| 1 | // C includes |
| 2 | #include <stdio.h> |
| 3 | #include <stdint.h> |
| 4 | #include <stdlib.h> |
| 5 | |
| 6 | // C++ includes |
| 7 | #include <chrono> |
| 8 | #include <mutex> |
| 9 | #include <random> |
| 10 | #include <thread> |
| 11 | |
| 12 | std::thread g_thread_1; |
| 13 | std::thread g_thread_2; |
| 14 | std::thread g_thread_3; |
| 15 | std::mutex g_mask_mutex; |
| 16 | |
| 17 | enum MaskAction { |
| 18 | eGet, |
| 19 | eAssign, |
| 20 | eClearBits |
| 21 | }; |
| 22 | |
| 23 | uint32_t mask_access (MaskAction action, uint32_t mask = 0); |
| 24 | |
| 25 | uint32_t |
| 26 | mask_access (MaskAction action, uint32_t mask) |
| 27 | { |
| 28 | static uint32_t g_mask = 0; |
| 29 | |
| 30 | std::lock_guard<std::mutex> lock(g_mask_mutex); |
| 31 | switch (action) |
| 32 | { |
| 33 | case eGet: |
| 34 | break; |
| 35 | |
| 36 | case eAssign: |
| 37 | g_mask |= mask; |
| 38 | break; |
| 39 | |
| 40 | case eClearBits: |
| 41 | g_mask &= ~mask; |
| 42 | break; |
| 43 | } |
| 44 | return g_mask; |
| 45 | } |
| 46 | |
| 47 | void * |
| 48 | thread_func (void *arg) |
| 49 | { |
| 50 | uint32_t thread_index = *((uint32_t *)arg); |
| 51 | uint32_t thread_mask = (1u << (thread_index)); |
| 52 | printf (format: "%s (thread index = %u) startng...\n" , __FUNCTION__, thread_index); |
| 53 | |
| 54 | std::default_random_engine generator; |
| 55 | std::uniform_int_distribution<int> distribution(0, 3000000); |
| 56 | |
| 57 | while (mask_access(action: eGet) & thread_mask) |
| 58 | { |
| 59 | // random micro second sleep from zero to 3 seconds |
| 60 | int usec = distribution(generator); |
| 61 | printf (format: "%s (thread = %u) doing a usleep (%d)...\n" , __FUNCTION__, thread_index, usec); |
| 62 | |
| 63 | std::chrono::microseconds duration(usec); |
| 64 | std::this_thread::sleep_for(rtime: duration); |
| 65 | printf (format: "%s (thread = %u) after usleep ...\n" , __FUNCTION__, thread_index); // Set break point at this line. |
| 66 | } |
| 67 | printf (format: "%s (thread index = %u) exiting...\n" , __FUNCTION__, thread_index); |
| 68 | return NULL; |
| 69 | } |
| 70 | |
| 71 | |
| 72 | int main (int argc, char const *argv[]) |
| 73 | { |
| 74 | uint32_t thread_index_1 = 1; |
| 75 | uint32_t thread_index_2 = 2; |
| 76 | uint32_t thread_index_3 = 3; |
| 77 | uint32_t thread_mask_1 = (1u << thread_index_1); |
| 78 | uint32_t thread_mask_2 = (1u << thread_index_2); |
| 79 | uint32_t thread_mask_3 = (1u << thread_index_3); |
| 80 | |
| 81 | // Make a mask that will keep all threads alive |
| 82 | mask_access (action: eAssign, mask: thread_mask_1 | thread_mask_2 | thread_mask_3); // And that line. |
| 83 | |
| 84 | // Create 3 threads |
| 85 | g_thread_1 = std::thread(thread_func, (void*)&thread_index_1); |
| 86 | g_thread_2 = std::thread(thread_func, (void*)&thread_index_2); |
| 87 | g_thread_3 = std::thread(thread_func, (void*)&thread_index_3); |
| 88 | |
| 89 | char line[64]; |
| 90 | while (mask_access(action: eGet) != 0) |
| 91 | { |
| 92 | printf (format: "Enter thread index to kill or ENTER for all:\n" ); |
| 93 | fflush (stdout); |
| 94 | // Kill threads by index, or ENTER for all threads |
| 95 | |
| 96 | if (fgets (s: line, n: sizeof(line), stdin)) |
| 97 | { |
| 98 | if (line[0] == '\n' || line[0] == '\r' || line[0] == '\0') |
| 99 | { |
| 100 | printf (format: "Exiting all threads...\n" ); |
| 101 | break; |
| 102 | } |
| 103 | int32_t index = strtoul (nptr: line, NULL, base: 0); |
| 104 | switch (index) |
| 105 | { |
| 106 | case 1: mask_access (action: eClearBits, mask: thread_mask_1); break; |
| 107 | case 2: mask_access (action: eClearBits, mask: thread_mask_2); break; |
| 108 | case 3: mask_access (action: eClearBits, mask: thread_mask_3); break; |
| 109 | } |
| 110 | continue; |
| 111 | } |
| 112 | |
| 113 | break; |
| 114 | } |
| 115 | |
| 116 | // Clear all thread bits to they all exit |
| 117 | mask_access (action: eClearBits, UINT32_MAX); |
| 118 | |
| 119 | // Join all of our threads |
| 120 | g_thread_1.join(); |
| 121 | g_thread_2.join(); |
| 122 | g_thread_3.join(); |
| 123 | |
| 124 | return 0; |
| 125 | } |
| 126 | |