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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 #if !defined(__QNX__)
    00122 #  include <sys/signal.h>
    00123 #endif
    00124 #include <sys/wait.h>
    00125 #include <search.h>
    00126
    00127 /* portability fallback for sighold(3) */
    00128 #if !defined(HAVE_SIGHOLD) && defined(HAVE_SIGPROCMASK) && defined(HAVE_SIGADDSET)
    00129 static int __RPM_sighold(int sig)
    00130 {
    00131     sigset_t set;
    00132     if (sigprocmask(SIG_SETMASK, NULL, &set) < 0)
    00133         return -1;
    00134     if (sigaddset(&set, sig) < 0)
    00135         return -1;
    00136     return sigprocmask(SIG_SETMASK, &set, NULL);
    00137 }
    00138 #define sighold(sig) __RPM_sighold(sig)
    00139 #endif
    00140
    00141 /* portability fallback for sigrelse(3) */
    00142 #if !defined(HAVE_SIGRELSE) && defined(HAVE_SIGPROCMASK) && defined(HAVE_SIGDELSET)
    00143 static int __RPM_sigrelse(int sig)
    00144 {
    00145     sigset_t set;
    00146     if (sigprocmask(SIG_SETMASK, NULL, &set) < 0)
    00147         return -1;
    00148     if (sigdelset(&set, sig) < 0)
    00149         return -1;
    00150     return sigprocmask(SIG_SETMASK, &set, NULL);
    00151 }
    00152 #define sigrelse(sig) __RPM_sigrelse(sig)
    00153 #endif
    00154
    00155 /* portability fallback for sigpause(3) */
    00156 #if !defined(HAVE_SIGPAUSE) && defined(HAVE_SIGEMPTYSET) && defined(HAVE_SIGADDSET) && defined(HAVE_SIGSUSPEND)
    00157 static int __RPM_sigpause(int sig)
    00158 {
    00159     sigset_t set;
    00160     if (sigemptyset(&set) < 0)
    00161         return -1;
    00162     if (sigaddset(&set, sig) < 0)
    00163         return -1;
    00164     return sigsuspend(&set);
    00165 }
    00166 #define sigpause(sig) __RPM_sigpause(sig)
    00167 #endif
    00168
    00169 /* portability fallback for insque(3)/remque(3) */
    00170 #if defined(__CYGWIN__) || defined(__MINGW32__) || defined(__QNX__)
    00171 struct qelem {
    00172   struct qelem *q_forw;
    00173   struct qelem *q_back;
    00174 };
    00175
    00176 static void __insque(struct qelem * elem, struct qelem * pred)
    00177 {
    00178   elem -> q_forw = pred -> q_forw;
    00179   pred -> q_forw -> q_back = elem;
    00180   elem -> q_back = pred;
    00181   pred -> q_forw = elem;
    00182 }
    00183 #define insque(_e, _p)  __insque((_e), (_p))
    00184
    00185 static  void __remque(struct qelem * elem)
    00186 {
    00187   elem -> q_forw -> q_back = elem -> q_back;
    00188   elem -> q_back -> q_forw = elem -> q_forw;
    00189 }
    00190 #define remque(_e)      __remque(_e)
    00191 #endif
    00192
    00193 #if defined(WITH_PTHREADS)
    00194
    00195 # if !defined(__QNX__)
    00196 /* XXX suggested in bugzilla #159024 */
    00197 #  if PTHREAD_MUTEX_DEFAULT != PTHREAD_MUTEX_NORMAL
    00198 #    error RPM expects PTHREAD_MUTEX_DEFAULT == PTHREAD_MUTEX_NORMAL
    00199 #  endif
    00200 # endif
    00201
    00202 #ifndef PTHREAD_RECURSIVE_MUTEX_INITIALIZER_NP
    00203 /*@unchecked@*/
    00204 static pthread_mutex_t rpmsigTbl_lock = PTHREAD_MUTEX_INITIALIZER;
    00205 #else
    00206 /*@unchecked@*/
    00207 /*@-type@*/
    00208 static pthread_mutex_t rpmsigTbl_lock = PTHREAD_RECURSIVE_MUTEX_INITIALIZER_NP;
    00209 /*@=type@*/
    00210 #endif
    00211
    00212 /*@-macromatchname@*/
    00213 #define DO_LOCK()       /*@-retvalint@*/pthread_mutex_lock(&rpmsigTbl_lock)/*@=retvalint@*/;
    00214 #define DO_UNLOCK()     pthread_mutex_unlock(&rpmsigTbl_lock);
