glibc/linuxthreads/internals.h

/* Linuxthreads - a simple clone()-based implementation of Posix        */
/* threads for Linux.                                                   */
/* Copyright (C) 1996 Xavier Leroy (Xavier.Leroy@inria.fr)              */
/*                                                                      */
/* This program is free software; you can redistribute it and/or        */
/* modify it under the terms of the GNU Library 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 Library General Public License for more details.                 */

#ifndef _INTERNALS_H
#define _INTERNALS_H	1

/* Internal data structures */

/* Includes */

#include <limits.h>
#include <unistd.h>
#include <stackinfo.h>

#include "descr.h"

extern long int testandset (int *spinlock);
extern int __compare_and_swap (long int *p, long int oldval, long int newval);

#include "semaphore.h"

#ifndef THREAD_GETMEM
# define THREAD_GETMEM(descr, member) descr->member
#endif
#ifndef THREAD_GETMEM_NC
# define THREAD_GETMEM_NC(descr, member) descr->member
#endif
#ifndef THREAD_SETMEM
# define THREAD_SETMEM(descr, member, value) descr->member = (value)
#endif
#ifndef THREAD_SETMEM_NC
# define THREAD_SETMEM_NC(descr, member, value) descr->member = (value)
#endif

typedef void (*destr_function)(void *);

struct pthread_key_struct {
  int in_use;                   /* already allocated? */
  destr_function destr;         /* destruction routine */
};


#define PTHREAD_START_ARGS_INITIALIZER(fct) \
  { (void *(*) (void *)) fct, NULL, {{0, }}, 0, { 0 } }


/* The type of thread handles. */

typedef struct pthread_handle_struct * pthread_handle;

struct pthread_handle_struct {
  struct _pthread_fastlock h_lock; /* Fast lock for sychronized access */
  pthread_descr h_descr;        /* Thread descriptor or NULL if invalid */
  char * h_bottom;              /* Lowest address in the stack thread */
};

/* The type of messages sent to the thread manager thread */

struct pthread_request {
  pthread_descr req_thread;     /* Thread doing the request */
  enum {                        /* Request kind */
    REQ_CREATE, REQ_FREE, REQ_PROCESS_EXIT, REQ_MAIN_THREAD_EXIT,
    REQ_POST, REQ_DEBUG, REQ_KICK, REQ_FOR_EACH_THREAD
  } req_kind;
  union {                       /* Arguments for request */
    struct {                    /* For REQ_CREATE: */
      const pthread_attr_t * attr; /* thread attributes */
      void * (*fn)(void *);     /*   start function */
      void * arg;               /*   argument to start function */
      sigset_t mask;            /*   signal mask */
    } create;
    struct {                    /* For REQ_FREE: */
      pthread_t thread_id;      /*   identifier of thread to free */
    } free;
    struct {                    /* For REQ_PROCESS_EXIT: */
      int code;                 /*   exit status */
    } exit;
    void * post;                /* For REQ_POST: the semaphore */
    struct {			/* For REQ_FOR_EACH_THREAD: callback */
      void (*fn)(void *, pthread_descr);
      void *arg;
    } for_each;
  } req_args;
};


/* Signals used for suspend/restart and for cancellation notification.  */

extern int __pthread_sig_restart;
extern int __pthread_sig_cancel;

/* Signal used for interfacing with gdb */

extern int __pthread_sig_debug;

/* Global array of thread handles, used for validating a thread id
   and retrieving the corresponding thread descriptor. Also used for
   mapping the available stack segments. */

extern struct pthread_handle_struct __pthread_handles[PTHREAD_THREADS_MAX];

/* Descriptor of the initial thread */

extern struct _pthread_descr_struct __pthread_initial_thread;

/* Descriptor of the manager thread */

extern struct _pthread_descr_struct __pthread_manager_thread;

/* Descriptor of the main thread */

extern pthread_descr __pthread_main_thread;

/* Limit between the stack of the initial thread (above) and the
   stacks of other threads (below). Aligned on a STACK_SIZE boundary.
   Initially 0, meaning that the current thread is (by definition)
   the initial thread. */

extern char *__pthread_initial_thread_bos;

