trace2: refactor Windows process ancestry trace2 event
In 353d3d77f4 (trace2: collect Windows-specific process information, 2019-02-22) we added process ancestry information for Windows to TRACE2 via a data_json event. It was only later in 2f732bf15e (tr2: log parent process name, 2021-07-21) that the specific cmd_ancestry event was added to TRACE2. In a future commit we will emit the ancestry information with the newer cmd_ancestry TRACE2 event. Right now, we rework this implementation of trace2_collect_process_info to separate the calculation of ancestors from building and emiting the JSON array via a data_json event. Signed-off-by: Matthew John Cheetham <mjcheetham@outlook.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
Matthew John Cheetham committed
Feb 13, 2026 at 19:54 UTC
c2a473b2b1b3b79e308a7cbed1eee46fb67aacd8
1 file changed
+25
-25
compat/win32/trace2_win32_process_info.c
+25
-25
@@ -3,6 +3,7 @@
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#include "../../git-compat-util.h"
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#include "../../json-writer.h"
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#include "../../repository.h"
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+#include "../../strvec.h"
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#include "../../trace2.h"
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#include "lazyload.h"
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#include <psapi.h>
@@ -32,12 +33,7 @@ static int find_pid(DWORD pid, HANDLE hSnapshot, PROCESSENTRY32 *pe32)
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}
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/*
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- * Accumulate JSON array of our parent processes:
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- * [
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- * exe-name-parent,
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- * exe-name-grand-parent,
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- * ...
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- * ]
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+ * Accumulate array of our parent process names.
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*
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* Note: we only report the filename of the process executable; the
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* only way to get its full pathname is to use OpenProcess()
@@ -73,7 +69,7 @@ static int find_pid(DWORD pid, HANDLE hSnapshot, PROCESSENTRY32 *pe32)
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* simple and avoid the alloc/realloc overhead. It is OK if we
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* truncate the search and return a partial answer.
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*/
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-static void get_processes(struct json_writer *jw, HANDLE hSnapshot)
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+static void get_processes(struct strvec *names, HANDLE hSnapshot)
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{
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PROCESSENTRY32 pe32;
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DWORD pid;
@@ -82,19 +78,19 @@ static void get_processes(struct json_writer *jw, HANDLE hSnapshot)
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pid = GetCurrentProcessId();
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while (find_pid(pid, hSnapshot, &pe32)) {
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- /* Only report parents. Omit self from the JSON output. */
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+ /* Only report parents. Omit self from the output. */
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if (nr_pids)
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- jw_array_string(jw, pe32.szExeFile);
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+ strvec_push(names, pe32.szExeFile);
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/* Check for cycle in snapshot. (Yes, it happened.) */
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for (k = 0; k < nr_pids; k++)
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if (pid == pid_list[k]) {
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- jw_array_string(jw, "(cycle)");
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+ strvec_push(names, "(cycle)");
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return;
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}
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if (nr_pids == NR_PIDS_LIMIT) {
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- jw_array_string(jw, "(truncated)");
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+ strvec_push(names, "(truncated)");
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return;
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}
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@@ -105,24 +101,14 @@ static void get_processes(struct json_writer *jw, HANDLE hSnapshot)
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}
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/*
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- * Emit JSON data for the current and parent processes. Individual
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- * trace2 targets can decide how to actually print it.
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+ * Collect the list of parent process names.
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*/
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-static void get_ancestry(void)
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+static void get_ancestry(struct strvec *names)
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{
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HANDLE hSnapshot = CreateToolhelp32Snapshot(TH32CS_SNAPPROCESS, 0);
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if (hSnapshot != INVALID_HANDLE_VALUE) {
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- struct json_writer jw = JSON_WRITER_INIT;
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-
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- jw_array_begin(&jw, 0);
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- get_processes(&jw, hSnapshot);
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- jw_end(&jw);
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-
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- trace2_data_json("process", the_repository, "windows/ancestry",
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- &jw);
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-
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- jw_release(&jw);
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+ get_processes(names, hSnapshot);
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CloseHandle(hSnapshot);
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}
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}
@@ -176,13 +162,27 @@ static void get_peak_memory_info(void)
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void trace2_collect_process_info(enum trace2_process_info_reason reason)
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{
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+ struct strvec names = STRVEC_INIT;
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+
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if (!trace2_is_enabled())
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return;
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switch (reason) {
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case TRACE2_PROCESS_INFO_STARTUP:
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get_is_being_debugged();
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- get_ancestry();
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+ get_ancestry(&names);
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+ if (names.nr) {
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+ struct json_writer jw = JSON_WRITER_INIT;
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+ jw_array_begin(&jw, 0);
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+ for (size_t i = 0; i < names.nr; i++)
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+ jw_array_string(&jw, names.v[i]);
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+ jw_end(&jw);
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+ trace2_data_json("process", the_repository,
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+ "windows/ancestry", &jw);
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+ jw_release(&jw);
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+ }
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+
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+ strvec_clear(&names);
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return;
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case TRACE2_PROCESS_INFO_EXIT: