diff options
Diffstat (limited to 'src/pkg/runtime/runtime.c')
| -rw-r--r-- | src/pkg/runtime/runtime.c | 35 |
1 files changed, 24 insertions, 11 deletions
diff --git a/src/pkg/runtime/runtime.c b/src/pkg/runtime/runtime.c index d995bf97ae..725c6d838e 100644 --- a/src/pkg/runtime/runtime.c +++ b/src/pkg/runtime/runtime.c @@ -20,22 +20,35 @@ enum { int32 runtime·gotraceback(bool *crash) { + // Keep a cached value to make gotraceback fast, + // since we call it on every call to gentraceback. + // The cached value is a uint32 in which the low bit + // is the "crash" setting and the top 31 bits are the + // gotraceback value. + static uint32 cache = ~(uint32)0; byte *p; + uint32 x; if(crash != nil) *crash = false; - p = runtime·getenv("GOTRACEBACK"); - if(p == nil || p[0] == '\0') { - if(m->traceback != 0) - return m->traceback; - return 1; // default is on - } - if(runtime·strcmp(p, (byte*)"crash") == 0) { - if(crash != nil) - *crash = true; - return 2; // extra information + if(m->traceback != 0) + return m->traceback; + x = runtime·atomicload(&cache); + if(x == ~(uint32)0) { + p = runtime·getenv("GOTRACEBACK"); + if(p == nil) + p = (byte*)""; + if(p[0] == '\0') + x = 1<<1; + else if(runtime·strcmp(p, (byte*)"crash") == 0) + x = (2<<1) | 1; + else + x = runtime·atoi(p)<<1; + runtime·atomicstore(&cache, x); } - return runtime·atoi(p); + if(crash != nil) + *crash = x&1; + return x>>1; } int32 |