1
2#include <pthread.h>
3#include <stdio.h>
4#include <stdlib.h>
5
6/* Simple test program, no race.  Parent and child both modify x and
7   use the hardware bus lock. */
8
9#undef PLAT_x86_darwin
10#undef PLAT_amd64_darwin
11#undef PLAT_x86_linux
12#undef PLAT_amd64_linux
13#undef PLAT_ppc32_linux
14#undef PLAT_ppc64_linux
15#undef PLAT_arm_linux
16#undef PLAT_s390x_linux
17
18#if defined(__APPLE__) && defined(__i386__)
19#  define PLAT_x86_darwin 1
20#elif defined(__APPLE__) && defined(__x86_64__)
21#  define PLAT_amd64_darwin 1
22#elif defined(__linux__) && defined(__i386__)
23#  define PLAT_x86_linux 1
24#elif defined(__linux__) && defined(__x86_64__)
25#  define PLAT_amd64_linux 1
26#elif defined(__linux__) && defined(__powerpc__) && !defined(__powerpc64__)
27#  define PLAT_ppc32_linux 1
28#elif defined(__linux__) && defined(__powerpc__) && defined(__powerpc64__)
29#  define PLAT_ppc64_linux 1
30#elif defined(__linux__) && defined(__arm__)
31#  define PLAT_arm_linux 1
32#elif defined(__linux__) && defined(__s390x__)
33#  define PLAT_s390x_linux 1
34#endif
35
36#if defined(PLAT_amd64_linux) || defined(PLAT_x86_linux) \
37    || defined(PLAT_amd64_darwin) || defined(PLAT_x86_darwin)
38#  define INC(_lval,_lqual) \
39      __asm__ __volatile__ ( \
40      "lock ; incl (%0)" : /*out*/ : /*in*/"r"(&(_lval)) : "memory", "cc" )
41#elif defined(PLAT_ppc32_linux) || defined(PLAT_ppc64_linux)
42#  define INC(_lval,_lqual)               \
43   __asm__ __volatile__(                  \
44      "1:\n"                              \
45      "        lwarx 15,0,%0\n"           \
46      "        addi 15,15,1\n"            \
47      "        stwcx. 15,0,%0\n"          \
48      "        bne- 1b\n"                 \
49      : /*out*/ : /*in*/ "b"(&(_lval))    \
50      : /*trash*/ "r15", "cr0", "memory"  \
51   )
52#elif defined(PLAT_arm_linux)
53#  define INC(_lval,_lqual) \
54  __asm__ __volatile__( \
55      "1:\n"                                 \
56      "        ldrex r8, [%0, #0]\n"         \
57      "        add   r8, r8, #1\n"           \
58      "        strex r9, r8, [%0, #0]\n"     \
59      "        cmp   r9, #0\n"               \
60      "        bne   1b\n"                   \
61      : /*out*/ : /*in*/ "r"(&(_lval))       \
62      : /*trash*/ "r8", "r9", "cc", "memory" \
63  );
64#elif defined(PLAT_s390x_linux)
65#  define INC(_lval,_lqual) \
66   __asm__ __volatile__( \
67      "1: l     0,%0\n"                            \
68      "   lr    1,0\n"                             \
69      "   ahi   1,1\n"                             \
70      "   cs    0,1,%0\n"                          \
71      "   jl    1b\n"                              \
72      : "+m" (_lval) :: "cc", "1","2" \
73   )
74#else
75#  error "Fix Me for this platform"
76#endif
77
78
79int x = 0;
80
81void* child_fn ( void* arg )
82{
83   INC(x, "childfn");
84   return NULL;
85}
86
87int main ( void )
88{
89   pthread_t child;
90
91   if (pthread_create(&child, NULL, child_fn, NULL)) {
92      perror("pthread_create");
93      exit(1);
94   }
95
96   INC(x, "main");
97
98   if (pthread_join(child, NULL)) {
99      perror("pthread join");
100      exit(1);
101   }
102
103   printf("x = %d\n", x);
104   return 0;
105}
106