rpmio/rpmsq.c

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00001 
00005 #include "system.h"
00006 
00007 #if defined(__LCLINT__)
00008 #define _BITS_SIGTHREAD_H       /* XXX avoid __sigset_t heartburn. */
00009 
00010 /*@-incondefs -protoparammatch@*/
00011 /*@-exportheader@*/
00012 /*@constant int SA_SIGINFO@*/
00013 extern int sighold(int sig)
00014         /*@globals errno, systemState @*/;
00015 extern int sigignore(int sig)
00016         /*@globals errno, systemState @*/;
00017 extern int sigpause(int sig)
00018         /*@globals errno, systemState @*/;
00019 extern int sigrelse(int sig)
00020         /*@globals errno, systemState @*/;
00021 extern void (*sigset(int sig, void (*disp)(int)))(int)
00022         /*@globals errno, systemState @*/;
00023 
00024 struct qelem;
00025 extern  void insque(struct qelem * __elem, struct qelem * __prev)
00026         /*@modifies  __elem, __prev @*/;
00027 extern  void remque(struct qelem * __elem)
00028         /*@modifies  __elem @*/;
00029 
00030 extern pthread_t pthread_self(void)
00031         /*@*/;
00032 extern int pthread_equal(pthread_t t1, pthread_t t2)
00033         /*@*/;
00034 
00035 extern int pthread_create(/*@out@*/ pthread_t *restrict thread,
00036                 const pthread_attr_t *restrict attr,
00037                 void *(*start_routine)(void*), void *restrict arg)
00038         /*@modifies *thread @*/;
00039 extern int pthread_join(pthread_t thread, /*@out@*/ void **value_ptr)
00040         /*@modifies *value_ptr @*/;
00041 
00042 extern int pthread_setcancelstate(int state, /*@out@*/ int *oldstate)
00043         /*@globals internalState @*/
00044         /*@modifies *oldstate, internalState @*/;
00045 extern int pthread_setcanceltype(int type, /*@out@*/ int *oldtype)
00046         /*@globals internalState @*/
00047         /*@modifies *oldtype, internalState @*/;
00048 extern void pthread_testcancel(void)
00049         /*@globals internalState @*/
00050         /*@modifies internalState @*/;
00051 extern void pthread_cleanup_pop(int execute)
00052         /*@globals internalState @*/
00053         /*@modifies internalState @*/;
00054 extern void pthread_cleanup_push(void (*routine)(void*), void *arg)
00055         /*@globals internalState @*/
00056         /*@modifies internalState @*/;
00057 extern void _pthread_cleanup_pop(/*@out@*/ struct _pthread_cleanup_buffer *__buffer, int execute)
00058         /*@globals internalState @*/
00059         /*@modifies internalState @*/;
00060 extern void _pthread_cleanup_push(/*@out@*/ struct _pthread_cleanup_buffer *__buffer, void (*routine)(void*), /*@out@*/ void *arg)
00061         /*@globals internalState @*/
00062         /*@modifies internalState @*/;
00063 
00064 extern int pthread_mutexattr_destroy(pthread_mutexattr_t *attr)
00065         /*@globals errno, internalState @*/
00066         /*@modifies *attr, errno, internalState @*/;
00067 extern int pthread_mutexattr_init(/*@out@*/ pthread_mutexattr_t *attr)
00068         /*@globals errno, internalState @*/
00069         /*@modifies *attr, errno, internalState @*/;
00070 
00071 int pthread_mutexattr_gettype(const pthread_mutexattr_t *restrict attr,
00072                 /*@out@*/ int *restrict type)
00073         /*@modifies *type @*/;
00074 int pthread_mutexattr_settype(pthread_mutexattr_t *attr, int type)
00075         /*@globals errno, internalState @*/
00076         /*@modifies *attr, errno, internalState @*/;
00077 
00078 extern int pthread_mutex_destroy(pthread_mutex_t *mutex)
00079         /*@modifies *mutex @*/;
00080 extern int pthread_mutex_init(/*@out@*/ pthread_mutex_t *restrict mutex,
00081                 /*@null@*/ const pthread_mutexattr_t *restrict attr)
00082         /*@globals errno, internalState @*/
