collector.c
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00001 /* 
00002  * 2003-
00003  * collector.c : R.Hanai
00004  * parallel root scanning, concurrent snapshot garbage collector 
00005  * with return barrier
00006  *
00007  * memos
00008  * BUGS: 
00009  * FIXED: copyobj in leo.c
00010  * TODO:
00011  *       memory barrier instructions
00012  *       heap expansion function
00013  *       write-barriers (copyobj() etc.)
00014  *       memory management (BIBOP/Lazy Buddy/etc.)
00015  *       polling / how to scan stacks of suspending threads
00016  *       mutexes => real-time locks
00017  *       make thr_self() faster => caching ids.
00018  *       scan large objects incrementally.
00019  *       
00020  *       mark stack overflow
00021  *       parallel marking (scalability)
00022  *
00023  *       <problematic functions>
00024  *       bindspecial: increment stack collectively
00025  */
00026 
00027 #include <sys/times.h>
00028 #include "eus.h"
00029 #include <sys/param.h>
00030 #include "time.h"
00031 #include "rgc_utils.h"
00032 #include "xccmem.h"
00033 
00034 
00035 #ifdef __ART_LINUX
00036 #include <linux/art_task.h>
00037 #endif
00038 
00039 #if Linux
00040 char *minmemory=(char *)1000000;
00041 #endif
00042 extern pointer K_DISPOSE;
00043 #define MAXDISPOSE 256
00044 static pointer dispose[MAXDISPOSE];
00045 static int gcmerge, dispose_count;
00046 
00047 extern struct {
00048   char using;
00049   mutex_t *lock;
00050   thread_t tid;
00051 } thread_table[]; /* defined in "mthread_posix.c" */
00052 
00053 struct _gc_data gc_data;
00054 barrier_t startup_barrier;
00055 
00056 #define GCDEBUG
00057 //#undef GCDEBUG
00058 #ifdef GCDEBUG
00059 static int white_cells, black_cells, free_cells;
00060 #endif
00061 
00062 #ifdef __PROFILE_GC
00063 static int gctime = 0;
00064 int allocd_words = 0;
00065 #endif
00066 
00067 static void do_scan_roots();
00068 static void init_sync_data();
00069 
00070 #define gcpush(v, off) \
00071 { \
00072   lgcsp->addr = (pointer)v; \
00073   lgcsp->offset = off; \
00074   lgcsp++; \
00075 }
00076 
00077 static pnewgcstack(oldsp)
00078      register ms_entry *oldsp;
00079 {
00080   register ms_entry *oldstack, *stk, *newstack, *newgcsp;
00081   long top, oldsize, newsize;
00082 
00083   oldstack=stk=collector_stack;
00084   oldsize=collector_stacklimit-oldstack;
00085   newsize=oldsize*2;
00086   top=oldsp-collector_stack;
00087   //  newgcsp=newstack=(pointer *)malloc(newsize * sizeof(pointer)+16);
00088   newgcsp=newstack=(ms_entry *)malloc(newsize * sizeof(ms_entry)+16);
00089   fprintf(stderr, "\n\x1b[1;31m;; extending pgcstack 0x%x[%d] --> 0x%x[%d] top=%x\x1b[0m\n",
00090           oldstack, oldsize, newstack, newsize, top);
00091   while (stk<oldsp) *newgcsp++= *stk++;
00092   collector_stack=newstack;
00093   collector_stacklimit= &(collector_stack[newsize-10]);
00094   collector_sp = &(collector_stack[top]);
00095   cfree(oldstack);
00096 }
00097 
00098 static call_disposers()
00099 { int i;
00100  context *ctx=current_ctx;
00101  pointer p,a,curclass;
00102  /*if (debug) fprintf(stderr, ";; disposal call=%d\n", dispose_count);*/
00103  for (i=0; i<dispose_count; i++) {
00104    p=dispose[i];
00105    p->nodispose=0;
00106    a=(pointer)findmethod(ctx,K_DISPOSE,classof(p), &curclass); 
00107    if (debug) fprintf(stderr, ";; (send %x :dispose)\n", p);
00108    if (a!=NIL) csend(ctx,p,K_DISPOSE,0);
00109  }}
00110 
00111 static struct _marking_state {
00112   int is_checking_pstack;
00113   int cur_mut_num;
00114 } marking_state;
00115 
00116 struct _sweeping_state sweeping_state;
00117 
00118 static inline void go_on_to_sweep_phase()
00119 {
00120   numunion nu;
00121   DPRINT2("mark->sweep: free rate = %lf", (double)freeheap / totalheap);
00122   gcmerge = totalheap * min(1.0, fltval(speval(GCMARGIN)))
00123     * max(0.1, fltval(speval(GCMERGE))); 
00124   /* default: GCMERGIN=0.25, GCMERGE=0.2 
00125      ==> no merge if heap occupancy rate is over 95% */
00126   dispose_count = 0; /* <= Is this O.K.? */
00127 
00128   sweeping_state.chp = chunklist;
00129   sweeping_state.p = &chunklist->rootcell;
00130   sweeping_state.tail = 
00131     (bpointer)((int)sweeping_state.p + (buddysize[sweeping_state.chp->chunkbix] << 2));
00132   gc_phase = PHASE_SWEEP; 
00133 }
00134 
00135 long marked_words = 0;
00136 
00137 static int mark_a_little(int m_unit)
00138 {
00139   extern _end();
00140   register ms_entry *lgcsp = collector_sp;
00141   register ms_entry *gcstack = collector_stack;
00142   register int credit = m_unit;
00143   unsigned int offset;
00144   register pointer p, p2;
00145   register bpointer bp;
00146   register int i, s;
00147   context *ctx;
