title: android Ndk undefined reference to sigemptsyset
body: <p>I am cross compiling some native code for android , I am using some linux timer related signal set (sigemptyset) in my code . everything works fine on my PC , When I build  my code using android ndk-build script I am getting the following errors </p>
  
  <pre><code>  jni/../src/Timer.cpp:74: undefined reference to `sigemptyset'
    jni/../src/Timer.cpp:75: undefined reference to `__libc_current_sigrtmin'
    jni/../src/Timer.cpp:75: undefined reference to `sigaddset'
    jni/../src/Timer.cpp:86: undefined reference to `sigemptyset'
    jni/../src/Timer.cpp:88: undefined reference to `__libc_current_sigrtmin' 
  </code></pre>
  
  <p>I have properly linked all the libraries , but still I get this undefined reference  error .</p>
  
  <p>Which library I have to use to provide refrence  for function realted signal.h  .</p>