thread.c

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/*
 *   This program is free software; you can redistribute it and/or modify
 *   it under the terms of the GNU General Public License as published by
 *   the Free Software Foundation; either version 2 of the License, or
 *   (at your option) any later version.
 *
 *   This program is distributed in the hope that it will be useful,
 *   but WITHOUT ANY WARRANTY; without even the implied warranty of
 *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *   GNU General Public License for more details.
 *
 *   You should have received a copy of the GNU General Public License
 *   along with this program; if not, write to the Free Software
 *   Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301, USA
 */
 
/**
 * $Id: 2e34607bb921e495aec9bcfbadf19f754b9eb41b $
 *
 * @brief Common thread instantiation and detach for worker and coordinator threads
 * @file io/thread.c
 *
 * @copyright 2026 Network RADIUS SAS (legal@networkradius.com)
 */
RCSID("$Id: 2e34607bb921e495aec9bcfbadf19f754b9eb41b $")
 
#include <freeradius-devel/io/thread.h>
#include <freeradius-devel/server/module_rlm.h>
#include <freeradius-devel/server/virtual_servers.h>
#include <freeradius-devel/server/main_config.h>
#include <freeradius-devel/tls/base.h>
#include <freeradius-devel/unlang/base.h>
#include <freeradius-devel/util/syserror.h>
 
#include <signal.h>
 
/** Create a joinable thread
 *
 * @param[out] thread           handle that was created by pthread_create.
 * @param[in] func              entry point for the thread.
 * @param[in] arg               Argument to pass to func.
 * @return
 *      - 0 on success.
 *      - -1 on failure.
 */
int fr_thread_create(pthread_t *thread, fr_thread_entry_t func, void *arg)
{
        pthread_attr_t                  attr;
        int                             rcode;
 
        /*
         *      Set the thread to wait around after it's exited so it
         *      can be joined.  This is more of a useful mechanism for
         *      the parent to determine if all the threads have exited
         *      so it can continue with a graceful shutdown.
         */
        pthread_attr_init(&attr);
        pthread_attr_setdetachstate(&attr, PTHREAD_CREATE_JOINABLE);
 
        rcode = pthread_create(thread, &attr, func, arg);
        if (rcode != 0) {
                fr_strerror_printf("Failed creating thread: %s", fr_syserror(rcode));
                pthread_attr_destroy(&attr);
                return -1;
        }
        pthread_attr_destroy(&attr);
 
        return 0;
}
 
/** Wait for multiple threads to signal readiness via a semaphore
 *
 * @param[in] sem               semaphore to wait on.
 * @param[in] head              head of the list to wait for
 * @return
 *      - 0 for success
 *      - <0 negative number of threads which failed to start
 */
int fr_thread_wait_list(fr_sem_t *sem, fr_dlist_head_t *head)
{
        unsigned int i, count;
        int rcode = 0;
 
        count = fr_dlist_num_elements(head);
 
        for (i = 0; i < count; i++) {
                SEM_WAIT_INTR(sem);
        }
 
        /*
         *      See if all of the threads have started.  If a thread fails, it cleans up any context that was
         *      allocated for it.
         */
        fr_dlist_foreach(head, fr_thread_t, thread) {
                if (thread->status != FR_THREAD_RUNNING) {
                        fr_dlist_remove(head, thread);
                        rcode--;
                }
        }
 
        return rcode;
}
 
/** Common setup for child threads: block signals, allocate a talloc context, and create an event list
 *
 * @param[out] out      structure describing the thread
 * @param[in]  name     Human-readable name used for the talloc context and error messages.
 * @return
 *      - 0 on success.
 *      - <0 on failure
 */
int fr_thread_setup(fr_thread_t *out, char const *name)
{
        TALLOC_CTX      *ctx;
        fr_event_list_t *el;
 
