view src/misc/ngx_google_perftools_module.c @ 6949:ff0c8e11edbc

Simplified and improved sendfile() code on Linux. The ngx_linux_sendfile() function is now used for both normal sendfile() and sendfile in threads. The ngx_linux_sendfile_thread() function was modified to use the same interface as ngx_linux_sendfile(), and is simply called from ngx_linux_sendfile() when threads are enabled. Special return code NGX_DONE is used to indicate that a thread task was posted and no further actions are needed. If number of bytes sent is less that what we were sending, we now always retry sending. This is needed for sendfile() in threads as the number of bytes we are sending might have been changed since the thread task was posted. And this is also needed for Linux 4.3+, as sendfile() might be interrupted at any time and provides no indication if it was interrupted or not (ticket #1174).
author Maxim Dounin <mdounin@mdounin.ru>
date Tue, 28 Mar 2017 18:15:39 +0300
parents d620f497c50f
children a27e0c7e198c
line wrap: on
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/*
 * Copyright (C) Igor Sysoev
 * Copyright (C) Nginx, Inc.
 */


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

/*
 * declare Profiler interface here because
 * <google/profiler.h> is C++ header file
 */

int ProfilerStart(u_char* fname);
void ProfilerStop(void);
void ProfilerRegisterThread(void);


static void *ngx_google_perftools_create_conf(ngx_cycle_t *cycle);
static ngx_int_t ngx_google_perftools_worker(ngx_cycle_t *cycle);


typedef struct {
    ngx_str_t  profiles;
} ngx_google_perftools_conf_t;


static ngx_command_t  ngx_google_perftools_commands[] = {

    { ngx_string("google_perftools_profiles"),
      NGX_MAIN_CONF|NGX_DIRECT_CONF|NGX_CONF_TAKE1,
      ngx_conf_set_str_slot,
      0,
      offsetof(ngx_google_perftools_conf_t, profiles),
      NULL },

    ngx_null_command
};


static ngx_core_module_t  ngx_google_perftools_module_ctx = {
    ngx_string("google_perftools"),
    ngx_google_perftools_create_conf,
    NULL
};


ngx_module_t  ngx_google_perftools_module = {
    NGX_MODULE_V1,
    &ngx_google_perftools_module_ctx,      /* module context */
    ngx_google_perftools_commands,         /* module directives */
    NGX_CORE_MODULE,                       /* module type */
    NULL,                                  /* init master */
    NULL,                                  /* init module */
    ngx_google_perftools_worker,           /* init process */
    NULL,                                  /* init thread */
    NULL,                                  /* exit thread */
    NULL,                                  /* exit process */
    NULL,                                  /* exit master */
    NGX_MODULE_V1_PADDING
};


static void *
ngx_google_perftools_create_conf(ngx_cycle_t *cycle)
{
    ngx_google_perftools_conf_t  *gptcf;

    gptcf = ngx_pcalloc(cycle->pool, sizeof(ngx_google_perftools_conf_t));
    if (gptcf == NULL) {
        return NULL;
    }

    /*
     * set by ngx_pcalloc()
     *
     *     gptcf->profiles = { 0, NULL };
     */

    return gptcf;
}


static ngx_int_t
ngx_google_perftools_worker(ngx_cycle_t *cycle)
{
    u_char                       *profile;
    ngx_google_perftools_conf_t  *gptcf;

    gptcf = (ngx_google_perftools_conf_t *)
                ngx_get_conf(cycle->conf_ctx, ngx_google_perftools_module);

    if (gptcf->profiles.len == 0) {
        return NGX_OK;
    }

    profile = ngx_alloc(gptcf->profiles.len + NGX_INT_T_LEN + 2, cycle->log);
    if (profile == NULL) {
        return NGX_OK;
    }

    if (getenv("CPUPROFILE")) {
        /* disable inherited Profiler enabled in master process */
        ProfilerStop();
    }

    ngx_sprintf(profile, "%V.%d%Z", &gptcf->profiles, ngx_pid);

    if (ProfilerStart(profile)) {
        /* start ITIMER_PROF timer */
        ProfilerRegisterThread();

    } else {
        ngx_log_error(NGX_LOG_CRIT, cycle->log, ngx_errno,
                      "ProfilerStart(%s) failed", profile);
    }

    ngx_free(profile);

    return NGX_OK;
}


/* ProfilerStop() is called on Profiler destruction */