ArceOS系统调用 - FastDDS移植
什么是FastDDS？
eProsima Fast DDS是DDS（数据分发服务）规范的 C++ 实现 ，该规范是由对象管理组 (OMG)定义的协议。eProsima Fast DDS库提供了应用程序编程接口 (API) 和通信协议，用于部署以数据为中心的发布者-订阅者 (DCPS) 模型，目的是在实时系统之间建立高效可靠的信息分发。eProsima Fast DDS在资源处理方面具有可预测、可扩展、灵活和高效的特点。为了满足这些要求，它利用类型化接口并依赖于多对多分布式网络范例，从而巧妙地分离了通信的发布者和订阅者端 。eProsima Fast DDS包括：
DDS API实现。Fast DDS-Gen，一种用于连接类型接口和中间件实现的生成工具。- 底层
RTPS有线协议实现。
鉴于以上所有情况，eProsima Fast DDS已被选为 机器人操作系统 2 (ROS 2)在每个长期 (LTS) 版本和大多数非 LTS 版本中支持的默认中间件。
分析FastDDS的在Linux中的系统调用
# 发布者
./DDSHelloWorldExample publisher
Starting
Publisher running 10 samples.
Publisher matched.
Message: HelloWorld with index: 1 SENT
Message: HelloWorld with index: 2 SENT
Message: HelloWorld with index: 3 SENT
Message: HelloWorld with index: 4 SENT
Message: HelloWorld with index: 5 SENT
Message: HelloWorld with index: 6 SENT
Message: HelloWorld with index: 7 SENT
Message: HelloWorld with index: 8 SENT
Message: HelloWorld with index: 9 SENT
Message: HelloWorld with index: 10 SENT
% time seconds usecs/call calls errors syscall
------ ----------- ----------- --------- --------- ----------------
68.00 0.008722 396 22 futex
13.44 0.001724 123 14 sendto
3.91 0.000502 41 12 munmap
2.54 0.000326 40 8 clone3
1.96 0.000251 13 19 8 setsockopt
1.93 0.000247 3 63 mmap
1.58 0.000203 5 39 close
1.43 0.000183 7 23 mprotect
0.76 0.000097 1 79 55 openat
0.54 0.000069 69 1 clock_nanosleep
0.51 0.000066 4 14 socket
0.38 0.000049 6 8 1 unlink
0.37 0.000048 16 3 3 shutdown
0.32 0.000041 2 15 brk
0.30 0.000038 4 9 epoll_ctl
0.27 0.000035 2 17 rt_sigprocmask
0.23 0.000030 0 33 10 newfstatat
0.20 0.000026 2 9 bind
0.20 0.000026 2 10 flock
0.20 0.000026 8 3 fallocate
0.19 0.000024 6 4 write
0.13 0.000017 0 18 recvmsg
0.06 0.000008 0 16 read
0.06 0.000008 1 6 getsockname
0.06 0.000008 8 1 link
0.06 0.000008 8 1 eventfd2
0.05 0.000006 1 5 ioctl
0.05 0.000006 3 2 getsockopt
0.04 0.000005 2 2 getrandom
0.03 0.000004 1 3 fchmod
0.03 0.000004 4 1 set_tid_address
0.03 0.000004 4 1 timerfd_create
0.03 0.000004 4 1 epoll_create1
0.02 0.000003 1 2 1 arch_prctl
0.02 0.000003 3 1 set_robust_list
0.02 0.000003 3 1 rseq
0.02 0.000002 0 5 getpid
0.01 0.000001 0 2 lseek
0.00 0.000000 0 1 rt_sigaction
0.00 0.000000 0 4 pread64
0.00 0.000000 0 1 1 access
0.00 0.000000 0 2 2 connect
0.00 0.000000 0 1 execve
0.00 0.000000 0 1 uname
0.00 0.000000 0 1 geteuid
0.00 0.000000 0 1 prlimit64
------ ----------- ----------- --------- --------- ----------------
100.00 0.012827 26 485 81 total
# 订阅者
/DDSHelloWorldExample subscriber
Starting
Subscriber running. Please press enter to stop the Subscriber
Subscriber matched.
Message HelloWorld 1 RECEIVED
Message HelloWorld 2 RECEIVED
Message HelloWorld 3 RECEIVED
Message HelloWorld 4 RECEIVED
Message HelloWorld 5 RECEIVED
Message HelloWorld 6 RECEIVED
Message HelloWorld 7 RECEIVED
Message HelloWorld 8 RECEIVED
Message HelloWorld 9 RECEIVED
Message HelloWorld 10 RECEIVED
Subscriber unmatched.
^Cstrace: Process 157950 detached
% time seconds usecs/call calls errors syscall
------ ----------- ----------- --------- --------- ----------------
17.85 0.002071 26 79 55 openat
10.09 0.001171 18 62 mmap
7.91 0.000918 65 14 3 setsockopt
6.89 0.000800 28 28 futex
6.46 0.000750 22 34 10 newfstatat
6.32 0.000733 81 9 sendto
5.66 0.000657 43 15 rt_sigprocmask
4.33 0.000502 22 22 mprotect
4.05 0.000470 16 28 close
3.83 0.000445 24 18 recvmsg
3.58 0.000415 59 7 clone3
3.12 0.000362 25 14 socket
2.22 0.000258 16 16 read
2.12 0.000246 15 16 brk
2.05 0.000238 79 3 fallocate
1.67 0.000194 21 9 epoll_ctl
1.39 0.000161 17 9 bind
1.22 0.000142 17 8 flock
1.12 0.000130 26 5 1 unlink
1.10 0.000128 32 4 write
0.90 0.000105 17 6 getsockname
0.83 0.000096 32 3 fchmod
0.73 0.000085 21 4 pread64
0.67 0.000078 15 5 ioctl
0.65 0.000076 15 5 getpid
0.50 0.000058 19 3 munmap
0.33 0.000038 19 2 getsockopt
0.32 0.000037 18 2 2 connect
0.29 0.000034 34 1 1 access
0.28 0.000033 16 2 lseek
0.26 0.000030 15 2 1 arch_prctl
0.22 0.000026 26 1 link
0.20 0.000023 23 1 timerfd_create
0.18 0.000021 21 1 eventfd2
0.17 0.000020 20 1 epoll_create1
0.16 0.000018 18 1 rt_sigaction
0.14 0.000016 8 2 getrandom
0.09 0.000010 10 1 uname
0.09 0.000010 10 1 geteuid
0.00 0.000000 0 1 execve
0.00 0.000000 0 1 set_tid_address
0.00 0.000000 0 1 set_robust_list
0.00 0.000000 0 1 prlimit64
0.00 0.000000 0 1 rseq
------ ----------- ----------- --------- --------- ----------------
100.00 0.011605 25 449 73 total
64位Linux系统调用整理
返回值放在%rax中
