367 lines
14 KiB
C
367 lines
14 KiB
C
/* Linuxthreads - a simple clone()-based implementation of Posix */
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/* threads for Linux. */
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/* Copyright (C) 1996 Xavier Leroy (Xavier.Leroy@inria.fr) */
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/* */
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/* This program is free software; you can redistribute it and/or */
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/* modify it under the terms of the GNU Library General Public License */
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/* as published by the Free Software Foundation; either version 2 */
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/* of the License, or (at your option) any later version. */
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/* */
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/* This program is distributed in the hope that it will be useful, */
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/* but WITHOUT ANY WARRANTY; without even the implied warranty of */
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/* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the */
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/* GNU Library General Public License for more details. */
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/* Internal data structures */
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/* Includes */
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#include <limits.h>
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#include <setjmp.h>
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#include <signal.h>
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#include <unistd.h>
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#include <sys/types.h>
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#include <bits/libc-tsd.h> /* for _LIBC_TSD_KEY_N */
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#include "pt-machine.h"
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#include "semaphore.h"
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#ifndef THREAD_GETMEM
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# define THREAD_GETMEM(descr, member) descr->member
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#endif
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#ifndef THREAD_GETMEM_NC
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# define THREAD_GETMEM_NC(descr, member) descr->member
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#endif
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#ifndef THREAD_SETMEM
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# define THREAD_SETMEM(descr, member, value) descr->member = (value)
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#endif
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#ifndef THREAD_SETMEM_NC
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# define THREAD_SETMEM_NC(descr, member, value) descr->member = (value)
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#endif
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/* Arguments passed to thread creation routine */
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struct pthread_start_args {
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void * (*start_routine)(void *); /* function to run */
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void * arg; /* its argument */
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sigset_t mask; /* initial signal mask for thread */
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int schedpolicy; /* initial scheduling policy (if any) */
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struct sched_param schedparam; /* initial scheduling parameters (if any) */
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};
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/* We keep thread specific data in a special data structure, a two-level
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array. The top-level array contains pointers to dynamically allocated
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arrays of a certain number of data pointers. So we can implement a
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sparse array. Each dynamic second-level array has
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PTHREAD_KEY_2NDLEVEL_SIZE
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entries. This value shouldn't be too large. */
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#define PTHREAD_KEY_2NDLEVEL_SIZE 32
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/* We need to address PTHREAD_KEYS_MAX key with PTHREAD_KEY_2NDLEVEL_SIZE
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keys in each subarray. */
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#define PTHREAD_KEY_1STLEVEL_SIZE \
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((PTHREAD_KEYS_MAX + PTHREAD_KEY_2NDLEVEL_SIZE - 1) \
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/ PTHREAD_KEY_2NDLEVEL_SIZE)
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typedef void (*destr_function)(void *);
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struct pthread_key_struct {
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int in_use; /* already allocated? */
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destr_function destr; /* destruction routine */
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};
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#define PTHREAD_START_ARGS_INITIALIZER(fct) \
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{ (void *(*) (void *)) fct, NULL, {{0, }}, 0, { 0 } }
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/* The type of thread descriptors */
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typedef struct _pthread_descr_struct * pthread_descr;
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struct _pthread_descr_struct {
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pthread_descr p_nextlive, p_prevlive;
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/* Double chaining of active threads */
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pthread_descr p_nextwaiting; /* Next element in the queue holding the thr */
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pthread_descr p_nextlock; /* can be on a queue and waiting on a lock */
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pthread_t p_tid; /* Thread identifier */
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int p_pid; /* PID of Unix process */
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int p_priority; /* Thread priority (== 0 if not realtime) */
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struct _pthread_fastlock * p_lock; /* Spinlock for synchronized accesses */
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int p_signal; /* last signal received */
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sigjmp_buf * p_signal_jmp; /* where to siglongjmp on a signal or NULL */
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sigjmp_buf * p_cancel_jmp; /* where to siglongjmp on a cancel or NULL */
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char p_terminated; /* true if terminated e.g. by pthread_exit */
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char p_detached; /* true if detached */
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char p_exited; /* true if the assoc. process terminated */
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void * p_retval; /* placeholder for return value */
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int p_retcode; /* placeholder for return code */
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pthread_descr p_joining; /* thread joining on that thread or NULL */
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struct _pthread_cleanup_buffer * p_cleanup; /* cleanup functions */
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char p_cancelstate; /* cancellation state */
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char p_canceltype; /* cancellation type (deferred/async) */
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char p_canceled; /* cancellation request pending */
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int * p_errnop; /* pointer to used errno variable */
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int p_errno; /* error returned by last system call */
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int * p_h_errnop; /* pointer to used h_errno variable */
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int p_h_errno; /* error returned by last netdb function */
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char * p_in_sighandler; /* stack address of sighandler, or NULL */
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char p_sigwaiting; /* true if a sigwait() is in progress */
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struct pthread_start_args p_start_args; /* arguments for thread creation */
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void ** p_specific[PTHREAD_KEY_1STLEVEL_SIZE]; /* thread-specific data */
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void * p_libc_specific[_LIBC_TSD_KEY_N]; /* thread-specific data for libc */
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int p_userstack; /* nonzero if the user provided the stack */
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void *p_guardaddr; /* address of guard area or NULL */
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size_t p_guardsize; /* size of guard area */
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pthread_descr p_self; /* Pointer to this structure */
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int p_nr; /* Index of descriptor in __pthread_handles */
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} __attribute__ ((aligned(32))); /* We need to align the structure so that
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doubles are aligned properly. This is 8
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bytes on MIPS and 16 bytes on MIPS64.
