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Diffstat (limited to '')
-rw-r--r-- | external/unbound/util/locks.c | 264 |
1 files changed, 264 insertions, 0 deletions
diff --git a/external/unbound/util/locks.c b/external/unbound/util/locks.c new file mode 100644 index 000000000..509895d02 --- /dev/null +++ b/external/unbound/util/locks.c @@ -0,0 +1,264 @@ +/** + * 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_t* thr, void* (*func)(void*), void* arg) +{ + pid_t pid = fork(); + switch(pid) { + default: /* main */ + *thr = (ub_thread_t)pid; + return; + case 0: /* child */ + *thr = (ub_thread_t)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_t is defined as pid_t. + * @param thread: the process id to wait for. + */ +void ub_thr_fork_wait(ub_thread_t 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_t 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_t* 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_t* lock) +{ + (void)InterlockedExchange(lock, 0); +} + +void lock_basic_lock(lock_basic_t* 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_t* 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_t* 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_t key, void* v) +{ + if(!TlsSetValue(key, v)) { + log_win_err("TlsSetValue failed", GetLastError()); + } +} + +void* ub_thread_key_get(ub_thread_key_t 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_t* 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 begintheadex routine setups for the C lib; aligns stack */ + *thr=(ub_thread_t)_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_t ub_thread_self(void) +{ + return GetCurrentThread(); +} + +void ub_thread_join(ub_thread_t 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 */ |