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glibc  2.9
Functions | Variables
manager.c File Reference
#include <assert.h>
#include <errno.h>
#include <sched.h>
#include <stddef.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <sys/poll.h>
#include <sys/mman.h>
#include <sys/param.h>
#include <sys/time.h>
#include <sys/wait.h>
#include <locale.h>
#include <resolv.h>
#include <ldsodefs.h>
#include "pthread.h"
#include "internals.h"
#include "spinlock.h"
#include "restart.h"
#include "semaphore.h"
#include <not-cancel.h>

Go to the source code of this file.

Functions

static pthread_descr thread_segment (int seg)
static int pthread_handle_create (pthread_t *thread, const pthread_attr_t *attr, void *(*start_routine)(void *), void *arg, sigset_t *mask, int father_pid, int report_events, td_thr_events_t *event_maskp)
static void pthread_handle_free (pthread_t th_id)
static void pthread_handle_exit (pthread_descr issuing_thread, int exitcode) __attribute__((noreturn))
static void pthread_reap_children (void)
static void pthread_kill_all_threads (int sig, int main_thread_also)
static void pthread_for_each_thread (void *arg, void(*fn)(void *, pthread_descr))
int __attribute__ ((noreturn))
int __pthread_manager_event (void *arg)
static int pthread_allocate_stack (const pthread_attr_t *attr, pthread_descr default_new_thread, int pagesize, char **out_new_thread, char **out_new_thread_bottom, char **out_guardaddr, size_t *out_guardsize, size_t *out_stacksize)
static void pthread_free (pthread_descr th)
static void pthread_exited (pid_t pid)
void __pthread_manager_sighandler (int sig)
void __pthread_manager_adjust_prio (int thread_prio)

Variables

const int __linuxthreads_pthread_threads_max = PTHREAD_THREADS_MAX
int __pthread_nonstandard_stacks
volatile int __pthread_handles_num = 2
volatile int __pthread_threads_debug
volatile td_thr_events_t __pthread_threads_events
volatile pthread_descr __pthread_last_event
static pthread_descr manager_thread
static volatile int terminated_children
static int main_thread_exiting
static pthread_t pthread_threads_counter

Function Documentation

int __attribute__ ( (noreturn)  )

Definition at line 116 of file manager.c.

{
  pthread_descr self = manager_thread = arg;
  int reqfd = __pthread_manager_reader;
  struct pollfd ufd;
  sigset_t manager_mask;
  int n;
  struct pthread_request request;

  /* If we have special thread_self processing, initialize it.  */
#ifdef INIT_THREAD_SELF
  INIT_THREAD_SELF(self, 1);
#endif
#if !(USE_TLS && HAVE___THREAD)
  /* Set the error variable.  */
  self->p_errnop = &self->p_errno;
  self->p_h_errnop = &self->p_h_errno;
#endif
  /* Block all signals except __pthread_sig_cancel and SIGTRAP */
  sigfillset(&manager_mask);
  sigdelset(&manager_mask, __pthread_sig_cancel); /* for thread termination */
  sigdelset(&manager_mask, SIGTRAP);            /* for debugging purposes */
  if (__pthread_threads_debug && __pthread_sig_debug > 0)
    sigdelset(&manager_mask, __pthread_sig_debug);
  sigprocmask(SIG_SETMASK, &manager_mask, NULL);
  /* Raise our priority to match that of main thread */
  __pthread_manager_adjust_prio(__pthread_main_thread->p_priority);
  /* Synchronize debugging of the thread manager */
  n = TEMP_FAILURE_RETRY(read_not_cancel(reqfd, (char *)&request,
                                    sizeof(request)));
  ASSERT(n == sizeof(request) && request.req_kind == REQ_DEBUG);
  ufd.fd = reqfd;
  ufd.events = POLLIN;
  /* Enter server loop */
  while(1) {
    n = __poll(&ufd, 1, 2000);

    /* Check for termination of the main thread */
    if (getppid() == 1) {
      pthread_kill_all_threads(SIGKILL, 0);
      _exit(0);
    }
    /* Check for dead children */
    if (terminated_children) {
      terminated_children = 0;
      pthread_reap_children();
    }
    /* Read and execute request */
    if (n == 1 && (ufd.revents & POLLIN)) {
      n = TEMP_FAILURE_RETRY(read_not_cancel(reqfd, (char *)&request,
                                        sizeof(request)));
#ifdef DEBUG
      if (n < 0) {
       char d[64];
       write(STDERR_FILENO, d, snprintf(d, sizeof(d), "*** read err %m\n"));
      } else if (n != sizeof(request)) {
       write(STDERR_FILENO, "*** short read in manager\n", 26);
      }
#endif