00083         /*@modifies *mutex, errno, internalState @*/;
00084 
00085 extern int pthread_mutex_lock(pthread_mutex_t *mutex)
00086         /*@globals errno @*/
00087         /*@modifies *mutex, errno @*/;
00088 extern int pthread_mutex_trylock(pthread_mutex_t *mutex)
00089         /*@globals errno @*/
00090         /*@modifies *mutex, errno @*/;
00091 extern int pthread_mutex_unlock(pthread_mutex_t *mutex)
00092         /*@globals errno @*/
00093         /*@modifies *mutex, errno @*/;
00094 
00095 extern int pthread_cond_destroy(pthread_cond_t *cond)
00096         /*@modifies *cond @*/;
00097 extern int pthread_cond_init(/*@out@*/ pthread_cond_t *restrict cond,
00098                 const pthread_condattr_t *restrict attr)
00099         /*@globals errno, internalState @*/
00100         /*@modifies *cond, errno, internalState @*/;
00101 
00102 extern int pthread_cond_timedwait(pthread_cond_t *restrict cond,
00103                 pthread_mutex_t *restrict mutex,
00104                 const struct timespec *restrict abstime)
00105         /*@modifies *cond, *mutex @*/;
00106 extern int pthread_cond_wait(pthread_cond_t *restrict cond,
00107                 pthread_mutex_t *restrict mutex)
00108         /*@modifies *cond, *mutex @*/;
00109 extern int pthread_cond_broadcast(pthread_cond_t *cond)
00110         /*@globals errno, internalState @*/
00111         /*@modifies *cond, errno, internalState @*/;
00112 extern int pthread_cond_signal(pthread_cond_t *cond)
00113         /*@globals errno, internalState @*/
00114         /*@modifies *cond, errno, internalState @*/;
00115 
00116 /*@=exportheader@*/
00117 /*@=incondefs =protoparammatch@*/
00118 #endif
00119 
00120 #include <signal.h>
00121 #include <sys/signal.h>
00122 #include <sys/wait.h>
00123 #include <search.h>
00124 
00125 #if defined(HAVE_PTHREAD_H)
00126 
00127 #include <pthread.h>
00128 
00129 /* XXX suggested in bugzilla #159024 */
00130 #if PTHREAD_MUTEX_DEFAULT != PTHREAD_MUTEX_NORMAL
00131   #error RPM expects PTHREAD_MUTEX_DEFAULT == PTHREAD_MUTEX_NORMAL
00132 #endif
00133 
00134 #ifndef PTHREAD_RECURSIVE_MUTEX_INITIALIZER_NP
00135 /*@unchecked@*/
00136 static pthread_mutex_t rpmsigTbl_lock = PTHREAD_MUTEX_INITIALIZER;
00137 #else
00138 /*@unchecked@*/
00139 /*@-type@*/
00140 static pthread_mutex_t rpmsigTbl_lock = PTHREAD_RECURSIVE_MUTEX_INITIALIZER_NP;
00141 /*@=type@*/
00142 #endif
00143 
00144 #define DO_LOCK()       pthread_mutex_lock(&rpmsigTbl_lock);
00145 #define DO_UNLOCK()     pthread_mutex_unlock(&rpmsigTbl_lock);
00146 #define INIT_LOCK()     \
00147     {   pthread_mutexattr_t attr; \
00148         (void) pthread_mutexattr_init(&attr); \
00149         (void) pthread_mutexattr_settype(&attr, PTHREAD_MUTEX_RECURSIVE); \
00150         (void) pthread_mutex_init (&rpmsigTbl_lock, &attr); \
00151         (void) pthread_mutexattr_destroy(&attr); \
00152         rpmsigTbl_sigchld->active = 0; \
00153     }
00154 #define ADD_REF(__tbl)  (__tbl)->active++
00155 #define SUB_REF(__tbl)  --(__tbl)->active
00156 #define CLEANUP_HANDLER(__handler, __arg, __oldtypeptr) \
00157     (void) pthread_setcanceltype (PTHREAD_CANCEL_ASYNCHRONOUS, (__oldtypeptr));\
00158         pthread_cleanup_push((__handler), (__arg));
00159 #define CLEANUP_RESET(__execute, __oldtype) \
00160     pthread_cleanup_pop(__execute); \
00161     (void) pthread_setcanceltype ((__oldtype), &(__oldtype));
00162 
00163 #define SAME_THREAD(_a, _b)     pthread_equal(((pthread_t)_a), ((pthread_t)_b))
00164 
00165 #define ME()    ((void *)pthread_self())
00166 
00167 #else
00168 
00169 #define DO_LOCK()
00170 #define DO_UNLOCK()
00171 #define INIT_LOCK()
00172 #define ADD_REF(__tbl)  /*@-noeffect@*/ (0) /*@=noeffect@*/
00173 #define SUB_REF(__tbl)  /*@-noeffect@*/ (0) /*@=noeffect@*/
