+╚─────────────────────────────────────────────────────────────────*/
+#endif
+#include "libc/calls/calls.h"
+#include "libc/calls/hefty/spawn.h"
+#include "libc/calls/struct/stat.h"
+#include "libc/log/check.h"
+#include "libc/macros.h"
+#include "libc/runtime/gc.h"
+#include "libc/runtime/runtime.h"
+#include "libc/stdio/stdio.h"
+#include "libc/str/str.h"
+#include "libc/sysv/consts/auxv.h"
+#include "libc/sysv/consts/clock.h"
+#include "libc/sysv/consts/fileno.h"
+#include "libc/sysv/consts/madv.h"
+#include "libc/sysv/consts/map.h"
+#include "libc/sysv/consts/o.h"
+#include "libc/sysv/consts/prot.h"
+#include "libc/time/time.h"
+#include "libc/x/x.h"
+
+/**
+ * @fileoverview Overcommit tutorial.
+ * You can allocate memory like a central banker prints money.
+ */
+
+/* #define kHugeAmount (10LU * 1024LU * 1024LU * 1024LU * 1024LU) */
+#define kHugeAmount (1LU * 1024LU * 1024LU * 1024LU)
+
+int copyfile2(const char *frompath, const char *topath, bool dontoverwrite) {
+  struct stat st;
+  ssize_t transferred;
+  int rc, fromfd, tofd;
+  int64_t inoffset, outoffset;
+  rc = -1;
+  if ((fromfd = open(frompath, O_RDONLY | O_DIRECT, 0)) != -1) {
+    if (fstat(fromfd, &st) != -1 &&
+        (tofd =
+             open(topath,
+                  O_WRONLY | O_CREAT | O_DIRECT | (dontoverwrite ? O_EXCL : 0),
+                  st.st_mode & 0777)) != -1) {
+      inoffset = 0;
+      outoffset = 0;
+      while (st.st_size &&
+             (transferred = copy_file_range(fromfd, &inoffset, tofd, &outoffset,
+                                            st.st_size, 0)) != -1) {
+        st.st_size -= transferred;
+      }
+      if (!st.st_size) rc = 0;
+      rc |= close(tofd);
+    }
+    rc |= close(fromfd);
+  }
+  return rc;
+}
+
+int main(int argc, char *argv[]) {
+  int fd, pid;
+  size_t size;
+  long double t1, t2;
+  const char *core, *core2, *core3;
+  volatile unsigned char *mem;
+  size = ROUNDUP(kHugeAmount, PAGESIZE);
+  core = gc(xasprintf("%s.%s", getauxval(AT_EXECFN), "core"));
+  core2 = gc(xasprintf("%s.%s", getauxval(AT_EXECFN), "core2"));
+  core3 = gc(xasprintf("%s.%s", getauxval(AT_EXECFN), "core3"));
+  CHECK_NE(-1, (fd = open(core, O_RDWR | O_CREAT | O_TRUNC | O_CLOEXEC, 0600)));
+  CHECK_NE(-1, ftruncate(fd, size));
+  CHECK_NE(MAP_FAILED,
+           (mem = mmap(NULL, size, PROT_READ | PROT_WRITE, MAP_SHARED, fd, 0)));
+  strcpy(&mem[0], "hello\n\n\n\n\n\n\n\n\n\n");
+  strcpy(&mem[kHugeAmount / 2], "hello\n\n\n\n\n\n\n\n\n\n");
+  CHECK_NE(-1, munmap(mem, size));
+  CHECK_NE(-1,
+           (pid = spawnve(
+                0, (int[3]){STDIN_FILENO, STDOUT_FILENO, STDERR_FILENO},
+                "o/examples/stat.com",
+                (char *const[]){"o/examples/stat.com", core, NULL}, environ)));
+  CHECK_NE(-1, waitpid(pid, NULL, 0));
+  CHECK_NE(-1, close(fd));
+
+  t1 = dtime(CLOCK_REALTIME);
+  CHECK_NE(-1, copyfile(core, core2, false));
+  t2 = dtime(CLOCK_REALTIME);
+  printf("%.6Lf\n", t2 - t1);
+
+  t1 = dtime(CLOCK_REALTIME);
+  CHECK_NE(-1, copyfile2(core, core3, false));
+  t2 = dtime(CLOCK_REALTIME);
+  printf("%.6Lf\n", t2 - t1);
+
+  /* CHECK_NE(-1, unlink(core)); */
+  return 0;
+}