      switch(request.req_kind) {
      case REQ_CREATE:
        request.req_thread->p_retcode =
          pthread_handle_create((pthread_t *) &request.req_thread->p_retval,
                                request.req_args.create.attr,
                                request.req_args.create.fn,
                                request.req_args.create.arg,
                                &request.req_args.create.mask,
                                request.req_thread->p_pid,
                            request.req_thread->p_report_events,
                            &request.req_thread->p_eventbuf.eventmask);
        restart(request.req_thread);
        break;
      case REQ_FREE:
       pthread_handle_free(request.req_args.free.thread_id);
        break;
      case REQ_PROCESS_EXIT:
        pthread_handle_exit(request.req_thread,
                            request.req_args.exit.code);
       /* NOTREACHED */
        break;
      case REQ_MAIN_THREAD_EXIT:
        main_thread_exiting = 1;
       /* Reap children in case all other threads died and the signal handler
          went off before we set main_thread_exiting to 1, and therefore did
          not do REQ_KICK. */
       pthread_reap_children();

        if (__pthread_main_thread->p_nextlive == __pthread_main_thread) {
          restart(__pthread_main_thread);
         /* The main thread will now call exit() which will trigger an
            __on_exit handler, which in turn will send REQ_PROCESS_EXIT
            to the thread manager. In case you are wondering how the
            manager terminates from its loop here. */
       }
        break;
      case REQ_POST:
        __new_sem_post(request.req_args.post);
        break;
      case REQ_DEBUG:
       /* Make gdb aware of new thread and gdb will restart the
          new thread when it is ready to handle the new thread. */
       if (__pthread_threads_debug && __pthread_sig_debug > 0)
         raise(__pthread_sig_debug);
        break;
      case REQ_KICK:
       /* This is just a prod to get the manager to reap some
          threads right away, avoiding a potential delay at shutdown. */
       break;
      case REQ_FOR_EACH_THREAD:
       pthread_for_each_thread(request.req_args.for_each.arg,
                               request.req_args.for_each.fn);
       restart(request.req_thread);
       break;
      }
    }
  }
}

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void __pthread_manager_adjust_prio ( int  thread_prio)

Definition at line 1114 of file manager.c.

{
  struct sched_param param;

  if (thread_prio <= manager_thread->p_priority) return;
  param.sched_priority =
    thread_prio < __sched_get_priority_max(SCHED_FIFO)
    ? thread_prio + 1 : thread_prio;
  __sched_setscheduler(manager_thread->p_pid, SCHED_FIFO, &param);
  manager_thread->p_priority = thread_prio;
}

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int __pthread_manager_event ( void *  arg)

Definition at line 236 of file manager.c.

{
  pthread_descr self = arg;
  /* If we have special thread_self processing, initialize it.  */
#ifdef INIT_THREAD_SELF
  INIT_THREAD_SELF(self, 1);
#endif

  /* Get the lock the manager will free once all is correctly set up.  */
  __pthread_lock (THREAD_GETMEM(self, p_lock), NULL);
  /* Free it immediately.  */
  __pthread_unlock (THREAD_GETMEM(self, p_lock));

  return __pthread_manager(arg);
}

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Definition at line 1090 of file manager.c.

{
  int kick_manager = terminated_children == 0 && main_thread_exiting;
  terminated_children = 1;

  /* If the main thread is terminating, kick the thread manager loop
     each time some threads terminate. This eliminates a two second
     shutdown delay caused by the thread manager sleeping in the
     call to __poll(). Instead, the thread manager is kicked into
     action, reaps the outstanding threads and resumes the main thread
     so that it can complete the shutdown. */

  if (kick_manager) {
    struct pthread_request request;
    request.req_thread = 0;
    request.req_kind = REQ_KICK;
    TEMP_FAILURE_RETRY(write_not_cancel(__pthread_manager_request,
                                   (char *) &request, sizeof(request)));
  }
}

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static int pthread_allocate_stack ( const pthread_attr_t attr,
pthread_descr  default_new_thread,
int  pagesize,
char **  out_new_thread,
char **  out_new_thread_bottom,
char **  out_guardaddr,
size_t out_guardsize,
size_t out_stacksize 
) [static]

Definition at line 341 of file manager.c.