00174 #define CLEANUP_HANDLER(__handler, __arg, __oldtypeptr)
00175 #define CLEANUP_RESET(__execute, __oldtype)
00176 
00177 #define SAME_THREAD(_a, _b)     (42)
00178 
00179 #define ME()    (((void *)getpid()))
00180 
00181 #endif  /* HAVE_PTHREAD_H */
00182 
00183 #include <rpmsq.h>
00184 
00185 #include "debug.h"
00186 
00187 #define _RPMSQ_DEBUG    0
00188 /*@unchecked@*/
00189 int _rpmsq_debug = _RPMSQ_DEBUG;
00190 
00191 /*@unchecked@*/
00192 static struct rpmsqElem rpmsqRock;
00193 
00194 /*@-compmempass@*/
00195 /*@unchecked@*/
00196 rpmsq rpmsqQueue = &rpmsqRock;
00197 /*@=compmempass@*/
00198 
00199 int rpmsqInsert(void * elem, void * prev)
00200 {
00201     rpmsq sq = (rpmsq) elem;
00202     int ret = -1;
00203 
00204     if (sq != NULL) {
00205 #ifdef _RPMSQ_DEBUG
00206 if (_rpmsq_debug)
00207 fprintf(stderr, "    Insert(%p): %p\n", ME(), sq);
00208 #endif
00209         ret = sighold(SIGCHLD);
00210         if (ret == 0) {
00211             sq->child = 0;
00212             sq->reaped = 0;
00213             sq->status = 0;
00214             sq->reaper = 1;
00215 /*@-bounds@*/
00216             sq->pipes[0] = sq->pipes[1] = -1;
00217 /*@=bounds@*/
00218 
00219             sq->id = ME();
00220             ret = pthread_mutex_init(&sq->mutex, NULL);
00221             insque(elem, (prev != NULL ? prev : rpmsqQueue));
00222             ret = sigrelse(SIGCHLD);
00223         }
00224     }
00225     return ret;
00226 }
00227 
00228 int rpmsqRemove(void * elem)
00229 {
00230     rpmsq sq = (rpmsq) elem;
00231     int ret = -1;
00232 
00233     if (elem != NULL) {
00234 
00235 #ifdef _RPMSQ_DEBUG
00236 if (_rpmsq_debug)
00237 fprintf(stderr, "    Remove(%p): %p\n", ME(), sq);
00238 #endif
00239         ret = sighold (SIGCHLD);
00240         if (ret == 0) {
00241             remque(elem);
00242            
00243             /* Unlock the mutex and then destroy it */ 
00244             if((ret = pthread_mutex_unlock(&sq->mutex)) == 0)
00245                 ret = pthread_mutex_destroy(&sq->mutex);
00246 
00247             sq->id = NULL;
00248 /*@-bounds@*/
00249             if (sq->pipes[1])   ret = close(sq->pipes[1]);
00250             if (sq->pipes[0])   ret = close(sq->pipes[0]);
00251             sq->pipes[0] = sq->pipes[1] = -1;
00252 /*@=bounds@*/
00253 #ifdef  NOTYET  /* rpmpsmWait debugging message needs */
00254             sq->reaper = 1;
00255             sq->status = 0;
00256             sq->reaped = 0;
00257             sq->child = 0;
00258 #endif
00259             ret = sigrelse(SIGCHLD);
00260         }
00261     }
00262     return ret;
00263 }
00264 
00265 /*@unchecked@*/
00266 sigset_t rpmsqCaught;
00267 
00268 /*@unchecked@*/
00269 /*@-fullinitblock@*/
00270 static struct rpmsig_s {
00271     int signum;
00272     void (*handler) (int signum, void * info, void * context);
00273     int active;
00274     struct sigaction oact;
00275 } rpmsigTbl[] = {
00276     { SIGINT,   rpmsqAction },
00277 #define rpmsigTbl_sigint        (&rpmsigTbl[0])
00278     { SIGQUIT,  rpmsqAction },
00279 #define rpmsigTbl_sigquit       (&rpmsigTbl[1])
00280     { SIGCHLD,  rpmsqAction },
00281 #define rpmsigTbl_sigchld       (&rpmsigTbl[2])
00282     { SIGHUP,   rpmsqAction },
00283 #define rpmsigTbl_sighup        (&rpmsigTbl[3])
00284     { SIGTERM,  rpmsqAction },
00285 #define rpmsigTbl_sigterm       (&rpmsigTbl[4])
00286     { SIGPIPE,  rpmsqAction },
00287 #define rpmsigTbl_sigpipe       (&rpmsigTbl[5])
00288     { -1,       NULL },
00289 };
00290 /*@=fullinitblock@*/
00291 
00292 void rpmsqAction(int signum,
00293                 /*@unused@*/ void * info, /*@unused@*/ void * context)
00294 {
00295     int save = errno;
00296     rpmsig tbl;
00297 
00298     for (tbl = rpmsigTbl; tbl->signum >= 0; tbl++) {
00299         if (tbl->signum != signum)