    00215 #define INIT_LOCK()     \
    00216     {   pthread_mutexattr_t attr; \
    00217         (void) pthread_mutexattr_init(&attr); \
    00218         (void) pthread_mutexattr_settype(&attr, PTHREAD_MUTEX_RECURSIVE); \
    00219         (void) pthread_mutex_init (&rpmsigTbl_lock, &attr); \
    00220         (void) pthread_mutexattr_destroy(&attr); \
    00221         rpmsigTbl_sigchld->active = 0; \
    00222     }
    00223 #define ADD_REF(__tbl)  (__tbl)->active++
    00224 #define SUB_REF(__tbl)  --(__tbl)->active
    00225 #define CLEANUP_HANDLER(__handler, __arg, __oldtypeptr) \
    00226     (void) pthread_setcanceltype (PTHREAD_CANCEL_ASYNCHRONOUS, (__oldtypeptr));\
    00227         pthread_cleanup_push((__handler), (__arg));
    00228 #define CLEANUP_RESET(__execute, __oldtype) \
    00229     pthread_cleanup_pop(__execute); \
    00230     (void) pthread_setcanceltype ((__oldtype), &(__oldtype));
    00231
    00232 #define SAME_THREAD(_a, _b)     pthread_equal(((pthread_t)_a), ((pthread_t)_b))
    00233 /*@-macromatchname@*/
    00234
    00235 #define ME() __tid2vp(pthread_self())
    00236 /*@shared@*/
    00237 static void *__tid2vp(pthread_t tid)
    00238         /*@*/
    00239 {
    00240     union { pthread_t tid; /*@shared@*/ void *vp; } u;
    00241     u.tid = tid;
    00242     return u.vp;
    00243 }
    00244
    00245 #else
    00246
    00247 /*@-macromatchname@*/
    00248 #define DO_LOCK() (0)
    00249 #define DO_UNLOCK() (0)
    00250 #define INIT_LOCK()
    00251 #define ADD_REF(__tbl)  /*@-noeffect@*/ (0) /*@=noeffect@*/
    00252 #define SUB_REF(__tbl)  /*@-noeffect@*/ (0) /*@=noeffect@*/
    00253 #define CLEANUP_HANDLER(__handler, __arg, __oldtypeptr)
    00254 #define CLEANUP_RESET(__execute, __oldtype)
    00255
    00256 #define SAME_THREAD(_a, _b)     (42)
    00257 /*@=macromatchname@*/
    00258
    00259 #define ME() __pid2vp(getpid())
    00260 /*@shared@*/
    00261 static void *__pid2vp(pid_t pid)
    00262         /*@*/
    00263 {
    00264     union { pid_t pid; /*@shared@*/ void *vp; } u;
    00265     u.pid = pid;
    00266     return u.vp;
    00267 }
    00268
    00269 #endif  /* WITH_PTHREADS */
    00270
    00271 #define _RPMSQ_INTERNAL
    00272 #include <rpmsq.h>
    00273
    00274 #include "debug.h"
    00275
    00276 #define _RPMSQ_DEBUG    0
    00277 /*@unchecked@*/
    00278 int _rpmsq_debug = _RPMSQ_DEBUG;
    00279
    00280 /* XXX __OpenBSD__ insque(3) needs rock->q_forw initialized. */
    00281 /*@unchecked@*/
    00282 /*@-fullinitblock @*/
    00283 static struct rpmsqElem rpmsqRock = { .q_forw = &rpmsqRock };
    00284 /*@=fullinitblock @*/
    00285
    00286 /*@-compmempass@*/
    00287 /*@unchecked@*/
    00288 rpmsq rpmsqQueue = &rpmsqRock;
    00289 /*@=compmempass@*/
    00290
    00291 int rpmsqInsert(void * elem, void * prev)
    00292 {
    00293     rpmsq sq = (rpmsq) elem;
    00294     int ret = -1;
    00295
    00296     if (sq != NULL) {
    00297 #ifdef _RPMSQ_DEBUG
    00298 if (_rpmsq_debug)
    00299 fprintf(stderr, "    Insert(%p): %p\n", ME(), sq);
    00300 #endif
    00301         ret = sighold(SIGCHLD);
    00302         if (ret == 0) {
    00303             sq->child = 0;
    00304             sq->reaped = 0;
    00305             sq->status = 0;
    00306            /* ==> Set to 1 to catch SIGCHLD, set to 0 to use waitpid(2).  */
    00307             sq->reaper = 1;
    00308             sq->pipes[0] = sq->pipes[1] = -1;
    00309
    00310             sq->id = ME();
