Merge "Fix zombie process issue caused by trace trigger" into main

#include <cmath>

#include <stdio.h>

#include <sys/time.h>

#include <sys/wait.h>

#include <android-base/macros.h>

#include <android-base/parsebool.h>

void VideoRenderQualityTracker::triggerTrace() {

    // Trigger perfetto to stop always-on-tracing (AOT) to collect trace into a file for video

    // freeze event, the collected trace categories are configured by AOT.

    const char* args[] = {"/system/bin/trigger_perfetto", "com.android.codec-video-freeze", NULL};

    static const char* args[] = {"/system/bin/trigger_perfetto",

                                 "com.android.codec-video-freeze", NULL};

    pid_t pid = fork();

    if (pid < 0) {

        ALOGI("Failed to fork for triggering trace");

        return;

    }

    if (pid == 0) {

        // child process.

    } else if (pid == 0) {

        // Child process.

        ALOGI("Trigger trace %s", args[1]);

        execvp(args[0], const_cast<char**>(args));

        ALOGW("Failed to trigger trace %s", args[1]);

        _exit(1);

    } else {

        // Parent process.

        int status;

        // Wait for the child process (pid) gets terminated, and allow the system to release

        // the resource associated with the child. Or the child process will remain in a

        // zombie state and get killed by llkd to cause foreground app crash.

        if (waitpid(pid, &status, 0) < 0) {

            ALOGW("Failed to waitpid for triggering trace");

        }

    }

    ALOGI("Triggered trace %s", args[1]);

}

} // namespace android