strace 来查看redis的启动过程

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ubuntu@VM-8-16-ubuntu:~$ strace redis-server

// 切换到了执行文件

execve("/usr/local/bin/redis-server", ["redis-server"], 0x7fff26814f30 /* 27 vars */) = 0
brk(NULL)                               = 0x5575ff3bb000
arch_prctl(0x3001 /* ARCH_??? */, 0x7ffe24c54730) = -1 EINVAL (Invalid argument)
mmap(NULL, 8192, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 0x7f1c37962000



access("/etc/ld.so.preload", R_OK)      = -1 ENOENT (No such file or directory)
openat(AT_FDCWD, "/etc/ld.so.cache", O_RDONLY|O_CLOEXEC) = 3
newfstatat(3, "", {st_mode=S_IFREG|0644, st_size=24629, ...}, AT_EMPTY_PATH) = 0
mmap(NULL, 24629, PROT_READ, MAP_PRIVATE, 3, 0) = 0x7f1c3795b000
close(3)                                = 0
openat(AT_FDCWD, "/lib/x86_64-linux-gnu/libm.so.6", O_RDONLY|O_CLOEXEC) = 3
read(3, "\177ELF\2\1\1\3\0\0\0\0\0\0\0\0\3\0>\0\1\0\0\0\0\0\0\0\0\0\0\0"..., 832) = 832


.............一堆系统和动态库调用逻辑................................................输出Redis启动ART图



ioctl(1, TCGETS, {B38400 opost isig icanon echo ...}) = 0
getpid()                                = 3420418
write(1, "                _._             "..., 1024                _._                                                  
           _.-``__ ''-._                                             
      _.-``    `.  `_.  ''-._           Redis 7.2.3 (00000000/0) 64 bit
  .-`` .-```.  ```\/    _.,_ ''-._                                  
 (    '      ,       .-`  | `,    )     Running in standalone mode
 |`-._`-...-` __...-.``-._|'` _.-'|     Port: 6379
 |    `-._   `._    /     _.-'    |     PID: 3420418
  `-._    `-._  `-./  _.-'    _.-'                                   
 |`-._`-._    `-.__.-'    _.-'_.-'|                                  
 |    `-._`-._        _.-'_.-'    |           https://redis.io       
  `-._    `-._`-.__.-'_.-'    _.-'                                   
 |`-._`-._    `-.__.-'    _.-'_.-'|                                  
 |    `-._`-._        _.-'_.-'    |                                  
  `-._    `-._`-.__.-'_.-'    _.-'                                   
      `-._    `-.__.-'    _.-'                                       
          `-) = 1024
write(1, "._        _.-'                  "..., 58._        _.-'                                           
) = 58
write(1, "              `-.__.-'          "..., 70              `-.__.-'                                               
) = 70
write(1, "\n", 1
)                       = 1、






...................................开始设置监听Socket.............................................
openat(AT_FDCWD, "/proc/sys/net/core/somaxconn", O_RDONLY) = 6
newfstatat(6, "", {st_mode=S_IFREG|0644, st_size=0, ...}, AT_EMPTY_PATH) = 0
read(6, "4096\n", 1024)                 = 5
close(6)                                = 0
socket(AF_INET, SOCK_STREAM, IPPROTO_TCP) = 6
setsockopt(6, SOL_SOCKET, SO_REUSEADDR, [1], 4) = 0
bind(6, {sa_family=AF_INET, sin_port=htons(6379), sin_addr=inet_addr("0.0.0.0")}, 16) = 0
listen(6, 511)                          = 0
fcntl(6, F_GETFL)                       = 0x2 (flags O_RDWR)
fcntl(6, F_SETFL, O_RDWR|O_NONBLOCK)    = 0
fcntl(6, F_GETFD)                       = 0
fcntl(6, F_SETFD, FD_CLOEXEC)           = 0
socket(AF_INET6, SOCK_STREAM, IPPROTO_TCP) = 7
setsockopt(7, SOL_IPV6, IPV6_V6ONLY, [1], 4) = 0
setsockopt(7, SOL_SOCKET, SO_REUSEADDR, [1], 4) = 0
bind(7, {sa_family=AF_INET6, sin6_port=htons(6379), sin6_flowinfo=htonl(0), inet_pton(AF_INET6, "::", &sin6_addr), sin6_scope_id=0}, 28) = 0
listen(7, 511)                          = 0
fcntl(7, F_GETFL)                       = 0x2 (flags O_RDWR)
fcntl(7, F_SETFL, O_RDWR|O_NONBLOCK)    = 0
fcntl(7, F_GETFD)                       = 0
fcntl(7, F_SETFD, FD_CLOEXEC)           = 0
epoll_ctl(5, EPOLL_CTL_ADD, 6, {events=EPOLLIN, data={u32=6, u64=6}}) = 0
epoll_ctl(5, EPOLL_CTL_ADD, 7, {events=EPOLLIN, data={u32=7, u64=7}}) = 0
rt_sigaction(SIGRT_1, {sa_handler=0x7f1c376dd8f0, sa_mask=[], sa_flags=SA_RESTORER|SA_ONSTACK|SA_RESTART|SA_SIGINFO, sa_restorer=0x7f1c3768e520}, NULL, 8) = 0
rt_sigprocmask(SIG_UNBLOCK, [RTMIN RT_1], NULL, 8) = 0
mmap(NULL, 8392704, PROT_NONE, MAP_PRIVATE|MAP_ANONYMOUS|MAP_STACK, -1, 0) = 0x7f1c36316000
mprotect(0x7f1c36317000, 8388608, PROT_READ|PROT_WRITE) = 0
rt_sigprocmask(SIG_BLOCK, ~[], [], 8)   = 0