{
  pthread_descr new_thread;
  char * new_thread_bottom;
  char * guardaddr;
  size_t stacksize, guardsize;

#ifdef USE_TLS
  /* TLS cannot work with fixed thread descriptor addresses.  */
  assert (default_new_thread == NULL);
#endif

  if (attr != NULL && attr->__stackaddr_set)
    {
#ifdef _STACK_GROWS_UP
      /* The user provided a stack. */
# ifdef USE_TLS
      /* This value is not needed.  */
      new_thread = (pthread_descr) attr->__stackaddr;
      new_thread_bottom = (char *) new_thread;
# else
      new_thread = (pthread_descr) attr->__stackaddr;
      new_thread_bottom = (char *) (new_thread + 1);
# endif
      guardaddr = attr->__stackaddr + attr->__stacksize;
      guardsize = 0;
#else
      /* The user provided a stack.  For now we interpret the supplied
        address as 1 + the highest addr. in the stack segment.  If a
        separate register stack is needed, we place it at the low end
        of the segment, relying on the associated stacksize to
        determine the low end of the segment.  This differs from many
        (but not all) other pthreads implementations.  The intent is
        that on machines with a single stack growing toward higher
        addresses, stackaddr would be the lowest address in the stack
        segment, so that it is consistently close to the initial sp
        value. */
# ifdef USE_TLS
      new_thread = (pthread_descr) attr->__stackaddr;
# else
      new_thread =
        (pthread_descr) ((long)(attr->__stackaddr) & -sizeof(void *)) - 1;
# endif
      new_thread_bottom = (char *) attr->__stackaddr - attr->__stacksize;
      guardaddr = new_thread_bottom;
      guardsize = 0;
#endif
#ifndef THREAD_SELF
      __pthread_nonstandard_stacks = 1;
#endif
#ifndef USE_TLS
      /* Clear the thread data structure.  */
      memset (new_thread, '\0', sizeof (*new_thread));
#endif
      stacksize = attr->__stacksize;
    }
  else
    {
#ifdef NEED_SEPARATE_REGISTER_STACK
      const size_t granularity = 2 * pagesize;
      /* Try to make stacksize/2 a multiple of pagesize */
#else
      const size_t granularity = pagesize;
#endif
      void *map_addr;

      /* Allocate space for stack and thread descriptor at default address */
#if FLOATING_STACKS
      if (attr != NULL)
       {
         guardsize = page_roundup (attr->__guardsize, granularity);
         stacksize = __pthread_max_stacksize - guardsize;
         stacksize = MIN (stacksize,
                        page_roundup (attr->__stacksize, granularity));
       }
      else
       {
         guardsize = granularity;
         stacksize = __pthread_max_stacksize - guardsize;
       }

      map_addr = mmap(NULL, stacksize + guardsize,
                    PROT_READ | PROT_WRITE | PROT_EXEC,
                    MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);
      if (map_addr == MAP_FAILED)
        /* No more memory available.  */
        return -1;

# ifdef NEED_SEPARATE_REGISTER_STACK
      guardaddr = map_addr + stacksize / 2;
      if (guardsize > 0)
       mprotect (guardaddr, guardsize, PROT_NONE);

      new_thread_bottom = (char *) map_addr;
#  ifdef USE_TLS
      new_thread = ((pthread_descr) (new_thread_bottom + stacksize
                                 + guardsize));
#  else
      new_thread = ((pthread_descr) (new_thread_bottom + stacksize
                                 + guardsize)) - 1;
#  endif
# elif _STACK_GROWS_DOWN
      guardaddr = map_addr;
      if (guardsize > 0)
       mprotect (guardaddr, guardsize, PROT_NONE);

      new_thread_bottom = (char *) map_addr + guardsize;
#  ifdef USE_TLS
      new_thread = ((pthread_descr) (new_thread_bottom + stacksize));
#  else
      new_thread = ((pthread_descr) (new_thread_bottom + stacksize)) - 1;
#  endif
# elif _STACK_GROWS_UP
      guardaddr = map_addr + stacksize;
      if (guardsize > 0)
       mprotect (guardaddr, guardsize, PROT_NONE);

      new_thread = (pthread_descr) map_addr;
#  ifdef USE_TLS
      new_thread_bottom = (char *) new_thread;
#  else
      new_thread_bottom = (char *) (new_thread + 1);
#  endif
# else
#  error You must define a stack direction
# endif /* Stack direction */
#else /* !FLOATING_STACKS */
      void *res_addr;

      if (attr != NULL)
       {
         guardsize = page_roundup (attr->__guardsize, granularity);
         stacksize = STACK_SIZE - guardsize;
         stacksize = MIN (stacksize,
                        page_roundup (attr->__stacksize, granularity));
       }
      else
       {
         guardsize = granularity;
         stacksize = STACK_SIZE - granularity;
       }

# ifdef NEED_SEPARATE_REGISTER_STACK
      new_thread = default_new_thread;
      new_thread_bottom = (char *) (new_thread + 1) - stacksize - guardsize;
      /* Includes guard area, unlike the normal case.  Use the bottom
       end of the segment as backing store for the register stack.
       Needed on IA64.  In this case, we also map the entire stack at
       once.  According to David Mosberger, that's cheaper.  It also
       avoids the risk of intermittent failures due to other mappings
       in the same region.  The cost is that we might be able to map
       slightly fewer stacks.  */

