Mercurial > hg > nginx-quic
view src/os/unix/ngx_thread_id.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 | 466bd63b63d1 |
children |
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/* * Copyright (C) Igor Sysoev * Copyright (C) Nginx, Inc. */ #include <ngx_config.h> #include <ngx_core.h> #include <ngx_thread_pool.h> #if (NGX_LINUX) /* * Linux thread id is a pid of thread created by clone(2), * glibc does not provide a wrapper for gettid(). */ ngx_tid_t ngx_thread_tid(void) { return syscall(SYS_gettid); } #elif (NGX_FREEBSD) && (__FreeBSD_version >= 900031) #include <pthread_np.h> ngx_tid_t ngx_thread_tid(void) { return pthread_getthreadid_np(); } #elif (NGX_DARWIN) /* * MacOSX thread has two thread ids: * * 1) MacOSX 10.6 (Snow Leoprad) has pthread_threadid_np() returning * an uint64_t value, which is obtained using the __thread_selfid() * syscall. It is a number above 300,000. */ ngx_tid_t ngx_thread_tid(void) { uint64_t tid; (void) pthread_threadid_np(NULL, &tid); return tid; } /* * 2) Kernel thread mach_port_t returned by pthread_mach_thread_np(). * It is a number in range 100-100,000. * * return pthread_mach_thread_np(pthread_self()); */ #else ngx_tid_t ngx_thread_tid(void) { return (uint64_t) (uintptr_t) pthread_self(); } #endif