sewardj | b411202 | 2007-11-09 22:49:28 +0000 | [diff] [blame^] | 1 | |
| 2 | #include <pthread.h> |
| 3 | #include <stdio.h> |
| 4 | #include <stdlib.h> |
| 5 | #include <assert.h> |
| 6 | |
| 7 | /* Simple test program, no race. Parent and child both modify x and |
| 8 | use the hardware bus lock (implicitly, since XCHG r,m on x86/amd64 |
| 9 | does not require an explicit LOCK prefix.). */ |
| 10 | |
| 11 | #undef PLAT_x86_linux |
| 12 | #undef PLAT_amd64_linux |
| 13 | #undef PLAT_ppc32_linux |
| 14 | #undef PLAT_ppc64_linux |
| 15 | #undef PLAT_ppc32_aix5 |
| 16 | #undef PLAT_ppc64_aix5 |
| 17 | |
| 18 | #if !defined(_AIX) && defined(__i386__) |
| 19 | # define PLAT_x86_linux 1 |
| 20 | #elif !defined(_AIX) && defined(__x86_64__) |
| 21 | # define PLAT_amd64_linux 1 |
| 22 | #elif !defined(_AIX) && defined(__powerpc__) && !defined(__powerpc64__) |
| 23 | # define PLAT_ppc32_linux 1 |
| 24 | #elif !defined(_AIX) && defined(__powerpc__) && defined(__powerpc64__) |
| 25 | # define PLAT_ppc64_linux 1 |
| 26 | #elif defined(_AIX) && defined(__64BIT__) |
| 27 | # define PLAT_ppc64_aix5 1 |
| 28 | #elif defined(_AIX) && !defined(__64BIT__) |
| 29 | # define PLAT_ppc32_aix5 1 |
| 30 | #endif |
| 31 | |
| 32 | |
| 33 | #if defined(PLAT_amd64_linux) || defined(PLAT_x86_linux) |
| 34 | # define XCHG_M_R(_addr,_lval) \ |
| 35 | __asm__ __volatile__( \ |
| 36 | "xchgl %0, %1" \ |
| 37 | : /*out*/ "+r"(_lval) \ |
| 38 | : /*in*/ "m"(_addr) \ |
| 39 | : "memory", "cc" \ |
| 40 | ) |
| 41 | # define XCHG_M_R_with_redundant_LOCK(_addr,_lval) \ |
| 42 | __asm__ __volatile__( \ |
| 43 | "lock xchgl %0, %1" \ |
| 44 | : /*out*/ "+r"(_lval) \ |
| 45 | : /*in*/ "m"(_addr) \ |
| 46 | : "memory", "cc" \ |
| 47 | ) |
| 48 | #else |
| 49 | # define XCHG_M_R(_addr,_lval) \ |
| 50 | do { int tmp = *(int*)(& _addr); \ |
| 51 | *(int*)(& _addr) = (_lval); \ |
| 52 | _lval = tmp; \ |
| 53 | } while (0) |
| 54 | # define XCHG_M_R_with_redundant_LOCK(_addr,_lval) \ |
| 55 | XCHG_M_R(_addr,_lval) |
| 56 | #endif |
| 57 | |
| 58 | int x = 0; |
| 59 | |
| 60 | void* child_fn ( void* arg ) |
| 61 | { |
| 62 | int v = 12345; |
| 63 | XCHG_M_R_with_redundant_LOCK(x, v); |
| 64 | assert(v == 0 || v == 6789); |
| 65 | return NULL; |
| 66 | } |
| 67 | |
| 68 | int main ( void ) |
| 69 | { |
| 70 | int v = 6789; |
| 71 | pthread_t child; |
| 72 | |
| 73 | if (pthread_create(&child, NULL, child_fn, NULL)) { |
| 74 | perror("pthread_create"); |
| 75 | exit(1); |
| 76 | } |
| 77 | |
| 78 | XCHG_M_R(x, v); |
| 79 | assert(v == 0 || v == 12345); |
| 80 | |
| 81 | if (pthread_join(child, NULL)) { |
| 82 | perror("pthread join"); |
| 83 | exit(1); |
| 84 | } |
| 85 | |
| 86 | if (v == 0 || v == 12345) |
| 87 | printf("success\n"); |
| 88 | else |
| 89 | printf("failure\n"); |
| 90 | |
| 91 | return v; |
| 92 | } |