| 1 | #define USE_THE_REPOSITORY_VARIABLE |
| 2 | |
| 3 | #include "../../git-compat-util.h" |
| 4 | #include "../../json-writer.h" |
| 5 | #include "../../repository.h" |
| 6 | #include "../../strvec.h" |
| 7 | #include "../../trace2.h" |
| 8 | #include "lazyload.h" |
| 9 | #include <psapi.h> |
| 10 | #include <tlhelp32.h> |
| 11 | |
| 12 | /* |
| 13 | * An arbitrarily chosen value to limit the size of the ancestor |
| 14 | * array built in git_processes(). |
| 15 | */ |
| 16 | #define NR_PIDS_LIMIT 10 |
| 17 | |
| 18 | /* |
| 19 | * Find the process data for the given PID in the given snapshot |
| 20 | * and update the PROCESSENTRY32 data. |
| 21 | */ |
| 22 | static int find_pid(DWORD pid, HANDLE hSnapshot, PROCESSENTRY32 *pe32) |
| 23 | { |
| 24 | pe32->dwSize = sizeof(PROCESSENTRY32); |
| 25 | |
| 26 | if (Process32First(hSnapshot, pe32)) { |
| 27 | do { |
| 28 | if (pe32->th32ProcessID == pid) |
| 29 | return 1; |
| 30 | } while (Process32Next(hSnapshot, pe32)); |
| 31 | } |
| 32 | return 0; |
| 33 | } |
| 34 | |
| 35 | /* |
| 36 | * Accumulate array of our parent process names. |
| 37 | * |
| 38 | * Note: we only report the filename of the process executable; the |
| 39 | * only way to get its full pathname is to use OpenProcess() |
| 40 | * and GetModuleFileNameEx() or QueryfullProcessImageName() |
| 41 | * and that seems rather expensive (on top of the cost of |
| 42 | * getting the snapshot). |
| 43 | * |
| 44 | * Note: we compute the set of parent processes by walking the PPID |
| 45 | * link in each visited PROCESSENTRY32 record. This search |
| 46 | * stops when an ancestor process is not found in the snapshot |
| 47 | * (because it exited before the current or intermediate parent |
| 48 | * process exited). |
| 49 | * |
| 50 | * This search may compute an incorrect result if the PPID link |
| 51 | * refers to the PID of an exited parent and that PID has been |
| 52 | * recycled and given to a new unrelated process. |
| 53 | * |
| 54 | * Worse, it is possible for a child or descendant of the |
| 55 | * current process to be given the recycled PID and cause a |
| 56 | * PPID-cycle. This would cause an infinite loop building our |
| 57 | * parent process array. |
| 58 | * |
| 59 | * Note: for completeness, the "System Idle" process has PID=0 and |
| 60 | * PPID=0 and could cause another PPID-cycle. We don't expect |
| 61 | * Git to be a descendant of the idle process, but because of |
| 62 | * PID recycling, it might be possible to get a PPID link value |
| 63 | * of 0. This too would cause an infinite loop. |
| 64 | * |
| 65 | * Therefore, we keep an array of the visited PPIDs to guard against |
| 66 | * cycles. |
| 67 | * |
| 68 | * We use a fixed-size array rather than ALLOC_GROW to keep things |
| 69 | * simple and avoid the alloc/realloc overhead. It is OK if we |
| 70 | * truncate the search and return a partial answer. |
| 71 | */ |
| 72 | static void get_processes(struct strvec *names, HANDLE hSnapshot) |
| 73 | { |
| 74 | PROCESSENTRY32 pe32; |
| 75 | DWORD pid; |
| 76 | DWORD pid_list[NR_PIDS_LIMIT]; |
| 77 | int k, nr_pids = 0; |
| 78 | |
| 79 | pid = GetCurrentProcessId(); |
| 80 | while (find_pid(pid, hSnapshot, &pe32)) { |
| 81 | /* Only report parents. Omit self from the output. */ |
| 82 | if (nr_pids) |
| 83 | strvec_push(names, pe32.szExeFile); |
| 84 | |
| 85 | /* Check for cycle in snapshot. (Yes, it happened.) */ |
| 86 | for (k = 0; k < nr_pids; k++) |
| 87 | if (pid == pid_list[k]) { |
| 88 | strvec_push(names, "(cycle)"); |
| 89 | return; |
| 90 | } |
| 91 | |