      /* First the main stack: */
      map_addr = (caddr_t)((char *)(new_thread + 1) - stacksize / 2);
      res_addr = mmap(map_addr, stacksize / 2,
                    PROT_READ | PROT_WRITE | PROT_EXEC,
                    MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);
      if (res_addr != map_addr)
       {
         /* Bad luck, this segment is already mapped. */
         if (res_addr != MAP_FAILED)
           munmap(res_addr, stacksize / 2);
         return -1;
       }
      /* Then the register stack:  */
      map_addr = (caddr_t)new_thread_bottom;
      res_addr = mmap(map_addr, stacksize/2,
                    PROT_READ | PROT_WRITE | PROT_EXEC,
                    MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);
      if (res_addr != map_addr)
       {
         if (res_addr != MAP_FAILED)
           munmap(res_addr, stacksize / 2);
         munmap((caddr_t)((char *)(new_thread + 1) - stacksize/2),
               stacksize/2);
         return -1;
       }

      guardaddr = new_thread_bottom + stacksize/2;
      /* We leave the guard area in the middle unmapped.       */
# else  /* !NEED_SEPARATE_REGISTER_STACK */
#  ifdef _STACK_GROWS_DOWN
      new_thread = default_new_thread;
      new_thread_bottom = (char *) (new_thread + 1) - stacksize;
      map_addr = new_thread_bottom - guardsize;
      res_addr = mmap(map_addr, stacksize + guardsize,
                    PROT_READ | PROT_WRITE | PROT_EXEC,
                    MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);
      if (res_addr != map_addr)
       {
         /* Bad luck, this segment is already mapped. */
         if (res_addr != MAP_FAILED)
           munmap (res_addr, stacksize + guardsize);
         return -1;
       }

      /* We manage to get a stack.  Protect the guard area pages if
        necessary.  */
      guardaddr = map_addr;
      if (guardsize > 0)
       mprotect (guardaddr, guardsize, PROT_NONE);
#  else
      /* The thread description goes at the bottom of this area, and
       * the stack starts directly above it.
       */
      new_thread = (pthread_descr)((unsigned long)default_new_thread &~ (STACK_SIZE - 1));
      map_addr = mmap(new_thread, stacksize + guardsize,
                    PROT_READ | PROT_WRITE | PROT_EXEC,
                    MAP_FIXED | MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);
      if (map_addr == MAP_FAILED)
         return -1;

      new_thread_bottom = map_addr + sizeof(*new_thread);
      guardaddr = map_addr + stacksize;
      if (guardsize > 0)
         mprotect (guardaddr, guardsize, PROT_NONE);

#  endif /* stack direction */
# endif  /* !NEED_SEPARATE_REGISTER_STACK */
#endif   /* !FLOATING_STACKS */
    }
  *out_new_thread = (char *) new_thread;
  *out_new_thread_bottom = new_thread_bottom;
  *out_guardaddr = guardaddr;
  *out_guardsize = guardsize;
#ifdef NEED_SEPARATE_REGISTER_STACK
  *out_stacksize = stacksize / 2;
#else
  *out_stacksize = stacksize;
#endif
  return 0;
}

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static void pthread_exited ( pid_t  pid) [static]

Definition at line 931 of file manager.c.

{
  pthread_descr th;
  int detached;
  /* Find thread with that pid */
  for (th = __pthread_main_thread->p_nextlive;
       th != __pthread_main_thread;
       th = th->p_nextlive) {
    if (th->p_pid == pid) {
      /* Remove thread from list of active threads */
      th->p_nextlive->p_prevlive = th->p_prevlive;
      th->p_prevlive->p_nextlive = th->p_nextlive;
      /* Mark thread as exited, and if detached, free its resources */
      __pthread_lock(th->p_lock, NULL);
      th->p_exited = 1;
      /* If we have to signal this event do it now.  */
      if (th->p_report_events)
       {
         /* See whether TD_REAP is in any of the mask.  */
         int idx = __td_eventword (TD_REAP);
         uint32_t mask = __td_eventmask (TD_REAP);

         if ((mask & (__pthread_threads_events.event_bits[idx]
                     | th->p_eventbuf.eventmask.event_bits[idx])) != 0)
           {
             /* Yep, we have to signal the reapage.  */
             th->p_eventbuf.eventnum = TD_REAP;
             th->p_eventbuf.eventdata = th;
             __pthread_last_event = th;

             /* Now call the function to signal the event.  */
             __linuxthreads_reap_event();
           }
       }
      detached = th->p_detached;
      __pthread_unlock(th->p_lock);
      if (detached)
       pthread_free(th);
      break;
    }
  }
  /* If all threads have exited and the main thread is pending on a
     pthread_exit, wake up the main thread and terminate ourselves. */
  if (main_thread_exiting &&
      __pthread_main_thread->p_nextlive == __pthread_main_thread) {
    restart(__pthread_main_thread);
    /* Same logic as REQ_MAIN_THREAD_EXIT. */
  }
}

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static void pthread_for_each_thread ( void *  arg,
void(*)(void *, pthread_descr fn 
) [static]

Definition at line 1040 of file manager.c.

