Mercurial > hg > nginx-quic
view src/os/unix/ngx_setproctitle.c @ 8751:555533169506
HTTP/2: fixed "task already active" with sendfile in threads.
With sendfile in threads, "task already active" alerts might appear in logs
if a write event happens on the main HTTP/2 connection, triggering a sendfile
in threads while another thread operation is already running. Observed
with "aio threads; aio_write on; sendfile on;" and with thread event handlers
modified to post a write event to the main HTTP/2 connection (though can
happen without any modifications).
Similarly, sendfile() with AIO preloading on FreeBSD can trigger duplicate
aio operation, resulting in "second aio post" alerts. This is, however,
harder to reproduce, especially on modern FreeBSD systems, since sendfile()
usually does not return EBUSY.
Fix is to avoid starting a sendfile operation if other thread operation
is active by checking r->aio in the thread handler (and, similarly, in
aio preload handler). The added check also makes duplicate calls protection
redundant, so it is removed.
author | Maxim Dounin <mdounin@mdounin.ru> |
---|---|
date | Thu, 25 Nov 2021 22:02:05 +0300 |
parents | 67653855682e |
children |
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/* * Copyright (C) Igor Sysoev * Copyright (C) Nginx, Inc. */ #include <ngx_config.h> #include <ngx_core.h> #if (NGX_SETPROCTITLE_USES_ENV) /* * To change the process title in Linux and Solaris we have to set argv[1] * to NULL and to copy the title to the same place where the argv[0] points to. * However, argv[0] may be too small to hold a new title. Fortunately, Linux * and Solaris store argv[] and environ[] one after another. So we should * ensure that is the continuous memory and then we allocate the new memory * for environ[] and copy it. After this we could use the memory starting * from argv[0] for our process title. * * The Solaris's standard /bin/ps does not show the changed process title. * You have to use "/usr/ucb/ps -w" instead. Besides, the UCB ps does not * show a new title if its length less than the origin command line length. * To avoid it we append to a new title the origin command line in the * parenthesis. */ extern char **environ; static char *ngx_os_argv_last; ngx_int_t ngx_init_setproctitle(ngx_log_t *log) { u_char *p; size_t size; ngx_uint_t i; size = 0; for (i = 0; environ[i]; i++) { size += ngx_strlen(environ[i]) + 1; } p = ngx_alloc(size, log); if (p == NULL) { return NGX_ERROR; } ngx_os_argv_last = ngx_os_argv[0]; for (i = 0; ngx_os_argv[i]; i++) { if (ngx_os_argv_last == ngx_os_argv[i]) { ngx_os_argv_last = ngx_os_argv[i] + ngx_strlen(ngx_os_argv[i]) + 1; } } for (i = 0; environ[i]; i++) { if (ngx_os_argv_last == environ[i]) { size = ngx_strlen(environ[i]) + 1; ngx_os_argv_last = environ[i] + size; ngx_cpystrn(p, (u_char *) environ[i], size); environ[i] = (char *) p; p += size; } } ngx_os_argv_last--; return NGX_OK; } void ngx_setproctitle(char *title) { u_char *p; #if (NGX_SOLARIS) ngx_int_t i; size_t size; #endif ngx_os_argv[1] = NULL; p = ngx_cpystrn((u_char *) ngx_os_argv[0], (u_char *) "nginx: ", ngx_os_argv_last - ngx_os_argv[0]); p = ngx_cpystrn(p, (u_char *) title, ngx_os_argv_last - (char *) p); #if (NGX_SOLARIS) size = 0; for (i = 0; i < ngx_argc; i++) { size += ngx_strlen(ngx_argv[i]) + 1; } if (size > (size_t) ((char *) p - ngx_os_argv[0])) { /* * ngx_setproctitle() is too rare operation so we use * the non-optimized copies */ p = ngx_cpystrn(p, (u_char *) " (", ngx_os_argv_last - (char *) p); for (i = 0; i < ngx_argc; i++) { p = ngx_cpystrn(p, (u_char *) ngx_argv[i], ngx_os_argv_last - (char *) p); p = ngx_cpystrn(p, (u_char *) " ", ngx_os_argv_last - (char *) p); } if (*(p - 1) == ' ') { *(p - 1) = ')'; } } #endif if (ngx_os_argv_last - (char *) p) { ngx_memset(p, NGX_SETPROCTITLE_PAD, ngx_os_argv_last - (char *) p); } ngx_log_debug1(NGX_LOG_DEBUG_CORE, ngx_cycle->log, 0, "setproctitle: \"%s\"", ngx_os_argv[0]); } #endif /* NGX_SETPROCTITLE_USES_ENV */