00300             continue;
00301 
00302         (void) sigaddset(&rpmsqCaught, signum);
00303 
00304         switch (signum) {
00305         case SIGCHLD:
00306             while (1) {
00307                 rpmsq sq;
00308                 int status = 0;
00309                 pid_t reaped = waitpid(0, &status, WNOHANG);
00310 
00311                 /* XXX errno set to ECHILD/EINVAL/EINTR. */
00312                 if (reaped <= 0)
00313                     /*@innerbreak@*/ break;
00314 
00315                 /* XXX insque(3)/remque(3) are dequeue, not ring. */
00316                 for (sq = rpmsqQueue->q_forw;
00317                      sq != NULL && sq != rpmsqQueue;
00318                      sq = sq->q_forw)
00319                 {
00320                     int ret;
00321 
00322                     if (sq->child != reaped)
00323                         /*@innercontinue@*/ continue;
00324                     sq->reaped = reaped;
00325                     sq->status = status;
00326 
00327                     /* Unlock the mutex.  The waiter will then be able to 
00328                      * aquire the lock.  
00329                      *
00330                      * XXX: jbj, wtd, if this fails? 
00331                      */
00332                     ret = pthread_mutex_unlock(&sq->mutex); 
00333 
00334                     /*@innerbreak@*/ break;
00335                 }
00336             }
00337             /*@switchbreak@*/ break;
00338         default:
00339             /*@switchbreak@*/ break;
00340         }
00341         break;
00342     }
00343     errno = save;
00344 }
00345 
00346 int rpmsqEnable(int signum, /*@null@*/ rpmsqAction_t handler)
00347         /*@globals rpmsigTbl @*/
00348         /*@modifies rpmsigTbl @*/
00349 {
00350     int tblsignum = (signum >= 0 ? signum : -signum);
00351     struct sigaction sa;
00352     rpmsig tbl;
00353     int ret = -1;
00354 
00355     (void) DO_LOCK ();
00356     if (rpmsqQueue->id == NULL)
00357         rpmsqQueue->id = ME();
00358     for (tbl = rpmsigTbl; tbl->signum >= 0; tbl++) {
00359         if (tblsignum != tbl->signum)
00360             continue;
00361 
00362         if (signum >= 0) {                      /* Enable. */
00363             if (ADD_REF(tbl) <= 0) {
00364                 (void) sigdelset(&rpmsqCaught, tbl->signum);
00365 
00366                 /* XXX Don't set a signal handler if already SIG_IGN */
00367                 (void) sigaction(tbl->signum, NULL, &tbl->oact);
00368                 if (tbl->oact.sa_handler == SIG_IGN)
00369                     continue;
00370 
00371                 (void) sigemptyset (&sa.sa_mask);
00372                 sa.sa_flags = SA_SIGINFO;
00373 #if defined(__LCLINT__) /* XXX glibc has union to track handler prototype. */
00374                 sa.sa_handler = (handler != NULL ? handler : tbl->handler);
00375 #else
00376                 sa.sa_sigaction = (handler != NULL ? handler : tbl->handler);
00377 #endif
00378                 if (sigaction(tbl->signum, &sa, &tbl->oact) < 0) {
00379                     SUB_REF(tbl);
00380                     break;
00381                 }
00382                 tbl->active = 1;                /* XXX just in case */
00383                 if (handler != NULL)
00384                     tbl->handler = handler;
00385             }
00386         } else {                                /* Disable. */
00387             if (SUB_REF(tbl) <= 0) {
00388                 if (sigaction(tbl->signum, &tbl->oact, NULL) < 0)
00389                     break;
00390                 tbl->active = 0;                /* XXX just in case */
00391                 tbl->handler = (handler != NULL ? handler : rpmsqAction);
00392             }
00393         }
00394         ret = tbl->active;
