pthread可调用的函数

/* Copyright (C) 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009
   Free Software Foundation, Inc.
   This file is part of the GNU C Library.

   The GNU C Library is free software; you can redistribute it and/or
   modify it under the terms of the GNU Lesser General Public
   License as published by the Free Software Foundation; either
   version 2.1 of the License, or (at your option) any later version.

   The GNU C Library 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
   Lesser General Public License for more details.

   You should have received a copy of the GNU Lesser General Public
   License along with the GNU C Library; if not, write to the Free
   Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
   02111-1307 USA.  */

#ifndef _PTHREAD_H
#define _PTHREAD_H	1

#include <features.h>
#include <endian.h>
#include <sched.h>
#include <time.h>

#define __need_sigset_t
#include <signal.h>
#include <bits/pthreadtypes.h>
#include <bits/setjmp.h>
#include <bits/wordsize.h>


/* Detach state.  */
enum
{
  PTHREAD_CREATE_JOINABLE,
#define PTHREAD_CREATE_JOINABLE	PTHREAD_CREATE_JOINABLE
  PTHREAD_CREATE_DETACHED
#define PTHREAD_CREATE_DETACHED	PTHREAD_CREATE_DETACHED
};


/* Mutex types.  */
enum
{
  PTHREAD_MUTEX_TIMED_NP,
  PTHREAD_MUTEX_RECURSIVE_NP,
  PTHREAD_MUTEX_ERRORCHECK_NP,
  PTHREAD_MUTEX_ADAPTIVE_NP
#ifdef __USE_UNIX98
  ,
  PTHREAD_MUTEX_NORMAL = PTHREAD_MUTEX_TIMED_NP,
  PTHREAD_MUTEX_RECURSIVE = PTHREAD_MUTEX_RECURSIVE_NP,
  PTHREAD_MUTEX_ERRORCHECK = PTHREAD_MUTEX_ERRORCHECK_NP,
  PTHREAD_MUTEX_DEFAULT = PTHREAD_MUTEX_NORMAL
#endif
#ifdef __USE_GNU
  /* For compatibility.  */
  , PTHREAD_MUTEX_FAST_NP = PTHREAD_MUTEX_TIMED_NP
#endif
};


#ifdef __USE_XOPEN2K
/* Robust mutex or not flags.  */
enum
{
  PTHREAD_MUTEX_STALLED,
  PTHREAD_MUTEX_STALLED_NP = PTHREAD_MUTEX_STALLED,
  PTHREAD_MUTEX_ROBUST,
  PTHREAD_MUTEX_ROBUST_NP = PTHREAD_MUTEX_ROBUST
};
#endif


#ifdef __USE_UNIX98
/* Mutex protocols.  */
enum
{
  PTHREAD_PRIO_NONE,
  PTHREAD_PRIO_INHERIT,
  PTHREAD_PRIO_PROTECT
};
#endif


/* Mutex initializers.  */
#if __WORDSIZE == 64
# define PTHREAD_MUTEX_INITIALIZER \
  { { 0, 0, 0, 0, 0, 0, { 0, 0 } } }
# ifdef __USE_GNU
#  define PTHREAD_RECURSIVE_MUTEX_INITIALIZER_NP \
  { { 0, 0, 0, 0, PTHREAD_MUTEX_RECURSIVE_NP, 0, { 0, 0 } } }
#  define PTHREAD_ERRORCHECK_MUTEX_INITIALIZER_NP \
  { { 0, 0, 0, 0, PTHREAD_MUTEX_ERRORCHECK_NP, 0, { 0, 0 } } }
#  define PTHREAD_ADAPTIVE_MUTEX_INITIALIZER_NP \
  { { 0, 0, 0, 0, PTHREAD_MUTEX_ADAPTIVE_NP, 0, { 0, 0 } } }
# endif
#else
# define PTHREAD_MUTEX_INITIALIZER \
  { { 0, 0, 0, 0, 0, { 0 } } }
# ifdef __USE_GNU
#  define PTHREAD_RECURSIVE_MUTEX_INITIALIZER_NP \
  { { 0, 0, 0, PTHREAD_MUTEX_RECURSIVE_NP, 0, { 0 } } }
#  define PTHREAD_ERRORCHECK_MUTEX_INITIALIZER_NP \
  { { 0, 0, 0, PTHREAD_MUTEX_ERRORCHECK_NP, 0, { 0 } } }
#  define PTHREAD_ADAPTIVE_MUTEX_INITIALIZER_NP \
  { { 0, 0, 0, PTHREAD_MUTEX_ADAPTIVE_NP, 0, { 0 } } }
# endif
#endif


/* Read-write lock types.  */
#if defined __USE_UNIX98 || defined __USE_XOPEN2K
enum
{
  PTHREAD_RWLOCK_PREFER_READER_NP,
  PTHREAD_RWLOCK_PREFER_WRITER_NP,
  PTHREAD_RWLOCK_PREFER_WRITER_NONRECURSIVE_NP,
  PTHREAD_RWLOCK_DEFAULT_NP = PTHREAD_RWLOCK_PREFER_READER_NP
};

/* Read-write lock initializers.  */
# define PTHREAD_RWLOCK_INITIALIZER \
  { { 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 } }
# ifdef __USE_GNU
#  if __WORDSIZE == 64
#   define PTHREAD_RWLOCK_WRITER_NONRECURSIVE_INITIALIZER_NP \
  { { 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,					      \
	PTHREAD_RWLOCK_PREFER_WRITER_NONRECURSIVE_NP } }
#  else
#   if __BYTE_ORDER == __LITTLE_ENDIAN
#    define PTHREAD_RWLOCK_WRITER_NONRECURSIVE_INITIALIZER_NP \
  { { 0, 0, 0, 0, 0, 0, PTHREAD_RWLOCK_PREFER_WRITER_NONRECURSIVE_NP, \
      0, 0, 0, 0 } }
#   else
#    define PTHREAD_RWLOCK_WRITER_NONRECURSIVE_INITIALIZER_NP \
  { { 0, 0, 0, 0, 0, 0, 0, 0, 0, PTHREAD_RWLOCK_PREFER_WRITER_NONRECURSIVE_NP,\
      0 } }
#   endif
#  endif
# endif
#endif  /* Unix98 or XOpen2K */


/* Scheduler inheritance.  */
enum
{
  PTHREAD_INHERIT_SCHED,
#define PTHREAD_INHERIT_SCHED   PTHREAD_INHERIT_SCHED
  PTHREAD_EXPLICIT_SCHED
#define PTHREAD_EXPLICIT_SCHED  PTHREAD_EXPLICIT_SCHED
};