/* Indicate whether at least one thread has a user-defined stack (if 1),
   or all threads have stacks supplied by LinuxThreads (if 0). */

extern int __pthread_nonstandard_stacks;

/* File descriptor for sending requests to the thread manager.
   Initially -1, meaning that __pthread_initialize_manager must be called. */

extern int __pthread_manager_request;

/* Other end of the pipe for sending requests to the thread manager. */

extern int __pthread_manager_reader;

/* Limits of the thread manager stack. */

extern char *__pthread_manager_thread_bos;
extern char *__pthread_manager_thread_tos;

#ifdef FLOATING_STACKS
/* Maximum stack size.  */
extern size_t __pthread_max_stacksize;
#endif

/* Pending request for a process-wide exit */

extern int __pthread_exit_requested, __pthread_exit_code;

/* Set to 1 by gdb if we're debugging */

extern volatile int __pthread_threads_debug;

/* Globally enabled events.  */
extern volatile td_thr_events_t __pthread_threads_events;

/* Pointer to descriptor of thread with last event.  */
extern volatile pthread_descr __pthread_last_event;

/* Flag which tells whether we are executing on SMP kernel. */
extern int __pthread_smp_kernel;

/* Return the handle corresponding to a thread id */

static inline pthread_handle thread_handle(pthread_t id)
{
  return &__pthread_handles[id % PTHREAD_THREADS_MAX];
}

/* Validate a thread handle. Must have acquired h->h_spinlock before. */

static inline int invalid_handle(pthread_handle h, pthread_t id)
{
  return h->h_descr == NULL || h->h_descr->p_tid != id || h->h_descr->p_terminated;
}

static inline int nonexisting_handle(pthread_handle h, pthread_t id)
{
  return h->h_descr == NULL || h->h_descr->p_tid != id;
}

/* Fill in defaults left unspecified by pt-machine.h.  */

/* We round up a value with page size. */
#ifndef page_roundup
#define page_roundup(v,p) ((((size_t) (v)) + (p) - 1) & ~((p) - 1))
#endif

/* The page size we can get from the system.  This should likely not be
   changed by the machine file but, you never know.  */
#ifndef PAGE_SIZE
#define PAGE_SIZE  (sysconf (_SC_PAGE_SIZE))
#endif

/* The max size of the thread stack segments.  If the default
   THREAD_SELF implementation is used, this must be a power of two and
   a multiple of PAGE_SIZE.  */
#ifndef STACK_SIZE
#define STACK_SIZE  (2 * 1024 * 1024)
#endif

/* The initial size of the thread stack.  Must be a multiple of PAGE_SIZE.  */
#ifndef INITIAL_STACK_SIZE
#define INITIAL_STACK_SIZE  (4 * PAGE_SIZE)
#endif

/* Size of the thread manager stack. The "- 32" avoids wasting space
   with some malloc() implementations. */
#ifndef THREAD_MANAGER_STACK_SIZE
#define THREAD_MANAGER_STACK_SIZE  (2 * PAGE_SIZE - 32)
#endif

/* The base of the "array" of thread stacks.  The array will grow down from
   here.  Defaults to the calculated bottom of the initial application
   stack.  */
#ifndef THREAD_STACK_START_ADDRESS
#define THREAD_STACK_START_ADDRESS  __pthread_initial_thread_bos
#endif

/* Get some notion of the current stack.  Need not be exactly the top
   of the stack, just something somewhere in the current frame.  */
#ifndef CURRENT_STACK_FRAME
#define CURRENT_STACK_FRAME  ({ char __csf; &__csf; })
#endif

