/* 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 #include #include #include #include #include #include #include /* 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 #include /* 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__ ((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 } #endif /* descr.h */