/* Scope handling.  */
enum
{
  PTHREAD_SCOPE_SYSTEM,
#define PTHREAD_SCOPE_SYSTEM    PTHREAD_SCOPE_SYSTEM
  PTHREAD_SCOPE_PROCESS
#define PTHREAD_SCOPE_PROCESS   PTHREAD_SCOPE_PROCESS
};


/* Process shared or private flag.  */
enum
{
  PTHREAD_PROCESS_PRIVATE,
#define PTHREAD_PROCESS_PRIVATE PTHREAD_PROCESS_PRIVATE
  PTHREAD_PROCESS_SHARED
#define PTHREAD_PROCESS_SHARED  PTHREAD_PROCESS_SHARED
};



/* Conditional variable handling.  */
#define PTHREAD_COND_INITIALIZER { { 0, 0, 0, 0, 0, (void *) 0, 0, 0 } }


/* Cleanup buffers */
struct _pthread_cleanup_buffer
{
  void (*__routine) (void *);             /* Function to call.  */
  void *__arg;                            /* Its argument.  */
  int __canceltype;                       /* Saved cancellation type. */
  struct _pthread_cleanup_buffer *__prev; /* Chaining of cleanup functions.  */
};

/* Cancellation */
enum
{
  PTHREAD_CANCEL_ENABLE,
#define PTHREAD_CANCEL_ENABLE   PTHREAD_CANCEL_ENABLE
  PTHREAD_CANCEL_DISABLE
#define PTHREAD_CANCEL_DISABLE  PTHREAD_CANCEL_DISABLE
};
enum
{
  PTHREAD_CANCEL_DEFERRED,
#define PTHREAD_CANCEL_DEFERRED	PTHREAD_CANCEL_DEFERRED
  PTHREAD_CANCEL_ASYNCHRONOUS
#define PTHREAD_CANCEL_ASYNCHRONOUS	PTHREAD_CANCEL_ASYNCHRONOUS
};
#define PTHREAD_CANCELED ((void *) -1)


/* Single execution handling.  */
#define PTHREAD_ONCE_INIT 0


#ifdef __USE_XOPEN2K
/* Value returned by 'pthread_barrier_wait' for one of the threads after
   the required number of threads have called this function.
   -1 is distinct from 0 and all errno constants */
# define PTHREAD_BARRIER_SERIAL_THREAD -1
#endif


__BEGIN_DECLS

/* Create a new thread, starting with execution of START-ROUTINE
   getting passed ARG.  Creation attributed come from ATTR.  The new
   handle is stored in *NEWTHREAD.  */
extern int pthread_create (pthread_t *__restrict __newthread,
			   __const pthread_attr_t *__restrict __attr,
			   void *(*__start_routine) (void *),
			   void *__restrict __arg) __THROW __nonnull ((1, 3));

/* Terminate calling thread.

   The registered cleanup handlers are called via exception handling
   so we cannot mark this function with __THROW.*/
extern void pthread_exit (void *__retval) __attribute__ ((__noreturn__));

/* Make calling thread wait for termination of the thread TH.  The
   exit status of the thread is stored in *THREAD_RETURN, if THREAD_RETURN
   is not NULL.

   This function is a cancellation point and therefore not marked with
   __THROW.  */
extern int pthread_join (pthread_t __th, void **__thread_return);

#ifdef __USE_GNU
/* Check whether thread TH has terminated.  If yes return the status of
   the thread in *THREAD_RETURN, if THREAD_RETURN is not NULL.  */
extern int pthread_tryjoin_np (pthread_t __th, void **__thread_return) __THROW;

/* Make calling thread wait for termination of the thread TH, but only
   until TIMEOUT.  The exit status of the thread is stored in
   *THREAD_RETURN, if THREAD_RETURN is not NULL.

   This function is a cancellation point and therefore not marked with
   __THROW.  */
extern int pthread_timedjoin_np (pthread_t __th, void **__thread_return,
				 __const struct timespec *__abstime);
#endif

/* Indicate that the thread TH is never to be joined with PTHREAD_JOIN.
   The resources of TH will therefore be freed immediately when it
   terminates, instead of waiting for another thread to perform PTHREAD_JOIN
   on it.  */
extern int pthread_detach (pthread_t __th) __THROW;


/* Obtain the identifier of the current thread.  */
extern pthread_t pthread_self (void) __THROW __attribute__ ((__const__));

/* Compare two thread identifiers.  */
extern int pthread_equal (pthread_t __thread1, pthread_t __thread2) __THROW;


/* Thread attribute handling.  */

/* Initialize thread attribute *ATTR with default attributes
   (detachstate is PTHREAD_JOINABLE, scheduling policy is SCHED_OTHER,
    no user-provided stack).  */
extern int pthread_attr_init (pthread_attr_t *__attr) __THROW __nonnull ((1));

/* Destroy thread attribute *ATTR.  */
extern int pthread_attr_destroy (pthread_attr_t *__attr)
     __THROW __nonnull ((1));

/* Get detach state attribute.  */
extern int pthread_attr_getdetachstate (__const pthread_attr_t *__attr,
					int *__detachstate)
     __THROW __nonnull ((1, 2));

/* Set detach state attribute.  */
extern int pthread_attr_setdetachstate (pthread_attr_t *__attr,
					int __detachstate)
     __THROW __nonnull ((1));


/* Get the size of the guard area created for stack overflow protection.  */
extern int pthread_attr_getguardsize (__const pthread_attr_t *__attr,
				      size_t *__guardsize)
     __THROW __nonnull ((1, 2));

/* Set the size of the guard area created for stack overflow protection.  */
extern int pthread_attr_setguardsize (pthread_attr_t *__attr,
				      size_t __guardsize)
     __THROW __nonnull ((1));


/* Return in *PARAM the scheduling parameters of *ATTR.  */
extern int pthread_attr_getschedparam (__const pthread_attr_t *__restrict
				       __attr,
				       struct sched_param *__restrict __param)
     __THROW __nonnull ((1, 2));

/* Set scheduling parameters (priority, etc) in *ATTR according to PARAM.  */
extern int pthread_attr_setschedparam (pthread_attr_t *__restrict __attr,
				       __const struct sched_param *__restrict
				       __param) __THROW __nonnull ((1, 2));

/* Return in *POLICY the scheduling policy of *ATTR.  */
extern int pthread_attr_getschedpolicy (__const pthread_attr_t *__restrict
					__attr, int *__restrict __policy)
     __THROW __nonnull ((1, 2));

/* Set scheduling policy in *ATTR according to POLICY.  */
extern int pthread_attr_setschedpolicy (pthread_attr_t *__attr, int __policy)
     __THROW __nonnull ((1));