00148 
00149  markloop:
00150   if(credit <= 0){ 
00151     /* write back the value of lgcsp */
00152   //fprintf(stderr, "GC stack size = %d\n", lgcsp - gcstack);
00153     collector_sp = lgcsp;
00154     marked_words -= m_unit - credit;
00155     return 1; /* still marking work is left */
00156   }
00157   if(lgcsp > gcstack){
00158     /* mark from mark stack */
00159 //    lgcsp -= (sizeof(ms_entry)/sizeof(pointer));
00160     lgcsp--;
00161     p = lgcsp->addr;
00162     offset = lgcsp->offset;
00163 
00164   start_mark:
00165     if(offset == 0){
00166 //      if(!ispointer(p)) goto markloop;  /* p may be an immediate */
00167       if(!ispointer(p) || !p) goto markloop;
00168 
00169       ASSERT((unsigned)p >= mingcheap);
00170       ASSERT((unsigned)p < maxgcheap);
00171 
00172       /* these checks aren't normally needed, 
00173          since this is not a conservative collector */
00174 //      if((int)p < (int)_end) goto markloop;
00175 //
00176       if(maxmemory < (char *)p) goto markloop;
00177 //      if((char *)p < minmemory) goto markloop;
00178     }
00179 
00180     /* here, p is a pointer to a live object */
00181     bp = bpointerof(p);
00182 
00183     if(marked(bp)) goto markloop; /* already marked */
00184 //    if(blacked(bp)) goto markloop; /* already marked */
00185 
00186     markon(bp); /* mark it first to avoid endless marking */
00187 
00188     if(pisclosure(p)){
00189       /*
00190         if (p->c.clo.env1>minmemory && p->c.clo.env1<maxmemory)
00191         fprintf(stderr, "Mark: closure %x's env1 points into heap %x\n", 
00192         p, p->c.clo.env1);
00193         if (p->c.clo.env2>minmemory && p->c.clo.env2<maxmemory)
00194         fprintf(stderr, "Mark: closure %x's env2 points into heap %x\n", 
00195         p, p->c.clo.env2);
00196       */
00197       goto markloop; /* avoid marking contents of closure */
00198     }
00199     if(bp->h.elmtype == ELM_FIXED){ /* contents are all pointers */
00200       s = buddysize[bp->h.bix & TAGMASK] - 1;
00201 
00202       if(s > 300){
00203         fprintf (stderr, "do_mark: too big object s=%d, header=%x at %x\n", 
00204                 s, bp->h, bp);
00205         //goto markloop;
00206       }
00207       while(lgcsp + s > collector_stacklimit){
00208         pnewgcstack(lgcsp);
00209         gcstack = collector_stack;
00210         lgcsp = collector_sp;
00211       }
00212       credit -= (s + 1);
00213       for(i = 0; i < s; i++){
00214         p2 = p->c.obj.iv[i];
00215         if(ispointer(p2)) 
00216           gcpush(p2, 0);
00217       }
00218       goto markloop;
00219     } else if (bp->h.elmtype == ELM_POINTER) { /* varing number of pointers */
00220       s = buddysize[bp->h.bix & TAGMASK] - 2;
00221       while (lgcsp + s > collector_stacklimit) {
00222         pnewgcstack(lgcsp);
00223         gcstack = collector_stack;
00224         lgcsp = collector_sp; /* 961003 kagami */
00225       }
00226       credit -= (s + 2);
00227       for (i = 0; i < s; i++) {
00228         p2 = p->c.vec.v[i];
00229         if (ispointer(p2))
00230           gcpush(p2, 0);
00231       }
00232       goto markloop;
00233     } 
00234 
00235     credit -= buddysize[bp->h.bix & TAGMASK];
00236     goto markloop;
00237 
00238   } else {
00239 
00240   /* get another root */
00241   next_root:
00242     credit--;
00243     if (!marking_state.is_checking_pstack) {
00244       for (i = marking_state.cur_mut_num; i < MAXTHREAD; i++) {
00245         ctx = euscontexts[i];
00246         if (ctx) {
00247           if (ctx->gsp > ctx->gcstack) {
00248             p = *--(ctx->gsp);
00249 
00250             ASSERT((unsigned)p >= mingcheap);
00251             ASSERT((unsigned)p < maxgcheap);
00252 
00253             offset = 0;
00254             marking_state.cur_mut_num = i;
00255 /*
00256   if(credit <= 0){ 
00257     // write back the value of lgcsp
00258     gcpush(p, 0);
00259     collector_sp = lgcsp;
00260     marked_words -= m_unit - credit;
00261     return 1; // still marking work is left
00262   }
00263           */
00264             goto start_mark;
00265           }
00266         }
00267       }
00268       marking_state.is_checking_pstack = 1;
00269       goto next_root;
00270     } else {
00271       mutex_lock(&pstack_lock);
00272       if(psp > pstack) {
00273 #ifdef COLLECTCACHE /* this is not yet correctly implemented */
00274 #define COLCACHE 10
00275         int i, ii;
00276         pointer array[COLCACHE];
00277         for (i = 0; i < COLCACHE; i++) {
00278           pointerpop(array[i]);
00279           if(psp > pstack)
00280         continue;
00281           break;
00282         }
00283         pcount = pcount + COLCACHE;