    00311 /*@-noeffect@*/
    00312             insque(elem, (prev != NULL ? prev : rpmsqQueue));
    00313 /*@=noeffect@*/
    00314             ret = sigrelse(SIGCHLD);
    00315         }
    00316     }
    00317     return ret;
    00318 }
    00319
    00320 int rpmsqRemove(void * elem)
    00321 {
    00322     rpmsq sq = (rpmsq) elem;
    00323     int ret = -1;
    00324
    00325     if (elem != NULL) {
    00326
    00327 #ifdef _RPMSQ_DEBUG
    00328 if (_rpmsq_debug)
    00329 fprintf(stderr, "    Remove(%p): %p\n", ME(), sq);
    00330 #endif
    00331         ret = sighold (SIGCHLD);
    00332         if (ret == 0) {
    00333 /*@-noeffect@*/
    00334             remque(elem);
    00335 /*@=noeffect@*/
    00336             sq->id = NULL;
    00337             if (sq->pipes[1] > 0)       ret = close(sq->pipes[1]);
    00338             if (sq->pipes[0] > 0)       ret = close(sq->pipes[0]);
    00339             sq->pipes[0] = sq->pipes[1] = -1;
    00340 #ifdef  NOTYET  /* rpmpsmWait debugging message needs */
    00341             sq->status = 0;
    00342             sq->reaped = 0;
    00343             sq->child = 0;
    00344 #endif
    00345             ret = sigrelse(SIGCHLD);
    00346         }
    00347     }
    00348     return ret;
    00349 }
    00350
    00351 /*@unchecked@*/
    00352 sigset_t rpmsqCaught;
    00353
    00354 /*@unchecked@*/
    00355 /*@-fullinitblock@*/
    00356 static struct rpmsig_s {
    00357     int signum;
    00358     void (*handler) (int signum, void * info, void * context);
    00359     int active;
    00360     struct sigaction oact;
    00361 } rpmsigTbl[] = {
    00362     { SIGINT,   rpmsqAction },
    00363 #define rpmsigTbl_sigint        (&rpmsigTbl[0])
    00364     { SIGQUIT,  rpmsqAction },
    00365 #define rpmsigTbl_sigquit       (&rpmsigTbl[1])
    00366     { SIGCHLD,  rpmsqAction },
    00367 #define rpmsigTbl_sigchld       (&rpmsigTbl[2])
    00368     { SIGHUP,   rpmsqAction },
    00369 #define rpmsigTbl_sighup        (&rpmsigTbl[3])         /* XXX unused */
    00370     { SIGTERM,  rpmsqAction },
    00371 #define rpmsigTbl_sigterm       (&rpmsigTbl[4])         /* XXX unused */
    00372     { SIGPIPE,  rpmsqAction },
    00373 #define rpmsigTbl_sigpipe       (&rpmsigTbl[5])         /* XXX unused */
    00374
    00375 #ifdef  NOTYET          /* XXX todo++ */
    00376 #if defined(SIGXCPU)
    00377     { SIGXCPU,  rpmsqAction },
    00378 #define rpmsigTbl_sigxcpu       (&rpmsigTbl[6])         /* XXX unused */
    00379 #endif
    00380 #if defined(SIGXFSZ)
    00381     { SIGXFSZ,  rpmsqAction },
    00382 #define rpmsigTbl_sigxfsz       (&rpmsigTbl[7])         /* XXX unused */
    00383 #endif
    00384 #endif
    00385
    00386     { -1,       NULL },
    00387 };
    00388 /*@=fullinitblock@*/
    00389
    00390 void rpmsqAction(int signum, /*@unused@*/ void * info,
    00391                 /*@unused@*/ void * context)
    00392 {
    00393     int save = errno;
    00394     rpmsig tbl;
    00395
    00396     for (tbl = rpmsigTbl; tbl->signum >= 0; tbl++) {
    00397         if (tbl->signum != signum)
    00398             continue;
    00399
    00400         (void) sigaddset(&rpmsqCaught, signum);
    00401
    00402         switch (signum) {
    00403         case SIGCHLD:
    00404             while (1) {
    00405                 rpmsq sq;
    00406                 int status = 0;
    00407                 pid_t reaped = waitpid(0, &status, WNOHANG);
    00408
    00409                 /* XXX errno set to ECHILD/EINVAL/EINTR. */