/* Recover thread descriptor for the current thread */

extern pthread_descr __pthread_find_self (void) __attribute__ ((const));

static inline pthread_descr thread_self (void) __attribute__ ((const));
static inline pthread_descr thread_self (void)
{
#ifdef THREAD_SELF
  return THREAD_SELF;
#else
  char *sp = CURRENT_STACK_FRAME;
  if (sp >= __pthread_initial_thread_bos)
    return &__pthread_initial_thread;
  else if (sp >= __pthread_manager_thread_bos
	   && sp < __pthread_manager_thread_tos)
    return &__pthread_manager_thread;
  else if (__pthread_nonstandard_stacks)
    return __pthread_find_self();
  else
#ifdef _STACK_GROWS_DOWN
    return (pthread_descr)(((unsigned long)sp | (STACK_SIZE-1))+1) - 1;
#else
    return (pthread_descr)((unsigned long)sp &~ (STACK_SIZE-1));
#endif
#endif
}

/* If MEMORY_BARRIER isn't defined in pt-machine.h, assume the architecture
   doesn't need a memory barrier instruction (e.g. Intel x86).  Some
   architectures distinguish between full, read and write barriers.  */

#ifndef MEMORY_BARRIER
#define MEMORY_BARRIER()
#endif
#ifndef READ_MEMORY_BARRIER
#define READ_MEMORY_BARRIER() MEMORY_BARRIER()
#endif
#ifndef WRITE_MEMORY_BARRIER
#define WRITE_MEMORY_BARRIER() MEMORY_BARRIER()
#endif

/* Max number of times we must spin on a spinlock calling sched_yield().
   After MAX_SPIN_COUNT iterations, we put the calling thread to sleep. */

#ifndef MAX_SPIN_COUNT
#define MAX_SPIN_COUNT 50
#endif

/* Max number of times the spinlock in the adaptive mutex implementation
   spins actively on SMP systems.  */

#ifndef MAX_ADAPTIVE_SPIN_COUNT
#define MAX_ADAPTIVE_SPIN_COUNT 100
#endif

/* Duration of sleep (in nanoseconds) when we can't acquire a spinlock
   after MAX_SPIN_COUNT iterations of sched_yield().
   With the 2.0 and 2.1 kernels, this MUST BE > 2ms.
   (Otherwise the kernel does busy-waiting for realtime threads,
    giving other threads no chance to run.) */

#ifndef SPIN_SLEEP_DURATION
#define SPIN_SLEEP_DURATION 2000001
#endif

/* Debugging */

#ifdef DEBUG
#include <assert.h>
#define ASSERT assert
#define MSG __pthread_message
#else
#define ASSERT(x)
#define MSG(msg,arg...)
#endif

/* Internal global functions */

extern void __pthread_do_exit (void *retval, char *currentframe)
     __attribute__ ((__noreturn__));
extern void __pthread_destroy_specifics (void);
extern void __pthread_perform_cleanup (char *currentframe);
extern void __pthread_init_max_stacksize (void);
extern int __pthread_initialize_manager (void);
extern void __pthread_message (char * fmt, ...);
extern int __pthread_manager (void *reqfd);
extern int __pthread_manager_event (void *reqfd);
extern void __pthread_manager_sighandler (int sig);
extern void __pthread_reset_main_thread (void);
extern void __pthread_once_fork_prepare (void);
extern void __pthread_once_fork_parent (void);
extern void __pthread_once_fork_child (void);
extern void __flockfilelist (void);
extern void __funlockfilelist (void);
extern void __fresetlockfiles (void);
extern void __pthread_manager_adjust_prio (int thread_prio);
extern void __pthread_initialize_minimal (void);

extern int __pthread_attr_setguardsize (pthread_attr_t *__attr,
					size_t __guardsize);
extern int __pthread_attr_getguardsize (const pthread_attr_t *__attr,
					size_t *__guardsize);
extern int __pthread_attr_setstackaddr (pthread_attr_t *__attr,
					void *__stackaddr);
extern int __pthread_attr_getstackaddr (const pthread_attr_t *__attr,
					void **__stackaddr);
extern int __pthread_attr_setstacksize (pthread_attr_t *__attr,
					size_t __stacksize);
extern int __pthread_attr_getstacksize (const pthread_attr_t *__attr,
					size_t *__stacksize);
extern int __pthread_attr_setstack (pthread_attr_t *__attr, void *__stackaddr,
				    size_t __stacksize);
extern int __pthread_attr_getstack (const pthread_attr_t *__attr, void **__stackaddr,
				    size_t *__stacksize);
extern int __pthread_getconcurrency (void);
extern int __pthread_setconcurrency (int __level);
extern int __pthread_mutex_timedlock (pthread_mutex_t *__mutex,
				      const struct timespec *__abstime);
extern int __pthread_mutexattr_getpshared (const pthread_mutexattr_t *__attr,
					   int *__pshared);
extern int __pthread_mutexattr_setpshared (pthread_mutexattr_t *__attr,
					   int __pshared);
extern int __pthread_mutexattr_gettype (const pthread_mutexattr_t *__attr,
					int *__kind);
extern void __pthread_kill_other_threads_np (void);