00284         mutex_unlock(&pstack_lock);
00285         for(ii = 0; ii < i; ii++){
00286 //          mark_a_little(array[ii], 0);
00287         }
00288         mutex_lock(&pstack_lock);
00289 #else
00290         pointerpop(p);
00291         offset = 0;
00292         mutex_unlock(&pstack_lock);
00293 /*
00294   if (credit <= 0) { 
00295     // write back the value of lgcsp
00296     gcpush(p, 0);
00297     collector_sp = lgcsp;
00298     marked_words -= m_unit - credit;
00299     return 1; // still marking work is left
00300   }
00301   */
00302         goto start_mark;
00303 #endif
00304       }
00305       mutex_unlock(&pstack_lock);
00306     }
00307   }
00308 
00309   /* marking finished, now we prepare for following sweeping */
00310   go_on_to_sweep_phase();
00311   return 0; 
00312 }
00313 
00314 
00315 int reclaim(bpointer p)
00316 {
00317   register int rbix, stat;
00318   register pointer s;
00319 
00320   s = makepointer(p);
00321   if(pisfilestream(s)){
00322     if(!isint (s->c.fstream.fname) && s->c.fstream.direction != NIL){
00323       if(s->c.fstream.fd == makeint (0)
00324          || s->c.fstream.fd == makeint (1)){
00325         fprintf(stderr, ";; gc! bogus stream at %x fd=%d\n",
00326                 (int) s, intval (s->c.fstream.fd));
00327       }else if((closestream (s) == 0) && debug)
00328         fprintf (stderr,
00329                  ";; gc: dangling stream(address=%x fd=%d) is closed\n",
00330                  (int) s, intval (s->c.fstream.fd));
00331     }
00332   }
00333   p->h.cix = -1; /* free tag */
00334   rbix = p->h.bix & TAGMASK;
00335 
00336   mutex_lock(&alloc_lock);
00337   rw_rdlock(&gc_lock);
00338 
00339   p->b.nextbcell = buddy[rbix].bp;
00340   buddy[rbix].bp = p;
00341   buddy[rbix].count++;
00342 
00343   freeheap += buddysize[rbix];
00344   //  sweepheap += buddysize[rbix];
00345 
00346   rw_unlock(&gc_lock);
00347   mutex_unlock(&alloc_lock);
00348   return 0;
00349 }
00350 
00351 static int rgc_credit = 0;
00352 
00353 /* the cell pointed by 'p' must not be marked */
00354 /* mergecell kindly returns next uncollectable cell address */
00355 static bpointer mergecell(register bpointer p, int cbix)
00356 {
00357   register bpointer np, p2;
00358 
00359   np = nextbuddy(p);
00360   while (p->h.b == 0 && ((int) (p->h.bix & TAGMASK)) < cbix) {
00361 //     if (colored(np)) return np;
00362 //    if (marked(np)) return np;
00363     rgc_credit--;
00364     if (marked(np) || np->h.cix == -1) return np;
00365     if (np->h.nodispose == 1) return np;
00366 
00367     p2 = mergecell(np, cbix); /* merge neighbor cell */
00368     if (np->h.b == 1 && rgc_credit >= 0) { /* can be merged */
00369           p->h.b = p->h.m; /* merge them into bigger cell */
00370       p->h.m = np->h.m;
00371       p->h.bix++;
00372       np = p2;
00373 #ifdef GCDEBUG
00374       white_cells++;
00375 #endif
00376     } else {
00377           reclaim(np);
00378       return p2;
00379     }
00380   }
00381   return np;
00382 }
00383 
00384 /*
00385  * suppose that { sweeping_state.p, 
00386  *                sweeping_state.chp,
00387  *                sweeping_state.tail } are correctly set.
00388  */
00389 static int sweep_a_little(int gcmerge, int s_unit)
00390 {
00391   register struct chunk *chp;
00392   register bpointer p, np, tail;
00393   
00394   rgc_credit = s_unit;
00395   /* restore the state of sweeper */
00396   chp = sweeping_state.chp;
00397   p = sweeping_state.p;
00398   tail = sweeping_state.tail;
00399   
00400   if (p == NULL) {
00401     goto next_chunk;
00402   }
00403   //ASSERT( tail && chp );
00404 
00405 cont_sweep:
00406   /* continue sweeping */
00407   while (p < tail) {
00408     if (rgc_credit <= 0) {
00409       sweeping_state.p = p;
00410       sweeping_state.tail = tail;
00411       return 1;
00412     }
00413 //#ifndef __USE_MARK_BITMAP
00414 //    sweeping_state.p = p;
00415 //#endif
00416     rgc_credit--;
00417     if (p->h.cix == -1) { /* free object */
00418 #ifdef GCDEBUG
00419       free_cells++;
00420 #endif
00421       p = nextbuddy(p);
00422       continue;
00423     }
00424     if (marked(p)) { /* (possibly) live object */
00425 //    if (blacked(p)) { /* (possibly) live object */
00426 #ifdef GCDEBUG
00427       black_cells++;
00428 #endif
00429       markoff(p);
00430       p = nextbuddy(p);
00431       continue;
00432     }
00433     if (p->h.nodispose == 1) {
00434       if(dispose_count >= MAXDISPOSE)
00435         fprintf(stderr, "no more space for disposal processing\n");
00436       else
00437         dispose[dispose_count++] = makepointer(p);
00438       p = nextbuddy(p);
00439     }
00440     if (gcmerge > freeheap) { /* reclaim and no merge */
