=> 0x7feb6409affa <xcb_writev+26>:	mov    (%rdi),%r10d
   0x7feb6409affd <xcb_writev+29>:	mov    %rdi,%rbx
   0x7feb6409b000 <xcb_writev+32>:	test   %r10d,%r10d
   0x7feb6409b003 <xcb_writev+35>:	jne    0x7feb6409b03d <xcb_writev+93>
   0x7feb6409b005 <xcb_writev+37>:	lea    0x18(%rdi),%r13
   0x7feb6409b009 <xcb_writev+41>:	mov    %rcx,%r12
   0x7feb6409b00c <xcb_writev+44>:	mov    %edx,(%rsp)
   0x7feb6409b00f <xcb_writev+47>:	mov    %rsi,0x8(%rsp)
   0x7feb6409b014 <xcb_writev+52>:	mov    %r13,%rdi
   0x7feb6409b017 <xcb_writev+55>:	callq  0x7feb6409a410 <pthread_mutex_lock@plt>
   0x7feb6409b01c <xcb_writev+60>:	add    %r12,0x5150(%rbx)
   0x7feb6409b023 <xcb_writev+67>:	mov    (%rsp),%edx
   0x7feb6409b026 <xcb_writev+70>:	mov    %rbx,%rdi
   0x7feb6409b029 <xcb_writev+73>:	mov    0x8(%rsp),%rsi
   0x7feb6409b02e <xcb_writev+78>:	callq  0x7feb6409ae80
   0x7feb6409b033 <xcb_writev+83>:	mov    %r13,%rdi