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static void pthread_free ( pthread_descr  th) [static]

Definition at line 854 of file manager.c.

{
  pthread_handle handle;
  pthread_readlock_info *iter, *next;

  ASSERT(th->p_exited);
  /* Make the handle invalid */
  handle =  thread_handle(th->p_tid);
  __pthread_lock(&handle->h_lock, NULL);
  handle->h_descr = NULL;
  handle->h_bottom = (char *)(-1L);
  __pthread_unlock(&handle->h_lock);
#ifdef FREE_THREAD
  FREE_THREAD(th, th->p_nr);
#endif
  /* One fewer threads in __pthread_handles */
  __pthread_handles_num--;

  /* Destroy read lock list, and list of free read lock structures.
     If the former is not empty, it means the thread exited while
     holding read locks! */

  for (iter = th->p_readlock_list; iter != NULL; iter = next)
    {
      next = iter->pr_next;
      free(iter);
    }

  for (iter = th->p_readlock_free; iter != NULL; iter = next)
    {
      next = iter->pr_next;
      free(iter);
    }

  /* If initial thread, nothing to free */
  if (!th->p_userstack)
    {
      size_t guardsize = th->p_guardsize;
      /* Free the stack and thread descriptor area */
      char *guardaddr = th->p_guardaddr;
#ifdef _STACK_GROWS_UP
# ifdef USE_TLS
      size_t stacksize = guardaddr - th->p_stackaddr;
      guardaddr = th->p_stackaddr;
# else
      size_t stacksize = guardaddr - (char *)th;
      guardaddr = (char *)th;
# endif
#else
      /* Guardaddr is always set, even if guardsize is 0.  This allows
        us to compute everything else.  */
# ifdef USE_TLS
      size_t stacksize = th->p_stackaddr - guardaddr - guardsize;
# else
      size_t stacksize = (char *)(th+1) - guardaddr - guardsize;
# endif
# ifdef NEED_SEPARATE_REGISTER_STACK
      /* Take account of the register stack, which is below guardaddr.  */
      guardaddr -= stacksize;
      stacksize *= 2;
# endif
#endif
      /* Unmap the stack.  */
      munmap(guardaddr, stacksize + guardsize);

    }

#ifdef USE_TLS
# if TLS_DTV_AT_TP
  th = (pthread_descr) ((char *) th + TLS_PRE_TCB_SIZE);
# endif
  _dl_deallocate_tls (th, true);
#endif
}

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static int pthread_handle_create ( pthread_t thread,
const pthread_attr_t attr,
void *(*)(void *)  start_routine,
void *  arg,
sigset_t mask,
int  father_pid,
int  report_events,
td_thr_events_t event_maskp 
) [static]

Definition at line 582 of file manager.c.

{
  size_t sseg;
  int pid;
  pthread_descr new_thread;
  char *stack_addr;
  char * new_thread_bottom;
  pthread_t new_thread_id;
  char *guardaddr = NULL;
  size_t guardsize = 0, stksize = 0;
  int pagesize = __getpagesize();
  int saved_errno = 0;

#ifdef USE_TLS
  new_thread = _dl_allocate_tls (NULL);
  if (new_thread == NULL)
    return EAGAIN;
# if TLS_DTV_AT_TP
  /* pthread_descr is below TP.  */
  new_thread = (pthread_descr) ((char *) new_thread - TLS_PRE_TCB_SIZE);
# endif
#else
  /* Prevent warnings.  */
  new_thread = NULL;
#endif