..............................初始化Bio里面的微型线程池，默认三个，调用三次clone.................................................


# clone3({flags=CLONE_VM|CLONE_FS|CLONE_FILES|CLONE_SIGHAND|CLONE_THREAD|CLONE_SYSVSEM|CLONE_SETTLS|CLONE_PARENT_SETTID|CLONE_CHILD_CLEARTID, child_tid=0x7f1c36b16910, parent_tid=0x7f1c36b16910, exit_signal=0, stack=0x7f1c36316000, stack_size=0x7ff480, tls=0x7f1c36b16640} => {parent_tid=[3420419]}, 88) = 3420419
rt_sigprocmask(SIG_SETMASK, [], NULL, 8) = 0
mmap(NULL, 8392704, PROT_NONE, MAP_PRIVATE|MAP_ANONYMOUS|MAP_STACK, -1, 0) = 0x7f1c35b15000
mprotect(0x7f1c35b16000, 8388608, PROT_READ|PROT_WRITE) = 0
rt_sigprocmask(SIG_BLOCK, ~[], [], 8)   = 0
# clone3({flags=CLONE_VM|CLONE_FS|CLONE_FILES|CLONE_SIGHAND|CLONE_THREAD|CLONE_SYSVSEM|CLONE_SETTLS|CLONE_PARENT_SETTID|CLONE_CHILD_CLEARTID, child_tid=0x7f1c36315910, parent_tid=0x7f1c36315910, exit_signal=0, stack=0x7f1c35b15000, stack_size=0x7ff480, tls=0x7f1c36315640} => {parent_tid=[3420420]}, 88) = 3420420
rt_sigprocmask(SIG_SETMASK, [], NULL, 8) = 0
mmap(NULL, 8392704, PROT_NONE, MAP_PRIVATE|MAP_ANONYMOUS|MAP_STACK, -1, 0) = 0x7f1c35314000
mprotect(0x7f1c35315000, 8388608, PROT_READ|PROT_WRITE) = 0
rt_sigprocmask(SIG_BLOCK, ~[], [], 8)   = 0
clone3({flags=CLONE_VM|CLONE_FS|CLONE_FILES|CLONE_SIGHAND|CLONE_THREAD|CLONE_SYSVSEM|CLONE_SETTLS|CLONE_PARENT_SETTID|CLONE_CHILD_CLEARTID, child_tid=0x7f1c35b14910, parent_tid=0x7f1c35b14910, exit_signal=0, stack=0x7f1c35314000, stack_size=0x7ff480, tls=0x7f1c35b14640} => {parent_tid=[3420421]}, 88) = 3420421
rt_sigprocmask(SIG_SETMASK, [], NULL, 8) = 0
rt_sigprocmask(SIG_SETMASK, ~[RTMIN RT_1], [], 8) = 0
mmap(NULL, 8392704, PROT_NONE, MAP_PRIVATE|MAP_ANONYMOUS|MAP_STACK, -1, 0) = 0x7f1c34b13000
mprotect(0x7f1c34b14000, 8388608, PROT_READ|PROT_WRITE) = 0
rt_sigprocmask(SIG_BLOCK, ~[], ~[KILL STOP RTMIN RT_1], 8) = 0
# clone3({flags=CLONE_VM|CLONE_FS|CLONE_FILES|CLONE_SIGHAND|CLONE_THREAD|CLONE_SYSVSEM|CLONE_SETTLS|CLONE_PARENT_SETTID|CLONE_CHILD_CLEARTID, child_tid=0x7f1c35313910, parent_tid=0x7f1c35313910, exit_signal=0, stack=0x7f1c34b13000, stack_size=0x7ff480, tls=0x7f1c35313640} => {parent_tid=[3420422]}, 88) = 3420422
rt_sigprocmask(SIG_SETMASK, ~[KILL STOP RTMIN RT_1], NULL, 8) = 0
rt_sigprocmask(SIG_SETMASK, [], NULL, 8) = 0
getpid()                                = 3420418
getpid()                                = 3420418
write(1, "3420418:M 15 Nov 2023 10:09:24.2"..., 563420418:M 15 Nov 2023 10:09:24.217 * Server initialized
) = 56
newfstatat(AT_FDCWD, "appendonlydir", 0x7ffe24c54660, 0) = -1 ENOENT (No such file or directory)
openat(AT_FDCWD, "dump.rdb", O_RDONLY)  = -1 ENOENT (No such file or directory)
getpid()                                = 3420418
getpid()                                = 3420418