extern void __pthread_restart_old(pthread_descr th);
extern void __pthread_suspend_old(pthread_descr self);
extern int __pthread_timedsuspend_old(pthread_descr self, const struct timespec *abs);

extern void __pthread_restart_new(pthread_descr th);
extern void __pthread_suspend_new(pthread_descr self);
extern int __pthread_timedsuspend_new(pthread_descr self, const struct timespec *abs);

extern void __pthread_wait_for_restart_signal(pthread_descr self);

extern int __pthread_yield (void);

extern int __pthread_rwlock_timedrdlock (pthread_rwlock_t *__restrict __rwlock,
					 __const struct timespec *__restrict
					 __abstime);
extern int __pthread_rwlock_timedwrlock (pthread_rwlock_t *__restrict __rwlock,
					 __const struct timespec *__restrict
					 __abstime);
extern int __pthread_rwlockattr_destroy (pthread_rwlockattr_t *__attr);

extern int __pthread_barrierattr_getpshared (__const pthread_barrierattr_t *
					     __restrict __attr,
					     int *__restrict __pshared);

extern int __pthread_spin_lock (pthread_spinlock_t *__lock);
extern int __pthread_spin_trylock (pthread_spinlock_t *__lock);
extern int __pthread_spin_unlock (pthread_spinlock_t *__lock);
extern int __pthread_spin_init (pthread_spinlock_t *__lock, int __pshared);
extern int __pthread_spin_destroy (pthread_spinlock_t *__lock);

extern int __pthread_clock_gettime (hp_timing_t freq, struct timespec *tp);
extern void __pthread_clock_settime (hp_timing_t offset);


/* Global pointers to old or new suspend functions */

extern void (*__pthread_restart)(pthread_descr);
extern void (*__pthread_suspend)(pthread_descr);
extern int (*__pthread_timedsuspend)(pthread_descr, const struct timespec *);

/* Prototypes for the function without cancelation support when the
   normal version has it.  */
extern int __libc_close (int fd);
extern int __libc_nanosleep (const struct timespec *requested_time,
			     struct timespec *remaining);
/* Prototypes for some of the new semaphore functions.  */
extern int __new_sem_post (sem_t * sem);
extern int __new_sem_init (sem_t *__sem, int __pshared, unsigned int __value);
extern int __new_sem_wait (sem_t *__sem);
extern int __new_sem_trywait (sem_t *__sem);
extern int __new_sem_getvalue (sem_t *__restrict __sem, int *__restrict __sval);
extern int __new_sem_destroy (sem_t *__sem);

/* Prototypes for compatibility functions.  */
extern int __pthread_attr_init_2_1 (pthread_attr_t *__attr);
extern int __pthread_attr_init_2_0 (pthread_attr_t *__attr);
extern int __pthread_create_2_1 (pthread_t *__restrict __thread,
				 const pthread_attr_t *__attr,
				 void *(*__start_routine) (void *),
				 void *__restrict __arg);
extern int __pthread_create_2_0 (pthread_t *__restrict thread,
				 const pthread_attr_t *__attr,
				 void *(*__start_routine) (void *),
				 void *__restrict arg);

/* The functions called the signal events.  */
extern void __linuxthreads_create_event (void);
extern void __linuxthreads_death_event (void);
extern void __linuxthreads_reap_event (void);

/* This function is called to initialize the pthread library.  */
extern void __pthread_initialize (void);

#endif /* internals.h */