/**
* util/locks.h - 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.
*/
#ifndef UTIL_LOCKS_H
#define UTIL_LOCKS_H
/**
* \file
* Locking primitives.
* If pthreads is available, these are used.
* If no locking exists, they do nothing.
*
* The idea is to have different sorts of locks for different tasks.
* This allows the locking code to be ported more easily.
*
* Types of locks that are supported.
* o lock_rw: lock that has many readers and one writer (to a data entry).
* o lock_basic: simple mutex. Blocking, one person has access only.
* This lock is meant for non performance sensitive uses.
* o lock_quick: speed lock. For performance sensitive locking of critical
* sections. Could be implemented by a mutex or a spinlock.
*
* Also thread creation and deletion functions are defined here.
*/
/* if you define your own LOCKRET before including locks.h, you can get most
* locking functions without the dependency on log_err. */
#ifndef LOCKRET
#include "util/log.h"
/**
* The following macro is used to check the return value of the
* pthread calls. They return 0 on success and an errno on error.
* The errno is logged to the logfile with a descriptive comment.
*/
#define LOCKRET(func) do {\
int lockret_err; \
if( (lockret_err=(func)) != 0) \
log_err("%s at %d could not " #func ": %s", \
__FILE__, __LINE__, strerror(lockret_err)); \
} while(0)
#endif
/** DEBUG: use thread debug whenever possible */
#if defined(HAVE_PTHREAD) && defined(HAVE_PTHREAD_SPINLOCK_T) && defined(ENABLE_LOCK_CHECKS)
# define USE_THREAD_DEBUG
#endif
#ifdef USE_THREAD_DEBUG
/******************* THREAD DEBUG ************************/
/* (some) checking; to detect races and deadlocks. */
#include "testcode/checklocks.h"
#else /* USE_THREAD_DEBUG */
#define lock_protect(lock, area, size) /* nop */
#define lock_unprotect(lock, area) /* nop */
#define lock_get_mem(lock) (0) /* nothing */
#define checklock_start() /* nop */
#define checklock_stop() /* nop */
#ifdef HAVE_PTHREAD
#include <pthread.h>
/******************* PTHREAD ************************/
/** use pthread mutex for basic lock */
typedef pthread_mutex_t lock_basic_t;
/** small front for pthread init func, NULL is default attrs. */
#define lock_basic_init(lock) LOCKRET(pthread_mutex_init(lock, NULL))
#define lock_basic_destroy(lock) LOCKRET(pthread_mutex_destroy(lock))
#define lock_basic_lock(lock) LOCKRET(pthread_mutex_lock(lock))
#define lock_basic_unlock(lock) LOCKRET(pthread_mutex_unlock(lock))
#ifndef HAVE_PTHREAD_RWLOCK_T
/** in case rwlocks are not supported, use a mutex. */
typedef pthread_mutex_t lock_rw_t;
#define lock_rw_init(lock) LOCKRET(pthread_mutex_init(lock, NULL))
#define lock_rw_destroy(lock) LOCKRET(pthread_mutex_destroy(lock))
#define lock_rw_rdlock(lock) LOCKRET(pthread_mutex_lock(lock))
#define lock_rw_wrlock(lock) LOCKRET(pthread_mutex_lock(lock))
#define lock_rw_unlock(lock) LOCKRET(pthread_mutex_unlock(lock))
#else /* HAVE_PTHREAD_RWLOCK_T */
/** we use the pthread rwlock */
typedef pthread_rwlock_t lock_rw_t;
/** small front for pthread init func, NULL is default attrs. */
#define lock_rw_init(lock) LOCKRET(pthread_rwlock_init(lock, NULL))
#define lock_rw_destroy(lock) LOCKRET(pthread_rwlock_destroy(lock))
#define lock_rw_rdlock(lock) LOCKRET(pthread_rwlock_rdlock(lock))
#define lock_rw_wrlock(lock) LOCKRET(pthread_rwlock_wrlock(lock))
#define lock_rw_unlock(lock) LOCKRET(pthread_rwlock_unlock(lock))
#endif /* HAVE_PTHREAD_RWLOCK_T */
#ifndef HAVE_PTHREAD_SPINLOCK_T
/** in case spinlocks are not supported, use a mutex. */
typedef pthread_mutex_t lock_quick_t;
/** small front for pthread init func, NULL is default attrs. */
#define lock_quick_init(lock) LOCKRET(pthread_mutex_init(lock, NULL))
#define lock_quick_destroy(lock) LOCKRET(pthread_mutex_destroy(lock))
#define lock_quick_lock(lock) LOCKRET(pthread_mutex_lock(lock))
#define lock_quick_unlock(lock) LOCKRET(pthread_mutex_unlock(lock))
#else /* HAVE_PTHREAD_SPINLOCK_T */
/** use pthread spinlock for the quick lock */
typedef pthread_spinlock_t lock_quick_t;
/**
* allocate process private since this is available whether
* Thread Process-Shared Synchronization is supported or not.