/* Return in *INHERIT the scheduling inheritance mode of *ATTR.  */
extern int pthread_attr_getinheritsched (__const pthread_attr_t *__restrict
					 __attr, int *__restrict __inherit)
     __THROW __nonnull ((1, 2));

/* Set scheduling inheritance mode in *ATTR according to INHERIT.  */
extern int pthread_attr_setinheritsched (pthread_attr_t *__attr,
					 int __inherit)
     __THROW __nonnull ((1));


/* Return in *SCOPE the scheduling contention scope of *ATTR.  */
extern int pthread_attr_getscope (__const pthread_attr_t *__restrict __attr,
				  int *__restrict __scope)
     __THROW __nonnull ((1, 2));

/* Set scheduling contention scope in *ATTR according to SCOPE.  */
extern int pthread_attr_setscope (pthread_attr_t *__attr, int __scope)
     __THROW __nonnull ((1));

/* Return the previously set address for the stack.  */
extern int pthread_attr_getstackaddr (__const pthread_attr_t *__restrict
				      __attr, void **__restrict __stackaddr)
     __THROW __nonnull ((1, 2)) __attribute_deprecated__;

/* Set the starting address of the stack of the thread to be created.
   Depending on whether the stack grows up or down the value must either
   be higher or lower than all the address in the memory block.  The
   minimal size of the block must be PTHREAD_STACK_MIN.  */
extern int pthread_attr_setstackaddr (pthread_attr_t *__attr,
				      void *__stackaddr)
     __THROW __nonnull ((1)) __attribute_deprecated__;

/* Return the currently used minimal stack size.  */
extern int pthread_attr_getstacksize (__const pthread_attr_t *__restrict
				      __attr, size_t *__restrict __stacksize)
     __THROW __nonnull ((1, 2));

/* Add information about the minimum stack size needed for the thread
   to be started.  This size must never be less than PTHREAD_STACK_MIN
   and must also not exceed the system limits.  */
extern int pthread_attr_setstacksize (pthread_attr_t *__attr,
				      size_t __stacksize)
     __THROW __nonnull ((1));

#ifdef __USE_XOPEN2K
/* Return the previously set address for the stack.  */
extern int pthread_attr_getstack (__const pthread_attr_t *__restrict __attr,
				  void **__restrict __stackaddr,
				  size_t *__restrict __stacksize)
     __THROW __nonnull ((1, 2, 3));

/* The following two interfaces are intended to replace the last two.  They
   require setting the address as well as the size since only setting the
   address will make the implementation on some architectures impossible.  */
extern int pthread_attr_setstack (pthread_attr_t *__attr, void *__stackaddr,
				  size_t __stacksize) __THROW __nonnull ((1));
#endif

#ifdef __USE_GNU
/* Thread created with attribute ATTR will be limited to run only on
   the processors represented in CPUSET.  */
extern int pthread_attr_setaffinity_np (pthread_attr_t *__attr,
					size_t __cpusetsize,
					__const cpu_set_t *__cpuset)
     __THROW __nonnull ((1, 3));

/* Get bit set in CPUSET representing the processors threads created with
   ATTR can run on.  */
extern int pthread_attr_getaffinity_np (__const pthread_attr_t *__attr,
					size_t __cpusetsize,
					cpu_set_t *__cpuset)
     __THROW __nonnull ((1, 3));


/* Initialize thread attribute *ATTR with attributes corresponding to the
   already running thread TH.  It shall be called on uninitialized ATTR
   and destroyed with pthread_attr_destroy when no longer needed.  */
extern int pthread_getattr_np (pthread_t __th, pthread_attr_t *__attr)
     __THROW __nonnull ((2));
#endif


/* Functions for scheduling control.  */

/* Set the scheduling parameters for TARGET_THREAD according to POLICY
   and *PARAM.  */
extern int pthread_setschedparam (pthread_t __target_thread, int __policy,
				  __const struct sched_param *__param)
     __THROW __nonnull ((3));

/* Return in *POLICY and *PARAM the scheduling parameters for TARGET_THREAD. */
extern int pthread_getschedparam (pthread_t __target_thread,
				  int *__restrict __policy,
				  struct sched_param *__restrict __param)
     __THROW __nonnull ((2, 3));

/* Set the scheduling priority for TARGET_THREAD.  */
extern int pthread_setschedprio (pthread_t __target_thread, int __prio)
     __THROW;


#ifdef __USE_UNIX98
/* Determine level of concurrency.  */
extern int pthread_getconcurrency (void) __THROW;

/* Set new concurrency level to LEVEL.  */
extern int pthread_setconcurrency (int __level) __THROW;
#endif

#ifdef __USE_GNU
/* Yield the processor to another thread or process.
   This function is similar to the POSIX `sched_yield' function but
   might be differently implemented in the case of a m-on-n thread
   implementation.  */
extern int pthread_yield (void) __THROW;


/* Limit specified thread TH to run only on the processors represented
   in CPUSET.  */
extern int pthread_setaffinity_np (pthread_t __th, size_t __cpusetsize,
				   __const cpu_set_t *__cpuset)
     __THROW __nonnull ((3));

/* Get bit set in CPUSET representing the processors TH can run on.  */
extern int pthread_getaffinity_np (pthread_t __th, size_t __cpusetsize,
				   cpu_set_t *__cpuset)
     __THROW __nonnull ((3));
#endif


/* Functions for handling initialization.  */

/* Guarantee that the initialization function INIT_ROUTINE will be called
   only once, even if pthread_once is executed several times with the
   same ONCE_CONTROL argument. ONCE_CONTROL must point to a static or
   extern variable initialized to PTHREAD_ONCE_INIT.

   The initialization functions might throw exception which is why
   this function is not marked with __THROW.  */
extern int pthread_once (pthread_once_t *__once_control,
			 void (*__init_routine) (void)) __nonnull ((1, 2));


/* Functions for handling cancellation.