| 92 | if (nr_pids == NR_PIDS_LIMIT) { |
| 93 | strvec_push(names, "(truncated)"); |
| 94 | return; |
| 95 | } |
| 96 | |
| 97 | pid_list[nr_pids++] = pid; |
| 98 | |
| 99 | pid = pe32.th32ParentProcessID; |
| 100 | } |
| 101 | } |
| 102 | |
| 103 | /* |
| 104 | * Collect the list of parent process names. |
| 105 | */ |
| 106 | static void get_ancestry(struct strvec *names) |
| 107 | { |
| 108 | HANDLE hSnapshot = CreateToolhelp32Snapshot(TH32CS_SNAPPROCESS, 0); |
| 109 | |
| 110 | if (hSnapshot != INVALID_HANDLE_VALUE) { |
| 111 | get_processes(names, hSnapshot); |
| 112 | CloseHandle(hSnapshot); |
| 113 | } |
| 114 | } |
| 115 | |
| 116 | /* |
| 117 | * Is a debugger attached to the current process? |
| 118 | * |
| 119 | * This will catch debug runs (where the debugger started the process). |
| 120 | * This is the normal case. Since this code is called during our startup, |
| 121 | * it will not report instances where a debugger is attached dynamically |
| 122 | * to a running git process, but that is relatively rare. |
| 123 | */ |
| 124 | static void get_is_being_debugged(void) |
| 125 | { |
| 126 | if (IsDebuggerPresent()) |
| 127 | trace2_data_intmax("process", the_repository, |
| 128 | "windows/debugger_present", 1); |
| 129 | } |
| 130 | |
| 131 | /* |
| 132 | * Emit JSON data with the peak memory usage of the current process. |
| 133 | */ |
| 134 | static void get_peak_memory_info(void) |
| 135 | { |
| 136 | DECLARE_PROC_ADDR(psapi.dll, BOOL, WINAPI, GetProcessMemoryInfo, |
| 137 | HANDLE, PPROCESS_MEMORY_COUNTERS, DWORD); |
| 138 | |
| 139 | if (INIT_PROC_ADDR(GetProcessMemoryInfo)) { |
| 140 | PROCESS_MEMORY_COUNTERS pmc; |
| 141 | |
| 142 | if (GetProcessMemoryInfo(GetCurrentProcess(), &pmc, |
| 143 | sizeof(pmc))) { |
| 144 | struct json_writer jw = JSON_WRITER_INIT; |
| 145 | |
| 146 | jw_object_begin(&jw, 0); |
| 147 | |
| 148 | #define KV(kv) #kv, (intmax_t)pmc.kv |
| 149 | |
| 150 | jw_object_intmax(&jw, KV(PageFaultCount)); |
| 151 | jw_object_intmax(&jw, KV(PeakWorkingSetSize)); |
| 152 | jw_object_intmax(&jw, KV(PeakPagefileUsage)); |
| 153 | |
| 154 | jw_end(&jw); |
| 155 | |
| 156 | trace2_data_json("process", the_repository, |
| 157 | "windows/memory", &jw); |
| 158 | jw_release(&jw); |
| 159 | } |
| 160 | } |
| 161 | } |
| 162 | |
| 163 | void trace2_collect_process_info(enum trace2_process_info_reason reason) |
| 164 | { |
| 165 | struct strvec names = STRVEC_INIT; |
| 166 | |
| 167 | if (!trace2_is_enabled()) |
| 168 | return; |
| 169 | |
| 170 | switch (reason) { |
| 171 | case TRACE2_PROCESS_INFO_STARTUP: |
| 172 | get_is_being_debugged(); |
| 173 | get_ancestry(&names); |
| 174 | if (names.nr) { |
| 175 | /* |
| 176 | Emit the ancestry data as a data_json event to |
| 177 | maintain compatibility for consumers of the older |
| 178 | "windows/ancestry" event. |
| 179 | */ |
| 180 | struct json_writer jw = JSON_WRITER_INIT; |
| 181 | jw_array_begin(&jw, 0); |
| 182 | for (size_t i = 0; i < names.nr; i++) |
| 183 | jw_array_string(&jw, names.v[i]); |
| 184 | jw_end(&jw); |
| 185 | trace2_data_json("process", the_repository, |
| 186 | "windows/ancestry", &jw); |
| 187 | jw_release(&jw); |
| 188 | |
| 189 | /* Emit the ancestry data with the new event. */ |
| 190 | trace2_cmd_ancestry(names.v); |
| 191 | } |
| 192 | |
| 193 | strvec_clear(&names); |
| 194 | return; |
| 195 | |
| 196 | case TRACE2_PROCESS_INFO_EXIT: |
| 197 | get_peak_memory_info(); |
| 198 | return; |
| 199 | |
| 200 | default: |
| 201 | BUG("trace2_collect_process_info: unknown reason '%d'", reason); |
| 202 | } |
| 203 | } |