00441 #ifdef GCDEBUG
00442       white_cells++;
00443 #endif
00444       np = nextbuddy(p);
00445       reclaim(p);
00446       p = np;
00447     } else { /* reclaim and merge *//* update free buddy list */
00448       np = mergecell(p, chp->chunkbix);
00449       reclaim(p);
00450       p = np;
00451     }
00452   }
00453   
00454 next_chunk:
00455   chp = sweeping_state.chp->nextchunk;
00456   if (chp == NULL) {
00457     DPRINT2("sweeping finished: free rate = %lf", (double)freeheap / totalheap);
00458     DPRINT2("white: %d black: %d free: %d", white_cells, black_cells, free_cells);
00459     gc_phase = PHASE_EPILOGUE;
00460     return 0; /* sweeping finished */
00461   }
00462   sweeping_state.chp = chp;
00463   p = &chp->rootcell;
00464   tail = (bpointer)((int)p + (buddysize[chp->chunkbix] << 2));
00465   goto cont_sweep;
00466 
00467 }
00468 
00469 #ifdef __USE_SIGNAL
00470 static void send_root_insertion_signals()
00471 {
00472   int i;
00473   thread_t self = pthread_self();
00474 
00475   for (i = 0; i < MAXTHREAD; i++)
00476     if (!pthread_equal(thread_table[i].tid, self) && euscontexts[i]) {
00477       if (pthread_kill(thread_table[i].tid, SIGUSR1) != 0) {
00478         perror("pthread_kill");
00479       }
00480     }
00481 }
00482 #endif
00483 
00484 void init_rgc(){
00485   void collect();
00486   unsigned int gc_thread;
00487 
00488   active_mutator_num = 1;
00489   gc_region_sync = 0;
00490   startup_barrier = barrier_init(2); /* mainthread and collector thread */
00491   gc_phase = PHASE_NOGC;
00492   ri_core_phase = 0;
00493   mut_stat_phase = 0x2;
00494   gc_wakeup_cnt = gc_cmp_cnt = 0;
00495 #ifdef __USE_POLLING
00496   gc_request_flag = 0;
00497 #endif
00498   init_sync_data();
00499   initmemory_rgc(); /* initialize object heap. define in "eus.c" */
00500   init_utils();
00501 #ifdef __USE_MARK_BITMAP
00502   allocate_bit_table(); /* allocate mark bit table */
00503   clear_bit_table();
00504 #endif
00505 
00506   collector_stack = collector_sp = 
00507     (ms_entry *)malloc(sizeof(ms_entry) * DEFAULT_MAX_RGCSTACK);
00508   collector_stacklimit = collector_stack + DEFAULT_MAX_RGCSTACK - 10;
00509    
00510 #ifdef __GC_SEPARATE_THREAD
00511   thr_create(0, 0, collect, 0, 0, &gc_thread);
00512   barrier_wait(startup_barrier);
00513 #endif
00514 }
00515 
00516 static pointer rgc_classtable = NULL;
00517 
00518 void rgc_add_to_classtable(pointer newclass) {
00519   static int clsidx = 0;
00520   int i;
00521   /* allocate class table for marking */
00522   if (rgc_classtable == NULL) {
00523     rgc_classtable = 
00524       rgc_alloc((MAXCLASS + 1), ELM_POINTER, vectorcp.cix, MAXCLASS + 1);
00525     rgc_classtable->c.vec.size = makeint(MAXCLASS);
00526     for (i = 0; i < MAXCLASS; i++)
00527       rgc_classtable->c.vec.v[i] = NIL;
00528   }
00529   rgc_classtable->c.vec.v[clsidx++] = newclass;
00530 }
00531 
00532 static void scan_global_roots()
00533 {
00534   int i;
00535   pointerpush(sysobj);
00536   pointerpush(pkglist);
00537   /* minimize scanning time for class table */
00538   pointerpush(rgc_classtable);
00539   /*
00540   for(i = 0; i < MAXCLASS; i++){
00541     if(ispointer(classtab[i].def)){
00542       pointerpush (classtab[i].def);
00543 //      ASSERT((unsigned)(classtab[i].def == 0) || 
00544 //      (unsigned)(classtab[i].def) >= mingcheap);
00545 //      ASSERT((unsigned)(classtab[i].def) < maxgcheap);
00546     }
00547   }
00548   */
00549 }
00550 
00551 static void scan_local_roots(int i)
00552 {
00553   register pointer *p;
00554   register bpointer q;
00555   register context *ctx = euscontexts[i];
00556 
00557   pgcpush(ctx->threadobj);
00558   pgcpush(ctx->specials);
00559   
00560   q = bpointerof(ctx->lastalloc);
00561   if (q && ispointer(q)) {
00562       pgcpush(ctx->lastalloc);
00563       ASSERT((unsigned)q >= mingcheap);
00564       ASSERT((unsigned)q < maxgcheap);
00565   }
00566 
00567 #ifdef __RETURN_BARRIER
00568   {
00569     pointer *frame_base, *p;
00570 
00571     //DPRINT3("start scanning current frame: %d ",i);
00572     mutex_lock(&ctx->rbar.lock); /* <-- this lock wouldn't be needed */
00573 
00574     if (ctx->callfp != NULL) 
00575       frame_base = (pointer *)ctx->callfp;
00576     else 
00577       frame_base = ctx->stack;
00578 
00579     for (p = ctx->vsp - 1; p >= frame_base; p--) {
00580         /*
00581          * stack frame can contain
00582          * 1, immediates
00583          * 2, references to the words in this LISP stack (static links, dynamic links)
00584          * 3, this would be a bug: references to the words in a native stack.
00585          *    (jmp_buf in blockframe and catchframe. 
00586          *    See "makeblock", "eussetjmp", "funlambda", "mkcatchframe")  
00587          */
00588       if (*p == NULL) continue;
00589       if (((int)(*p) & 3)) continue; 
00590       if ((ctx->stack <= (pointer *)*p) && ((pointer *)*p <= ctx->stacklimit)) 
00591         continue;
00592       if ((pointer *)*p >= (pointer *)maxgcheap) continue;
00593       if ((pointer *)*p < (pointer *)mingcheap) continue;
00594 
00595           pgcpush(*p);    
00596       ASSERT((unsigned)(*p) >= mingcheap);
00597       ASSERT((unsigned)(*p) < maxgcheap);
00598     }
00599 
00600     if (frame_base == ctx->stack) {
00601       ctx->rbar.pointer = NULL;
00602     } else {
00603       ctx->rbar.pointer = frame_base;
00604     }
00605     mutex_unlock(&ctx->rbar.lock); /* <-- this lock wouldn't be needed */
00606     //DPRINT3("scanning current frame completed");
00607   }
00608 
00609 #else /* original snapshot gc */
00610 
00611   /* push roots in thread's stack */
00612   for (p = ctx->vsp - 1; p >= ctx->stack; p--) {
00613     // for(p = ctx->stack; p < ctx->vsp; p++) {
00614     if (*p == NULL) continue;
00615     if (((int)(*p) & 3)) continue; 
00616     if ((ctx->stack <= (pointer *)*p) && ((pointer *)*p <= ctx->stacklimit)) 
00617       continue;
00618     if ((pointer *)*p >= (pointer *)maxgcheap) continue;
00619     if ((pointer *)*p < (pointer *)mingcheap) continue;
00620 
00621         pgcpush(*p);    
00622     ASSERT((unsigned)(*p) >= mingcheap);
00623     ASSERT((unsigned)(*p) < maxgcheap);
00624   }
00625 #endif 
00626 }
00627 
00628 #if 0
00629 static void scan_suspending_thread_roots()
00630 {
00631   int id, c;
00632   for(id = 0; id < MAXTHREAD; id++){
00633     if(thread_table[id].using){
00634       mutex_lock(&mut_stat_table[id].lock); 
00635       if(mut_stat_table[id].stat == 0x3){ /* 'suspended' & 'need_scan' */
00636         mut_stat_table[id].stat = 0x5; /* 'suspended' & 'scanning' */
00637         mutex_unlock(&mut_stat_table[id].lock); 
00638         scan_local_roots(id);
00639         finish_access_before_read();
00640         do{
00641           c = read_volatile_int(frame_scan_sync);
00642         }while(cas_int(frame_scan_sync, c, c + 1));
00643         mutex_lock(&mut_stat_table[id].lock);
00644         mut_stat_table[id].stat = 0x1; /* 'suspended' */
00645       }
00646       mutex_unlock(&mut_stat_table[id].lock); 
00647     }
00648   }
00649 }
00650 #endif
00651 
00652 #ifdef __RETURN_BARRIER
00653 #define INSERT_UNIT 4 /* 2 or 4 will be good */
00654 
00655 static void scan_remaining_roots()
00656 {
00657   int i, local_root_count, inserted_root_count;
00658   static char idx[MAXTHREAD];
00659 
00660   local_root_count = 0;
00661 
00662   for (i = 0; i < MAXTHREAD; i++) {
00663     if (euscontexts[i] && euscontexts[i]->rbar.pointer) {
00664       idx[local_root_count] = i;
00665       local_root_count++;
00666     }
00667   }
00668 
00669   inserted_root_count = local_root_count;
00670   
00671   do {
00672     for (i = 0; i < local_root_count; i++) {
00673       context *ctx;
00674       register pointer *p;
00675       int counter, tid;
00676 
00677       tid = idx[i];
00678       ctx = euscontexts[tid];
00679       if ((ctx)->rbar.pointer == NULL) continue;
00680       
00681       mutex_lock(&((ctx)->rbar.lock));
00682       //DPRINT3("scheduler inserting thread : %d's local roots", i);
00683       p = (ctx)->rbar.pointer - 1;
00684       counter = INSERT_UNIT;
00685 
00686       while (1) {
00687         if (p < ctx->stack) break;
00688         if ((((int)(*p) & 3) == 0)
00689             && ((ctx->stack > (pointer *)*p) || ((pointer *)*p > ctx->stacklimit))
00690             && (((pointer *)*p >= (pointer *)mingcheap && (pointer *)*p < (pointer *)maxgcheap))) {
00691               pgcpush(*p);
00692       ASSERT((unsigned)(*p) >= mingcheap);
00693       ASSERT((unsigned)(*p) < maxgcheap);
00694         }
00695         p--;
00696         counter--;
00697         if(counter == 0) break;
00698       }
00699       (ctx)->rbar.pointer = p + 1;
00700           
00701       if (p < ctx->stack) {
00702         (ctx)->rbar.pointer = NULL;
00703         inserted_root_count--;
00704       }
00705       mutex_unlock(&(ctx)->rbar.lock);
00706     }
00707   }
00708   while (inserted_root_count != 0);
00709 }
00710 #endif /* __RETURN_BARRIER */
00711 
00712 unsigned int gs[MAXTHREAD];
00713 /*
00714  * suppose that we don't have collector_lock
00715  */
00716 void notify_gc()
00717 {
00718   int id, phase, c;
00719   unsigned int s, e;
00720 //  unlock_collector;
00721   /* reset synchronization variables */
00722 //  lock_collector;
00723 /*  if (gc_phase != PHASE_NOGC) {
00724     unlock_collector;
00725     return;
00726   }
00727 */
00728   id = thr_self(); 
