GCToOSInterface::QueryPerformanceCounter() in linux

[HJLeee]

Hello,

I was wondering if GCToOSInterface::QueryPerformanceCounter() in gcenv.unix.cpp is used for linux.

runtime/src/coreclr/gc/unix/gcenv.unix.cpp

Lines 1411 to 1425 in 7993e51

	int64_t GCToOSInterface::QueryPerformanceCounter()
	{
	// TODO: This is not a particularly efficient implementation - we certainly could
	// do much more specific platform-dependent versions if we find that this method
	// runs hot. However, most likely it does not.
	struct timeval tv;
	if (gettimeofday(&tv, NULL) == -1)
	{
	assert(!"gettimeofday() failed");
	// TODO (segilles) unconditional asserts
	return 0;
	}
	return (int64_t) tv.tv_sec * (int64_t) tccSecondsToMicroSeconds + (int64_t) tv.tv_usec;
	}

It is surely compiled but setting a breakpoint to GCToOSInterface::QueryPerformanceCounter() points one in gcenv.os.cpp only.

(gdb) info b
Num     Type           Disp Enb Address            What
1       breakpoint     keep y   0x00007ffff7076a95 in GCToOSInterface::QueryPerformanceCounter() at /home/leee/dotnet/runtime/src/coreclr/vm/gcenv.os.cpp:1019
        breakpoint already hit 2 times

I'd appreciate it If you tell me why the same function exists.

[jkotas]

The GC linked into libcoreclr.so uses the implementation from gcenv.os.cpp.

The implementation in gcenv.unix.cpp is used for standalone GC library and for native AOT.

The plan is to delete gcenv.os.cpp and use gcenv.unix.cpp everywhere: #72684