...........................................开始epoll_wait事件循环...................................................................


write(1, "3420418:M 15 Nov 2023 10:09:24.2"..., 693420418:M 15 Nov 2023 10:09:24.217 * Ready to accept connections tcp
) = 69
epoll_wait(5, [], 10128, 0)             = 0
openat(AT_FDCWD, "/proc/self/stat", O_RDONLY) = 8
read(8, "3420418 (redis-server) R 3420415"..., 4095) = 341
close(8)                                = 0
epoll_wait(5, [], 10128, 100)           = 0
openat(AT_FDCWD, "/proc/self/stat", O_RDONLY) = 8
read(8, "3420418 (redis-server) R 3420415"..., 4095) = 341
close(8)                                = 0
epoll_wait(5, [], 10128, 100)           = 0
openat(AT_FDCWD, "/proc/self/stat", O_RDONLY) = 8
read(8, "3420418 (redis-server) R 3420415"..., 4095) = 341
close(8)                                = 0
epoll_wait(5, [], 10128, 100)           = 0
openat(AT_FDCWD, "/proc/self/stat", O_RDONLY) = 8
read(8, "3420418 (redis-server) R 3420415"..., 4095) = 341
close(8)                                = 0
epoll_wait(5, [], 10128, 100)           = 0
openat(AT_FDCWD, "/proc/self/stat", O_RDONLY) = 8
read(8, "3420418 (redis-server) R 3420415"..., 4095) = 341
close(8)                                = 0
epoll_wait(5, [], 10128, 100)           = 0
openat(AT_FDCWD, "/proc/self/stat", O_RDONLY) = 8
read(8, "3420418 (redis-server) R 3420415"..., 4095) = 341
close(8)                                = 0
epoll_wait(5, [], 10128, 100)           = 0
openat(AT_FDCWD, "/proc/self/stat", O_RDONLY) = 8
read(8, "3420418 (redis-server) R 3420415"..., 4095) = 341
close(8)                                = 0
epoll_wait(5, [], 10128, 100)           = 0
openat(AT_FDCWD, "/proc/self/stat", O_RDONLY) = 8
read(8, "3420418 (redis-server) R 3420415"..., 4095) = 341
close(8)                                = 0
epoll_wait(5, [], 10128, 100)           = 0
openat(AT_FDCWD, "/proc/self/stat", O_RDONLY) = 8
read(8, "3420418 (redis-server) R 3420415"..., 4095) = 341
close(8)                                = 0
epoll_wait(5, [], 10128, 100)           = 0
openat(AT_FDCWD, "/proc/self/stat", O_RDONLY) = 8
read(8, "3420418 (redis-server) R 3420415"..., 4095) = 341
close(8)                                = 0
epoll_wait(5, [], 10128, 100)           = 0
openat(AT_FDCWD, "/proc/self/stat", O_RDONLY) = 8
read(8, "3420418 (redis-server) R 3420415"..., 4095) = 341
close(8)                                = 0
epoll_wait(5, [], 10128, 100)           = 0
openat(AT_FDCWD, "/proc/self/stat", O_RDONLY) = 8
read(8, "3420418 (redis-server) R 3420415"..., 4095) = 341
close(8)                                = 0
epoll_wait(5, [], 10128, 100)           = 0
openat(AT_FDCWD, "/proc/self/stat", O_RDONLY) = 8
read(8, "3420418 (redis-server) R 3420415"..., 4095) = 341
close(8)                                = 0
epoll_wait(5, [], 10128, 100)           = 0

..................................无限................................................