  /* First check whether we have to change the policy and if yes, whether
     we can  do this.  Normally this should be done by examining the
     return value of the __sched_setscheduler call in pthread_start_thread
     but this is hard to implement.  FIXME  */
  if (attr != NULL && attr->__schedpolicy != SCHED_OTHER && geteuid () != 0)
    return EPERM;
  /* Find a free segment for the thread, and allocate a stack if needed */
  for (sseg = 2; ; sseg++)
    {
      if (sseg >= PTHREAD_THREADS_MAX)
       {
#ifdef USE_TLS
# if TLS_DTV_AT_TP
         new_thread = (pthread_descr) ((char *) new_thread + TLS_PRE_TCB_SIZE);
# endif
         _dl_deallocate_tls (new_thread, true);
#endif
         return EAGAIN;
       }
      if (__pthread_handles[sseg].h_descr != NULL)
       continue;
      if (pthread_allocate_stack(attr, thread_segment(sseg),
                             pagesize, &stack_addr, &new_thread_bottom,
                                 &guardaddr, &guardsize, &stksize) == 0)
       {
#ifdef USE_TLS
         new_thread->p_stackaddr = stack_addr;
#else
         new_thread = (pthread_descr) stack_addr;
#endif
         break;
       }
    }
  __pthread_handles_num++;
  /* Allocate new thread identifier */
  pthread_threads_counter += PTHREAD_THREADS_MAX;
  new_thread_id = sseg + pthread_threads_counter;
  /* Initialize the thread descriptor.  Elements which have to be
     initialized to zero already have this value.  */
#if !defined USE_TLS || !TLS_DTV_AT_TP
  new_thread->p_header.data.tcb = new_thread;
  new_thread->p_header.data.self = new_thread;
#endif
#if TLS_MULTIPLE_THREADS_IN_TCB || !defined USE_TLS || !TLS_DTV_AT_TP
  new_thread->p_multiple_threads = 1;
#endif
  new_thread->p_tid = new_thread_id;
  new_thread->p_lock = &(__pthread_handles[sseg].h_lock);
  new_thread->p_cancelstate = PTHREAD_CANCEL_ENABLE;
  new_thread->p_canceltype = PTHREAD_CANCEL_DEFERRED;
#if !(USE_TLS && HAVE___THREAD)
  new_thread->p_errnop = &new_thread->p_errno;
  new_thread->p_h_errnop = &new_thread->p_h_errno;
  new_thread->p_resp = &new_thread->p_res;
#endif
  new_thread->p_guardaddr = guardaddr;
  new_thread->p_guardsize = guardsize;
  new_thread->p_nr = sseg;
  new_thread->p_inheritsched = attr ? attr->__inheritsched : 0;
  new_thread->p_alloca_cutoff = stksize / 4 > __MAX_ALLOCA_CUTOFF
                             ? __MAX_ALLOCA_CUTOFF : stksize / 4;

  /* Copy the stack guard canary.  */
#ifdef THREAD_COPY_STACK_GUARD
  THREAD_COPY_STACK_GUARD (new_thread);
#endif

  /* Copy the pointer guard value.  */
#ifdef THREAD_COPY_POINTER_GUARD
  THREAD_COPY_POINTER_GUARD (new_thread);
#endif

  /* Initialize the thread handle */
  __pthread_init_lock(&__pthread_handles[sseg].h_lock);
  __pthread_handles[sseg].h_descr = new_thread;
  __pthread_handles[sseg].h_bottom = new_thread_bottom;
  /* Determine scheduling parameters for the thread */
  new_thread->p_start_args.schedpolicy = -1;
  if (attr != NULL) {
    new_thread->p_detached = attr->__detachstate;
    new_thread->p_userstack = attr->__stackaddr_set;

    switch(attr->__inheritsched) {
    case PTHREAD_EXPLICIT_SCHED:
      new_thread->p_start_args.schedpolicy = attr->__schedpolicy;
      memcpy (&new_thread->p_start_args.schedparam, &attr->__schedparam,
             sizeof (struct sched_param));
      break;
    case PTHREAD_INHERIT_SCHED:
      new_thread->p_start_args.schedpolicy = __sched_getscheduler(father_pid);
      __sched_getparam(father_pid, &new_thread->p_start_args.schedparam);
      break;
    }
    new_thread->p_priority =
      new_thread->p_start_args.schedparam.sched_priority;
  }
  /* Finish setting up arguments to pthread_start_thread */
  new_thread->p_start_args.start_routine = start_routine;
  new_thread->p_start_args.arg = arg;
  new_thread->p_start_args.mask = *mask;
  /* Make the new thread ID available already now.  If any of the later
     functions fail we return an error value and the caller must not use
     the stored thread ID.  */
  *thread = new_thread_id;
  /* Raise priority of thread manager if needed */
  __pthread_manager_adjust_prio(new_thread->p_priority);
  /* Do the cloning.  We have to use two different functions depending
     on whether we are debugging or not.  */
  pid = 0;    /* Note that the thread never can have PID zero.  */
  if (report_events)
    {
      /* See whether the TD_CREATE event bit is set in any of the
         masks.  */
      int idx = __td_eventword (TD_CREATE);
      uint32_t mask = __td_eventmask (TD_CREATE);

      if ((mask & (__pthread_threads_events.event_bits[idx]
                 | event_maskp->event_bits[idx])) != 0)
       {
         /* Lock the mutex the child will use now so that it will stop.  */
         __pthread_lock(new_thread->p_lock, NULL);

         /* We have to report this event.  */
#ifdef NEED_SEPARATE_REGISTER_STACK
         /* Perhaps this version should be used on all platforms. But
          this requires that __clone2 be uniformly supported
          everywhere.

