glibc/linuxthreads/descr.h

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/* 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 _DESCR_H
#define _DESCR_H 1
#define __need_res_state
#include <resolv.h>
#include <sched.h>
#include <setjmp.h>
#include <signal.h>
#include <stdint.h>
#include <sys/types.h>
#include <hp-timing.h>
#include <tls.h>
/* Fast thread-specific data internal to libc. */
enum __libc_tsd_key_t { _LIBC_TSD_KEY_MALLOC = 0,
_LIBC_TSD_KEY_DL_ERROR,
_LIBC_TSD_KEY_RPC_VARS,
_LIBC_TSD_KEY_LOCALE,
_LIBC_TSD_KEY_CTYPE_B,
_LIBC_TSD_KEY_CTYPE_TOLOWER,
_LIBC_TSD_KEY_CTYPE_TOUPPER,
_LIBC_TSD_KEY_N };
/* The type of thread descriptors */
typedef struct _pthread_descr_struct *pthread_descr;
/* Some more includes. */
#include <pt-machine.h>
#include <linuxthreads_db/thread_dbP.h>
/* Arguments passed to thread creation routine */
struct pthread_start_args {
void *(*start_routine)(void *); /* function to run */
void *arg; /* its argument */
sigset_t mask; /* initial signal mask for thread */
int schedpolicy; /* initial scheduling policy (if any) */
struct sched_param schedparam; /* initial scheduling parameters (if any) */
};
/* Callback interface for removing the thread from waiting on an
object if it is cancelled while waiting or about to wait.
This hold a pointer to the object, and a pointer to a function
which ``extricates'' the thread from its enqueued state.
The function takes two arguments: pointer to the wait object,
and a pointer to the thread. It returns 1 if an extrication
actually occured, and hence the thread must also be signalled.
It returns 0 if the thread had already been extricated. */
typedef struct _pthread_extricate_struct {
void *pu_object;
int (*pu_extricate_func)(void *, pthread_descr);
} pthread_extricate_if;
/* Atomic counter made possible by compare_and_swap */
struct pthread_atomic {
long p_count;
int p_spinlock;
};
/* Context info for read write locks. The pthread_rwlock_info structure
is information about a lock that has been read-locked by the thread
in whose list this structure appears. The pthread_rwlock_context
is embedded in the thread context and contains a pointer to the
head of the list of lock info structures, as well as a count of
read locks that are untracked, because no info structure could be
allocated for them. */
struct _pthread_rwlock_t;
typedef struct _pthread_rwlock_info {
struct _pthread_rwlock_info *pr_next;
struct _pthread_rwlock_t *pr_lock;
int pr_lock_count;
} pthread_readlock_info;
/* We keep thread specific data in a special data structure, a two-level
array. The top-level array contains pointers to dynamically allocated
arrays of a certain number of data pointers. So we can implement a
sparse array. Each dynamic second-level array has
PTHREAD_KEY_2NDLEVEL_SIZE
entries. This value shouldn't be too large. */
#define PTHREAD_KEY_2NDLEVEL_SIZE 32
/* We need to address PTHREAD_KEYS_MAX key with PTHREAD_KEY_2NDLEVEL_SIZE
keys in each subarray. */
#define PTHREAD_KEY_1STLEVEL_SIZE \
((PTHREAD_KEYS_MAX + PTHREAD_KEY_2NDLEVEL_SIZE - 1) \
/ PTHREAD_KEY_2NDLEVEL_SIZE)
union dtv;
struct _pthread_descr_struct
{
#if !defined USE_TLS || !TLS_DTV_AT_TP
/* This overlaps tcbhead_t (see tls.h), as used for TLS without threads. */
union
{
struct
{
void *tcb; /* Pointer to the TCB. This is not always
the address of this thread descriptor. */
union dtv *dtvp;
pthread_descr self; /* Pointer to this structure */
int multiple_threads;
# ifdef NEED_DL_SYSINFO
uintptr_t sysinfo;
# endif
} data;
void *__padding[16];
} p_header;
# define p_multiple_threads p_header.data.multiple_threads
#elif TLS_MULTIPLE_THREADS_IN_TCB
int p_multiple_threads;
#endif
pthread_descr p_nextlive, p_prevlive;
/* Double chaining of active threads */
pthread_descr p_nextwaiting; /* Next element in the queue holding the thr */
pthread_descr p_nextlock; /* can be on a queue and waiting on a lock */