00729 //  gs[id] = current_utime();
00730 
00731   gc_phase = PHASE_PROLOGUE;
00732   gc_point_sync = 0;
00733   phase = ri_core_phase;
00734   mut_stat_phase = mut_stat_phase ^ 0x2;
00735 #ifdef __USE_POLLING
00736   //  for(id = 0; id < MAXTHREAD; id++){
00737   //    if(thread_table[id].using){
00738   //      mutex_lock(&mut_stat_table[id].lock);    
00739   //      mut_stat_table[id].stat |= 0x2; /* set 'need_scan' flag */
00740   //      if(mut_stat_table[id].stat & 0x1){ /* 'suspended'? */
00741   //        do{
00742   //          c = gc_point_sync;
00743   //        }while(cas_int(gc_point_sync, c, c + 1));
00744   //      }
00745   //      mutex_unlock(&mut_stat_table[id].lock);    
00746   //    }
00747   //  }
00748 #endif
00749 #ifdef __USE_SIGNAL
00750   send_root_insertion_signals();
00751 #else /* __USE_POLLING */
00752   gc_request_flag = 1;
00753 #endif
00754   marking_state.is_checking_pstack = 0;
00755   marking_state.cur_mut_num = 0;
00756   marked_words = 0;
00757   unlock_collector;
00758   
00759   do {
00760     c = gc_point_sync;
00761   } while(cas_int(gc_point_sync, c, c + 1));
00762 
00763   if (gc_point_sync + gc_region_sync < active_mutator_num) {
00764     sched_yield(); // nanosleep(0) might be better
00765   } else {
00766     lock_collector;
00767     if (phase == ri_core_phase) {
00768       do_scan_roots(); 
00769     }
00770     unlock_collector;
00771   }
00772   
00773   /* wait until root scanning(core) is finished */
00774   lock_collector;
00775   while (phase == ri_core_phase) 
00776     cond_wait(&ri_end_cv, &collector_lock); 
00777 //  unlock_collector;
00778 //  e = current_utime();
00779 //  if(id == 0)fprintf(stderr, " (%d:%d) ", e - gs[id], id);
00780 }
00781 
00782 
00783 /* suppose that we have collector lock */
00784 static void do_scan_roots()
00785 { 
00786   int tid;
00787   unsigned int s, e;
00788 
00789     //s = current_utime();
00790   scan_global_roots();
00791 
00792   /* write barriers get activated */
00793   /* objects are allocated as black after here */
00794   gc_phase = PHASE_ROOT_CORE; 
00795   for (tid = 0; tid < MAXTHREAD; tid++) {
00796     if (euscontexts[tid]) {
00797       mutex_lock(&mut_stat_table[tid].lock);
00798       scan_local_roots(tid);
00799       //      mut_stat_table[tid].stat = 0x0; /* 'running' */
00800       mut_stat_table[tid].stat = 
00801         (mut_stat_table[tid].stat ^ 0x2) & 0xfffffffd; /* 'running' */
00802       mutex_unlock(&mut_stat_table[tid].lock);
00803     }
00804   }
00805     //e = current_utime();
00806     //fprintf(stderr, "stopped: %d\n", e - s);
00807 
00808   gc_request_flag = 0;
00809   ri_core_phase = 1 - ri_core_phase; /* release other mutator threads */
00810   gc_phase = PHASE_ROOT_REM; 
00811   cond_broadcast(&ri_end_cv);
00812   gc_wakeup_cnt++; /* now, we release collector threads */
00813   cond_broadcast(&gc_wakeup_cv);
00814   DPRINT2("root scan finished: free rate = %lf", (double)freeheap / totalheap);
00815 }
00816 
00817 
00818 static void wait_until_next_gc_cycle()
00819 {
00820   /*
00821     numunion nu;
00822     int thr;
00823     double threshold;
00824     static long used;
00825 
00826     used += pastfree + newheap + sweepheap - freeheap;
00827     newheap = 0;
00828     threshold = max(DEFAULT_GC_THRESHOLD, fltval(speval(GCMARGIN)));
00829     thr = (int)((double)totalheap * threshold);
00830     used = freeheap;
00831     while(freeheap > thr && gc_counter >= gc_request_counter){
00832     nanosleep(&treq, NULL); // take a rest
00833     }
00834     used = used - freeheap;
00835     pastfree = freeheap;
00836   */
00837 
00838   /*
00839     mutex_lock(&gc_state_lock);
00840     while(gc_counter >= gc_request_counter){
00841     cond_wait(&wake_up_gc_thread_cv, &gc_state_lock);
00842     }
00843     mutex_unlock(&gc_state_lock);
00844   */
00845 }
00846 
00847 //#define myctx (euscontexts[thr_self()])
00848 //static long rgc_marktime, rgc_sweeptime;
00849 
00850 static int do_gc_epilogue()
00851 {
00852   /*
00853     if (gc_net_free < 0.8) { // hard external fragmentation
00854       DPRINT1("\x1b[1;31mexpand heap(do_gc_epilogue, free/total=%d/%d)\x1b[0m",
00855               freeheap, totalheap);
00856       newchunk(DEFAULT_EXPAND_SIZE_IDX);
00857       //do_allocate_heap(totalheap * (0.9 - gc_net_free));
00858     }
00859   */
00860 #ifdef __USE_MARK_BITMAP
00861     clear_bit_table();
00862 #endif
00863     if (gc_cmp_cnt < gc_wakeup_cnt)
00864       gc_cmp_cnt++;
00865     gc_phase = PHASE_NOGC;
00866 
00867     if (debug) {
00868       fprintf(stderr, " free/total=%d/%d\n",
00869           freeheap, totalheap);
00870 //      fprintf(stderr, " mark=%d sweep%d\n", rgc_marktime, rgc_sweeptime);
00871     }
00872 /* GC thread doesn't have its own context.
