Hi! I think you can debug your code with gdb, maybe some other modules or filters prevent sending the data.
On 11 July 2017 at 22:57:50, Johan Andersson (n...@firemail.cc) wrote: Hi Andreas and Zhang, Thank you for your hint with the http_echo_module! I read through their code to get a hang of how the event loop and the event handling actually works. If I replace the hello_world command in my config files with the echo/echo_flush/echo_sleep commands, everything works as expected. If I use my modified hello_world module (code below), I still get a three second pause and then all three "hello world" at once. So I do not think that my configuration (which is the default Debian Stretch configuration) is at fault. I pasted the whole debug log here: https://pastebin.com/raw/uwuK4UJB When I look into the debug log, I see four writev lines corresponding to the initial header and the three "helloworld" outputs. So I think the socket gets its data, but perhaps I am missing some magic socket options? Which would be strange, as I cannot see the http_echo_module doing such a thing. This is my current code (all error handling omitted -- I will take care of that): struct ngx_http_hello_world_ctx { int counter; ngx_event_t event; }; static int numberOfMessages = 3; static ngx_int_t ngx_http_hello_world_handler(ngx_http_request_t *r) { struct ngx_http_hello_world_ctx * ctx = ngx_http_get_module_ctx(r, ngx_http_hello_world_module); if(ctx == NULL) { ctx = ngx_pcalloc(r->pool, sizeof(struct ngx_http_hello_world_ctx)); ngx_http_set_ctx(r, ctx, ngx_http_hello_world_module); } ctx->counter = 0; ctx->event.data = r; ctx->event.handler = ngx_http_hello_world_event_handler; ctx->event.log = r->connection->log; r->headers_out.content_type.len = sizeof("text/html") - 1; r->headers_out.content_type.data = (u_char *) "text/html"; r->headers_out.status = NGX_HTTP_OK; ngx_http_send_header(r); r->main->count++; // Increments reference count ngx_add_timer(&ctx->event, 0); return ngx_http_output_filter(r, NULL); } static void ngx_http_hello_world_event_handler(ngx_event_t *ev) { ngx_http_request_t * r = ev->data; struct ngx_http_hello_world_ctx * ctx = ngx_http_get_module_ctx(r, ngx_http_hello_world_module); if(ctx->counter < numberOfMessages) { ngx_buf_t *b; ngx_chain_t out; b = ngx_pcalloc(r->pool, sizeof(ngx_buf_t)); out.buf = b; out.next = NULL; b->pos = ngx_hello_world; b->last = ngx_hello_world + sizeof(ngx_hello_world); b->memory = 1; b->flush = 1; b->last_buf = (ctx->counter == numberOfMessages); ngx_http_output_filter(r, &out); ngx_http_send_special(r, NGX_HTTP_FLUSH); ctx->counter++; if(ctx->counter == numberOfMessages) { ctx->counter = 0; ngx_http_send_special(r, NGX_HTTP_LAST); ngx_http_finalize_request(r, NGX_OK); // Decrements reference count } else { ngx_add_timer(&ctx->event, 1000); } } } Cheers Johan On 2017-07-10 04:04, Zhang Chao wrote: > Hello! > > You mustn’t use standard sleep function for it will block Nginx’s > events loop, alternatively, you need to put your write event to a > timer, set the proper handler when the timer expires. > BTW, you should always check the return value of ngx_http_send_header > and ngx_http_output_filter. > > On 10 July 2017 at 01:43:46, Johan Andersson (n...@firemail.cc) wrote: > >> Hi everyone, >> >> I have some issues writing my nginx modules. >> >> I am on Debian Stretch, installed nginx with the default >> configuration, >> and took the hello_world module. It works without a hitch. Then I >> changed the handler to send three "hello world" responses, and sleep >> for >> one second between each response. >> >> However, when I look at the result in my browser, the page loads, >> pauses >> for three seconds, and then displays all three "hello world" >> messages at >> once. >> >> Actually I was flushing each response, so I expected each "hello >> world" >> message to appear one after the other, with one second pause between >> >> them. >> >> Am I doing something wrong? Is this event the correct way to achieve >> >> this? All functions return NGX_OK. This is my code: >> >> static ngx_int_t ngx_http_hello_world_handler(ngx_http_request_t *r) >> >> { >> ngx_buf_t *b; >> ngx_chain_t out; >> ngx_int_t result; >> >> r->headers_out.content_type.len = sizeof("text/html") - 1; >> r->headers_out.content_type.data = (u_char *) "text/html"; >> r->headers_out.status = NGX_HTTP_OK; >> //r->headers_out.content_length_n = sizeof(ngx_hello_world); >> ngx_http_send_header(r); >> >> for(int i = 0; i < 3; i++) >> { >> b = ngx_pcalloc(r->pool, sizeof(ngx_buf_t)); >> >> out.buf = b; >> out.next = NULL; >> >> b->pos = ngx_hello_world; >> b->last = ngx_hello_world + sizeof(ngx_hello_world); >> b->memory = 1; >> b->flush = 1; >> b->last_buf = (i == 2); >> >> result = ngx_http_output_filter(r, &out); >> ngx_http_send_special(r, NGX_HTTP_FLUSH); >> >> sleep(1); >> } >> >> return result; >> } >> >> Cheers >> Johann >> _______________________________________________ >> nginx mailing list >> nginx@nginx.org >> http://mailman.nginx.org/mailman/listinfo/nginx > _______________________________________________ > nginx mailing list > nginx@nginx.org > http://mailman.nginx.org/mailman/listinfo/nginx _______________________________________________ nginx mailing list nginx@nginx.org http://mailman.nginx.org/mailman/listinfo/nginx
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