00395         break;
00396     }
00397     (void) DO_UNLOCK ();
00398     return ret;
00399 }
00400 
00401 pid_t rpmsqFork(rpmsq sq)
00402 {
00403     pid_t pid;
00404     int xx;
00405     int nothreads = 0;   /* XXX: Shouldn't this be a global? */
00406 
00407     if (sq->reaper) {
00408         xx = rpmsqInsert(sq, NULL);
00409 #ifdef _RPMSQ_DEBUG
00410 if (_rpmsq_debug)
00411 fprintf(stderr, "    Enable(%p): %p\n", ME(), sq);
00412 #endif
00413         xx = rpmsqEnable(SIGCHLD, NULL);
00414     }
00415 
00416     xx = pipe(sq->pipes);
00417 
00418     xx = sighold(SIGCHLD);
00419 
00420     /* 
00421      * Initialize the cond var mutex.   We have to aquire the lock we 
00422      * use for the condition before we fork.  Otherwise it is possible for
00423      * the child to exit, we get sigchild and the sig handler to send 
00424      * the condition signal before we are waiting on the condition.
00425      */
00426     if (!nothreads) {
00427         if(pthread_mutex_lock(&sq->mutex)) {
00428             /* Yack we did not get the lock, lets just give up */
00429 /*@-bounds@*/
00430             xx = close(sq->pipes[0]);
00431             xx = close(sq->pipes[1]);
00432             sq->pipes[0] = sq->pipes[1] = -1;
00433 /*@=bounds@*/
00434             goto out;
00435         }
00436     }
00437 
00438     pid = fork();
00439     if (pid < (pid_t) 0) {              /* fork failed.  */
00440 /*@-bounds@*/
00441         xx = close(sq->pipes[0]);
00442         xx = close(sq->pipes[1]);
00443         sq->pipes[0] = sq->pipes[1] = -1;
00444 /*@=bounds@*/
00445         goto out;
00446     } else if (pid == (pid_t) 0) {      /* Child. */
00447         int yy;
00448 
00449         /* Block to permit parent time to wait. */
00450 /*@-bounds@*/
00451         xx = close(sq->pipes[1]);
00452         xx = read(sq->pipes[0], &yy, sizeof(yy));
00453         xx = close(sq->pipes[0]);
00454         sq->pipes[0] = sq->pipes[1] = -1;
00455 /*@=bounds@*/
00456 
00457 #ifdef _RPMSQ_DEBUG
00458 if (_rpmsq_debug)
00459 fprintf(stderr, "     Child(%p): %p child %d\n", ME(), sq, getpid());
00460 #endif
00461 
00462     } else {                            /* Parent. */
00463 
00464         sq->child = pid;
00465 
00466 #ifdef _RPMSQ_DEBUG
00467 if (_rpmsq_debug)
00468 fprintf(stderr, "    Parent(%p): %p child %d\n", ME(), sq, sq->child);
00469 #endif
00470 
00471     }
00472 
00473 out:
00474     xx = sigrelse(SIGCHLD);
00475     return sq->child;
00476 }
00477 
00484 static int rpmsqWaitUnregister(rpmsq sq)
00485         /*@globals fileSystem, internalState @*/
00486         /*@modifies sq, fileSystem, internalState @*/
00487 {
00488     int nothreads = 0;
00489     int ret = 0;
00490     int xx;
00491 
00492     /* Protect sq->reaped from handler changes. */
00493     ret = sighold(SIGCHLD);
00494 
00495     /* Start the child, linux often runs child before parent. */
00496 /*@-bounds@*/
00497     if (sq->pipes[0] >= 0)
00498         xx = close(sq->pipes[0]);
00499     if (sq->pipes[1] >= 0)
00500         xx = close(sq->pipes[1]);
00501     sq->pipes[0] = sq->pipes[1] = -1;
00502 /*@=bounds@*/
00503 
00504     /* Put a stopwatch on the time spent waiting to measure performance gain. */
00505     (void) rpmswEnter(&sq->op, -1);
00506 
00507     /* Wait for handler to receive SIGCHLD. */
00508     /*@-infloops@*/
00509     while (ret == 0 && sq->reaped != sq->child) {
00510         if (nothreads)
00511             /* Note that sigpause re-enables SIGCHLD. */
00512             ret = sigpause(SIGCHLD);
00513         else {
00514             xx = sigrelse(SIGCHLD);
00515             
00516             /* 
00517              * We start before the fork with this mutex locked;
00518              * The only one that unlocks this the signal handler.
