view src/os/unix/ngx_os.h @ 9270:3d455e37abf8

Core: PID file writing synchronization. Now, ngx_daemon() does not call exit() in the parent process immediately, but instead waits for the child process to signal it actually started (and wrote the PID file if configured to). This ensures that the PID file already exists when the parent process exits. To make sure that signal handlers won't cause unexpected logging in the parent process if the child process dies (for example, due to errors when writing the PID file), ngx_init_signals() is moved to the child process. This resolves "PID file ... not readable (yet?) after start" and "Failed to parse PID from file..." errors as observed with systemd. Note that the errors observed are considered to be a bug in systemd, which isn't able to work properly with traditional Unix daemons. Still, the workaround is implemented to make sure there will be no OS vendor patches trying to address this.
author Maxim Dounin <mdounin@mdounin.ru>
date Mon, 13 May 2024 06:13:22 +0300
parents 56fc55e32f23
children
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/*
 * Copyright (C) Igor Sysoev
 * Copyright (C) Nginx, Inc.
 */


#ifndef _NGX_OS_H_INCLUDED_
#define _NGX_OS_H_INCLUDED_


#include <ngx_config.h>
#include <ngx_core.h>


#define NGX_IO_SENDFILE    1


typedef ssize_t (*ngx_recv_pt)(ngx_connection_t *c, u_char *buf, size_t size);
typedef ssize_t (*ngx_recv_chain_pt)(ngx_connection_t *c, ngx_chain_t *in,
    off_t limit);
typedef ssize_t (*ngx_send_pt)(ngx_connection_t *c, u_char *buf, size_t size);
typedef ngx_chain_t *(*ngx_send_chain_pt)(ngx_connection_t *c, ngx_chain_t *in,
    off_t limit);

typedef struct {
    ngx_recv_pt        recv;
    ngx_recv_chain_pt  recv_chain;
    ngx_recv_pt        udp_recv;
    ngx_send_pt        send;
    ngx_send_pt        udp_send;
    ngx_send_chain_pt  udp_send_chain;
    ngx_send_chain_pt  send_chain;
    ngx_uint_t         flags;
} ngx_os_io_t;


ngx_int_t ngx_os_init(ngx_log_t *log);
void ngx_os_status(ngx_log_t *log);
ngx_int_t ngx_os_specific_init(ngx_log_t *log);
void ngx_os_specific_status(ngx_log_t *log);
ngx_int_t ngx_daemon(ngx_log_t *log);
ngx_int_t ngx_daemon_sync(ngx_log_t *log);
ngx_int_t ngx_os_signal_process(ngx_cycle_t *cycle, char *sig, ngx_pid_t pid);


ssize_t ngx_unix_recv(ngx_connection_t *c, u_char *buf, size_t size);
ssize_t ngx_readv_chain(ngx_connection_t *c, ngx_chain_t *entry, off_t limit);
ssize_t ngx_udp_unix_recv(ngx_connection_t *c, u_char *buf, size_t size);
ssize_t ngx_unix_send(ngx_connection_t *c, u_char *buf, size_t size);
ngx_chain_t *ngx_writev_chain(ngx_connection_t *c, ngx_chain_t *in,
    off_t limit);
ssize_t ngx_udp_unix_send(ngx_connection_t *c, u_char *buf, size_t size);
ngx_chain_t *ngx_udp_unix_sendmsg_chain(ngx_connection_t *c, ngx_chain_t *in,
    off_t limit);


#if (IOV_MAX > 64)
#define NGX_IOVS_PREALLOCATE  64
#else
#define NGX_IOVS_PREALLOCATE  IOV_MAX
#endif


typedef struct {
    struct iovec  *iovs;
    ngx_uint_t     count;
    size_t         size;
    ngx_uint_t     nalloc;
} ngx_iovec_t;

ngx_chain_t *ngx_output_chain_to_iovec(ngx_iovec_t *vec, ngx_chain_t *in,
    size_t limit, ngx_log_t *log);


ssize_t ngx_writev(ngx_connection_t *c, ngx_iovec_t *vec);


extern ngx_os_io_t  ngx_os_io;
extern ngx_int_t    ngx_ncpu;
extern ngx_int_t    ngx_max_sockets;
extern ngx_uint_t   ngx_inherited_nonblocking;
extern ngx_uint_t   ngx_tcp_nodelay_and_tcp_nopush;


#if (NGX_FREEBSD)
#include <ngx_freebsd.h>


#elif (NGX_LINUX)
#include <ngx_linux.h>


#elif (NGX_SOLARIS)
#include <ngx_solaris.h>


#elif (NGX_DARWIN)
#include <ngx_darwin.h>
#endif


#endif /* _NGX_OS_H_INCLUDED_ */