    00410                 if (reaped <= 0)
    00411                     /*@innerbreak@*/ break;
    00412
    00413                 /* XXX insque(3)/remque(3) are dequeue, not ring. */
    00414                 for (sq = rpmsqQueue->q_forw;
    00415                      sq != NULL && sq != rpmsqQueue;
    00416                      sq = sq->q_forw)
    00417                 {
    00418                     int ret;
    00419
    00420                     if (sq->child != reaped)
    00421                         /*@innercontinue@*/ continue;
    00422                     sq->reaped = reaped;
    00423                     sq->status = status;
    00424
    00425                     ret = close(sq->pipes[1]);  sq->pipes[1] = -1;
    00426
    00427                     /*@innerbreak@*/ break;
    00428                 }
    00429             }
    00430             /*@switchbreak@*/ break;
    00431         default:
    00432             /*@switchbreak@*/ break;
    00433         }
    00434         break;
    00435     }
    00436     errno = save;
    00437 }
    00438
    00439 int rpmsqEnable(int signum, /*@null@*/ rpmsqAction_t handler)
    00440         /*@globals rpmsigTbl @*/
    00441         /*@modifies rpmsigTbl @*/
    00442 {
    00443     int tblsignum = (signum >= 0 ? signum : -signum);
    00444     struct sigaction sa;
    00445     rpmsig tbl;
    00446     int ret = -1;
    00447     int xx;
    00448
    00449     xx = DO_LOCK ();
    00450     if (rpmsqQueue->id == NULL)
    00451         rpmsqQueue->id = ME();
    00452     for (tbl = rpmsigTbl; tbl->signum >= 0; tbl++) {
    00453         if (tblsignum != tbl->signum)
    00454             continue;
    00455
    00456         if (signum >= 0) {                      /* Enable. */
    00457             if (ADD_REF(tbl) <= 0) {
    00458                 (void) sigdelset(&rpmsqCaught, tbl->signum);
    00459
    00460                 /* XXX Don't set a signal handler if already SIG_IGN */
    00461                 (void) sigaction(tbl->signum, NULL, &tbl->oact);
    00462                 if (tbl->oact.sa_handler == SIG_IGN)
    00463                     continue;
    00464
    00465                 (void) sigemptyset (&sa.sa_mask);
    00466                 sa.sa_flags = SA_SIGINFO;
    00467 #if defined(__LCLINT__) /* XXX glibc has union to track handler prototype. */
    00468                 sa.sa_handler = (handler != NULL ? handler : tbl->handler);
    00469 #else
    00470                 sa.sa_sigaction = (void *) (handler != NULL ? handler : tbl->handler);
    00471 #endif
    00472                 if (sigaction(tbl->signum, &sa, &tbl->oact) < 0) {
    00473                     xx = SUB_REF(tbl);
    00474                     break;
    00475                 }
    00476                 tbl->active = 1;                /* XXX just in case */
    00477                 if (handler != NULL)
    00478                     tbl->handler = handler;
    00479             }
    00480         } else {                                /* Disable. */
    00481             if (SUB_REF(tbl) <= 0) {
    00482                 if (sigaction(tbl->signum, &tbl->oact, NULL) < 0)
    00483                     break;
    00484                 tbl->active = 0;                /* XXX just in case */
    00485                 tbl->handler = (handler != NULL ? handler : rpmsqAction);
    00486             }
    00487         }
    00488         ret = tbl->active;
    00489         break;
    00490     }
    00491     xx = DO_UNLOCK ();