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32 bytes might give better cache
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utilization. */
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/* The type of thread handles. */
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typedef struct pthread_handle_struct * pthread_handle;
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struct pthread_handle_struct {
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struct _pthread_fastlock h_lock; /* Fast lock for sychronized access */
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pthread_descr h_descr; /* Thread descriptor or NULL if invalid */
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char * h_bottom; /* Lowest address in the stack thread */
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};
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/* The type of messages sent to the thread manager thread */
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struct pthread_request {
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pthread_descr req_thread; /* Thread doing the request */
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enum { /* Request kind */
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REQ_CREATE, REQ_FREE, REQ_PROCESS_EXIT, REQ_MAIN_THREAD_EXIT,
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REQ_POST, REQ_DEBUG
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} req_kind;
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union { /* Arguments for request */
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struct { /* For REQ_CREATE: */
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const pthread_attr_t * attr; /* thread attributes */
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void * (*fn)(void *); /* start function */
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void * arg; /* argument to start function */
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sigset_t mask; /* signal mask */
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} create;
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struct { /* For REQ_FREE: */
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pthread_t thread_id; /* identifier of thread to free */
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} free;
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struct { /* For REQ_PROCESS_EXIT: */
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int code; /* exit status */
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} exit;
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void * post; /* For REQ_POST: the semaphore */
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} req_args;
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};
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/* Signals used for suspend/restart and for cancellation notification. */
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extern int __pthread_sig_restart;
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extern int __pthread_sig_cancel;
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/* Signal used for interfacing with gdb */
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extern int __pthread_sig_debug;
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/* Global array of thread handles, used for validating a thread id
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and retrieving the corresponding thread descriptor. Also used for
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mapping the available stack segments. */
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extern struct pthread_handle_struct __pthread_handles[PTHREAD_THREADS_MAX];
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/* Descriptor of the initial thread */
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extern struct _pthread_descr_struct __pthread_initial_thread;
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/* Descriptor of the manager thread */
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extern struct _pthread_descr_struct __pthread_manager_thread;
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/* Descriptor of the main thread */
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extern pthread_descr __pthread_main_thread;
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/* Limit between the stack of the initial thread (above) and the
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stacks of other threads (below). Aligned on a STACK_SIZE boundary.
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Initially 0, meaning that the current thread is (by definition)
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the initial thread. */
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extern char *__pthread_initial_thread_bos;
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/* Indicate whether at least one thread has a user-defined stack (if 1),
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or all threads have stacks supplied by LinuxThreads (if 0). */
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extern int __pthread_nonstandard_stacks;
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/* File descriptor for sending requests to the thread manager.
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Initially -1, meaning that __pthread_initialize_manager must be called. */
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extern int __pthread_manager_request;
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/* Other end of the pipe for sending requests to the thread manager. */
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extern int __pthread_manager_reader;
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/* Limits of the thread manager stack. */
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extern char *__pthread_manager_thread_bos;
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extern char *__pthread_manager_thread_tos;
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/* Pending request for a process-wide exit */
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extern int __pthread_exit_requested, __pthread_exit_code;
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/* Set to 1 by gdb if we're debugging */
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extern volatile int __pthread_threads_debug;
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/* Return the handle corresponding to a thread id */
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static inline pthread_handle thread_handle(pthread_t id)
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{
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return &__pthread_handles[id % PTHREAD_THREADS_MAX];
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}
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/* Validate a thread handle. Must have acquired h->h_spinlock before. */
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static inline int invalid_handle(pthread_handle h, pthread_t id)
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{
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return h->h_descr == NULL || h->h_descr->p_tid != id;
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}
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/* Fill in defaults left unspecified by pt-machine.h. */
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/* The page size we can get from the system. This should likely not be
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changed by the machine file but, you never know. */
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#ifndef PAGE_SIZE
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#define PAGE_SIZE (sysconf (_SC_PAGE_SIZE))
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#endif
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/* The max size of the thread stack segments. If the default
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THREAD_SELF implementation is used, this must be a power of two and
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a multiple of PAGE_SIZE. */
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#ifndef STACK_SIZE
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#define STACK_SIZE (2 * 1024 * 1024)
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#endif
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/* The initial size of the thread stack. Must be a multiple of PAGE_SIZE. */
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#ifndef INITIAL_STACK_SIZE
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#define INITIAL_STACK_SIZE (4 * PAGE_SIZE)
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#endif