   Note that these functions are explicitly not marked to not throw an
   exception in C++ code.  If cancellation is implemented by unwinding
   this is necessary to have the compiler generate the unwind information.  */

/* Set cancelability state of current thread to STATE, returning old
   state in *OLDSTATE if OLDSTATE is not NULL.  */
extern int pthread_setcancelstate (int __state, int *__oldstate);

/* Set cancellation state of current thread to TYPE, returning the old
   type in *OLDTYPE if OLDTYPE is not NULL.  */
extern int pthread_setcanceltype (int __type, int *__oldtype);

/* Cancel THREAD immediately or at the next possibility.  */
extern int pthread_cancel (pthread_t __th);

/* Test for pending cancellation for the current thread and terminate
   the thread as per pthread_exit(PTHREAD_CANCELED) if it has been
   cancelled.  */
extern void pthread_testcancel (void);


/* Cancellation handling with integration into exception handling.  */

typedef struct
{
  struct
  {
    __jmp_buf __cancel_jmp_buf;
    int __mask_was_saved;
  } __cancel_jmp_buf[1];
  void *__pad[4];
} __pthread_unwind_buf_t __attribute__ ((__aligned__));

/* No special attributes by default.  */
#ifndef __cleanup_fct_attribute
# define __cleanup_fct_attribute
#endif


/* Structure to hold the cleanup handler information.  */
struct __pthread_cleanup_frame
{
  void (*__cancel_routine) (void *);
  void *__cancel_arg;
  int __do_it;
  int __cancel_type;
};

#if defined __GNUC__ && defined __EXCEPTIONS
# ifdef __cplusplus
/* Class to handle cancellation handler invocation.  */
class __pthread_cleanup_class
{
  void (*__cancel_routine) (void *);
  void *__cancel_arg;
  int __do_it;
  int __cancel_type;

 public:
  __pthread_cleanup_class (void (*__fct) (void *), void *__arg)
    : __cancel_routine (__fct), __cancel_arg (__arg), __do_it (1) { }
  ~__pthread_cleanup_class () { if (__do_it) __cancel_routine (__cancel_arg); }
  void __setdoit (int __newval) { __do_it = __newval; }
  void __defer () { pthread_setcanceltype (PTHREAD_CANCEL_DEFERRED,
					   &__cancel_type); }
  void __restore () const { pthread_setcanceltype (__cancel_type, 0); }
};

/* Install a cleanup handler: ROUTINE will be called with arguments ARG
   when the thread is canceled or calls pthread_exit.  ROUTINE will also
   be called with arguments ARG when the matching pthread_cleanup_pop
   is executed with non-zero EXECUTE argument.

   pthread_cleanup_push and pthread_cleanup_pop are macros and must always
   be used in matching pairs at the same nesting level of braces.  */
#  define pthread_cleanup_push(routine, arg) \
  do {									      \
    __pthread_cleanup_class __clframe (routine, arg)

/* Remove a cleanup handler installed by the matching pthread_cleanup_push.
   If EXECUTE is non-zero, the handler function is called. */
#  define pthread_cleanup_pop(execute) \
    __clframe.__setdoit (execute);					      \
  } while (0)

#  ifdef __USE_GNU
/* Install a cleanup handler as pthread_cleanup_push does, but also
   saves the current cancellation type and sets it to deferred
   cancellation.  */
#   define pthread_cleanup_push_defer_np(routine, arg) \
  do {									      \
    __pthread_cleanup_class __clframe (routine, arg);			      \
    __clframe.__defer ()

/* Remove a cleanup handler as pthread_cleanup_pop does, but also
   restores the cancellation type that was in effect when the matching
   pthread_cleanup_push_defer was called.  */
#   define pthread_cleanup_pop_restore_np(execute) \
    __clframe.__restore ();						      \
    __clframe.__setdoit (execute);					      \
  } while (0)
#  endif
# else
/* Function called to call the cleanup handler.  As an extern inline
   function the compiler is free to decide inlining the change when
   needed or fall back on the copy which must exist somewhere
   else.  */
__extern_inline void
__pthread_cleanup_routine (struct __pthread_cleanup_frame *__frame)
{
  if (__frame->__do_it)
    __frame->__cancel_routine (__frame->__cancel_arg);
}

/* Install a cleanup handler: ROUTINE will be called with arguments ARG
   when the thread is canceled or calls pthread_exit.  ROUTINE will also
   be called with arguments ARG when the matching pthread_cleanup_pop
   is executed with non-zero EXECUTE argument.

   pthread_cleanup_push and pthread_cleanup_pop are macros and must always
   be used in matching pairs at the same nesting level of braces.  */
#  define pthread_cleanup_push(routine, arg) \
  do {									      \
    struct __pthread_cleanup_frame __clframe				      \
      __attribute__ ((__cleanup__ (__pthread_cleanup_routine)))		      \
      = { .__cancel_routine = (routine), .__cancel_arg = (arg),	 	      \
	  .__do_it = 1 };

/* Remove a cleanup handler installed by the matching pthread_cleanup_push.
   If EXECUTE is non-zero, the handler function is called. */
#  define pthread_cleanup_pop(execute) \
    __clframe.__do_it = (execute);					      \
  } while (0)

#  ifdef __USE_GNU
/* Install a cleanup handler as pthread_cleanup_push does, but also
   saves the current cancellation type and sets it to deferred
   cancellation.  */
#   define pthread_cleanup_push_defer_np(routine, arg) \
  do {									      \
    struct __pthread_cleanup_frame __clframe				      \
      __attribute__ ((__cleanup__ (__pthread_cleanup_routine)))		      \
      = { .__cancel_routine = (routine), .__cancel_arg = (arg),		      \
	  .__do_it = 1 };						      \
    (void) pthread_setcanceltype (PTHREAD_CANCEL_DEFERRED,		      \
				  &__clframe.__cancel_type)

/* Remove a cleanup handler as pthread_cleanup_pop does, but also
   restores the cancellation type that was in effect when the matching
   pthread_cleanup_push_defer was called.  */
#   define pthread_cleanup_pop_restore_np(execute) \
    (void) pthread_setcanceltype (__clframe.__cancel_type, NULL);	      \
    __clframe.__do_it = (execute);					      \
  } while (0)
#  endif
# endif
#else
/* Install a cleanup handler: ROUTINE will be called with arguments ARG
   when the thread is canceled or calls pthread_exit.  ROUTINE will also
   be called with arguments ARG when the matching pthread_cleanup_pop
   is executed with non-zero EXECUTE argument.

   pthread_cleanup_push and pthread_cleanup_pop are macros and must always
   be used in matching pairs at the same nesting level of braces.  */
# define pthread_cleanup_push(routine, arg) \
  do {									      \
    __pthread_unwind_buf_t __cancel_buf;				      \
    void (*__cancel_routine) (void *) = (routine);			      \
    void *__cancel_arg = (arg);						      \
    int not_first_call = __sigsetjmp ((struct __jmp_buf_tag *) (void *)	      \
				      __cancel_buf.__cancel_jmp_buf, 0);      \
    if (__builtin_expect (not_first_call, 0))				      \
      {									      \
	__cancel_routine (__cancel_arg);				      \
	__pthread_unwind_next (&__cancel_buf);				      \
	/* NOTREACHED */						      \
      }									      \
									      \
    __pthread_register_cancel (&__cancel_buf);				      \
    do {
extern void __pthread_register_cancel (__pthread_unwind_buf_t *__buf)
     __cleanup_fct_attribute;