    00492     return ret;
    00493 }
    00494
    00495 pid_t rpmsqFork(rpmsq sq)
    00496 {
    00497     pid_t pid;
    00498     int xx;
    00499
    00500     if (sq->reaper) {
    00501         xx = rpmsqInsert(sq, NULL);
    00502 #ifdef _RPMSQ_DEBUG
    00503 if (_rpmsq_debug)
    00504 fprintf(stderr, "    Enable(%p): %p\n", ME(), sq);
    00505 #endif
    00506         xx = rpmsqEnable(SIGCHLD, NULL);
    00507     }
    00508
    00509     xx = pipe(sq->pipes);
    00510
    00511     xx = sighold(SIGCHLD);
    00512
    00513     pid = fork();
    00514     if (pid < (pid_t) 0) {              /* fork failed.  */
    00515         sq->child = (pid_t)-1;
    00516         xx = close(sq->pipes[0]);
    00517         xx = close(sq->pipes[1]);
    00518         sq->pipes[0] = sq->pipes[1] = -1;
    00519         goto out;
    00520     } else if (pid == (pid_t) 0) {      /* Child. */
    00521         int yy;
    00522
    00523         /* Block to permit parent time to wait. */
    00524         xx = close(sq->pipes[1]);
    00525         if (sq->reaper)
    00526             xx = (int)read(sq->pipes[0], &yy, sizeof(yy));
    00527         xx = close(sq->pipes[0]);
    00528         sq->pipes[0] = sq->pipes[1] = -1;
    00529
    00530 #ifdef _RPMSQ_DEBUG
    00531 if (_rpmsq_debug)
    00532 fprintf(stderr, "     Child(%p): %p child %d\n", ME(), sq, (int)getpid());
    00533 #endif
    00534
    00535     } else {                            /* Parent. */
    00536
    00537         sq->child = pid;
    00538
    00539 #ifdef _RPMSQ_DEBUG
    00540 if (_rpmsq_debug)
    00541 fprintf(stderr, "    Parent(%p): %p child %d\n", ME(), sq, (int)sq->child);
    00542 #endif
    00543
    00544     }
    00545
    00546 out:
    00547     xx = sigrelse(SIGCHLD);
    00548     return sq->child;
    00549 }
    00550
    00557 static int rpmsqWaitUnregister(rpmsq sq)
    00558         /*@globals fileSystem, internalState @*/
    00559         /*@modifies sq, fileSystem, internalState @*/
    00560 {
    00561     int nothreads = 0;
    00562     int ret = 0;
    00563     int xx;
    00564
    00565 assert(sq->reaper);
    00566     /* Protect sq->reaped from handler changes. */
    00567     ret = sighold(SIGCHLD);
    00568
    00569     /* Start the child, linux often runs child before parent. */
    00570     if (sq->pipes[0] >= 0)
    00571         xx = close(sq->pipes[0]);
    00572     if (sq->pipes[1] >= 0)
    00573         xx = close(sq->pipes[1]);
    00574
    00575     /* Re-initialize the pipe to receive SIGCHLD receipt confirmation. */
    00576     xx = pipe(sq->pipes);
    00577
    00578     /* Put a stopwatch on the time spent waiting to measure performance gain. */
    00579     (void) rpmswEnter(&sq->op, -1);
    00580
    00581     /* Wait for handler to receive SIGCHLD. */
    00582     /*@-infloops@*/
    00583     while (ret == 0 && sq->reaped != sq->child) {
    00584         if (nothreads)
    00585             /* Note that sigpause re-enables SIGCHLD. */
    00586             ret = sigpause(SIGCHLD);
    00587         else {
    00588             xx = sigrelse(SIGCHLD);
    00589
    00590             /* Signal handler does close(sq->pipes[1]) triggering 0b EOF read */
    00591             if (read(sq->pipes[0], &xx, sizeof(xx)) == 0) {
    00592                 xx = close(sq->pipes[0]);       sq->pipes[0] = -1;
    00593                 ret = 1;
    00594             }
    00595
    00596             xx = sighold(SIGCHLD);
    00597         }
    00598     }
