+/*
+ * Copyright © 2012 Collabora, Ltd.
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining
+ * a copy of this software and associated documentation files (the
+ * "Software"), to deal in the Software without restriction, including
+ * without limitation the rights to use, copy, modify, merge, publish,
+ * distribute, sublicense, and/or sell copies of the Software, and to
+ * permit persons to whom the Software is furnished to do so, subject to
+ * the following conditions:
+ *
+ * The above copyright notice and this permission notice (including the
+ * next paragraph) shall be included in all copies or substantial
+ * portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+ * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+ * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+ * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
+ * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
+ * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
+ * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+
+/*
+ * Based on weston shared/os-compatibility.c
+ */
+
+#ifndef WIN32
+#include "anon_file.h"
+
+#include <unistd.h>
+#include <fcntl.h>
+#include <errno.h>
+
+#ifdef __FreeBSD__
+#include <sys/mman.h>
+#elif defined(HAVE_MEMFD_CREATE)
+#include <sys/syscall.h>
+#include <linux/memfd.h>
+#endif
+
+#if !(defined(__FreeBSD__) || defined(HAVE_MEMFD_CREATE) || defined(HAVE_MKOSTEMP))
+static int
+set_cloexec_or_close(int fd)
+{
+ long flags;
+
+ if (fd == -1)
+ return -1;
+
+ flags = fcntl(fd, F_GETFD);
+ if (flags == -1)
+ goto err;
+
+ if (fcntl(fd, F_SETFD, flags | FD_CLOEXEC) == -1)
+ goto err;
+
+ return fd;
+
+err:
+ close(fd);
+ return -1;
+}
+#endif
+
+#if !(defined(__FreeBSD__) || defined(HAVE_MEMFD_CREATE))
+static int
+create_tmpfile_cloexec(char *tmpname)
+{
+ int fd;
+
+#ifdef HAVE_MKOSTEMP
+ fd = mkostemp(tmpname, O_CLOEXEC);
+#else
+ fd = mkstemp(tmpname);
+#endif
+
+ if (fd < 0) {
+ return fd;
+ }
+
+#ifndef HAVE_MKOSTEMP
+ fd = set_cloexec_or_close(fd);
+#endif
+
+ unlink(tmpname);
+ return fd;
+}
+#endif
+
+/*
+ * Create a new, unique, anonymous file of the given size, and
+ * return the file descriptor for it. The file descriptor is set
+ * CLOEXEC. The file is immediately suitable for mmap()'ing
+ * the given size at offset zero.
+ *
+ * An optional name for debugging can be provided as the second argument.
+ *
+ * The file should not have a permanent backing store like a disk,
+ * but may have if XDG_RUNTIME_DIR is not properly implemented in OS.
+ *
+ * If memfd or SHM_ANON is supported, the filesystem is not touched at all.
+ * Otherwise, the file name is deleted from the file system.
+ *
+ * The file is suitable for buffer sharing between processes by
+ * transmitting the file descriptor over Unix sockets using the
+ * SCM_RIGHTS methods.
+ */
+int
+os_create_anonymous_file(off_t size, char *debug_name)
+{
+ int fd, ret;
+#ifdef __FreeBSD__
+ (void*)debug_name;
+ fd = shm_open(SHM_ANON, O_CREAT | O_RDWR | O_CLOEXEC, 0600);
+#elif defined(HAVE_MEMFD_CREATE)
+ if (!debug_name)
+ debug_name = "mesa-shared";
+ fd = syscall(SYS_memfd_create, debug_name, MFD_CLOEXEC);
+#else
+ const char *path;
+ char *name;
+
+ path = getenv("XDG_RUNTIME_DIR");
+ if (!path) {
+ errno = ENOENT;
+ return -1;
+ }
+
+ if (debug_name)
+ asprintf(&name, "%s/mesa-shared-%s-XXXXXX", path, debug_name);
+ else
+ asprintf(&name, "%s/mesa-shared-XXXXXX", path);
+ if (!name)
+ return -1;
+
+ fd = create_tmpfile_cloexec(name);
+
+ free(name);
+#endif
+
+ if (fd < 0)
+ return -1;
+
+ ret = ftruncate(fd, size);
+ if (ret < 0) {
+ close(fd);
+ return -1;
+ }
+
+ return fd;
+}
+#endif
projects / mesa.git / commitdiff