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/* Size of the thread manager stack. The "- 32" avoids wasting space
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with some malloc() implementations. */
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#ifndef THREAD_MANAGER_STACK_SIZE
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#define THREAD_MANAGER_STACK_SIZE (2 * PAGE_SIZE - 32)
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#endif
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/* The base of the "array" of thread stacks. The array will grow down from
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here. Defaults to the calculated bottom of the initial application
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stack. */
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#ifndef THREAD_STACK_START_ADDRESS
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#define THREAD_STACK_START_ADDRESS __pthread_initial_thread_bos
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#endif
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/* Get some notion of the current stack. Need not be exactly the top
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of the stack, just something somewhere in the current frame. */
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#ifndef CURRENT_STACK_FRAME
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#define CURRENT_STACK_FRAME ({ char __csf; &__csf; })
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#endif
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/* Recover thread descriptor for the current thread */
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extern pthread_descr __pthread_find_self (void) __attribute__ ((const));
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static inline pthread_descr thread_self (void) __attribute__ ((const));
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static inline pthread_descr thread_self (void)
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{
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#ifdef THREAD_SELF
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return THREAD_SELF;
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#else
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char *sp = CURRENT_STACK_FRAME;
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if (sp >= __pthread_initial_thread_bos)
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return &__pthread_initial_thread;
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else if (sp >= __pthread_manager_thread_bos
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&& sp < __pthread_manager_thread_tos)
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return &__pthread_manager_thread;
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else if (__pthread_nonstandard_stacks)
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return __pthread_find_self();
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else
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return (pthread_descr)(((unsigned long)sp | (STACK_SIZE-1))+1) - 1;
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#endif
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}
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/* Max number of times we must spin on a spinlock calling sched_yield().
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After MAX_SPIN_COUNT iterations, we put the calling thread to sleep. */
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#ifndef MAX_SPIN_COUNT
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#define MAX_SPIN_COUNT 50
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#endif
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/* Duration of sleep (in nanoseconds) when we can't acquire a spinlock
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after MAX_SPIN_COUNT iterations of sched_yield().
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With the 2.0 and 2.1 kernels, this MUST BE > 2ms.
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(Otherwise the kernel does busy-waiting for realtime threads,
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giving other threads no chance to run.) */
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#ifndef SPIN_SLEEP_DURATION
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#define SPIN_SLEEP_DURATION 2000001
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#endif
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/* Debugging */
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#ifdef DEBUG
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#include <assert.h>
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#define ASSERT assert
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#define MSG __pthread_message
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#else
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#define ASSERT(x)
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#define MSG(msg,arg...)
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#endif
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/* Internal global functions */
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void __pthread_destroy_specifics(void);
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void __pthread_perform_cleanup(void);
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int __pthread_initialize_manager(void);
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void __pthread_message(char * fmt, ...);
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int __pthread_manager(void *reqfd);
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void __pthread_manager_sighandler(int sig);
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void __pthread_reset_main_thread(void);
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void __fresetlockfiles(void);
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void __pthread_manager_adjust_prio(int thread_prio);
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extern int __pthread_attr_setguardsize __P ((pthread_attr_t *__attr,
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size_t __guardsize));
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extern int __pthread_attr_getguardsize __P ((__const pthread_attr_t *__attr,
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size_t *__guardsize));
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extern int __pthread_attr_setstackaddr __P ((pthread_attr_t *__attr,
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void *__stackaddr));
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extern int __pthread_attr_getstackaddr __P ((__const pthread_attr_t *__attr,
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void **__stackaddr));
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extern int __pthread_attr_setstacksize __P ((pthread_attr_t *__attr,
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size_t __stacksize));
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extern int __pthread_attr_getstacksize __P ((__const pthread_attr_t *__attr,
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size_t *__stacksize));
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extern int __pthread_getconcurrency __P ((void));
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extern int __pthread_setconcurrency __P ((int __level));
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extern int __pthread_mutexattr_gettype __P ((__const pthread_mutexattr_t *__attr,
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int *__kind));
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extern void __pthread_kill_other_threads_np __P ((void));
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/* Prototypes for the function without cancelation support when the
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normal version has it. */
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extern int __libc_close (int fd);
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extern int __libc_nanosleep (const struct timespec *requested_time,
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struct timespec *remaining);
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extern ssize_t __libc_read (int fd, void *buf, size_t count);
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extern pid_t __libc_waitpid (pid_t pid, int *stat_loc, int options);
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extern ssize_t __libc_write (int fd, const void *buf, size_t count);
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/* Prototypes for some of the new semaphore functions. */
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extern int __new_sem_post (sem_t * sem);
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