ALog Prologue now keeps only last part of source path (filename), using us timestamps

[Coldwings]

This pull request introduces a change to the ALog Prologue module. The modification made is to keep only the last part of the source path, specifically the filename, while utilizing microsecond timestamps.

Microsecond timestamps shares photon thread timestamp photon::now.

[beef9999]

Why not move to alog.cpp?

[Coldwings]

update_now() _rdtsc() last_tsc are defined as inline or static unit in thread.cpp, alog_update_now() needs to call those functions and set last_tsc now so time update can also used by thread scheduler.

[lihuiba]

better specialize make_named_value()

[lihuiba]

better return sec and usec directly as an std::pair, so that they are returned in registers.

#include <stdio.h>
#include <inttypes.h>
#include <utility>

std::pair<uint64_t, uint64_t> foo();


int main(int argc, char** argv) {
	auto x = foo();
	return (x.first + x.second) >> 3;
}

sec/usec are returned in rax/rdx as a result:

(gdb) disassemble main
Dump of assembler code for function main:
   0x0000000000001050 <+0>:	sub    $0x8,%rsp
   0x0000000000001054 <+4>:	callq  0x1030 <_Z3foov@plt>
   0x0000000000001059 <+9>:	add    $0x8,%rsp
   0x000000000000105d <+13>:	add    %rdx,%rax
   0x0000000000001060 <+16>:	shr    $0x3,%rax
   0x0000000000001064 <+20>:	retq
End of assembler dump.

[Coldwings]

updated: return struct timeval as result