ossp-pkg/pth/pth_tcb.c
1.45
/*
** GNU Pth - The GNU Portable Threads
** Copyright (c) 1999-2007 Ralf S. Engelschall <rse@engelschall.com>
**
** This file is part of GNU Pth, a non-preemptive thread scheduling
** library which can be found at http://www.gnu.org/software/pth/.
**
** This library is free software; you can redistribute it and/or
** modify it under the terms of the GNU Lesser General Public
** License as published by the Free Software Foundation; either
** version 2.1 of the License, or (at your option) any later version.
**
** This library 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
** Lesser General Public License for more details.
**
** You should have received a copy of the GNU Lesser General Public
** License along with this library; if not, write to the Free Software
** Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307
** USA, or contact Ralf S. Engelschall <rse@engelschall.com>.
**
** pth_tcb.c: Pth thread control block handling
*/
/* Patient: Doctor, it hurts when I do this!
Doctor: Well, then don't do it. */
#include "pth_p.h"
#if cpp
#define PTH_TCB_NAMELEN 40
/* thread control block */
struct pth_st {
/* priority queue handling */
pth_t q_next; /* next thread in pool */
pth_t q_prev; /* previous thread in pool */
int q_prio; /* (relative) priority of thread when queued */
/* standard thread control block ingredients */
int prio; /* base priority of thread */
char name[PTH_TCB_NAMELEN];/* name of thread (mainly for debugging) */
int dispatches; /* total number of thread dispatches */
pth_state_t state; /* current state indicator for thread */
/* timing */
pth_time_t spawned; /* time point at which thread was spawned */
pth_time_t lastran; /* time point at which thread was last running */
pth_time_t running; /* time range the thread was already running */
/* event handling */
pth_event_t events; /* events the tread is waiting for */
/* per-thread signal handling */
sigset_t sigpending; /* set of pending signals */
int sigpendcnt; /* number of pending signals */
/* machine context */
pth_mctx_t mctx; /* last saved machine state of thread */
char *stack; /* pointer to thread stack */
unsigned int stacksize; /* size of thread stack */
long *stackguard; /* stack overflow guard */
int stackloan; /* stack type */
void *(*start_func)(void *); /* start routine */
void *start_arg; /* start argument */
/* thread joining */
int joinable; /* whether thread is joinable */
void *join_arg; /* joining argument */
/* per-thread specific storage */
const void **data_value; /* thread specific values */
int data_count; /* number of stored values */
/* cancellation support */
int cancelreq; /* cancellation request is pending */
unsigned int cancelstate; /* cancellation state of thread */
pth_cleanup_t *cleanups; /* stack of thread cleanup handlers */
/* mutex ring */
pth_ring_t mutexring; /* ring of aquired mutex structures */
#ifdef PTH_EX
/* per-thread exception handling */
ex_ctx_t ex_ctx; /* exception handling context */
#endif
};
#endif /* cpp */
intern const char *pth_state_names[] = {
"scheduler", "new", "ready", "running", "waiting", "dead"
};
#if defined(MINSIGSTKSZ) && !defined(SIGSTKSZ)
#define SIGSTKSZ MINSIGSTKSZ
#endif
#if !defined(SIGSTKSZ)
#define SIGSTKSZ 8192
#endif
/* allocate a thread control block */
intern pth_t pth_tcb_alloc(unsigned int stacksize, void *stackaddr)
{
pth_t t;
if (stacksize > 0 && stacksize < SIGSTKSZ)
stacksize = SIGSTKSZ;
if ((t = (pth_t)malloc(sizeof(struct pth_st))) == NULL)
return NULL;
t->stacksize = stacksize;
t->stack = NULL;
t->stackguard = NULL;
t->stackloan = (stackaddr != NULL ? TRUE : FALSE);
if (stacksize > 0) { /* stacksize == 0 means "main" thread */
if (stackaddr != NULL)
t->stack = (char *)(stackaddr);
else {
if ((t->stack = (char *)malloc(stacksize)) == NULL) {
pth_shield { free(t); }
return NULL;
}
}
#if PTH_STACKGROWTH < 0
/* guard is at lowest address (alignment is guarrantied) */
t->stackguard = (long *)((long)t->stack); /* double cast to avoid alignment warning */
#else
/* guard is at highest address (be careful with alignment) */
t->stackguard = (long *)(t->stack+(((stacksize/sizeof(long))-1)*sizeof(long)));
#endif
*t->stackguard = 0xDEAD;
}
return t;
}
/* free a thread control block */
intern void pth_tcb_free(pth_t t)
{
if (t == NULL)
return;
if (t->stack != NULL && !t->stackloan)
free(t->stack);
if (t->data_value != NULL)
free(t->data_value);
if (t->cleanups != NULL)
pth_cleanup_popall(t, FALSE);
free(t);
return;
}