00519              * So if we get the lock the child has been reaped.
00520              */
00521             ret = pthread_mutex_lock(&sq->mutex);
00522             xx = sighold(SIGCHLD);
00523         }
00524     }
00525     /*@=infloops@*/
00526 
00527     /* Accumulate stopwatch time spent waiting, potential performance gain. */
00528     sq->ms_scriptlets += rpmswExit(&sq->op, -1)/1000;
00529 
00530     xx = sigrelse(SIGCHLD);
00531 
00532 #ifdef _RPMSQ_DEBUG
00533 if (_rpmsq_debug)
00534 fprintf(stderr, "      Wake(%p): %p child %d reaper %d ret %d\n", ME(), sq, sq->child, sq->reaper, ret);
00535 #endif
00536 
00537     /* Remove processed SIGCHLD item from queue. */
00538     xx = rpmsqRemove(sq);
00539 
00540     /* Disable SIGCHLD handler on refcount == 0. */
00541     xx = rpmsqEnable(-SIGCHLD, NULL);
00542 #ifdef _RPMSQ_DEBUG
00543 if (_rpmsq_debug)
00544 fprintf(stderr, "   Disable(%p): %p\n", ME(), sq);
00545 #endif
00546 
00547     return ret;
00548 }
00549 
00550 pid_t rpmsqWait(rpmsq sq)
00551 {
00552 
00553 #ifdef _RPMSQ_DEBUG
00554 if (_rpmsq_debug)
00555 fprintf(stderr, "      Wait(%p): %p child %d reaper %d\n", ME(), sq, sq->child, sq->reaper);
00556 #endif
00557 
00558     if (sq->reaper) {
00559         (void) rpmsqWaitUnregister(sq);
00560     } else {
00561         pid_t reaped;
00562         int status;
00563         do {
00564             reaped = waitpid(sq->child, &status, 0);
00565         } while (reaped >= 0 && reaped != sq->child);
00566         sq->reaped = reaped;
00567         sq->status = status;
00568 #ifdef _RPMSQ_DEBUG
00569 if (_rpmsq_debug)
00570 fprintf(stderr, "   Waitpid(%p): %p child %d reaped %d\n", ME(), sq, sq->child, sq->reaped);
00571 #endif
00572     }
00573 
00574 #ifdef _RPMSQ_DEBUG
00575 if (_rpmsq_debug)
00576 fprintf(stderr, "      Fini(%p): %p child %d status 0x%x\n", ME(), sq, sq->child, sq->status);
00577 #endif
00578 
00579     return sq->reaped;
00580 }
00581 
00582 void * rpmsqThread(void * (*start) (void * arg), void * arg)
00583 {
00584     pthread_t pth;
00585     int ret;
00586 
00587     ret = pthread_create(&pth, NULL, start, arg);
00588     return (ret == 0 ? (void *)pth : NULL);
00589 }
00590 
00591 int rpmsqJoin(void * thread)
00592 {
00593     pthread_t pth = (pthread_t) thread;
00594     if (thread == NULL)
00595         return EINVAL;
00596     return pthread_join(pth, NULL);
00597 }
00598 
00599 int rpmsqThreadEqual(void * thread)
00600 {
00601     pthread_t t1 = (pthread_t) thread;
00602     pthread_t t2 = pthread_self();
00603     return pthread_equal(t1, t2);
00604 }
00605 
00609 static void
00610 sigchld_cancel (void *arg)
00611         /*@globals rpmsigTbl, fileSystem, internalState @*/
00612         /*@modifies rpmsigTbl, fileSystem, internalState @*/
00613 {
00614     pid_t child = *(pid_t *) arg;
00615     pid_t result;
00616 
00617     (void) kill(child, SIGKILL);
00618 
00619     do {
00620         result = waitpid(child, NULL, 0);
00621     } while (result == (pid_t)-1 && errno == EINTR);
00622 
