@page libssh_tutor_threads Chapter 8: Threads with libssh
@section threads_with_libssh How to use libssh with threads
libssh may be used in multithreaded applications, but under several conditions :
- Your system must support libpthread or, in Windows environment,
CriticalSection based mutex control.
- Since version 0.8.0, threads initialization is called automatically in the
library constructor if libssh is dynamically linked. This means it is no
longer necessary to call ssh_init()/ssh_finalize().
- If libssh is statically linked, threading must be initialized by calling
ssh_init() before using any of libssh provided functions. This initialization
must be done outside of any threading context. Don't forget to call
ssh_finalize() to avoid memory leak
- At all times, you may use different sessions inside threads, make parallel
connections, read/write on different sessions and so on. You *cannot* use a
single session (or channels for a single session) in several threads at the same
time. This will most likely lead to internal state corruption. This limitation is
being worked out and will maybe disappear later.
@subsection threads_init Initialization of threads
Since version 0.8.0, it is no longer necessary to call ssh_init()/ssh_finalize()
if libssh is dynamically linked.
If libssh is statically linked, call ssh_init() before using any of libssh
@subsection threads_pthread Using libpthread with libssh
Since version 0.8.0, libpthread is the default threads library used by libssh.
To use libpthread, simply link it to you application.
If you are using libssh statically linked, don't forget to call ssh_init()
before using any of libssh provided functions (and ssh_finalize() in the end).
@subsection threads_other Using another threading library
Since version 0.8.0, libssh does not support custom threading libraries.
The change makes sense since the newer versions for libcrypto (OpenSSL) and
libgcrypt don't support custom threading libraries.
The default used threading library is libpthread.
Alternatively, in Windows environment, CriticalSection based mutex control can
If your system does not support libpthread nor CriticalSection based mutex
control, unfortunately, you cannot use libssh in multithreaded scenarios.
Good luck !