* This means only threads inside this process may access the lock.
* (not threads from another process that shares memory).
* spinlocks are not supported on all pthread platforms.
*/
#define lock_quick_init(lock) LOCKRET(pthread_spin_init(lock, PTHREAD_PROCESS_PRIVATE))
#define lock_quick_destroy(lock) LOCKRET(pthread_spin_destroy(lock))
#define lock_quick_lock(lock) LOCKRET(pthread_spin_lock(lock))
#define lock_quick_unlock(lock) LOCKRET(pthread_spin_unlock(lock))
#endif /* HAVE SPINLOCK */
/** Thread creation */
typedef pthread_t ub_thread_t;
/** Pass where to store tread_t in thr. Use default NULL attributes. */
#define ub_thread_create(thr, func, arg) LOCKRET(pthread_create(thr, NULL, func, arg))
/** get self id. */
#define ub_thread_self() pthread_self()
/** wait for another thread to terminate */
#define ub_thread_join(thread) LOCKRET(pthread_join(thread, NULL))
typedef pthread_key_t ub_thread_key_t;
#define ub_thread_key_create(key, f) LOCKRET(pthread_key_create(key, f))
#define ub_thread_key_set(key, v) LOCKRET(pthread_setspecific(key, v))
#define ub_thread_key_get(key) pthread_getspecific(key)
#else /* we do not HAVE_PTHREAD */
#ifdef HAVE_SOLARIS_THREADS
/******************* SOLARIS THREADS ************************/
#include <synch.h>
#include <thread.h>
typedef rwlock_t lock_rw_t;
#define lock_rw_init(lock) LOCKRET(rwlock_init(lock, USYNC_THREAD, NULL))
#define lock_rw_destroy(lock) LOCKRET(rwlock_destroy(lock))
#define lock_rw_rdlock(lock) LOCKRET(rw_rdlock(lock))
#define lock_rw_wrlock(lock) LOCKRET(rw_wrlock(lock))
#define lock_rw_unlock(lock) LOCKRET(rw_unlock(lock))
/** use basic mutex */
typedef mutex_t lock_basic_t;
#define lock_basic_init(lock) LOCKRET(mutex_init(lock, USYNC_THREAD, NULL))
#define lock_basic_destroy(lock) LOCKRET(mutex_destroy(lock))
#define lock_basic_lock(lock) LOCKRET(mutex_lock(lock))
#define lock_basic_unlock(lock) LOCKRET(mutex_unlock(lock))
/** No spinlocks in solaris threads API. Use a mutex. */
typedef mutex_t lock_quick_t;
#define lock_quick_init(lock) LOCKRET(mutex_init(lock, USYNC_THREAD, NULL))
#define lock_quick_destroy(lock) LOCKRET(mutex_destroy(lock))
#define lock_quick_lock(lock) LOCKRET(mutex_lock(lock))
#define lock_quick_unlock(lock) LOCKRET(mutex_unlock(lock))
/** Thread creation, create a default thread. */
typedef thread_t ub_thread_t;
#define ub_thread_create(thr, func, arg) LOCKRET(thr_create(NULL, NULL, func, arg, NULL, thr))
#define ub_thread_self() thr_self()
#define ub_thread_join(thread) LOCKRET(thr_join(thread, NULL, NULL))
typedef thread_key_t ub_thread_key_t;
#define ub_thread_key_create(key, f) LOCKRET(thr_keycreate(key, f))
#define ub_thread_key_set(key, v) LOCKRET(thr_setspecific(key, v))
void* ub_thread_key_get(ub_thread_key_t key);
#else /* we do not HAVE_SOLARIS_THREADS and no PTHREADS */
/******************* WINDOWS THREADS ************************/
#ifdef HAVE_WINDOWS_THREADS
#include <windows.h>
/* Use a mutex */
typedef LONG lock_rw_t;
#define lock_rw_init(lock) lock_basic_init(lock)
