1 /* { dg-do run } */
2 /* { dg-require-effective-target split_stack } */
3 /* { dg-require-effective-target pthread_h } */
4 /* { dg-require-effective-target ucontext_h } */
5 /* { dg-options "-pthread -fsplit-stack" } */
6
7 #include <stdlib.h>
8 #include <pthread.h>
9 #include <ucontext.h>
10
11 extern void __splitstack_getcontext (void *context[10]);
12
13 extern void __splitstack_setcontext (void *context[10]);
14
15 extern void *__splitstack_makecontext (size_t, void *context[10], size_t *);
16
17 extern void __splitstack_block_signals (int *, int *);
18
19 extern void __splitstack_block_signals_context (void *context[10], int *,
20 int *);
21
22 extern void *__splitstack_find (void *, void *, size_t *, void **, void **,
23 void **);
24
25 extern void *__splitstack_find_context (void *context[10], size_t *, void **,
26 void **, void **);
27
28 static ucontext_t c1;
29 static void *s1[10];
30
31 static ucontext_t c2;
32 static void *s2[10];
33
34 static void swap (ucontext_t *, void *fs[10], ucontext_t *, void *ts[10])
35 __attribute__ ((no_split_stack));
36
37 static void
swap(ucontext_t * fu,void * fs[10],ucontext_t * tu,void * ts[10])38 swap (ucontext_t *fu, void *fs[10], ucontext_t *tu, void *ts[10])
39 {
40 __splitstack_getcontext (fs);
41 __splitstack_setcontext (ts);
42 swapcontext (fu, tu);
43 __splitstack_setcontext (fs);
44 }
45
46 /* Use a noinline function to ensure that the buffer is not removed
47 from the stack. */
48 static void use_buffer (char *buf) __attribute__ ((noinline));
49 static void
use_buffer(char * buf)50 use_buffer (char *buf)
51 {
52 buf[0] = '\0';
53 }
54
55 static void
down(int i,const char * msg,ucontext_t * me,void * mes[10],ucontext_t * other,void * others[10])56 down (int i, const char *msg, ucontext_t *me, void *mes[10],
57 ucontext_t *other, void *others[10])
58 {
59 char buf[10000];
60
61 if (i > 0)
62 {
63 use_buffer (buf);
64 swap (me, mes, other, others);
65 down (i - 1, msg, me, mes, other, others);
66 }
67 else
68 {
69 int c = 0;
70 void *stack;
71 size_t stack_size;
72 void *next_segment = NULL;
73 void *next_sp = NULL;
74 void *initial_sp = NULL;
75
76 stack = __splitstack_find_context (mes, &stack_size, &next_segment,
77 &next_sp, &initial_sp);
78 if (stack != NULL)
79 {
80 ++c;
81 while (__splitstack_find (next_segment, next_sp, &stack_size,
82 &next_segment, &next_sp, &initial_sp)
83 != NULL)
84 ++c;
85 }
86 }
87 }
88
89 static void
go1(void)90 go1 (void)
91 {
92 down (1000, "go1", &c1, s1, &c2, s2);
93 pthread_exit (NULL);
94 }
95
96 static void
go2(void)97 go2 (void)
98 {
99 down (1000, "go2", &c2, s2, &c1, s1);
100 pthread_exit (NULL);
101 }
102
103 struct thread_context
104 {
105 ucontext_t *u;
106 void **s;
107 };
108
109 static void *start_thread (void *) __attribute__ ((no_split_stack));
110
111 static void *
start_thread(void * context)112 start_thread (void *context)
113 {
114 struct thread_context *tc = (struct thread_context *) context;
115 int block;
116
117 block = 0;
118 __splitstack_block_signals (&block, NULL);
119 __splitstack_setcontext (tc->s);
120 setcontext (tc->u);
121 abort ();
122 }
123
124 int
main(int argc,char ** argv)125 main (int argc __attribute__ ((unused)), char **argv __attribute__ ((unused)))
126 {
127 pthread_t tid;
128 int err;
129 size_t size;
130 struct thread_context tc;
131 int block;
132
133 if (getcontext (&c1) < 0)
134 abort ();
135
136 c2 = c1;
137
138 c1.uc_stack.ss_sp = __splitstack_makecontext (8192, &s1[0], &size);
139 if (c1.uc_stack.ss_sp == NULL)
140 abort ();
141 c1.uc_stack.ss_flags = 0;
142 c1.uc_stack.ss_size = size;
143 c1.uc_link = NULL;
144 block = 0;
145 __splitstack_block_signals_context (&s1[0], &block, NULL);
146 makecontext (&c1, go1, 0);
147
148 c2.uc_stack.ss_sp = __splitstack_makecontext (8192, &s2[0], &size);
149 if (c2.uc_stack.ss_sp == NULL)
150 abort ();
151 c2.uc_stack.ss_flags = 0;
152 c2.uc_stack.ss_size = size;
153 c2.uc_link = NULL;
154 __splitstack_block_signals_context (&s2[0], &block, NULL);
155 makecontext (&c2, go2, 0);
156
157 block = 0;
158 __splitstack_block_signals (&block, NULL);
159
160 tc.u = &c1;
161 tc.s = &s1[0];
162 err = pthread_create (&tid, NULL, start_thread, &tc);
163 if (err != 0)
164 abort ();
165
166 err = pthread_join (tid, NULL);
167 if (err != 0)
168 abort ();
169
170 return 0;
171 }
172