00623     (void) DO_LOCK ();
00624     if (SUB_REF (rpmsigTbl_sigchld) == 0) {
00625         (void) rpmsqEnable(-SIGQUIT, NULL);
00626         (void) rpmsqEnable(-SIGINT, NULL);
00627     }
00628     (void) DO_UNLOCK ();
00629 }
00630 
00634 int
00635 rpmsqExecve (const char ** argv)
00636         /*@globals rpmsigTbl @*/
00637         /*@modifies rpmsigTbl @*/
00638 {
00639     int oldtype;
00640     int status = -1;
00641     pid_t pid = 0;
00642     pid_t result;
00643     sigset_t newMask, oldMask;
00644     rpmsq sq = memset(alloca(sizeof(*sq)), 0, sizeof(*sq));
00645 
00646 #ifndef PTHREAD_RECURSIVE_MUTEX_INITIALIZER_NP
00647         INIT_LOCK ();
00648 #endif
00649 
00650     (void) DO_LOCK ();
00651     if (ADD_REF (rpmsigTbl_sigchld) == 0) {
00652         if (rpmsqEnable(SIGINT, NULL) < 0) {
00653             SUB_REF (rpmsigTbl_sigchld);
00654             goto out;
00655         }
00656         if (rpmsqEnable(SIGQUIT, NULL) < 0) {
00657             SUB_REF (rpmsigTbl_sigchld);
00658             goto out_restore_sigint;
00659         }
00660     }
00661     (void) DO_UNLOCK ();
00662 
00663     (void) sigemptyset (&newMask);
00664     (void) sigaddset (&newMask, SIGCHLD);
00665     if (sigprocmask (SIG_BLOCK, &newMask, &oldMask) < 0) {
00666         (void) DO_LOCK ();
00667         if (SUB_REF (rpmsigTbl_sigchld) == 0)
00668             goto out_restore_sigquit_and_sigint;
00669         goto out;
00670     }
00671 
00672     CLEANUP_HANDLER(sigchld_cancel, &pid, &oldtype);
00673 
00674     pid = fork ();
00675     if (pid < (pid_t) 0) {              /* fork failed.  */
00676         goto out;
00677     } else if (pid == (pid_t) 0) {      /* Child. */
00678 
00679         /* Restore the signals.  */
00680         (void) sigaction (SIGINT, &rpmsigTbl_sigint->oact, NULL);
00681         (void) sigaction (SIGQUIT, &rpmsigTbl_sigquit->oact, NULL);
00682         (void) sigprocmask (SIG_SETMASK, &oldMask, NULL);
00683 
00684         /* Reset rpmsigTbl lock and refcnt. */
00685         INIT_LOCK ();
00686 
00687         (void) execve (argv[0], (char *const *) argv, environ);
00688         _exit (127);
00689     } else {                            /* Parent. */
00690         do {
00691             result = waitpid(pid, &status, 0);
00692         } while (result == (pid_t)-1 && errno == EINTR);
00693         if (result != pid)
00694             status = -1;
00695     }
00696 
00697     CLEANUP_RESET(0, oldtype);
00698 
00699     (void) DO_LOCK ();
00700     if ((SUB_REF (rpmsigTbl_sigchld) == 0 &&
00701         (rpmsqEnable(-SIGINT, NULL) < 0 || rpmsqEnable (-SIGQUIT, NULL) < 0))
00702       || sigprocmask (SIG_SETMASK, &oldMask, NULL) != 0)
00703     {
00704         status = -1;
00705     }
00706     goto out;
00707 
00708 out_restore_sigquit_and_sigint:
00709     (void) rpmsqEnable(-SIGQUIT, NULL);
00710 out_restore_sigint:
00711     (void) rpmsqEnable(-SIGINT, NULL);
00712 out:
00713     (void) DO_UNLOCK ();
00714     return status;
00715 }

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