          And there is some argument for changing the __clone2
          interface to pass sp and bsp instead, making it more IA64
          specific, but allowing stacks to grow outward from each
          other, to get less paging and fewer mmaps.  */
         pid = __clone2(pthread_start_thread_event,
               (void **)new_thread_bottom,
                      (char *)stack_addr - new_thread_bottom,
                      CLONE_VM | CLONE_FS | CLONE_FILES | CLONE_SIGHAND | CLONE_SYSVSEM |
                      __pthread_sig_cancel, new_thread);
#elif _STACK_GROWS_UP
         pid = __clone(pthread_start_thread_event, (void *) new_thread_bottom,
                     CLONE_VM | CLONE_FS | CLONE_FILES | CLONE_SIGHAND | CLONE_SYSVSEM |
                     __pthread_sig_cancel, new_thread);
#else
         pid = __clone(pthread_start_thread_event, stack_addr,
                     CLONE_VM | CLONE_FS | CLONE_FILES | CLONE_SIGHAND | CLONE_SYSVSEM |
                     __pthread_sig_cancel, new_thread);
#endif
         saved_errno = errno;
         if (pid != -1)
           {
             /* Now fill in the information about the new thread in
               the newly created thread's data structure.  We cannot let
               the new thread do this since we don't know whether it was
               already scheduled when we send the event.  */
             new_thread->p_eventbuf.eventdata = new_thread;
             new_thread->p_eventbuf.eventnum = TD_CREATE;
             __pthread_last_event = new_thread;

             /* We have to set the PID here since the callback function
               in the debug library will need it and we cannot guarantee
               the child got scheduled before the debugger.  */
             new_thread->p_pid = pid;

             /* Now call the function which signals the event.  */
             __linuxthreads_create_event ();

             /* Now restart the thread.  */
             __pthread_unlock(new_thread->p_lock);
           }
       }
    }
  if (pid == 0)
    {
#ifdef NEED_SEPARATE_REGISTER_STACK
      pid = __clone2(pthread_start_thread,
                   (void **)new_thread_bottom,
                     (char *)stack_addr - new_thread_bottom,
                   CLONE_VM | CLONE_FS | CLONE_FILES | CLONE_SIGHAND | CLONE_SYSVSEM |
                   __pthread_sig_cancel, new_thread);
#elif _STACK_GROWS_UP
      pid = __clone(pthread_start_thread, (void *) new_thread_bottom,
                  CLONE_VM | CLONE_FS | CLONE_FILES | CLONE_SIGHAND | CLONE_SYSVSEM |
                  __pthread_sig_cancel, new_thread);
#else
      pid = __clone(pthread_start_thread, stack_addr,
                  CLONE_VM | CLONE_FS | CLONE_FILES | CLONE_SIGHAND | CLONE_SYSVSEM |
                  __pthread_sig_cancel, new_thread);
#endif /* !NEED_SEPARATE_REGISTER_STACK */
      saved_errno = errno;
    }
  /* Check if cloning succeeded */
  if (pid == -1) {
    /* Free the stack if we allocated it */
    if (attr == NULL || !attr->__stackaddr_set)
      {
#ifdef NEED_SEPARATE_REGISTER_STACK
       size_t stacksize = ((char *)(new_thread->p_guardaddr)
                         - new_thread_bottom);
       munmap((caddr_t)new_thread_bottom,
              2 * stacksize + new_thread->p_guardsize);
#elif _STACK_GROWS_UP
# ifdef USE_TLS
       size_t stacksize = guardaddr - stack_addr;
       munmap(stack_addr, stacksize + guardsize);
# else
       size_t stacksize = guardaddr - (char *)new_thread;
       munmap(new_thread, stacksize + guardsize);
# endif
#else
# ifdef USE_TLS
       size_t stacksize = stack_addr - new_thread_bottom;
# else
       size_t stacksize = (char *)(new_thread+1) - new_thread_bottom;
# endif
       munmap(new_thread_bottom - guardsize, guardsize + stacksize);
#endif
      }
#ifdef USE_TLS
# if TLS_DTV_AT_TP
    new_thread = (pthread_descr) ((char *) new_thread + TLS_PRE_TCB_SIZE);
# endif
    _dl_deallocate_tls (new_thread, true);
#endif
    __pthread_handles[sseg].h_descr = NULL;
    __pthread_handles[sseg].h_bottom = NULL;
    __pthread_handles_num--;
    return saved_errno;
  }
  /* Insert new thread in doubly linked list of active threads */
  new_thread->p_prevlive = __pthread_main_thread;
  new_thread->p_nextlive = __pthread_main_thread->p_nextlive;
  __pthread_main_thread->p_nextlive->p_prevlive = new_thread;
  __pthread_main_thread->p_nextlive = new_thread;
  /* Set pid field of the new thread, in case we get there before the
     child starts. */
  new_thread->p_pid = pid;
  return 0;
}