    00599     /*@=infloops@*/
    00600
    00601     /* Accumulate stopwatch time spent waiting, potential performance gain. */
    00602     sq->ms_scriptlets += rpmswExit(&sq->op, -1)/1000;
    00603
    00604     xx = sigrelse(SIGCHLD);
    00605
    00606 #ifdef _RPMSQ_DEBUG
    00607 if (_rpmsq_debug)
    00608 fprintf(stderr, "      Wake(%p): %p child %d reaper %d ret %d\n", ME(), sq, (int)sq->child, sq->reaper, ret);
    00609 #endif
    00610
    00611     /* Remove processed SIGCHLD item from queue. */
    00612     xx = rpmsqRemove(sq);
    00613
    00614     /* Disable SIGCHLD handler on refcount == 0. */
    00615     xx = rpmsqEnable(-SIGCHLD, NULL);
    00616 #ifdef _RPMSQ_DEBUG
    00617 if (_rpmsq_debug)
    00618 fprintf(stderr, "   Disable(%p): %p\n", ME(), sq);
    00619 #endif
    00620
    00621     return ret;
    00622 }
    00623
    00624 pid_t rpmsqWait(rpmsq sq)
    00625 {
    00626
    00627 #ifdef _RPMSQ_DEBUG
    00628 if (_rpmsq_debug)
    00629 fprintf(stderr, "      Wait(%p): %p child %d reaper %d\n", ME(), sq, (int)sq->child, sq->reaper);
    00630 #endif
    00631
    00632     if (sq->reaper) {
    00633         (void) rpmsqWaitUnregister(sq);
    00634     } else {
    00635         pid_t reaped;
    00636         int status;
    00637         do {
    00638             reaped = waitpid(sq->child, &status, 0);
    00639         } while (reaped >= 0 && reaped != sq->child);
    00640         sq->reaped = reaped;
    00641         sq->status = status;
    00642 #ifdef _RPMSQ_DEBUG
    00643 if (_rpmsq_debug)
    00644 fprintf(stderr, "   Waitpid(%p): %p child %d reaped %d\n", ME(), sq, (int)sq->child, (int)sq->reaped);
    00645 #endif
    00646     }
    00647
    00648 #ifdef _RPMSQ_DEBUG
    00649 if (_rpmsq_debug)
    00650 fprintf(stderr, "      Fini(%p): %p child %d status 0x%x\n", ME(), sq, (int)sq->child, sq->status);
    00651 #endif
    00652
    00653     return sq->reaped;
    00654 }
    00655
    00656 void * rpmsqThread(void * (*start) (void * arg), void * arg)
    00657 {
    00658 #if defined(WITH_PTHREADS)
    00659     pthread_t pth;
    00660     int ret;
    00661
    00662     ret = pthread_create(&pth, NULL, start, arg);
    00663     return (ret == 0 ? (void *)pth : NULL);
    00664 #else
    00665     (void) start;
    00666     (void) arg;
    00667     return NULL;
    00668 #endif
    00669 }
    00670
    00671 int rpmsqJoin(void * thread)
    00672 {
    00673 #if defined(WITH_PTHREADS)
    00674     pthread_t pth = (pthread_t) thread;
    00675     if (thread == NULL)
    00676         return EINVAL;
    00677     return pthread_join(pth, NULL);
    00678 #else
    00679     (void) thread;
    00680     return EINVAL;
    00681 #endif
    00682 }
    00683
    00684 int rpmsqThreadEqual(void * thread)
    00685 {
    00686 #if defined(WITH_PTHREADS)
    00687     pthread_t t1 = (pthread_t) thread;
    00688     pthread_t t2 = pthread_self();
    00689     return pthread_equal(t1, t2);
    00690 #else
    00691     (void) thread;
    00692     return 0;
    00693 #endif
    00694 }
    00695
    00699 #if defined(WITH_PTHREADS)
    00700 static void
    00701 sigchld_cancel (void *arg)
    00702         /*@globals rpmsigTbl, fileSystem, internalState @*/
    00703         /*@modifies rpmsigTbl, fileSystem, internalState @*/
    00704 {
    00705     pid_t child = *(pid_t *) arg;
    00706     pid_t result;
    00707     int xx;
    00708
    00709     xx = kill(child, SIGKILL);
    00710
    00711     do {
    00712         result = waitpid(child, NULL, 0);
