Merge "[ravenwood] Better log redirection to stdout" into main
diff --git a/ravenwood/runtime-jni/ravenwood_initializer.cpp b/ravenwood/runtime-jni/ravenwood_initializer.cpp
index 391c5d5..8a35ade 100644
--- a/ravenwood/runtime-jni/ravenwood_initializer.cpp
+++ b/ravenwood/runtime-jni/ravenwood_initializer.cpp
@@ -26,6 +26,10 @@
#include <fcntl.h>
#include <set>
+#include <fstream>
+#include <iostream>
+#include <string>
+#include <cstdlib>
#include "jni_helper.h"
@@ -182,17 +186,82 @@
}
}
+// Find the PPID of child_pid using /proc/N/stat. The 4th field is the PPID.
+// Also returns child_pid's process name (2nd field).
+static pid_t getppid_of(pid_t child_pid, std::string& out_process_name) {
+ if (child_pid < 0) {
+ return -1;
+ }
+ std::string stat_file = "/proc/" + std::to_string(child_pid) + "/stat";
+ std::ifstream stat_stream(stat_file);
+ if (!stat_stream.is_open()) {
+ ALOGW("Unable to open '%s': %s", stat_file.c_str(), strerror(errno));
+ return -1;
+ }
+
+ std::string field;
+ int field_count = 0;
+ while (std::getline(stat_stream, field, ' ')) {
+ if (++field_count == 4) {
+ return atoi(field.c_str());
+ }
+ if (field_count == 2) {
+ out_process_name = field;
+ }
+ }
+ ALOGW("Unexpected format in '%s'", stat_file.c_str());
+ return -1;
+}
+
+// Find atest's PID. Climb up the process tree, and find "atest-py3".
+static pid_t find_atest_pid() {
+ auto ret = getpid(); // self (isolation runner process)
+
+ while (ret != -1) {
+ std::string proc;
+ ret = getppid_of(ret, proc);
+ if (proc == "(atest-py3)") {
+ return ret;
+ }
+ }
+
+ return ret;
+}
+
+// If $RAVENWOOD_LOG_OUT is set, redirect stdout/err to this file.
+// Originally it was added to allow to monitor log in realtime, with
+// RAVENWOOD_LOG_OUT=$(tty) atest...
+//
+// As a special case, if $RAVENWOOD_LOG_OUT is set to "-", we try to find
+// atest's process and send the output to its stdout. It's sort of hacky, but
+// this allows shell redirection to work on Ravenwood output too,
+// so e.g. `atest ... |tee atest.log` would work on Ravenwood's output.
+// (which wouldn't work with `RAVENWOOD_LOG_OUT=$(tty)`).
+//
+// Otherwise -- if $RAVENWOOD_LOG_OUT isn't set -- atest/tradefed just writes
+// the test's output to its own log file.
static void maybeRedirectLog() {
auto ravenwoodLogOut = getenv("RAVENWOOD_LOG_OUT");
- if (ravenwoodLogOut == NULL) {
+ if (ravenwoodLogOut == NULL || *ravenwoodLogOut == '\0') {
return;
}
- ALOGI("RAVENWOOD_LOG_OUT set. Redirecting output to %s", ravenwoodLogOut);
+ std::string path;
+ if (strcmp("-", ravenwoodLogOut) == 0) {
+ pid_t ppid = find_atest_pid();
+ if (ppid < 0) {
+ ALOGI("RAVENWOOD_LOG_OUT set to '-', but unable to find atest's PID");
+ return;
+ }
+ path = std::format("/proc/{}/fd/1", ppid);
+ } else {
+ path = ravenwoodLogOut;
+ }
+ ALOGI("RAVENWOOD_LOG_OUT set. Redirecting output to '%s'", path.c_str());
// Redirect stdin / stdout to /dev/tty.
- int ttyFd = open(ravenwoodLogOut, O_WRONLY | O_APPEND);
+ int ttyFd = open(path.c_str(), O_WRONLY | O_APPEND);
if (ttyFd == -1) {
- ALOGW("$RAVENWOOD_LOG_OUT is set to %s, but failed to open: %s ", ravenwoodLogOut,
+ ALOGW("$RAVENWOOD_LOG_OUT is set, but failed to open '%s': %s ", path.c_str(),
strerror(errno));
return;
}