00873     if (speval(QGCHOOK) != NIL) {
00874       pointer gchook=speval(QGCHOOK);
00875       vpush(makeint(freeheap)); vpush(makeint(totalheap));
00876       ufuncall(ctx,gchook,gchook,(pointer)(ctx->vsp-2),ctx->bindfp,2);
00877       ctx->vsp -= 2;
00878     }
00879     breakck;
00880 */
00881 
00882     DPRINT2("GC cycle finished: free rate = %lf", (double)freeheap / totalheap);
00883     return 0;
00884 }
00885 
00886 void do_a_little_gc_work(int m_unit, int s_unit)
00887 {
00888   unsigned int s, e;
00889 //  s = current_utime();
00890   switch (gc_phase) {
00891     case PHASE_ROOT_REM:
00892 #ifdef __RETURN_BARRIER
00893       scan_remaining_roots();
00894 #endif
00895       gc_phase = PHASE_MARK;
00896       break;
00897     case PHASE_MARK:
00898       mark_a_little(m_unit);
00899     break;
00900     case PHASE_SWEEP:
00901       sweep_a_little(gcmerge, s_unit);
00902     break;
00903     case PHASE_EPILOGUE:
00904       do_gc_epilogue();
00905     default: 
00906       ;
00907   }
00908 //  e = current_utime();
00909 //  if(e-s > 100) printf("<<%d, %d::%d, %d>>\n", e-s, gc_phase,
00910 //      rgc_credit, marking_state.is_checking_pstack);
00911 }
00912 
00913 void collect()
00914 {
00915   int i;
00916   unsigned s, e;
00917 
00918 #ifdef __PROFILE_GC
00919   int tmp_free;
00920   reset_utime(); /* for rdtsc */
00921 #endif
00922 
00923   /* synchronize with mainthread */
00924   barrier_wait(startup_barrier);
00925 
00926 #ifdef __PROFILE_GC
00927   //  times(&buf1);
00928 #endif
00929 
00930   /* gc main loop */
00931   for (;;) { 
00932 
00933     /* gc thread waits until the core of root scanning is finished. */
00934     lock_collector;
00935     while (gc_cmp_cnt == gc_wakeup_cnt) {
00936       cond_wait(&gc_wakeup_cv, &collector_lock);
00937     }
00938 
00939     while (gc_phase != PHASE_NOGC) {
00940      // printf(".");fflush(stdout);
00941       do_a_little_gc_work(M_UNIT, S_UNIT);
00942       unlock_collector;
00943       //usleep(0);
00944       lock_collector;
00945     };
00946     unlock_collector;
00947       
00948 #ifdef __PROFILE_GC
00949     //    times(&buf2);
00950     //    gctime = buf2.tms_utime+buf2.tms_stime-buf1.tms_utime-buf1.tms_stime;
00951     //    fprintf(stderr, "gc thread time = %d\n", gctime*1000/HZ);
00952     //    fprintf(stderr, "freeheap=%d\n", freeheap*4);
00953     //    tmp_free = freeheap;
00954 #endif
00955 
00956     //    DPRINT3("took %d micro, not gc consump_rate %f", 
00957     //            e-s, (float)(tmp_free-freeheap)/(e-s));
00958   }
00959   
00960   /* never come here */
00961 }
00962 
00963 
00964 #ifdef __EAGER_GC_CONTROL
00965 static int change_collector_thread_sched_policy(int t_sect_length)
00966 {
00967 #ifdef __ART_LINUX
00968   if(art_enter(ART_PRIO_MAX, ART_TASK_PERIODIC, t_sect_length) == -1){
00969     DPRINT2("collector error: art_enter");
00970     return -1;    
00971   }
00972 #else /* LINUX */
00973 #endif
00974   return 0;
00975 }
00976 static int restore_collector_thread_sched_policy()
00977 {
00978 #ifdef __ART_LINUX
00979   if(art_exit() == -1){
00980     DPRINT2("collector error: art_exit");
00981     return -1;    
00982   }
00983 #else /* LINUX */
00984 #endif
00985   return 0;
00986 }
00987 #endif /* __EAGER_GC_CONTROL */
00988 
00989 #ifdef __USE_POLLING
00990 void enter_gc_region(int id)
00991 {
00992   int c, phase;
00993   mutex_lock(&mut_stat_table[id].lock);    
00994   //  mut_stat_table[id].stat |= 0x1; /* set 'suspended' flag */
00995   //  if(mut_stat_table[id].stat & 0x2){ /* 'need_scan'? */
00996   do {
00997     c = gc_region_sync;
00998   } while (cas_int(gc_region_sync, c, c + 1));
00999   mutex_unlock(&mut_stat_table[id].lock);    
01000 
01001   if (gc_request_flag) {
01002     phase = ri_core_phase;
01003     if (gc_point_sync + gc_region_sync == active_mutator_num) {
01004       lock_collector;
01005       if (phase == ri_core_phase)
01006         do_scan_roots(); 
01007       unlock_collector;
01008     }
01009   }
01010   //  }
01011 }
01012 
01013 void exit_gc_region(int id)
01014 {
01015   int c;
01016  try_exit:
01017   mutex_lock(&mut_stat_table[id].lock);
01018   if (mut_stat_table[id].stat & 0x2 == mut_stat_phase) { /* 'need_scan'? */
01019     //    mut_stat_table[id].stat = 0x4; /* set 'scanning' and clear 'need_scan' */
01020     //    mutex_unlock(&mut_stat_table[id].lock);
01021     //    insert_my_roots();
01022     mutex_unlock(&mut_stat_table[id].lock);
01023     sched_yield(); /* this wouldn't go well on ART-Linux */
01024     goto try_exit;
01025   } else {
01026     //    mut_stat_table[id].stat &= 0x0; /* clear 'suspended' flag */
01027     do {
01028       c = gc_region_sync;
01029     } while (cas_int(gc_region_sync, c, c - 1));
01030     mutex_unlock(&mut_stat_table[id].lock);
01031   }
01032 }
01033 
01034 #endif /* __USE_POLLING */
01035 
01036 int ps_sem = 1;
01037 /* initialize data for syncronization */
01038 static void init_sync_data()
01039 {
01040   int i;
01041   mutex_init(&pstack_lock, NULL);
01042   mutex_init(&collector_lock, NULL);
01043   cond_init(&gc_wakeup_cv, NULL);
01044   cond_init(&ri_end_cv, NULL);
01045   mutex_init(&gc_state_lock, NULL);
01046   for (i = 0; i < MAXTHREAD; i++) {
01047     mutex_init(&mut_stat_table[i].lock, NULL);
01048   }
01049 }
01050 
01051 /**********************************************************
01052   mutator interface routines
01053 *********************************************************/
01054 
01055 #ifdef __USE_POLLING
01056 void scan_roots()
01057 {
01058   int c;
01059   unsigned int e;
01060   int myid = thr_self();
01061   int phase = ri_core_phase;
01062 
01063   myid = thr_self();
01064   //gs[myid] = current_utime();
01065 
01066   do {
01067     c = gc_point_sync;
01068   } while (cas_int(gc_point_sync, c, c + 1));
01069 
01070   if (gc_point_sync + gc_region_sync < active_mutator_num) {
01071     sched_yield(); // nanosleep(0) might be better
01072   } else {
01073     lock_collector;
01074     if (phase == ri_core_phase)
01075       do_scan_roots(); 
01076     unlock_collector;
01077   }
01078   
01079   /* wait until root scanning(core) is finished */
01080   lock_collector;
01081   while (phase == ri_core_phase)
01082     cond_wait(&ri_end_cv, &collector_lock);
01083   unlock_collector;
01084   //e = current_utime();
01085   //if(myid == 0)fprintf(stderr, " (%d:%d) ", e-gs[myid], myid);
01086   
01087   return;
01088 }
01089 
01090 /* function-version polling code */
01091 int check_gc_request()
01092 {
01093   if (!gc_request_flag) 
01094     return 0;
01095   scan_roots();
01096   return 1;
01097 }
01098 #endif
01099 
01100 #ifdef __USE_SIGNAL
01101 /*
01102  * it is not recommended to use pthreads tools in signal handlers
01103  * (mutex, conditional variables,...)