#ifndef __APPLE__
        /*
         *      OSX doesn't use pthread_signmask in its setcontext
         *      function, and seems to apply the signal mask of the
         *      thread to the entire process when setcontext is
         *      called.
         */
        {
                sigset_t sigset;
 
                sigfillset(&sigset);
 
                /*
                 *      In debug builds, remove SIGPROF from the set
                 *      if we're planning on using gperftools.
                 *
                 *      SIGPROF is using during profiling, and must
                 *      reach the thread in order for profiling to
                 *      work.
                 */
#if !defined(NDEBUG) && defined(HAVE_GPERFTOOLS_PROFILER_H)
                sigdelset(&sigset, SIGPROF);
#endif
                pthread_sigmask(SIG_BLOCK, &sigset, NULL);
        }
#endif
 
        ctx = talloc_init("%s", name);
        if (!ctx) {
                ERROR("%s - Failed allocating memory", name);
                return -1;
        }
 
        el = fr_event_list_alloc(ctx, NULL, NULL);
        if (!el) {
                PERROR("%s - Failed creating event list", name);
                talloc_free(ctx);
                return -1;
        }
 
        /*
         *      Do NOT initialize the entire structure.  Fields like "id" and "entry" have already been
         *      initialize and used by the main thread coordinator.
         */
        out->name = talloc_strdup(ctx, name);
        out->ctx = ctx;
        out->el = el;
        out->status = FR_THREAD_INITIALIZING;
 
        return 0;
}
 
/** Instantiate thread-specific data for modules, virtual servers, xlats, unlang, and TLS
 *
 * @param[in] ctx       to allocate thread-specific data in.
 * @param[in] el        event list for this thread.
 * @return
 *      - 0 on success.
 *      - -1 on failure.
 */
int fr_thread_instantiate(TALLOC_CTX *ctx, fr_event_list_t *el)
{
#ifdef WITH_TLS
        /*
         *      Modules may use thread-specific OpenSSL contexts, so initialize this first.
         */
        if (fr_openssl_thread_init(main_config->openssl_async_pool_init,
                                   main_config->openssl_async_pool_max) < 0) return -1;
#endif
 
        if (modules_rlm_thread_instantiate(ctx, el) < 0) return -1;
 
        if (virtual_servers_thread_instantiate(ctx, el) < 0) return -1;
 
        if (xlat_thread_instantiate(ctx, el) < 0) return -1;
 
        if (unlang_thread_instantiate(ctx) < 0) return -1;
 
        return 0;
}
 
/** Detach thread-specific data for modules, virtual servers, xlats
 *
 * Calls detach in reverse order of instantiation.
 */
void fr_thread_detach(void)
{
        xlat_thread_detach();
        virtual_servers_thread_detach();
        (void) modules_rlm_coord_detach();
        modules_rlm_thread_detach();
}
 
 
/** Signal the parent that we're done.
 *
 * @param[out]  thread which is starting
 * @param[in]   sem semaphore to signal.
 */
void fr_thread_start(fr_thread_t *thread, fr_sem_t *sem)
{
        thread->status = FR_THREAD_RUNNING;
 
        INFO("%s - Starting", thread->name);
 
        sem_post(sem);
}
 
/** Signal the parent that we're done.
 *
 * @param[out]  thread which is exiting
 * @param[in]   status to write
 * @param[in]   sem semaphore to signal.
 */
void fr_thread_exit(fr_thread_t *thread, fr_thread_status_t status, fr_sem_t *sem)
{
        /*
         *      Maybe nothing was initialized, so we don't need to do anything.
         */
        if (thread->status == FR_THREAD_FREE) return;
 
        INFO("%s - Exiting", thread->name);
 
        thread->status = status;
 
        /*
         *      Not looping at this point, but may catch timer/fd
         *      insertions being done after the thread should have
         *      exited.
         */
        if (thread->el) fr_event_loop_exit(thread->el, 1);
 
        TALLOC_FREE(thread->ctx);
 
        sem_post(sem);
}