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static void pthread_handle_exit ( pthread_descr  issuing_thread,
int  exitcode 
) [static]

Definition at line 1056 of file manager.c.

{
  pthread_descr th;
  __pthread_exit_requested = 1;
  __pthread_exit_code = exitcode;
  /* A forced asynchronous cancellation follows.  Make sure we won't
     get stuck later in the main thread with a system lock being held
     by one of the cancelled threads.  Ideally one would use the same
     code as in pthread_atfork(), but we can't distinguish system and
     user handlers there.  */
  __flockfilelist();
  /* Send the CANCEL signal to all running threads, including the main
     thread, but excluding the thread from which the exit request originated
     (that thread must complete the exit, e.g. calling atexit functions
     and flushing stdio buffers). */
  for (th = issuing_thread->p_nextlive;
       th != issuing_thread;
       th = th->p_nextlive) {
    kill(th->p_pid, __pthread_sig_cancel);
  }
  /* Now, wait for all these threads, so that they don't become zombies
     and their times are properly added to the thread manager's times. */
  for (th = issuing_thread->p_nextlive;
       th != issuing_thread;
       th = th->p_nextlive) {
    waitpid(th->p_pid, NULL, __WCLONE);
  }
  __fresetlockfiles();
  restart(issuing_thread);
  _exit(0);
}

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static void pthread_handle_free ( pthread_t  th_id) [static]

Definition at line 1000 of file manager.c.

{
  pthread_handle handle = thread_handle(th_id);
  pthread_descr th;

  __pthread_lock(&handle->h_lock, NULL);
  if (nonexisting_handle(handle, th_id)) {
    /* pthread_reap_children has deallocated the thread already,
       nothing needs to be done */
    __pthread_unlock(&handle->h_lock);
    return;
  }
  th = handle->h_descr;
  if (th->p_exited) {
    __pthread_unlock(&handle->h_lock);
    pthread_free(th);
  } else {
    /* The Unix process of the thread is still running.
       Mark the thread as detached so that the thread manager will
       deallocate its resources when the Unix process exits. */
    th->p_detached = 1;
    __pthread_unlock(&handle->h_lock);
  }
}

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static void pthread_kill_all_threads ( int  sig,
int  main_thread_also 
) [static]

Definition at line 1027 of file manager.c.

{
  pthread_descr th;
  for (th = __pthread_main_thread->p_nextlive;
       th != __pthread_main_thread;
       th = th->p_nextlive) {
    kill(th->p_pid, sig);
  }
  if (main_thread_also) {
    kill(__pthread_main_thread->p_pid, sig);
  }
}

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static void pthread_reap_children ( void  ) [static]

Definition at line 981 of file manager.c.

{
  pid_t pid;
  int status;

  while ((pid = waitpid_not_cancel(-1, &status, WNOHANG | __WCLONE)) > 0) {
    pthread_exited(pid);
    if (WIFSIGNALED(status)) {
      /* If a thread died due to a signal, send the same signal to
         all other threads, including the main thread. */
      pthread_kill_all_threads(WTERMSIG(status), 1);
      _exit(0);
    }
  }
}

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static pthread_descr thread_segment ( int  seg) [inline, static]

Definition at line 72 of file manager.c.

{
# ifdef _STACK_GROWS_UP
  return (pthread_descr)(THREAD_STACK_START_ADDRESS + (seg - 1) * STACK_SIZE)
         + 1;
# else
  return (pthread_descr)(THREAD_STACK_START_ADDRESS - (seg - 1) * STACK_SIZE)
         - 1;
# endif
}

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Variable Documentation

Definition at line 42 of file manager.c.

volatile int __pthread_handles_num = 2

Definition at line 51 of file manager.c.

Definition at line 61 of file manager.c.

Definition at line 47 of file manager.c.

Definition at line 55 of file manager.c.

Definition at line 58 of file manager.c.

Definition at line 91 of file manager.c.

Definition at line 63 of file manager.c.

Definition at line 96 of file manager.c.

volatile int terminated_children [static]

Definition at line 86 of file manager.c.