diff options
author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-28 09:22:22 +0000 |
---|---|---|
committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-28 09:22:22 +0000 |
commit | 3f13df4d019cfcbef3f9909e3b993896d3c934e6 (patch) | |
tree | 6c515810bee8549d81e68c548a26a63909f8e716 /libsync.h | |
parent | Initial commit. (diff) | |
download | libdrm-upstream.tar.xz libdrm-upstream.zip |
Adding upstream version 2.4.114.upstream/2.4.114upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to '')
-rw-r--r-- | libsync.h | 148 |
1 files changed, 148 insertions, 0 deletions
diff --git a/libsync.h b/libsync.h new file mode 100644 index 0000000..f1a2f96 --- /dev/null +++ b/libsync.h @@ -0,0 +1,148 @@ +/* + * sync abstraction + * Copyright 2015-2016 Collabora Ltd. + * + * Based on the implementation from the Android Open Source Project, + * + * Copyright 2012 Google, Inc + * + * 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 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. + */ + +#ifndef _LIBSYNC_H +#define _LIBSYNC_H + +#include <assert.h> +#include <errno.h> +#include <stdint.h> +#include <string.h> +#include <sys/ioctl.h> +#include <sys/poll.h> +#include <unistd.h> + +#if defined(__cplusplus) +extern "C" { +#endif + +#ifndef SYNC_IOC_MERGE +/* duplicated from linux/sync_file.h to avoid build-time dependency + * on new (v4.7) kernel headers. Once distro's are mostly using + * something newer than v4.7 drop this and #include <linux/sync_file.h> + * instead. + */ +struct sync_merge_data { + char name[32]; + int32_t fd2; + int32_t fence; + uint32_t flags; + uint32_t pad; +}; +#define SYNC_IOC_MAGIC '>' +#define SYNC_IOC_MERGE _IOWR(SYNC_IOC_MAGIC, 3, struct sync_merge_data) +#endif + + +static inline int sync_wait(int fd, int timeout) +{ + struct pollfd fds = {0}; + int ret; + + fds.fd = fd; + fds.events = POLLIN; + + do { + ret = poll(&fds, 1, timeout); + if (ret > 0) { + if (fds.revents & (POLLERR | POLLNVAL)) { + errno = EINVAL; + return -1; + } + return 0; + } else if (ret == 0) { + errno = ETIME; + return -1; + } + } while (ret == -1 && (errno == EINTR || errno == EAGAIN)); + + return ret; +} + +static inline int sync_merge(const char *name, int fd1, int fd2) +{ + struct sync_merge_data data = {0}; + int ret; + + data.fd2 = fd2; + strncpy(data.name, name, sizeof(data.name)); + + do { + ret = ioctl(fd1, SYNC_IOC_MERGE, &data); + } while (ret == -1 && (errno == EINTR || errno == EAGAIN)); + + if (ret < 0) + return ret; + + return data.fence; +} + +/* accumulate fd2 into fd1. If *fd1 is not a valid fd then dup fd2, + * otherwise sync_merge() and close the old *fd1. This can be used + * to implement the pattern: + * + * init() + * { + * batch.fence_fd = -1; + * } + * + * // does *NOT* take ownership of fd + * server_sync(int fd) + * { + * if (sync_accumulate("foo", &batch.fence_fd, fd)) { + * ... error ... + * } + * } + */ +static inline int sync_accumulate(const char *name, int *fd1, int fd2) +{ + int ret; + + assert(fd2 >= 0); + + if (*fd1 < 0) { + *fd1 = dup(fd2); + return 0; + } + + ret = sync_merge(name, *fd1, fd2); + if (ret < 0) { + /* leave *fd1 as it is */ + return ret; + } + + close(*fd1); + *fd1 = ret; + + return 0; +} + +#if defined(__cplusplus) +} +#endif + +#endif |