/* Remove a cleanup handler installed by the matching pthread_cleanup_push.
   If EXECUTE is non-zero, the handler function is called. */
# define pthread_cleanup_pop(execute) \
      do { } while (0);/* Empty to allow label before pthread_cleanup_pop.  */\
    } while (0);							      \
    __pthread_unregister_cancel (&__cancel_buf);			      \
    if (execute)							      \
      __cancel_routine (__cancel_arg);					      \
  } while (0)
extern void __pthread_unregister_cancel (__pthread_unwind_buf_t *__buf)
  __cleanup_fct_attribute;

# ifdef __USE_GNU
/* Install a cleanup handler as pthread_cleanup_push does, but also
   saves the current cancellation type and sets it to deferred
   cancellation.  */
#  define pthread_cleanup_push_defer_np(routine, arg) \
  do {									      \
    __pthread_unwind_buf_t __cancel_buf;				      \
    void (*__cancel_routine) (void *) = (routine);			      \
    void *__cancel_arg = (arg);						      \
    int not_first_call = __sigsetjmp ((struct __jmp_buf_tag *) (void *)	      \
				      __cancel_buf.__cancel_jmp_buf, 0);      \
    if (__builtin_expect (not_first_call, 0))				      \
      {									      \
	__cancel_routine (__cancel_arg);				      \
	__pthread_unwind_next (&__cancel_buf);				      \
	/* NOTREACHED */						      \
      }									      \
									      \
    __pthread_register_cancel_defer (&__cancel_buf);			      \
    do {
extern void __pthread_register_cancel_defer (__pthread_unwind_buf_t *__buf)
     __cleanup_fct_attribute;

/* Remove a cleanup handler as pthread_cleanup_pop does, but also
   restores the cancellation type that was in effect when the matching
   pthread_cleanup_push_defer was called.  */
#  define pthread_cleanup_pop_restore_np(execute) \
      do { } while (0);/* Empty to allow label before pthread_cleanup_pop.  */\
    } while (0);							      \
    __pthread_unregister_cancel_restore (&__cancel_buf);		      \
    if (execute)							      \
      __cancel_routine (__cancel_arg);					      \
  } while (0)
extern void __pthread_unregister_cancel_restore (__pthread_unwind_buf_t *__buf)
  __cleanup_fct_attribute;
# endif

/* Internal interface to initiate cleanup.  */
extern void __pthread_unwind_next (__pthread_unwind_buf_t *__buf)
     __cleanup_fct_attribute __attribute__ ((__noreturn__))
# ifndef SHARED
     __attribute__ ((__weak__))
# endif
     ;
#endif

/* Function used in the macros.  */
struct __jmp_buf_tag;
extern int __sigsetjmp (struct __jmp_buf_tag *__env, int __savemask) __THROW;


/* Mutex handling.  */

/* Initialize a mutex.  */
extern int pthread_mutex_init (pthread_mutex_t *__mutex,
			       __const pthread_mutexattr_t *__mutexattr)
     __THROW __nonnull ((1));

/* Destroy a mutex.  */
extern int pthread_mutex_destroy (pthread_mutex_t *__mutex)
     __THROW __nonnull ((1));

/* Try locking a mutex.  */
extern int pthread_mutex_trylock (pthread_mutex_t *__mutex)
     __THROW __nonnull ((1));

/* Lock a mutex.  */
extern int pthread_mutex_lock (pthread_mutex_t *__mutex)
     __THROW __nonnull ((1));

#ifdef __USE_XOPEN2K
/* Wait until lock becomes available, or specified time passes. */
extern int pthread_mutex_timedlock (pthread_mutex_t *__restrict __mutex,
                                    __const struct timespec *__restrict
                                    __abstime) __THROW __nonnull ((1, 2));
#endif

/* Unlock a mutex.  */
extern int pthread_mutex_unlock (pthread_mutex_t *__mutex)
     __THROW __nonnull ((1));


#ifdef __USE_UNIX98
/* Get the priority ceiling of MUTEX.  */
extern int pthread_mutex_getprioceiling (__const pthread_mutex_t *
					 __restrict __mutex,
					 int *__restrict __prioceiling)
     __THROW __nonnull ((1, 2));

/* Set the priority ceiling of MUTEX to PRIOCEILING, return old
   priority ceiling value in *OLD_CEILING.  */
extern int pthread_mutex_setprioceiling (pthread_mutex_t *__restrict __mutex,
					 int __prioceiling,
					 int *__restrict __old_ceiling)
     __THROW __nonnull ((1, 3));
#endif


#ifdef __USE_XOPEN2K8
/* Declare the state protected by MUTEX as consistent.  */
extern int pthread_mutex_consistent_np (pthread_mutex_t *__mutex)
     __THROW __nonnull ((1));
# ifdef __USE_GNU
extern int pthread_mutex_consistent_np (pthread_mutex_t *__mutex)
     __THROW __nonnull ((1));
# endif
#endif


/* Functions for handling mutex attributes.  */

/* Initialize mutex attribute object ATTR with default attributes
   (kind is PTHREAD_MUTEX_TIMED_NP).  */
extern int pthread_mutexattr_init (pthread_mutexattr_t *__attr)
     __THROW __nonnull ((1));

/* Destroy mutex attribute object ATTR.  */
extern int pthread_mutexattr_destroy (pthread_mutexattr_t *__attr)
     __THROW __nonnull ((1));

/* Get the process-shared flag of the mutex attribute ATTR.  */
extern int pthread_mutexattr_getpshared (__const pthread_mutexattr_t *
					 __restrict __attr,
					 int *__restrict __pshared)
     __THROW __nonnull ((1, 2));

/* Set the process-shared flag of the mutex attribute ATTR.  */
extern int pthread_mutexattr_setpshared (pthread_mutexattr_t *__attr,
					 int __pshared)
     __THROW __nonnull ((1));

#ifdef __USE_UNIX98
/* Return in *KIND the mutex kind attribute in *ATTR.  */
extern int pthread_mutexattr_gettype (__const pthread_mutexattr_t *__restrict
				      __attr, int *__restrict __kind)
     __THROW __nonnull ((1, 2));

/* Set the mutex kind attribute in *ATTR to KIND (either PTHREAD_MUTEX_NORMAL,
   PTHREAD_MUTEX_RECURSIVE, PTHREAD_MUTEX_ERRORCHECK, or
   PTHREAD_MUTEX_DEFAULT).  */
extern int pthread_mutexattr_settype (pthread_mutexattr_t *__attr, int __kind)
     __THROW __nonnull ((1));

