view src/os/win32/ngx_process.h @ 8045:aa28c802409f

Resolver: make TCP write timer event cancelable. Similar to 70e65bf8dfd7, the change is made to ensure that the ability to cancel resolver tasks is fully controlled by the caller. As mentioned in the referenced commit, it is safe to make this timer cancelable because resolve tasks can have their own timeouts that are not cancelable. The scenario where this may become a problem is a periodic background resolve task (not tied to a specific request or a client connection), which receives a response with short TTL, large enough to warrant fallback to a TCP query. With each event loop wakeup, we either have a previously set write timer instance or schedule a new one. The non-cancelable write timer can delay or block graceful shutdown of a worker even if the ngx_resolver_ctx_t->cancelable flag is set by the API user, and there are no other tasks or connections. We use the resolver API in this way to maintain the list of upstream server addresses specified with the 'resolve' parameter, and there could be third-party modules implementing similar logic.
author Aleksei Bavshin <a.bavshin@f5.com>
date Wed, 01 Jun 2022 20:17:23 -0700
parents 8b84d60ef13d
children
line wrap: on
line source


/*
 * Copyright (C) Igor Sysoev
 * Copyright (C) Nginx, Inc.
 */


#ifndef _NGX_PROCESS_H_INCLUDED_
#define _NGX_PROCESS_H_INCLUDED_


typedef DWORD               ngx_pid_t;
#define NGX_INVALID_PID     0


#define ngx_getpid          GetCurrentProcessId
#define ngx_getppid()       0
#define ngx_log_pid         ngx_pid


#define NGX_PROCESS_SYNC_NAME                                                 \
    (sizeof("ngx_cache_manager_mutex_") + NGX_INT32_LEN)


typedef uint64_t            ngx_cpuset_t;


typedef struct {
    HANDLE                  handle;
    ngx_pid_t               pid;
    char                   *name;

    HANDLE                  term;
    HANDLE                  quit;
    HANDLE                  reopen;

    u_char                  term_event[NGX_PROCESS_SYNC_NAME];
    u_char                  quit_event[NGX_PROCESS_SYNC_NAME];
    u_char                  reopen_event[NGX_PROCESS_SYNC_NAME];

    unsigned                just_spawn:1;
    unsigned                exiting:1;
} ngx_process_t;


typedef struct {
    char                   *path;
    char                   *name;
    char                   *args;
    char *const            *argv;
    char *const            *envp;
    HANDLE                  child;
} ngx_exec_ctx_t;


ngx_pid_t ngx_spawn_process(ngx_cycle_t *cycle, char *name, ngx_int_t respawn);
ngx_pid_t ngx_execute(ngx_cycle_t *cycle, ngx_exec_ctx_t *ctx);

#define ngx_debug_point()
#define ngx_sched_yield()   SwitchToThread()


#define NGX_MAX_PROCESSES         (MAXIMUM_WAIT_OBJECTS - 4)

#define NGX_PROCESS_RESPAWN       -2
#define NGX_PROCESS_JUST_RESPAWN  -3


extern int                  ngx_argc;
extern char               **ngx_argv;
extern char               **ngx_os_argv;

extern ngx_int_t            ngx_last_process;
extern ngx_process_t        ngx_processes[NGX_MAX_PROCESSES];

extern ngx_pid_t            ngx_pid;
extern ngx_pid_t            ngx_parent;


#endif /* _NGX_PROCESS_H_INCLUDED_ */