wownero/external/unbound/util/locks.c
Erik de Castro Lopo a85b5759f3 Upgrade unbound library
These files were pulled from the 1.6.3 release tarball.

This new version builds against OpenSSL version 1.1 which will be
the default in the new Debian Stable which is due to be released
RealSoonNow (tm).
2017-06-17 23:04:00 +10:00

264 lines
7.9 KiB
C

/**
* util/locks.c - unbound locking primitives
*
* Copyright (c) 2007, NLnet Labs. All rights reserved.
*
* This software is open source.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* Redistributions of source code must retain the above copyright notice,
* this list of conditions and the following disclaimer.
*
* Redistributions in binary form must reproduce the above copyright notice,
* this list of conditions and the following disclaimer in the documentation
* and/or other materials provided with the distribution.
*
* Neither the name of the NLNET LABS nor the names of its contributors may
* be used to endorse or promote products derived from this software without
* specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
* A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
* HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED
* TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
* PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
* LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
* NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
* SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
/**
* \file
* Implementation of locking and threading support.
* A place for locking debug code since most locking functions are macros.
*/
#include "config.h"
#include "util/locks.h"
#include <signal.h>
#ifdef HAVE_SYS_WAIT_H
#include <sys/wait.h>
#endif
/** block all signals, masks them away. */
void
ub_thread_blocksigs(void)
{
#if defined(HAVE_PTHREAD) || defined(HAVE_SOLARIS_THREADS) || defined(HAVE_SIGPROCMASK)
# if defined(HAVE_PTHREAD) || defined(HAVE_SOLARIS_THREADS)
int err;
# endif
sigset_t sigset;
sigfillset(&sigset);
#ifdef HAVE_PTHREAD
if((err=pthread_sigmask(SIG_SETMASK, &sigset, NULL)))
fatal_exit("pthread_sigmask: %s", strerror(err));
#else
# ifdef HAVE_SOLARIS_THREADS
if((err=thr_sigsetmask(SIG_SETMASK, &sigset, NULL)))
fatal_exit("thr_sigsetmask: %s", strerror(err));
# else
/* have nothing, do single process signal mask */
if(sigprocmask(SIG_SETMASK, &sigset, NULL))
fatal_exit("sigprocmask: %s", strerror(errno));
# endif /* HAVE_SOLARIS_THREADS */
#endif /* HAVE_PTHREAD */
#endif /* have signal stuff */
}
/** unblock one signal, so we can catch it */
void ub_thread_sig_unblock(int sig)
{
#if defined(HAVE_PTHREAD) || defined(HAVE_SOLARIS_THREADS) || defined(HAVE_SIGPROCMASK)
# if defined(HAVE_PTHREAD) || defined(HAVE_SOLARIS_THREADS)
int err;
# endif
sigset_t sigset;
sigemptyset(&sigset);
sigaddset(&sigset, sig);
#ifdef HAVE_PTHREAD
if((err=pthread_sigmask(SIG_UNBLOCK, &sigset, NULL)))
fatal_exit("pthread_sigmask: %s", strerror(err));
#else
# ifdef HAVE_SOLARIS_THREADS
if((err=thr_sigsetmask(SIG_UNBLOCK, &sigset, NULL)))
fatal_exit("thr_sigsetmask: %s", strerror(err));
# else
/* have nothing, do single thread case */
if(sigprocmask(SIG_UNBLOCK, &sigset, NULL))
fatal_exit("sigprocmask: %s", strerror(errno));
# endif /* HAVE_SOLARIS_THREADS */
#endif /* HAVE_PTHREAD */
#else
(void)sig;
#endif /* have signal stuff */
}
#if !defined(HAVE_PTHREAD) && !defined(HAVE_SOLARIS_THREADS) && !defined(HAVE_WINDOWS_THREADS)
/**
* No threading available: fork a new process.
* This means no shared data structure, and no locking.
* Only the main thread ever returns. Exits on errors.
* @param thr: the location where to store the thread-id.
* @param func: function body of the thread. Return value of func is lost.
* @param arg: user argument to func.
*/
void
ub_thr_fork_create(ub_thread_type* thr, void* (*func)(void*), void* arg)