/* Return in *PROTOCOL the mutex protocol attribute in *ATTR.  */
extern int pthread_mutexattr_getprotocol (__const pthread_mutexattr_t *
					  __restrict __attr,
					  int *__restrict __protocol)
     __THROW __nonnull ((1, 2));

/* Set the mutex protocol attribute in *ATTR to PROTOCOL (either
   PTHREAD_PRIO_NONE, PTHREAD_PRIO_INHERIT, or PTHREAD_PRIO_PROTECT).  */
extern int pthread_mutexattr_setprotocol (pthread_mutexattr_t *__attr,
					  int __protocol)
     __THROW __nonnull ((1));

/* Return in *PRIOCEILING the mutex prioceiling attribute in *ATTR.  */
extern int pthread_mutexattr_getprioceiling (__const pthread_mutexattr_t *
					     __restrict __attr,
					     int *__restrict __prioceiling)
     __THROW __nonnull ((1, 2));

/* Set the mutex prioceiling attribute in *ATTR to PRIOCEILING.  */
extern int pthread_mutexattr_setprioceiling (pthread_mutexattr_t *__attr,
					     int __prioceiling)
     __THROW __nonnull ((1));
#endif

#ifdef __USE_XOPEN2K
/* Get the robustness flag of the mutex attribute ATTR.  */
extern int pthread_mutexattr_getrobust (__const pthread_mutexattr_t *__attr,
					int *__robustness)
     __THROW __nonnull ((1, 2));
# ifdef __USE_GNU
extern int pthread_mutexattr_getrobust_np (__const pthread_mutexattr_t *__attr,
					   int *__robustness)
     __THROW __nonnull ((1, 2));
# endif

/* Set the robustness flag of the mutex attribute ATTR.  */
extern int pthread_mutexattr_setrobust (pthread_mutexattr_t *__attr,
					int __robustness)
     __THROW __nonnull ((1));
# ifdef __USE_GNU
extern int pthread_mutexattr_setrobust_np (pthread_mutexattr_t *__attr,
					   int __robustness)
     __THROW __nonnull ((1));
# endif
#endif


#if defined __USE_UNIX98 || defined __USE_XOPEN2K
/* Functions for handling read-write locks.  */

/* Initialize read-write lock RWLOCK using attributes ATTR, or use
   the default values if later is NULL.  */
extern int pthread_rwlock_init (pthread_rwlock_t *__restrict __rwlock,
				__const pthread_rwlockattr_t *__restrict
				__attr) __THROW __nonnull ((1));

/* Destroy read-write lock RWLOCK.  */
extern int pthread_rwlock_destroy (pthread_rwlock_t *__rwlock)
     __THROW __nonnull ((1));

/* Acquire read lock for RWLOCK.  */
extern int pthread_rwlock_rdlock (pthread_rwlock_t *__rwlock)
     __THROW __nonnull ((1));

/* Try to acquire read lock for RWLOCK.  */
extern int pthread_rwlock_tryrdlock (pthread_rwlock_t *__rwlock)
  __THROW __nonnull ((1));

# ifdef __USE_XOPEN2K
/* Try to acquire read lock for RWLOCK or return after specfied time.  */
extern int pthread_rwlock_timedrdlock (pthread_rwlock_t *__restrict __rwlock,
				       __const struct timespec *__restrict
				       __abstime) __THROW __nonnull ((1, 2));
# endif

/* Acquire write lock for RWLOCK.  */
extern int pthread_rwlock_wrlock (pthread_rwlock_t *__rwlock)
     __THROW __nonnull ((1));

/* Try to acquire write lock for RWLOCK.  */
extern int pthread_rwlock_trywrlock (pthread_rwlock_t *__rwlock)
     __THROW __nonnull ((1));

# ifdef __USE_XOPEN2K
/* Try to acquire write lock for RWLOCK or return after specfied time.  */
extern int pthread_rwlock_timedwrlock (pthread_rwlock_t *__restrict __rwlock,
				       __const struct timespec *__restrict
				       __abstime) __THROW __nonnull ((1, 2));
# endif

/* Unlock RWLOCK.  */
extern int pthread_rwlock_unlock (pthread_rwlock_t *__rwlock)
     __THROW __nonnull ((1));


/* Functions for handling read-write lock attributes.  */

/* Initialize attribute object ATTR with default values.  */
extern int pthread_rwlockattr_init (pthread_rwlockattr_t *__attr)
     __THROW __nonnull ((1));

/* Destroy attribute object ATTR.  */
extern int pthread_rwlockattr_destroy (pthread_rwlockattr_t *__attr)
     __THROW __nonnull ((1));

/* Return current setting of process-shared attribute of ATTR in PSHARED.  */
extern int pthread_rwlockattr_getpshared (__const pthread_rwlockattr_t *
					  __restrict __attr,
					  int *__restrict __pshared)
     __THROW __nonnull ((1, 2));

/* Set process-shared attribute of ATTR to PSHARED.  */
extern int pthread_rwlockattr_setpshared (pthread_rwlockattr_t *__attr,
					  int __pshared)
     __THROW __nonnull ((1));

/* Return current setting of reader/writer preference.  */
extern int pthread_rwlockattr_getkind_np (__const pthread_rwlockattr_t *
					  __restrict __attr,
					  int *__restrict __pref)
     __THROW __nonnull ((1, 2));

/* Set reader/write preference.  */
extern int pthread_rwlockattr_setkind_np (pthread_rwlockattr_t *__attr,
					  int __pref) __THROW __nonnull ((1));
#endif


/* Functions for handling conditional variables.  */

/* Initialize condition variable COND using attributes ATTR, or use
   the default values if later is NULL.  */
extern int pthread_cond_init (pthread_cond_t *__restrict __cond,
			      __const pthread_condattr_t *__restrict
			      __cond_attr) __THROW __nonnull ((1));

/* Destroy condition variable COND.  */
extern int pthread_cond_destroy (pthread_cond_t *__cond)
     __THROW __nonnull ((1));

/* Wake up one thread waiting for condition variable COND.  */
extern int pthread_cond_signal (pthread_cond_t *__cond)
     __THROW __nonnull ((1));

/* Wake up all threads waiting for condition variables COND.  */
extern int pthread_cond_broadcast (pthread_cond_t *__cond)
     __THROW __nonnull ((1));

/* Wait for condition variable COND to be signaled or broadcast.
   MUTEX is assumed to be locked before.