01104  */
01105 void sighandler(int x)
01106 {
01107   int idx;
01108   DPRINT2("start root scanning");
01109   notify_ri_start();
01110   idx = thr_self();
01111   scan_local_roots(thr_self());
01112   barrier_wait(end_ri_barrier);
01113   DPRINT2("mutators restart");
01114 }
01115 #endif
01116 
01117 /* MAXSTACK 65536 */
01118 #define PMAXSTACK (MAXSTACK * 110)
01119 pointer pstack[PMAXSTACK];
01120 volatile pointer *psp = pstack;
01121 pointer *pstacklimit = pstack + PMAXSTACK;
01122 mutex_t pstack_lock;
01123 
01124 /***********************************************************
01125     barrier-synchronization functions
01126 ***********************************************************/
01127 
01128 barrier_t barrier_init(int n_clients)
01129 {
01130   barrier_t barrier = (barrier_t)malloc(sizeof(struct barrier_struct));
01131   if (barrier != NULL) {
01132     barrier->n_clients = n_clients;
01133     barrier->n_waiting = 0;
01134     barrier->phase = 0;
01135     mutex_init(&barrier->lock, NULL);
01136     cond_init(&barrier->wait_cv, NULL);
01137   }
01138   return barrier;
01139 }
01140 
01141 void barrier_reset(barrier_t barrier, int n_clients)
01142 {
01143   /* called when active_mutator_num was changed */
01144   /* this implementation is not good */
01145   barrier->n_clients = n_clients;
01146 }
01147 
01148 void barrier_destroy(barrier_t barrier)
01149 {
01150   mutex_destroy(&barrier->lock);
01151   cond_destroy(&barrier->wait_cv);
01152   free(barrier);
01153 }
01154 
01155 void barrier_wait(barrier_t barrier)
01156 {
01157   int my_phase;
01158   mutex_lock(&barrier->lock);
01159   my_phase = barrier->phase;
01160   barrier->n_waiting++;
01161   if (barrier->n_waiting == barrier->n_clients) {
01162     barrier->n_waiting = 0;
01163     barrier->phase = 1 - my_phase;
01164     cond_broadcast(&barrier->wait_cv);
01165   }
01166   while (barrier->phase == my_phase) {
01167     cond_wait(&barrier->wait_cv, &barrier->lock);
01168   }
01169   mutex_unlock(&barrier->lock);
01170 }
01171 
01172 /***********************************************************
01173   other functions
01174 ***********************************************************/
01175 
01176 
01177 unsigned int do_allocate_heap(unsigned int req_words)
01178 {
01179   int i, k; 
01180   unsigned int rem_words = req_words;
01181 
01182   while (buddysize[MAXBUDDY-1] <= rem_words) {
01183     k = newchunk(MAXBUDDY-1);
01184     rem_words -= buddysize[k];
01185   }
01186   for (i = MAXBUDDY - 2; i >= 20/* or DEFAULTCHUNKINDEX */; i--) {
01187     if (buddysize[i] < rem_words){
01188       k = newchunk(i);
01189       rem_words -= buddysize[k];
01190     }
01191   }
01192   return req_words - rem_words;
01193 }
01194 
01195 unsigned int allocate_heap()
01196 { /*
01197    * k  buddy[k]
01198    * 22 85971 word 343884 byte
01199    * 23 139104 word 556416 byte
01200    * 24 225075 word 900300 byte
01201    * 25 364179 word 1456716 byte
01202    * 26 589254 word 2357016 byte
01203    * 27 953433 word 3813732 byte
01204    * 28 1542687 word 6170748 byte
01205    * 29 2496120 word 9984480 byte
01206    * 30 4038807 word 16155228 byte
01207    */
01208     return do_allocate_heap(INITIAL_HEAP_SIZE * 1000);
01209 }
01210 
01211 extern long long values[];
01212 
01213 pointer RGCCOUNT(register context *ctx, int n, pointer argv[])
01214 {
01215   ckarg(0);
01216   return makeint(gc_cmp_cnt);
01217 }
01218 
01219 pointer RGC_GCTIME(register context *ctx, int n, pointer argv[])
01220 {
01221   struct tms buf;
01222   ckarg(0);
01223   times(&buf);
01224   return makeint((buf.tms_utime + buf.tms_stime) * 1000/HZ );
01225 }
01226 
01227 #ifdef __PROFILE_GC
01228 pointer RGCALLOCATED(register context *ctx, int n, pointer argv[])
01229 {
01230   ckarg(0);
01231   return makeint(allocd_words);
01232 }
01233 #endif
01234 
01235 void rgcfunc(register context *ctx, pointer mod)
01236 {
01237   pointer p = Spevalof(PACKAGE);
01238   pointer_update(Spevalof(PACKAGE), syspkg);
01239   defun(ctx, "RGCCOUNT", mod, RGCCOUNT,NULL);
01240   defun(ctx, "RGCTIME", mod, RGC_GCTIME,NULL);
01241 #ifdef __PROFILE_GC
01242   defun(ctx, "RGCALLOCATED", mod, RGCALLOCATED,NULL);
01243 #endif
01244   pointer_update(Spevalof(PACKAGE), p);
01245 }


euslisp
Author(s): Toshihiro Matsui
autogenerated on Thu Jun 6 2019 18:05:53