Establish native micro runtime checkpoint

1 files changed, 26 insertions, 0 deletions

diff --git a/research/experiments/004-direct-document-path/peak-launcher.c b/research/experiments/004-direct-document-path/peak-launcher.c
new file mode 100644
index 0000000..e9f6c00
--- /dev/null
+++ b/research/experiments/004-direct-document-path/peak-launcher.c
@@ -0,0 +1,26 @@
+#define _GNU_SOURCE
+/* Fork from a small native launcher so a Python orchestrator's pre-exec RSS
+ * cannot become the measured worker's high-water mark. */
+#include <stdio.h>
+#include <sys/resource.h>
+#include <sys/wait.h>
+#include <unistd.h>
+
+int main(int argc, char **argv) {
+    if (argc < 2) return 2;
+    pid_t child = fork();
+    if (child < 0) return 2;
+    if (!child) {
+        execvp(argv[1], argv + 1);
+        _exit(127);
+    }
+    struct rusage usage;
+    int status;
+    if (wait4(child, &status, 0, &usage) < 0 || !WIFEXITED(status) ||
+        WEXITSTATUS(status)) return 1;
+    long user_ns = usage.ru_utime.tv_sec * 1000000000L + usage.ru_utime.tv_usec * 1000L;
+    long system_ns = usage.ru_stime.tv_sec * 1000000000L + usage.ru_stime.tv_usec * 1000L;
+    fprintf(stderr, "PURE_PEAK_RSS_KIB=%ld\nPURE_USER_NS=%ld\nPURE_SYSTEM_NS=%ld\n",
+            usage.ru_maxrss, user_ns, system_ns);
+    return 0;
+}