Compilation error due to missing pthread.h in LogModule on Linux

[yarduoc]

When attempting to compile the module on Ubuntu 24.04, the compilation fails due to the absence of pthread.h in the log_module.cpp file. Specifically, the error messages point to the lack of declaration for pthread_mutex_init, pthread_mutex_lock, and pthread_mutex_unlock.

Here’s the error output encountered:

error: ‘pthread_mutex_init’ was not declared in this scope; did you mean ‘pthread_mutex_t’?
error: ‘pthread_mutex_unlock’ was not declared in this scope; did you mean ‘pthread_mutex_t’?
error: ‘pthread_mutex_lock’ was not declared in this scope; did you mean ‘pthread_mutex_t’?

Looking at the log_module.h, it appears that the inclusion of pthread.h has been commented out under the #else directive for Linux:

#ifndef LINUX
#include <windows.h>
#else
// #include <pthread.h>
#include <stdarg.h>
#define printf_s(fileptr,str)  (fprintf(fileptr,"%s",str))
#define __in
#endif // ??????????????????????

The code compiles perfectly when the commented-out line (#include <pthread.h>) is uncommented.

Questions:

• Was the exclusion of pthread.h intentional for Linux, or is this an oversight?
• Is there a specific reason for this exclusion that I should be aware of?
• What would be the recommended approach for compiling the package without running into this error?

Environment:

• Operating System: Ubuntu 24.04 (x86_64 architecture)
• Kernel Version: 6.8.0-50-generic
• ROS 2 Distribution: Jazzy
• C++ Compiler: GCC 13.3.0
• CMake Version: 3.28.3
• Colcon Version: 0.18.4

[hippo5329]

I sent a pull-request to fix this issue

#24