1 #include "stlport_prefix.h"
2 
3 #if defined(__unix) && defined(__GNUC__)
4 
5 #ifdef __FreeBSD__
6 #  include <osreldate.h>
7 #endif
8 
9 #if (defined(__FreeBSD__) && (__FreeBSD_version < 503001)) || defined(__sun) || defined (__hpux)
10 /* Note: __cxa_finalize and __cxa_atexit present in libc in FreeBSD 5.3 */
11 
12 #include <stdlib.h>
13 #include <stdio.h>
14 #include <pthread.h>
15 
16 /* __asm__ (".symver " "__cxa_finalize" "," "__cxa_finalize" "@" "STLPORT_5_0_0"); */
17 /* __asm__ (".symver " "__cxa_finalize" "," "__cxa_finalize" "@@" "STLPORT_5_0_0"); */
18 
19 /* Not atomic! */
20 /* But we can use static mutexes here: I hope that performance issue isn't very
21    significant on unloading (for only few calls, ~10) - ptr */
22 
23 /*
24 #define atomic_compare_and_exchange_bool_acq(mem, newval, oldval) \
25   ({ __typeof (mem) __gmemp = (mem);                                  \
26      __typeof (*mem) __gnewval = (newval);                            \
27                                                                       \
28      *__gmemp == (oldval) ? (*__gmemp = __gnewval, 0) : 1; })
29 */
30 
31 enum {
32   ef_free, /* `ef_free' MUST be zero!  */
33   ef_us,
34   ef_on,
35   ef_at,
36   ef_cxa
37 };
38 
39 struct exit_function
40 {
41   /* `flavour' should be of type of the `enum' above but since we need
42      this element in an atomic operation we have to use `long int'.  */
43   long int flavor;
44   union {
45     void (*at)(void);
46     struct {
47       void (*fn)(int status, void *arg);
48       void *arg;
49     } on;
50     struct {
51       void (*fn)(void *arg, int status);
52       void *arg;
53       void *dso_handle;
54     } cxa;
55   } func;
56 };
57 
58 struct exit_function_list
59 {
60   struct exit_function_list *next;
61   size_t idx;
62   struct exit_function fns[32];
63 };
64 
65 struct exit_function *__new_exitfn (void);
66 
67 /* Register a function to be called by exit or when a shared library
68    is unloaded.  This function is only called from code generated by
69    the C++ compiler.  */
__cxa_atexit(void (* func)(void *),void * arg,void * d)70 int __cxa_atexit(void (*func)(void *), void *arg, void *d)
71 {
72   struct exit_function *new = __new_exitfn ();
73 
74   if ( new == NULL )
75     return -1;
76 
77   new->flavor = ef_cxa;
78   new->func.cxa.fn = (void (*) (void *, int)) func;
79   new->func.cxa.arg = arg;
80   new->func.cxa.dso_handle = d;
81   return 0;
82 }
83 
84 
85 /* We change global data, so we need locking.  */
86 #ifdef __linux__
87 static pthread_mutex_t lock = PTHREAD_RECURSIVE_MUTEX_INITIALIZER_NP;
88 #endif
89 /* #ifdef __FreeBSD__ */
90 #if 0
91 static pthread_mutex_t lock =
92   { PTHREAD_MUTEX_RECURSIVE /* PTHREAD_MUTEX_DEFAULT */, PTHREAD_PRIO_NONE, {NULL,NULL},
93     NULL, { NULL }, /* MUTEX_FLAGS_PRIVATE */ 0x1, 0, 0, 0, {NULL, NULL},
94     { 0, 0, 0, 0 } };
95 #endif
96 #ifdef __sun
97 static pthread_mutex_t lock =
98   {{0, 0, 0, PTHREAD_MUTEX_RECURSIVE, _MUTEX_MAGIC}, {{{0}}}, 0};
99 #endif
100 #ifdef __hpux
101 static pthread_mutex_t lock = PTHREAD_MUTEX_RECURSIVE_INITIALIZER_NP;
102 #  ifdef __ia64
103 void *__dso_handle = (void *) &__dso_handle;
104 #  endif
105 #endif
106 
107 
108 static struct exit_function_list initial;
109 struct exit_function_list *__exit_funcs = &initial;
110 
__new_exitfn(void)111 struct exit_function *__new_exitfn(void)
112 {
113   struct exit_function_list *l;
114   size_t i = 0;
115 
116 #ifndef __FreeBSD__
117   pthread_mutex_lock( &lock );
118 #endif
119 
120   for (l = __exit_funcs; l != NULL; l = l->next) {
121     for (i = 0; i < l->idx; ++i)
122       if (l->fns[i].flavor == ef_free)
123         break;
124     if ( i < l->idx )
125       break;
126 
127     if (l->idx < sizeof (l->fns) / sizeof (l->fns[0])) {
128       i = l->idx++;
129       break;
130     }
131   }
132 
133   if (l == NULL) {
134     l = (struct exit_function_list *)malloc( sizeof(struct exit_function_list) );
135     if (l != NULL) {
136       l->next = __exit_funcs;
137       __exit_funcs = l;
138 
139       l->idx = 1;
140       i = 0;
141     }
142   }
143 
144   /* Mark entry as used, but we don't know the flavor now.  */
145   if ( l != NULL )
146     l->fns[i].flavor = ef_us;
147 
148 #ifndef __FreeBSD__
149   pthread_mutex_unlock( &lock );
150 #endif
151 
152   return l == NULL ? NULL : &l->fns[i];
153 }
154 
155 /* If D is non-NULL, call all functions registered with `__cxa_atexit'
156    with the same dso handle.  Otherwise, if D is NULL, call all of the
157    registered handlers.  */
158 
159 /*
160  * Note, that original __cxa_finalize don't use lock, but use __exit_funcs
161  * i.e. global data.
162  */
__cxa_finalize(void * d)163 void __cxa_finalize(void *d)
164 {
165   struct exit_function_list *funcs;
166 
167 #ifndef __FreeBSD__
168   pthread_mutex_lock( &lock );
169 #endif
170 
171   for (funcs = __exit_funcs; funcs; funcs = funcs->next) {
172     struct exit_function *f;
173 
174     for (f = &funcs->fns[funcs->idx - 1]; f >= &funcs->fns[0]; --f) {
175       if ( (d == NULL || d == f->func.cxa.dso_handle) && (f->flavor == ef_cxa) ) {
176         f->flavor = ef_free;
177         (*f->func.cxa.fn) (f->func.cxa.arg, 0);
178       }
179     }
180   }
181 
182   /* Remove the registered fork handlers.  We do not have to
183      unregister anything if the program is going to terminate anyway.  */
184 #ifdef UNREGISTER_ATFORK
185   if (d != NULL)
186     UNREGISTER_ATFORK (d);
187 #endif
188 #ifndef __FreeBSD__
189   pthread_mutex_unlock( &lock );
190 #endif
191 }
192 
193 /* __asm__ (".symver " "__cxa_finalize" "," "__cxa_finalize" "@@" "STLPORT_5_0_0"); */
194 /* void __cxa_finalize(void *d) __attribute__ ((weak)); */
195 
196 #endif /* OS name */
197 #endif /* __unix */
198 
199