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| author | jan.nijtmans <nijtmans@users.sourceforge.net> | 2021-02-18 07:55:08 (GMT) |
|---|---|---|
| committer | jan.nijtmans <nijtmans@users.sourceforge.net> | 2021-02-18 07:55:08 (GMT) |
| commit | f2c4a32d7fbff5e3b59d4d1594a55ea3dbf52837 (patch) | |
| tree | d93f9cf3071d00faacdd74958733879ebc6b28d6 /generic | |
| parent | cf0af45b5ac5705ecec34ff416e57f64db10a03d (diff) | |
| download | tcl-f2c4a32d7fbff5e3b59d4d1594a55ea3dbf52837.zip tcl-f2c4a32d7fbff5e3b59d4d1594a55ea3dbf52837.tar.gz tcl-f2c4a32d7fbff5e3b59d4d1594a55ea3dbf52837.tar.bz2 | |
Performance optimization in TzsetIfNecessary() function. Cherry-picked from sebres-8-6-clock-speedup-cr2 branch
Diffstat (limited to 'generic')
| -rw-r--r-- | generic/tclClock.c | 19 | ||||
| -rw-r--r-- | generic/tclEnv.c | 9 | ||||
| -rw-r--r-- | generic/tclInt.h | 7 |
3 files changed, 34 insertions, 1 deletions
diff --git a/generic/tclClock.c b/generic/tclClock.c index 37883bb..2c5173a 100644 --- a/generic/tclClock.c +++ b/generic/tclClock.c @@ -2029,10 +2029,27 @@ ClockSecondsObjCmd( static void TzsetIfNecessary(void) { - static char* tzWas = (char*)INT2PTR(-1); /* Previous value of TZ, protected by + static char *tzWas = (char *)INT2PTR(-1); /* Previous value of TZ, protected by * clockMutex. */ + static long tzLastRefresh = 0; /* Used for latency before next refresh */ + static size_t tzEnvEpoch = 0; /* Last env epoch, for faster signaling, + that TZ changed via TCL */ const char *tzIsNow; /* Current value of TZ */ + /* + * Prevent performance regression on some platforms by resolving of system time zone: + * small latency for check whether environment was changed (once per second) + * no latency if environment was changed with tcl-env (compare both epoch values) + */ + Tcl_Time now; + Tcl_GetTime(&now); + if (now.sec == tzLastRefresh && tzEnvEpoch == TclEnvEpoch) { + return; + } + + tzEnvEpoch = TclEnvEpoch; + tzLastRefresh = now.sec; + Tcl_MutexLock(&clockMutex); tzIsNow = getenv("TZ"); if (tzIsNow != NULL && (tzWas == NULL || tzWas == (char*)INT2PTR(-1) diff --git a/generic/tclEnv.c b/generic/tclEnv.c index 15dd8b5..e4246a1 100644 --- a/generic/tclEnv.c +++ b/generic/tclEnv.c @@ -36,6 +36,11 @@ TCL_DECLARE_MUTEX(envMutex) /* To serialize access to environ. */ # define techar char #endif + +/* MODULE_SCOPE */ +size_t TclEnvEpoch = 0; /* Epoch of the tcl environment + * (if changed with tcl-env). */ + static struct { int cacheSize; /* Number of env strings in cache. */ char **cache; /* Array containing all of the environment @@ -417,6 +422,7 @@ Tcl_PutEnv( value[0] = '\0'; TclSetEnv(name, value+1); } + TclEnvEpoch++; Tcl_DStringFree(&nameString); return 0; @@ -625,6 +631,7 @@ EnvTraceProc( if (flags & TCL_TRACE_ARRAY) { TclSetupEnv(interp); + TclEnvEpoch++; return NULL; } @@ -645,6 +652,7 @@ EnvTraceProc( value = Tcl_GetVar2(interp, "env", name2, TCL_GLOBAL_ONLY); TclSetEnv(name2, value); + TclEnvEpoch++; } /* @@ -668,6 +676,7 @@ EnvTraceProc( if (flags & TCL_TRACE_UNSETS) { TclUnsetEnv(name2); + TclEnvEpoch++; } return NULL; } diff --git a/generic/tclInt.h b/generic/tclInt.h index df29da8..5da21b0 100644 --- a/generic/tclInt.h +++ b/generic/tclInt.h @@ -4977,6 +4977,13 @@ typedef struct NRE_callback { #define Tcl_Free(ptr) TclpFree(ptr) #endif +/* + * Other externals. + */ + +MODULE_SCOPE size_t TclEnvEpoch; /* Epoch of the tcl environment + * (if changed with tcl-env). */ + #endif /* _TCLINT */ /* |