1 files changed, 91 insertions, 0 deletions
diff --git a/stdio/fflush.c b/stdio/fflush.c
new file mode 100644
index 0000000..99a758d
--- /dev/null
+++ b/stdio/fflush.c
@@ -0,0 +1,91 @@
+/*-*- mode:c;indent-tabs-mode:nil;c-basic-offset:2;tab-width:8;coding:utf-8 -*-│
+│vi: set net ft=c ts=8 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/alg/arraylist.internal.h"
+#include "libc/bits/bits.h"
+#include "libc/bits/pushpop.h"
+#include "libc/calls/calls.h"
+#include "libc/errno.h"
+#include "libc/macros.internal.h"
+#include "libc/mem/mem.h"
+#include "libc/runtime/runtime.h"
+#include "libc/stdio/fflush.internal.h"
+#include "libc/stdio/internal.h"
+#include "libc/stdio/stdio.h"
+#include "libc/sysv/consts/o.h"
+
+/**
+ * Blocks until data from stream buffer is written out.
+ *
+ * @param f is the stream handle
+ * @return is 0 on success or -1 on error
+ */
+int fflush(FILE *f) {
+  size_t i;
+  ssize_t rc;
+  if (!f) {
+    for (i = __fflush.handles.i; i; --i) {
+      if ((f = __fflush.handles.p[i - 1])) {
+        if (fflush(f) == -1) return -1;
+      }
+    }
+  } else if (f->fd != -1) {
+    while (f->beg && !f->end && (f->iomode & O_ACCMODE) != O_RDONLY) {
+      if ((rc = write(f->fd, f->buf, f->beg)) == -1) {
+        f->state = errno;
+        return -1;
+      }
+      if (rc != f->beg) abort();
+      f->beg = 0;
+    }
+  } else if (f->beg && f->beg < f->size) {
+    f->buf[f->beg] = 0;
+  }
+  return 0;
+}
+
+textstartup int __fflush_register(FILE *f) {
+  size_t i;
+  struct StdioFlush *sf;
+  sf = &__fflush;
+  if (!sf->handles.p) {
+    sf->handles.p = &sf->handles_initmem[0];
+    pushmov(&sf->handles.n, ARRAYLEN(sf->handles_initmem));
+    __cxa_atexit(fflush, NULL, NULL);
+  }
+  for (i = sf->handles.i; i; --i) {
+    if (!sf->handles.p[i - 1]) {
+      sf->handles.p[i - 1] = f;
+      return 0;
+    }
+  }
+  return append(&sf->handles, &f);
+}
+
+void __fflush_unregister(FILE *f) {
+  size_t i;
+  struct StdioFlush *sf;
+  sf = &__fflush;
+  sf = pushpop(sf);
+  for (i = sf->handles.i; i; --i) {
+    if (sf->handles.p[i - 1] == f) {
+      pushmov(&sf->handles.p[i - 1], NULL);
+      return;
+    }
+  }
+}