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#include <stdio.h>
#include "util.h"
#if (defined(sun) && ! defined(sparc)) || defined(vax)
#include <signal.h>
#include <sys/types.h>
#include <sys/time.h>
static char *save_stack_base; static char *stack_lo_addr; static char *stack_hi_addr; static int stack_size;
static int restart_global_flag; static char *old_file_name; static char *new_file_name;
char *util_save_sp; /* set by util_restart_save_state() */ extern char *sbrk();
static void grow_stack() { int i, space[256];
for(i = 0; i < 256; i++) { space[i] = 0; } if ((char *) &i > stack_lo_addr) { grow_stack(); } }
/* ARGSUSED */ static int handle_sigquit(int sig, int code, struct sigcontext *scp) { if (util_restart_save_state()) { /* we are restarting ! -- return from signal */
} else { /* copy stack to user data space */ stack_lo_addr = util_save_sp; stack_size = stack_hi_addr - stack_lo_addr + 1; save_stack_base = sbrk(stack_size); (void) memcpy(save_stack_base, stack_lo_addr, stack_size);
/* write a new executable */ (void) fprintf(stderr, "Writing executable %s ...\n", new_file_name); (void) util_save_image(old_file_name, new_file_name);
/* terminate if signal was a QUIT */ if (sig == SIGQUIT) { (void) _exit(1); } } }
static void restart_program() { (void) fprintf(stderr, "Continuing execution ...\n");
/* create the stack */ grow_stack();
#ifdef vax
asm("movl _util_save_sp,sp"); #endif
#ifdef sun
asm("movl _util_save_sp,sp"); #endif
/* copy the stack back from user space */ (void) memcpy(stack_lo_addr, save_stack_base, stack_size);
/* remove the sbrk for the stack */ if (sbrk(-stack_size) < 0) { perror("sbrk"); }
util_restart_restore_state(); /* jump back into handle_sigquit() */ }
void util_restart(char const *old, char const *neW, int interval) { struct itimerval itimer;
#ifdef vax
#ifdef ultrix
stack_hi_addr = (char *) 0x7fffe3ff; /* ultrix */ #else
stack_hi_addr = (char *) 0x7fffebff; /* bsd 4.3 */ #endif
#endif
#ifdef sun
stack_hi_addr = (char *) 0x0effffff; /* Sun OS 3.2, 3.4 */ #endif
old_file_name = old; new_file_name = neW;
(void) signal(SIGQUIT, handle_sigquit);
if (interval > 0) { (void) signal(SIGVTALRM, handle_sigquit); itimer.it_interval.tv_sec = interval; itimer.it_interval.tv_usec = 0; itimer.it_value.tv_sec = interval; itimer.it_value.tv_usec = 0; if (setitimer(ITIMER_VIRTUAL, &itimer, (struct itimerval *) 0) < 0) { perror("setitimer"); exit(1); } }
if (restart_global_flag) { restart_program(); } restart_global_flag = 1; }
#else
/* ARGSUSED */ void util_restart(char const *old, char const *neW, int interval) { (void) fprintf(stderr, "util_restart: not supported on your operating system/hardware\n"); }
#endif
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