Mercurial > hg > nginx
view src/core/ngx_module.c @ 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 | 3600bbfb43e3 |
children |
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/* * Copyright (C) Igor Sysoev * Copyright (C) Maxim Dounin * Copyright (C) Nginx, Inc. */ #include <ngx_config.h> #include <ngx_core.h> #define NGX_MAX_DYNAMIC_MODULES 128 static ngx_uint_t ngx_module_index(ngx_cycle_t *cycle); static ngx_uint_t ngx_module_ctx_index(ngx_cycle_t *cycle, ngx_uint_t type, ngx_uint_t index); ngx_uint_t ngx_max_module; static ngx_uint_t ngx_modules_n; ngx_int_t ngx_preinit_modules(void) { ngx_uint_t i; for (i = 0; ngx_modules[i]; i++) { ngx_modules[i]->index = i; ngx_modules[i]->name = ngx_module_names[i]; } ngx_modules_n = i; ngx_max_module = ngx_modules_n + NGX_MAX_DYNAMIC_MODULES; return NGX_OK; } ngx_int_t ngx_cycle_modules(ngx_cycle_t *cycle) { /* * create a list of modules to be used for this cycle, * copy static modules to it */ cycle->modules = ngx_pcalloc(cycle->pool, (ngx_max_module + 1) * sizeof(ngx_module_t *)); if (cycle->modules == NULL) { return NGX_ERROR; } ngx_memcpy(cycle->modules, ngx_modules, ngx_modules_n * sizeof(ngx_module_t *)); cycle->modules_n = ngx_modules_n; return NGX_OK; } ngx_int_t ngx_init_modules(ngx_cycle_t *cycle) { ngx_uint_t i; for (i = 0; cycle->modules[i]; i++) { if (cycle->modules[i]->init_module) { if (cycle->modules[i]->init_module(cycle) != NGX_OK) { return NGX_ERROR; } } } return NGX_OK; } ngx_int_t ngx_count_modules(ngx_cycle_t *cycle, ngx_uint_t type) { ngx_uint_t i, next, max; ngx_module_t *module; next = 0; max = 0; /* count appropriate modules, set up their indices */ for (i = 0; cycle->modules[i]; i++) { module = cycle->modules[i]; if (module->type != type) { continue; } if (module->ctx_index != NGX_MODULE_UNSET_INDEX) { /* if ctx_index was assigned, preserve it */ if (module->ctx_index > max) { max = module->ctx_index; } if (module->ctx_index == next) { next++; } continue; } /* search for some free index */ module->ctx_index = ngx_module_ctx_index(cycle, type, next); if (module->ctx_index > max) { max = module->ctx_index; } next = module->ctx_index + 1; } /* * make sure the number returned is big enough for previous * cycle as well, else there will be problems if the number * will be stored in a global variable (as it's used to be) * and we'll have to roll back to the previous cycle */ if (cycle->old_cycle && cycle->old_cycle->modules) { for (i = 0; cycle->old_cycle->modules[i]; i++) { module = cycle->old_cycle->modules[i]; if (module->type != type) { continue; } if (module->ctx_index > max) { max = module->ctx_index; } } } /* prevent loading of additional modules */ cycle->modules_used = 1; return max + 1; } ngx_int_t ngx_add_module(ngx_conf_t *cf, ngx_str_t *file, ngx_module_t *module, char **order) { void *rv; ngx_uint_t i, m, before; ngx_core_module_t *core_module; if (cf->cycle->modules_n >= ngx_max_module) { ngx_conf_log_error(NGX_LOG_EMERG, cf, 0, "too many modules loaded"); return NGX_ERROR; } if (module->version != nginx_version) { ngx_conf_log_error(NGX_LOG_EMERG, cf, 0, "module \"%V\" version %ui instead of %ui", file, module->version, (ngx_uint_t) nginx_version); return NGX_ERROR; } if (ngx_strcmp(module->signature, NGX_MODULE_SIGNATURE) != 0) { ngx_conf_log_error(NGX_LOG_EMERG, cf, 0, "module \"%V\" is not binary compatible", file); return NGX_ERROR; } for (m = 0; cf->cycle->modules[m]; m++) { if (ngx_strcmp(cf->cycle->modules[m]->name, module->name) == 0) { ngx_conf_log_error(NGX_LOG_EMERG, cf, 0, "module \"%s\" is already loaded", module->name); return NGX_ERROR; } } /* * if the module wasn't previously loaded, assign an index */ if (module->index == NGX_MODULE_UNSET_INDEX) { module->index = ngx_module_index(cf->cycle); if (module->index >= ngx_max_module) { ngx_conf_log_error(NGX_LOG_EMERG, cf, 0, "too many modules loaded"); return NGX_ERROR; } } /* * put the module into the cycle->modules array */ before = cf->cycle->modules_n; if (order) { for (i = 0; order[i]; i++) { if (ngx_strcmp(order[i], module->name) == 0) { i++; break; } } for ( /* void */ ; order[i]; i++) { #if 0 ngx_log_debug2(NGX_LOG_DEBUG_CORE, cf->log, 0, "module: %s before %s", module->name, order[i]); #endif for (m = 0; m < before; m++) { if (ngx_strcmp(cf->cycle->modules[m]->name, order[i]) == 0) { ngx_log_debug3(NGX_LOG_DEBUG_CORE, cf->log, 0, "module: %s before %s:%i", module->name, order[i], m); before = m; break; } } } } /* put the module before modules[before] */ if (before != cf->cycle->modules_n) { ngx_memmove(&cf->cycle->modules[before + 1], &cf->cycle->modules[before], (cf->cycle->modules_n - before) * sizeof(ngx_module_t *)); } cf->cycle->modules[before] = module; cf->cycle->modules_n++; if (module->type == NGX_CORE_MODULE) { /* * we are smart enough to initialize core modules; * other modules are expected to be loaded before * initialization - e.g., http modules must be loaded * before http{} block */ core_module = module->ctx; if (core_module->create_conf) { rv = core_module->create_conf(cf->cycle); if (rv == NULL) { return NGX_ERROR; } cf->cycle->conf_ctx[module->index] = rv; } } return NGX_OK; } static ngx_uint_t ngx_module_index(ngx_cycle_t *cycle) { ngx_uint_t i, index; ngx_module_t *module; index = 0; again: /* find an unused index */ for (i = 0; cycle->modules[i]; i++) { module = cycle->modules[i]; if (module->index == index) { index++; goto again; } } /* check previous cycle */ if (cycle->old_cycle && cycle->old_cycle->modules) { for (i = 0; cycle->old_cycle->modules[i]; i++) { module = cycle->old_cycle->modules[i]; if (module->index == index) { index++; goto again; } } } return index; } static ngx_uint_t ngx_module_ctx_index(ngx_cycle_t *cycle, ngx_uint_t type, ngx_uint_t index) { ngx_uint_t i; ngx_module_t *module; again: /* find an unused ctx_index */ for (i = 0; cycle->modules[i]; i++) { module = cycle->modules[i]; if (module->type != type) { continue; } if (module->ctx_index == index) { index++; goto again; } } /* check previous cycle */ if (cycle->old_cycle && cycle->old_cycle->modules) { for (i = 0; cycle->old_cycle->modules[i]; i++) { module = cycle->old_cycle->modules[i]; if (module->type != type) { continue; } if (module->ctx_index == index) { index++; goto again; } } } return index; }