#define lock_rw_destroy(lock) lock_basic_destroy(lock)
#define lock_rw_rdlock(lock) lock_basic_lock(lock)
#define lock_rw_wrlock(lock) lock_basic_lock(lock)
#define lock_rw_unlock(lock) lock_basic_unlock(lock)
/** the basic lock is a mutex, implemented opaquely, for error handling. */
typedef LONG lock_basic_t;
void lock_basic_init(lock_basic_t* lock);
void lock_basic_destroy(lock_basic_t* lock);
void lock_basic_lock(lock_basic_t* lock);
void lock_basic_unlock(lock_basic_t* lock);
/** on windows no spinlock, use mutex too. */
typedef LONG lock_quick_t;
#define lock_quick_init(lock) lock_basic_init(lock)
#define lock_quick_destroy(lock) lock_basic_destroy(lock)
#define lock_quick_lock(lock) lock_basic_lock(lock)
#define lock_quick_unlock(lock) lock_basic_unlock(lock)
/** Thread creation, create a default thread. */
typedef HANDLE ub_thread_t;
void ub_thread_create(ub_thread_t* thr, void* (*func)(void*), void* arg);
ub_thread_t ub_thread_self(void);
void ub_thread_join(ub_thread_t thr);
typedef DWORD ub_thread_key_t;
void ub_thread_key_create(ub_thread_key_t* key, void* f);
void ub_thread_key_set(ub_thread_key_t key, void* v);
void* ub_thread_key_get(ub_thread_key_t key);
#else /* we do not HAVE_SOLARIS_THREADS, PTHREADS or WINDOWS_THREADS */
/******************* NO THREADS ************************/
#define THREADS_DISABLED 1
/** In case there is no thread support, define locks to do nothing */
typedef int lock_rw_t;
#define lock_rw_init(lock) /* nop */
#define lock_rw_destroy(lock) /* nop */
#define lock_rw_rdlock(lock) /* nop */
#define lock_rw_wrlock(lock) /* nop */
#define lock_rw_unlock(lock) /* nop */
/** define locks to do nothing */
typedef int lock_basic_t;
#define lock_basic_init(lock) /* nop */
#define lock_basic_destroy(lock) /* nop */
#define lock_basic_lock(lock) /* nop */
#define lock_basic_unlock(lock) /* nop */
/** define locks to do nothing */
typedef int lock_quick_t;
#define lock_quick_init(lock) /* nop */
#define lock_quick_destroy(lock) /* nop */
#define lock_quick_lock(lock) /* nop */
#define lock_quick_unlock(lock) /* nop */
/** Thread creation, threads do not exist */
typedef pid_t ub_thread_t;
/** ub_thread_create is simulated with fork (extremely heavy threads,
* with no shared memory). */
#define ub_thread_create(thr, func, arg) \
ub_thr_fork_create(thr, func, arg)
#define ub_thread_self() getpid()
#define ub_thread_join(thread) ub_thr_fork_wait(thread)
void ub_thr_fork_wait(ub_thread_t thread);
void ub_thr_fork_create(ub_thread_t* thr, void* (*func)(void*), void* arg);
typedef void* ub_thread_key_t;
#define ub_thread_key_create(key, f) (*(key)) = NULL
#define ub_thread_key_set(key, v) (key) = (v)
#define ub_thread_key_get(key) (key)
#endif /* HAVE_WINDOWS_THREADS */
#endif /* HAVE_SOLARIS_THREADS */
#endif /* HAVE_PTHREAD */
#endif /* USE_THREAD_DEBUG */
/**
* Block all signals for this thread.
* fatal exit on error.
*/
void ub_thread_blocksigs(void);
/**
* unblock one signal for this thread.
*/
void ub_thread_sig_unblock(int sig);
#endif /* UTIL_LOCKS_H */
