title: Why glibc and pthread library both defined same APIs?
body: <p>Why glibc and pthread library both defined same APIs ? Here is the snapshot</p>
  
  <pre><code>ubuntu@ubuntu:/lib$ objdump -T /lib/i386-linux-gnu/libc.so.6 |grep pthread_cond_signal
  000f8360 g    DF .text  00000039  GLIBC_2.3.2 pthread_cond_signal
  0012b940 g    DF .text  00000039 (GLIBC_2.0)  pthread_cond_signal
  
  ubuntu@ubuntu:/lib$ objdump -T /lib/i386-linux-gnu/libpthread.so.0 |grep pthread_cond_signal
  0000b350 g    DF .text  0000007c (GLIBC_2.0)  pthread_cond_signal
  0000af90 g    DF .text  000000fc  GLIBC_2.3.2 pthread_cond_signal
  </code></pre>