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vm: speed up nano-count primitive on Mac OS X

release
Slava Pestov 2010-04-11 20:26:11 -07:00
parent 72e71a3318
commit a417b0e70d
2 changed files with 14 additions and 8 deletions
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3
vm/os-genunix.cpp
View File

@ -38,8 +38,7 @@ const char *default_image_path()
u64 nano_count() u64 nano_count()
{ {
struct timespec t; struct timespec t;
int ret; int ret = clock_gettime(CLOCK_MONOTONIC,&t);
ret = clock_gettime(CLOCK_MONOTONIC,&t);
if(ret != 0) if(ret != 0)
fatal_error("clock_gettime failed", 0); fatal_error("clock_gettime failed", 0);
return (u64)t.tv_sec * 1000000000 + t.tv_nsec; return (u64)t.tv_sec * 1000000000 + t.tv_nsec;

19
vm/os-macosx.mm
View File

@ -87,12 +87,19 @@ Protocol *objc_getProtocol(char *name)
u64 nano_count() u64 nano_count()
{ {
u64 t = mach_absolute_time(); u64 time = mach_absolute_time();
mach_timebase_info_data_t info;
kern_return_t ret = mach_timebase_info(&info); static u64 scaling_factor = 0;
if(ret != 0) if(!scaling_factor)
fatal_error("mach_timebase_info failed",ret); {
return t * (info.numer/info.denom); mach_timebase_info_data_t info;
kern_return_t ret = mach_timebase_info(&info);
if(ret != 0)
fatal_error("mach_timebase_info failed",ret);
scaling_factor = info.numer/info.denom;
}
return time * scaling_factor;
} }
} }