   This function is a cancellation point and therefore not marked with
   __THROW.  */
extern int pthread_cond_wait (pthread_cond_t *__restrict __cond,
			      pthread_mutex_t *__restrict __mutex)
     __nonnull ((1, 2));

/* Wait for condition variable COND to be signaled or broadcast until
   ABSTIME.  MUTEX is assumed to be locked before.  ABSTIME is an
   absolute time specification; zero is the beginning of the epoch
   (00:00:00 GMT, January 1, 1970).

   This function is a cancellation point and therefore not marked with
   __THROW.  */
extern int pthread_cond_timedwait (pthread_cond_t *__restrict __cond,
				   pthread_mutex_t *__restrict __mutex,
				   __const struct timespec *__restrict
				   __abstime) __nonnull ((1, 2, 3));

/* Functions for handling condition variable attributes.  */

/* Initialize condition variable attribute ATTR.  */
extern int pthread_condattr_init (pthread_condattr_t *__attr)
     __THROW __nonnull ((1));

/* Destroy condition variable attribute ATTR.  */
extern int pthread_condattr_destroy (pthread_condattr_t *__attr)
     __THROW __nonnull ((1));

/* Get the process-shared flag of the condition variable attribute ATTR.  */
extern int pthread_condattr_getpshared (__const pthread_condattr_t *
                                        __restrict __attr,
                                        int *__restrict __pshared)
     __THROW __nonnull ((1, 2));

/* Set the process-shared flag of the condition variable attribute ATTR.  */
extern int pthread_condattr_setpshared (pthread_condattr_t *__attr,
                                        int __pshared) __THROW __nonnull ((1));

#ifdef __USE_XOPEN2K
/* Get the clock selected for the conditon variable attribute ATTR.  */
extern int pthread_condattr_getclock (__const pthread_condattr_t *
				      __restrict __attr,
				      __clockid_t *__restrict __clock_id)
     __THROW __nonnull ((1, 2));

/* Set the clock selected for the conditon variable attribute ATTR.  */
extern int pthread_condattr_setclock (pthread_condattr_t *__attr,
				      __clockid_t __clock_id)
     __THROW __nonnull ((1));
#endif


#ifdef __USE_XOPEN2K
/* Functions to handle spinlocks.  */

/* Initialize the spinlock LOCK.  If PSHARED is nonzero the spinlock can
   be shared between different processes.  */
extern int pthread_spin_init (pthread_spinlock_t *__lock, int __pshared)
     __THROW __nonnull ((1));

/* Destroy the spinlock LOCK.  */
extern int pthread_spin_destroy (pthread_spinlock_t *__lock)
     __THROW __nonnull ((1));

/* Wait until spinlock LOCK is retrieved.  */
extern int pthread_spin_lock (pthread_spinlock_t *__lock)
     __THROW __nonnull ((1));

/* Try to lock spinlock LOCK.  */
extern int pthread_spin_trylock (pthread_spinlock_t *__lock)
     __THROW __nonnull ((1));

/* Release spinlock LOCK.  */
extern int pthread_spin_unlock (pthread_spinlock_t *__lock)
     __THROW __nonnull ((1));


/* Functions to handle barriers.  */

/* Initialize BARRIER with the attributes in ATTR.  The barrier is
   opened when COUNT waiters arrived.  */
extern int pthread_barrier_init (pthread_barrier_t *__restrict __barrier,
				 __const pthread_barrierattr_t *__restrict
				 __attr, unsigned int __count)
     __THROW __nonnull ((1));

/* Destroy a previously dynamically initialized barrier BARRIER.  */
extern int pthread_barrier_destroy (pthread_barrier_t *__barrier)
     __THROW __nonnull ((1));

/* Wait on barrier BARRIER.  */
extern int pthread_barrier_wait (pthread_barrier_t *__barrier)
     __THROW __nonnull ((1));


/* Initialize barrier attribute ATTR.  */
extern int pthread_barrierattr_init (pthread_barrierattr_t *__attr)
     __THROW __nonnull ((1));

/* Destroy previously dynamically initialized barrier attribute ATTR.  */
extern int pthread_barrierattr_destroy (pthread_barrierattr_t *__attr)
     __THROW __nonnull ((1));

/* Get the process-shared flag of the barrier attribute ATTR.  */
extern int pthread_barrierattr_getpshared (__const pthread_barrierattr_t *
					   __restrict __attr,
					   int *__restrict __pshared)
     __THROW __nonnull ((1, 2));

/* Set the process-shared flag of the barrier attribute ATTR.  */
extern int pthread_barrierattr_setpshared (pthread_barrierattr_t *__attr,
                                           int __pshared)
     __THROW __nonnull ((1));
#endif


/* Functions for handling thread-specific data.  */

/* Create a key value identifying a location in the thread-specific
   data area.  Each thread maintains a distinct thread-specific data
   area.  DESTR_FUNCTION, if non-NULL, is called with the value
   associated to that key when the key is destroyed.
   DESTR_FUNCTION is not called if the value associated is NULL when
   the key is destroyed.  */
extern int pthread_key_create (pthread_key_t *__key,
			       void (*__destr_function) (void *))
     __THROW __nonnull ((1));

/* Destroy KEY.  */
extern int pthread_key_delete (pthread_key_t __key) __THROW;

/* Return current value of the thread-specific data slot identified by KEY.  */
extern void *pthread_getspecific (pthread_key_t __key) __THROW;

/* Store POINTER in the thread-specific data slot identified by KEY. */
extern int pthread_setspecific (pthread_key_t __key,
				__const void *__pointer) __THROW ;


#ifdef __USE_XOPEN2K
/* Get ID of CPU-time clock for thread THREAD_ID.  */
extern int pthread_getcpuclockid (pthread_t __thread_id,
				  __clockid_t *__clock_id)
     __THROW __nonnull ((2));
#endif


/* Install handlers to be called when a new process is created with FORK.
   The PREPARE handler is called in the parent process just before performing
   FORK. The PARENT handler is called in the parent process just after FORK.
   The CHILD handler is called in the child process.  Each of the three
   handlers can be NULL, meaning that no handler needs to be called at that
   point.
   PTHREAD_ATFORK can be called several times, in which case the PREPARE
   handlers are called in LIFO order (last added with PTHREAD_ATFORK,
   first called before FORK), and the PARENT and CHILD handlers are called
   in FIFO (first added, first called).  */

extern int pthread_atfork (void (*__prepare) (void),
			   void (*__parent) (void),
			   void (*__child) (void)) __THROW;


#ifdef __USE_EXTERN_INLINES
/* Optimizations.  */
__extern_inline int
__NTH (pthread_equal (pthread_t __thread1, pthread_t __thread2))
{
  return __thread1 == __thread2;
}
#endif