{
pid_t pid = fork();
switch(pid) {
default: /* main */
*thr = (ub_thread_type)pid;
return;
case 0: /* child */
*thr = (ub_thread_type)getpid();
(void)(*func)(arg);
exit(0);
case -1: /* error */
fatal_exit("could not fork: %s", strerror(errno));
}
}
/**
* There is no threading. Wait for a process to terminate.
* Note that ub_thread_type is defined as pid_t.
* @param thread: the process id to wait for.
*/
void ub_thr_fork_wait(ub_thread_type thread)
{
int status = 0;
if(waitpid((pid_t)thread, &status, 0) == -1)
log_err("waitpid(%d): %s", (int)thread, strerror(errno));
if(status != 0)
log_warn("process %d abnormal exit with status %d",
(int)thread, status);
}
#endif /* !defined(HAVE_PTHREAD) && !defined(HAVE_SOLARIS_THREADS) && !defined(HAVE_WINDOWS_THREADS) */
#ifdef HAVE_SOLARIS_THREADS
void* ub_thread_key_get(ub_thread_key_type key)
{
void* ret=NULL;
LOCKRET(thr_getspecific(key, &ret));
return ret;
}
#endif
#ifdef HAVE_WINDOWS_THREADS
/** log a windows GetLastError message */
static void log_win_err(const char* str, DWORD err)
{
LPTSTR buf;
if(FormatMessage(FORMAT_MESSAGE_FROM_SYSTEM |
FORMAT_MESSAGE_IGNORE_INSERTS | FORMAT_MESSAGE_ALLOCATE_BUFFER,
NULL, err, 0, (LPTSTR)&buf, 0, NULL) == 0) {
/* could not format error message */
log_err("%s, GetLastError=%d", str, (int)err);
return;
}
log_err("%s, (err=%d): %s", str, (int)err, buf);
LocalFree(buf);
}
void lock_basic_init(lock_basic_type* lock)
{
/* implement own lock, because windows HANDLE as Mutex usage
* uses too many handles and would bog down the whole system. */
(void)InterlockedExchange(lock, 0);
}
void lock_basic_destroy(lock_basic_type* lock)
{
(void)InterlockedExchange(lock, 0);
}
void lock_basic_lock(lock_basic_type* lock)
{
LONG wait = 1; /* wait 1 msec at first */
while(InterlockedExchange(lock, 1)) {
/* if the old value was 1 then if was already locked */
Sleep(wait); /* wait with sleep */
wait *= 2; /* exponential backoff for waiting */
}
/* the old value was 0, but we inserted 1, we locked it! */
}
void lock_basic_unlock(lock_basic_type* lock)
{
/* unlock it by inserting the value of 0. xchg for cache coherency. */
(void)InterlockedExchange(lock, 0);
}
void ub_thread_key_create(ub_thread_key_type* key, void* f)
{
*key = TlsAlloc();
if(*key == TLS_OUT_OF_INDEXES) {
*key = 0;
log_win_err("TlsAlloc Failed(OUT_OF_INDEXES)", GetLastError());
}
else ub_thread_key_set(*key, f);
}
void ub_thread_key_set(ub_thread_key_type key, void* v)
{
if(!TlsSetValue(key, v)) {
log_win_err("TlsSetValue failed", GetLastError());
}
}
void* ub_thread_key_get(ub_thread_key_type key)
{
void* ret = (void*)TlsGetValue(key);
if(ret == NULL && GetLastError() != ERROR_SUCCESS) {
log_win_err("TlsGetValue failed", GetLastError());
}
return ret;
}
void ub_thread_create(ub_thread_type* thr, void* (*func)(void*), void* arg)
{
#ifndef HAVE__BEGINTHREADEX
*thr = CreateThread(NULL, /* default security (no inherit handle) */
0, /* default stack size */
(LPTHREAD_START_ROUTINE)func, arg,
0, /* default flags, run immediately */
NULL); /* do not store thread identifier anywhere */
#else
/* the beginthreadex routine setups for the C lib; aligns stack */
*thr=(ub_thread_type)_beginthreadex(NULL, 0, (void*)func, arg, 0, NULL);
#endif
if(*thr == NULL) {
log_win_err("CreateThread failed", GetLastError());
fatal_exit("thread create failed");
}
}
ub_thread_type ub_thread_self(void)
{
return GetCurrentThread();
}
void ub_thread_join(ub_thread_type thr)
{
DWORD ret = WaitForSingleObject(thr, INFINITE);
if(ret == WAIT_FAILED) {
log_win_err("WaitForSingleObject(Thread):WAIT_FAILED",
GetLastError());
} else if(ret == WAIT_TIMEOUT) {
log_win_err("WaitForSingleObject(Thread):WAIT_TIMEOUT",
GetLastError());
}
/* and close the handle to the thread */
if(!CloseHandle(thr)) {
log_win_err("CloseHandle(Thread) failed", GetLastError());
}
}
#endif /* HAVE_WINDOWS_THREADS */