Android NDK and pthread

Issue

I'm compiling Qt/C++ project with android NDK standalone toolchain. I’ve created standalone toolchain with make-standalone-toolchain.sh --arch=arm --toolchain=arm-linux-androideabi-4.9 --platform=android-21 command. NDK version is android-ndk-r10e. Target project uses some functions from pthread library. At compile time, I get the following error:

error: 'pthread_getaffinity_np' was not declared in this scope
const int err = pthread_getaffinity_np(_pthreadId, sizeof(cpu_set_t), &cpuSetMask);
compilation terminated due to -Wfatal-errors.

I've checked the header of pthread included in ndk toolchain and I did not find the declaration of pthread_getaffinity_np function.

Is pthread functionality for Android limited? How to use pthread with Android NDK properly?

Solution

Is pthread functionality for Android limited?

AFAIK, Yes.

http://mobilepearls.com/labs/native-android-api/#pthreads
https://web.archive.org/web/20180602101341/http://mobilepearls.com/labs/native-android-api/#pthreads

POSIX threads (pthreads)
The android libc, bionic, provides built-in support for pthreads, so no
additional linking (-lpthreads) is necessary. It does not implement full
POSIX threads functionality and leaves out support for read/write locks,
pthread_cancel(), process-shared mutexes and condition variables as well as
other more advanced features. Read the bionic OVERVIEW.txt for more
information.

TLS, thread-local storage, is limited to 59 pthread_key_t slots available
to applications, lower than the posix minimum of 128.

Answered By - Kazuki Sakamoto