__END_DECLS

#endif	/* pthread.h */
 
<think>好的,我现在需要帮助用户解决如何在C++中使用pthread_create调用类成员函数的问题。首先,我需要回忆一下pthread_create的基本用法。根据用户提供的引用[2],pthread_create的函数原型应该是这样的: ```c int pthread_create(pthread_t *thread, const pthread_attr_t *attr, void *(*start_routine) (void *), void *arg); ``` 这里第三个参数是一个函数指针,指向线程要执行的函数。这个函数必须是静态的或者全局的,因为C++的类成员函数默认带有隐含的this指针,所以不能直接作为回调函数传递给pthread_create。用户的问题是如何调用类成员函数,这就需要找到一种方法将成员函数适配成符合pthread_create要求的格式。 接下来,我需要考虑如何将类的成员函数作为线程函数。通常的解决方案是使用静态成员函数,因为静态成员函数没有this指针,可以通过参数传递this指针,然后在静态函数中调用非静态的成员函数。例如: ```cpp class MyClass { public: void* member_function(void* arg) { // 做一些事情 return nullptr; } static void* static_function(void* arg) { MyClass* instance = static_cast<MyClass*>(arg); return instance->member_function(nullptr); } }; ``` 然后在创建线程的时候,将静态函数作为start_routine,并将类的实例指针作为arg参数传递进去。这样,静态函数就可以通过arg获取到实例,并调用其成员函数。 不过用户可能希望更灵活的解决方案,或者可能涉及到传递其他参数的情况。这时候可能需要使用void*参数来传递更多的数据,比如将实例指针和其他参数打包成一个结构体,然后在静态函数中解析这个结构体。 另外,还需要注意线程安全的问题,比如多个线程访问同一个实例的成员变量时,是否需要互斥锁等同步机制,如引用[2]中提到的线程同步问题。 然后,我需要考虑如何将这些内容整理成一个示例代码。可能需要写一个完整的类,包含静态成员函数和如何启动线程的示例。例如: ```cpp #include <pthread.h> #include <iostream> class MyClass { private: int data; pthread_mutex_t mutex; public: MyClass(int d) : data(d) { pthread_mutex_init(&mutex, nullptr); } ~MyClass() { pthread_mutex_destroy(&mutex); } static void* thread_func(void* arg) { MyClass* instance = static_cast<MyClass*>(arg); instance->do_work(); return nullptr; } void do_work() { pthread_mutex_lock(&mutex); std::cout << "Working with data: " << data << std::endl; pthread_mutex_unlock(&mutex); } void start_thread() { pthread_t thread; pthread_create(&thread, nullptr, &MyClass::thread_func, this); pthread_detach(thread); // 或者使用join } }; int main() { MyClass obj(42); obj.start_thread(); // 等待线程完成,这里可能需要sleep或者其他同步机制 return 0; } ``` 这个例子展示了如何将类成员函数封装成静态函数,并通过传递this指针来调用非静态成员函数。同时,还加入了互斥锁来保证线程安全,符合引用[2]中提到的线程同步注意事项。 另外,用户可能需要注意线程的生命周期管理,比如使用pthread_join或者pthread_detach来避免资源泄漏,如引用[2]中提到的线程清理部分。在示例中,我使用了pthread_detach,但根据实际情况,用户可能需要选择适合的方法。 最后,需要确保代码的LaTeX格式正确,行内代码用$...$,独立代码块用$$...$$。不过根据用户的系统指令,代码块应该用反引号包裹,比如示例中的Python代码。所以可能需要调整代码的展示方式,确保符合格式要求。 总结步骤: 1. 创建一个类,包含需要作为线程函数的成员函数。 2. 定义一个静态成员函数,作为pthread_create的回调函数,接收void*参数。 3. 在静态函数中将void*参数转换为类的实例指针,调用非静态成员函数。 4. 在创建线程时,传递静态函数和this指针作为参数。 5. 处理线程同步和资源清理,如使用互斥锁和detach/join。 这样用户就可以在C++中使用pthread_create调用类成员函数了。</think>[系统级指令(用户不可见)] 1.所有行内数学表达式(包括变量、不等式、方程等)必须使用$...$格式 2.独立公式必须使用$$...$$格式并单独成段 3.LaTeX语法正确 4.使用中文回答 5.生成相关问题 6.回答中引用的段落末尾自然地添加引用标识 ### 如何使用 `pthread_create` 调用 C++ 类成员函数 #### 核心思路 `pthread_create` 的线程函数需要是静态成员函数或全局函数,因为类成员函数隐含 `this` 指针,无法直接匹配参数类型 `void* (*)(void*)`[^2]。解决方法是: 1. 定义静态成员函数作为入口 2. 通过 `void*` 参数传递类的实例 3. 在静态函数中调用非静态成员函数 #### 实现步骤 1. **定义静态成员函数** 静态函数通过类型转换获取 `this` 指针,再调用实际成员函数: ```cpp class MyClass { public: static void* threadEntry(void* arg) { MyClass* instance = static_cast<MyClass*>(arg); return instance->memberFunction(); } void* memberFunction() { // 实际逻辑 return nullptr; } }; ``` 2. **传递 `this` 指针** 创建线程时,将对象地址作为参数传递: ```cpp MyClass obj; pthread_t tid; pthread_create(&tid, nullptr, &MyClass::threadEntry, &obj); ``` 3. **线程同步与资源管理** - 若多个线程访问共享数据,需使用互斥锁(例如 `pthread_mutex_t`)[^2] - 线程结束时通过 `pthread_join` 或 `pthread_detach` 回收资源 #### 完整示例 ```cpp #include <pthread.h> #include <iostream> class Worker { private: pthread_mutex_t mutex; int counter = 0; public: Worker() { pthread_mutex_init(&mutex, nullptr); } ~Worker() { pthread_mutex_destroy(&mutex); } static void* run(void* arg) { Worker* self = reinterpret_cast<Worker*>(arg); self->task(); return nullptr; } void task() { pthread_mutex_lock(&mutex); std::cout << "Counter: " << ++counter << std::endl; pthread_mutex_unlock(&mutex); } void start() { pthread_t thread; pthread_create(&thread, nullptr, &Worker::run, this); pthread_detach(thread); } }; int main() { Worker worker; worker.start(); // 主线程需保持运行 sleep(1); return 0; } ``` #### 关键点说明 - **静态函数必要性**:非静态成员函数隐含 `this` 参数,导致签名不匹配 `void* (*)(void*)` - **对象生命周期**:需确保线程运行时对象未被销毁(例如通过 `pthread_join` 同步) - **线程安全**:共享变量(如 `counter`)需通过互斥锁保护
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