    00713     } while (result == (pid_t)-1 && errno == EINTR);
    00714
    00715     xx = DO_LOCK ();
    00716     if (SUB_REF (rpmsigTbl_sigchld) == 0) {
    00717         xx = rpmsqEnable(-SIGQUIT, NULL);
    00718         xx = rpmsqEnable(-SIGINT, NULL);
    00719     }
    00720     xx = DO_UNLOCK ();
    00721 }
    00722 #endif
    00723
    00727 int
    00728 rpmsqExecve (const char ** argv)
    00729         /*@globals rpmsigTbl @*/
    00730         /*@modifies rpmsigTbl @*/
    00731 {
    00732 #if defined(WITH_PTHREADS)
    00733     int oldtype;
    00734 #endif
    00735     int status = -1;
    00736     pid_t pid = 0;
    00737     pid_t result;
    00738     sigset_t newMask, oldMask;
    00739     rpmsq sq = memset(alloca(sizeof(*sq)), 0, sizeof(*sq));
    00740     int xx;
    00741
    00742 #ifndef PTHREAD_RECURSIVE_MUTEX_INITIALIZER_NP
    00743         INIT_LOCK ();
    00744 #endif
    00745
    00746     xx = DO_LOCK ();
    00747     if (ADD_REF (rpmsigTbl_sigchld) == 0) {
    00748         if (rpmsqEnable(SIGINT, NULL) < 0) {
    00749             xx = SUB_REF (rpmsigTbl_sigchld);
    00750             goto out;
    00751         }
    00752         if (rpmsqEnable(SIGQUIT, NULL) < 0) {
    00753             xx = SUB_REF (rpmsigTbl_sigchld);
    00754             goto out_restore_sigint;
    00755         }
    00756     }
    00757     xx = DO_UNLOCK ();
    00758
    00759     (void) sigemptyset (&newMask);
    00760     (void) sigaddset (&newMask, SIGCHLD);
    00761     if (sigprocmask (SIG_BLOCK, &newMask, &oldMask) < 0) {
    00762         xx = DO_LOCK ();
    00763         if (SUB_REF (rpmsigTbl_sigchld) == 0)
    00764             goto out_restore_sigquit_and_sigint;
    00765         goto out;
    00766     }
    00767
    00768 /*@-sysunrecog@*/
    00769     CLEANUP_HANDLER(sigchld_cancel, &pid, &oldtype);
    00770 /*@=sysunrecog@*/
    00771
    00772     pid = fork ();
    00773     if (pid < (pid_t) 0) {              /* fork failed.  */
    00774         goto out;
    00775     } else if (pid == (pid_t) 0) {      /* Child. */
    00776
    00777         /* Restore the signals.  */
    00778         (void) sigaction (SIGINT, &rpmsigTbl_sigint->oact, NULL);
    00779         (void) sigaction (SIGQUIT, &rpmsigTbl_sigquit->oact, NULL);
    00780         (void) sigprocmask (SIG_SETMASK, &oldMask, NULL);
    00781
    00782         /* Reset rpmsigTbl lock and refcnt. */
    00783         INIT_LOCK ();
    00784
    00785         (void) execve (argv[0], (char *const *) argv, environ);
    00786         _exit (127);
    00787     } else {                            /* Parent. */
    00788         do {
    00789             result = waitpid(pid, &status, 0);
    00790         } while (result == (pid_t)-1 && errno == EINTR);
    00791         if (result != pid)
    00792             status = -1;
    00793     }
    00794
    00795     CLEANUP_RESET(0, oldtype);
    00796
    00797     xx = DO_LOCK ();
    00798     if ((SUB_REF (rpmsigTbl_sigchld) == 0 &&
    00799         (rpmsqEnable(-SIGINT, NULL) < 0 || rpmsqEnable (-SIGQUIT, NULL) < 0))
    00800       || sigprocmask (SIG_SETMASK, &oldMask, NULL) != 0)
    00801     {
    00802         status = -1;
    00803     }
    00804     goto out;
    00805
    00806 out_restore_sigquit_and_sigint:
    00807     xx = rpmsqEnable(-SIGQUIT, NULL);
    00808 out_restore_sigint:
    00809     xx = rpmsqEnable(-SIGINT, NULL);
    00810 out:
    00811     xx = DO_UNLOCK ();
    00812     return status;
    00813 }