pthread_t p_tid; /* Thread identifier */
int p_pid; /* PID of Unix process */
int p_priority; /* Thread priority (== 0 if not realtime) */
struct _pthread_fastlock * p_lock; /* Spinlock for synchronized accesses */
int p_signal; /* last signal received */
sigjmp_buf * p_signal_jmp; /* where to siglongjmp on a signal or NULL */
sigjmp_buf * p_cancel_jmp; /* where to siglongjmp on a cancel or NULL */
char p_terminated; /* true if terminated e.g. by pthread_exit */
char p_detached; /* true if detached */
char p_exited; /* true if the assoc. process terminated */
void * p_retval; /* placeholder for return value */
int p_retcode; /* placeholder for return code */
pthread_descr p_joining; /* thread joining on that thread or NULL */
struct _pthread_cleanup_buffer * p_cleanup; /* cleanup functions */
char p_cancelstate; /* cancellation state */
char p_canceltype; /* cancellation type (deferred/async) */
char p_canceled; /* cancellation request pending */
char * p_in_sighandler; /* stack address of sighandler, or NULL */
char p_sigwaiting; /* true if a sigwait() is in progress */
struct pthread_start_args p_start_args; /* arguments for thread creation */
void ** p_specific[PTHREAD_KEY_1STLEVEL_SIZE]; /* thread-specific data */
#if !(USE_TLS && HAVE___THREAD)
void * p_libc_specific[_LIBC_TSD_KEY_N]; /* thread-specific data for libc */
int * p_errnop; /* pointer to used errno variable */
int p_errno; /* error returned by last system call */
int * p_h_errnop; /* pointer to used h_errno variable */
int p_h_errno; /* error returned by last netdb function */
struct __res_state *p_resp; /* Pointer to resolver state */
#endif
struct __res_state p_res; /* per-thread resolver state */
int p_userstack; /* nonzero if the user provided the stack */
void *p_guardaddr; /* address of guard area or NULL */
size_t p_guardsize; /* size of guard area */
int p_nr; /* Index of descriptor in __pthread_handles */
int p_report_events; /* Nonzero if events must be reported. */
td_eventbuf_t p_eventbuf; /* Data for event. */
struct pthread_atomic p_resume_count; /* number of times restart() was
called on thread */
char p_woken_by_cancel; /* cancellation performed wakeup */
char p_condvar_avail; /* flag if conditional variable became avail */
char p_sem_avail; /* flag if semaphore became available */
pthread_extricate_if *p_extricate; /* See above */
pthread_readlock_info *p_readlock_list; /* List of readlock info structs */
pthread_readlock_info *p_readlock_free; /* Free list of structs */
int p_untracked_readlock_count; /* Readlocks not tracked by list */
int p_inheritsched; /* copied from the thread attribute */
#if HP_TIMING_AVAIL
hp_timing_t p_cpuclock_offset; /* Initial CPU clock for thread. */
#endif
#ifdef USE_TLS
char *p_stackaddr; /* Stack address. */
#endif
size_t p_alloca_cutoff; /* Maximum size which should be allocated
using alloca() instead of malloc(). */
/* New elements must be added at the end. */
} __attribute__ ((aligned(32))); /* We need to align the structure so that
doubles are aligned properly. This is 8
bytes on MIPS and 16 bytes on MIPS64.
32 bytes might give better cache
utilization. */
/* 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;
/* Descriptor of the initial thread */
extern struct _pthread_descr_struct __pthread_initial_thread;
/* Limits of the thread manager stack. */
extern char *__pthread_manager_thread_bos;
extern char *__pthread_manager_thread_tos;
/* Descriptor of the manager thread */
extern struct _pthread_descr_struct __pthread_manager_thread;
extern pthread_descr __pthread_manager_threadp attribute_hidden;
/* 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;
/* 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
/* 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__ ((pure));
static inline pthread_descr thread_self (void) __attribute__ ((pure));
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
}
#endif /* descr.h */