From ee4512ed481a126dadd33334186e0e759d7f2f47 Mon Sep 17 00:00:00 2001 From: Jeff Hostetler Date: Fri, 22 Feb 2019 14:25:01 -0800 Subject: trace2: create new combined trace facility Create a new unified tracing facility for git. The eventual intent is to replace the current trace_printf* and trace_performance* routines with a unified set of git_trace2* routines. In addition to the usual printf-style API, trace2 provides higer-level event verbs with fixed-fields allowing structured data to be written. This makes post-processing and analysis easier for external tools. Trace2 defines 3 output targets. These are set using the environment variables "GIT_TR2", "GIT_TR2_PERF", and "GIT_TR2_EVENT". These may be set to "1" or to an absolute pathname (just like the current GIT_TRACE). * GIT_TR2 is intended to be a replacement for GIT_TRACE and logs command summary data. * GIT_TR2_PERF is intended as a replacement for GIT_TRACE_PERFORMANCE. It extends the output with columns for the command process, thread, repo, absolute and relative elapsed times. It reports events for child process start/stop, thread start/stop, and per-thread function nesting. * GIT_TR2_EVENT is a new structured format. It writes event data as a series of JSON records. Calls to trace2 functions log to any of the 3 output targets enabled without the need to call different trace_printf* or trace_performance* routines. Signed-off-by: Jeff Hostetler Signed-off-by: Junio C Hamano --- trace2/tr2_tls.h | 97 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 97 insertions(+) create mode 100644 trace2/tr2_tls.h (limited to 'trace2/tr2_tls.h') diff --git a/trace2/tr2_tls.h b/trace2/tr2_tls.h new file mode 100644 index 0000000000..bb80e3f8e7 --- /dev/null +++ b/trace2/tr2_tls.h @@ -0,0 +1,97 @@ +#ifndef TR2_TLS_H +#define TR2_TLS_H + +#include "strbuf.h" + +/* + * Arbitry limit for thread names for column alignment. + */ +#define TR2_MAX_THREAD_NAME (24) + +struct tr2tls_thread_ctx { + struct strbuf thread_name; + uint64_t *array_us_start; + int alloc; + int nr_open_regions; /* plays role of "nr" in ALLOC_GROW */ + int thread_id; +}; + +/* + * Create TLS data for the current thread. This gives us a place to + * put per-thread data, such as thread start time, function nesting + * and a per-thread label for our messages. + * + * We assume the first thread is "main". Other threads are given + * non-zero thread-ids to help distinguish messages from concurrent + * threads. + * + * Truncate the thread name if necessary to help with column alignment + * in printf-style messages. + * + * In this and all following functions the term "self" refers to the + * current thread. + */ +struct tr2tls_thread_ctx *tr2tls_create_self(const char *thread_name); + +/* + * Get our TLS data. + */ +struct tr2tls_thread_ctx *tr2tls_get_self(void); + +/* + * return true if the current thread is the main thread. + */ +int tr2tls_is_main_thread(void); + +/* + * Free our TLS data. + */ +void tr2tls_unset_self(void); + +/* + * Begin a new nested region and remember the start time. + */ +void tr2tls_push_self(uint64_t us_now); + +/* + * End the innermost nested region. + */ +void tr2tls_pop_self(void); + +/* + * Pop any extra (above the first) open regions on the current + * thread and discard. During a thread-exit, we should only + * have region[0] that was pushed in trace2_thread_start() if + * the thread exits normally. + */ +void tr2tls_pop_unwind_self(void); + +/* + * Compute the elapsed time since the innermost region in the + * current thread started and the given time (usually now). + */ +uint64_t tr2tls_region_elasped_self(uint64_t us); + +/* + * Compute the elapsed time since the main thread started + * and the given time (usually now). This is assumed to + * be the absolute run time of the process. + */ +uint64_t tr2tls_absolute_elapsed(uint64_t us); + +/* + * Initialize the tr2 TLS system. + */ +void tr2tls_init(void); + +/* + * Free all tr2 TLS resources. + */ +void tr2tls_release(void); + +/* + * Protected increment of an integer. + */ +int tr2tls_locked_increment(int *p); + +#endif /* TR2_TLS_H */ -- cgit v1.2.3