X-Git-Url: http://git.lttng.org./?a=blobdiff_plain;f=liblttng-ust%2Flttng-clock.c;h=27ecccd91cc2da6e1ad97bb1b80ede3a66030a42;hb=14b6f89117234871ef9f750c4d282975397e30b7;hp=93a5075d8a2b0db1693246fa44ac09df298c4ee8;hpb=4c41b460614826ada066a7e0c26a8b116336bab2;p=lttng-ust.git diff --git a/liblttng-ust/lttng-clock.c b/liblttng-ust/lttng-clock.c index 93a5075d..27ecccd9 100644 --- a/liblttng-ust/lttng-clock.c +++ b/liblttng-ust/lttng-clock.c @@ -9,6 +9,7 @@ #include #include #include +#include #include #include #include @@ -17,57 +18,167 @@ #include "clock.h" #include "getenv.h" -struct lttng_trace_clock *lttng_trace_clock; +struct lttng_ust_trace_clock *lttng_ust_trace_clock; static -struct lttng_trace_clock user_tc; +struct lttng_ust_trace_clock user_tc; static void *clock_handle; -int lttng_ust_trace_clock_set_read64_cb(uint64_t (*read64)(void)) +static +uint64_t trace_clock_freq_monotonic(void) { - if (CMM_LOAD_SHARED(lttng_trace_clock)) + return 1000000000ULL; +} + +static +int trace_clock_uuid_monotonic(char *uuid) +{ + int ret = 0; + size_t len; + FILE *fp; + + /* + * boot_id needs to be read once before being used concurrently + * to deal with a Linux kernel race. A fix is proposed for + * upstream, but the work-around is needed for older kernels. + */ + fp = fopen("/proc/sys/kernel/random/boot_id", "r"); + if (!fp) { + return -ENOENT; + } + len = fread(uuid, 1, LTTNG_UST_UUID_STR_LEN - 1, fp); + if (len < LTTNG_UST_UUID_STR_LEN - 1) { + ret = -EINVAL; + goto end; + } + uuid[LTTNG_UST_UUID_STR_LEN - 1] = '\0'; +end: + fclose(fp); + return ret; +} + +static +const char *trace_clock_name_monotonic(void) +{ + return "monotonic"; +} + +static +const char *trace_clock_description_monotonic(void) +{ + return "Monotonic Clock"; +} + +int lttng_ust_trace_clock_set_read64_cb(lttng_ust_clock_read64_function read64_cb) +{ + if (CMM_LOAD_SHARED(lttng_ust_trace_clock)) return -EBUSY; - user_tc.read64 = read64; + user_tc.read64 = read64_cb; + return 0; +} + +int lttng_ust_trace_clock_get_read64_cb(lttng_ust_clock_read64_function *read64_cb) +{ + struct lttng_ust_trace_clock *ltc = CMM_LOAD_SHARED(lttng_ust_trace_clock); + + if (caa_likely(!ltc)) { + *read64_cb = &trace_clock_read64_monotonic; + } else { + cmm_read_barrier_depends(); /* load ltc before content */ + *read64_cb = ltc->read64; + } return 0; } -int lttng_ust_trace_clock_set_freq_cb(uint64_t (*freq)(void)) +int lttng_ust_trace_clock_set_freq_cb(lttng_ust_clock_freq_function freq_cb) { - if (CMM_LOAD_SHARED(lttng_trace_clock)) + if (CMM_LOAD_SHARED(lttng_ust_trace_clock)) return -EBUSY; - user_tc.freq = freq; + user_tc.freq = freq_cb; return 0; } -int lttng_ust_trace_clock_set_uuid_cb(int (*uuid)(char *uuid)) +int lttng_ust_trace_clock_get_freq_cb(lttng_ust_clock_freq_function *freq_cb) { - if (CMM_LOAD_SHARED(lttng_trace_clock)) + struct lttng_ust_trace_clock *ltc = CMM_LOAD_SHARED(lttng_ust_trace_clock); + + if (caa_likely(!ltc)) { + *freq_cb = &trace_clock_freq_monotonic; + } else { + cmm_read_barrier_depends(); /* load ltc before content */ + *freq_cb = ltc->freq; + } + return 0; +} + +int lttng_ust_trace_clock_set_uuid_cb(lttng_ust_clock_uuid_function uuid_cb) +{ + if (CMM_LOAD_SHARED(lttng_ust_trace_clock)) return -EBUSY; - user_tc.uuid = uuid; + user_tc.uuid = uuid_cb; + return 0; +} + +int lttng_ust_trace_clock_get_uuid_cb(lttng_ust_clock_uuid_function *uuid_cb) +{ + struct lttng_ust_trace_clock *ltc = CMM_LOAD_SHARED(lttng_ust_trace_clock); + + if (caa_likely(!ltc)) { + *uuid_cb = &trace_clock_uuid_monotonic; + } else { + cmm_read_barrier_depends(); /* load ltc before content */ + *uuid_cb = ltc->uuid; + } return 0; } -int lttng_ust_trace_clock_set_name_cb(const char *(*name)(void)) +int lttng_ust_trace_clock_set_name_cb(lttng_ust_clock_name_function name_cb) { - if (CMM_LOAD_SHARED(lttng_trace_clock)) + if (CMM_LOAD_SHARED(lttng_ust_trace_clock)) return -EBUSY; - user_tc.name = name; + user_tc.name = name_cb; return 0; } -int lttng_ust_trace_clock_set_description_cb(const char *(*description)(void)) +int lttng_ust_trace_clock_get_name_cb(lttng_ust_clock_name_function *name_cb) { - if (CMM_LOAD_SHARED(lttng_trace_clock)) + struct lttng_ust_trace_clock *ltc = CMM_LOAD_SHARED(lttng_ust_trace_clock); + + if (caa_likely(!ltc)) { + *name_cb = &trace_clock_name_monotonic; + } else { + cmm_read_barrier_depends(); /* load ltc before content */ + *name_cb = ltc->name; + } + return 0; +} + +int lttng_ust_trace_clock_set_description_cb(lttng_ust_clock_description_function description_cb) +{ + if (CMM_LOAD_SHARED(lttng_ust_trace_clock)) return -EBUSY; - user_tc.description = description; + user_tc.description = description_cb; + return 0; +} + +int lttng_ust_trace_clock_get_description_cb(lttng_ust_clock_description_function *description_cb) +{ + struct lttng_ust_trace_clock *ltc = CMM_LOAD_SHARED(lttng_ust_trace_clock); + + if (caa_likely(!ltc)) { + *description_cb = &trace_clock_description_monotonic; + } else { + cmm_read_barrier_depends(); /* load ltc before content */ + *description_cb = ltc->description; + } return 0; } int lttng_ust_enable_trace_clock_override(void) { - if (CMM_LOAD_SHARED(lttng_trace_clock)) + if (CMM_LOAD_SHARED(lttng_ust_trace_clock)) return -EBUSY; if (!user_tc.read64) return -EINVAL; @@ -79,7 +190,7 @@ int lttng_ust_enable_trace_clock_override(void) return -EINVAL; /* Use default uuid cb when NULL */ cmm_smp_mb(); /* Store callbacks before trace clock */ - CMM_STORE_SHARED(lttng_trace_clock, &user_tc); + CMM_STORE_SHARED(lttng_ust_trace_clock, &user_tc); return 0; }