From: Jeff Hostetler via GitGitGadget Date: Wed, 12 Oct 2022 18:52:23 GMT Subject: [PATCH v2 0/7] Trace2 timers and counters and some cleanup Message-ID: In-Reply-To: Here is version 2 of this series to add timers and counters to Trace2. Changes since V1: * I dropped the commits concerning compiler errors in Clang 11.0.0 on MacOS. I've sent them to the mailing list in a separate series, since they had nothing to do with the main topic of this series. * I moved the documentation changes earlier in the series to get it out of the way (and eliminate the need to update it later commits). * After a long conversation on the mailing list, I redid the two thread-name commits to simplify and hopefully eliminate the remaining misunderstandings and/or short-comings of my previous attempt and explanations. We now use a "const char *" for the field in the thread-ctx that we format and detach from a strbuf during thread-start. The goal here is to move away from a modifyable strbuf in the thread-ctx itself (to avoid giving the appearance that a caller could modify the thread-name at some point, when that was not intended). The last 2 commits add the stopwatch timers and the global counters and are unchanged from the previous version. Jeff Hostetler (7): trace2: use size_t alloc,nr_open_regions in tr2tls_thread_ctx tr2tls: clarify TLS terminology api-trace2.txt: elminate section describing the public trace2 API trace2: rename the thread_name argument to trace2_thread_start trace2: convert ctx.thread_name from strbuf to pointer trace2: add stopwatch timers trace2: add global counter mechanism Documentation/technical/api-trace2.txt | 190 +++++++++++++++++-------- Makefile | 2 + t/helper/test-trace2.c | 187 ++++++++++++++++++++++++ t/t0211-trace2-perf.sh | 95 +++++++++++++ t/t0211/scrub_perf.perl | 6 + trace2.c | 121 +++++++++++++++- trace2.h | 101 +++++++++++-- trace2/tr2_ctr.c | 101 +++++++++++++ trace2/tr2_ctr.h | 104 ++++++++++++++ trace2/tr2_tgt.h | 14 ++ trace2/tr2_tgt_event.c | 47 +++++- trace2/tr2_tgt_normal.c | 39 +++++ trace2/tr2_tgt_perf.c | 43 +++++- trace2/tr2_tls.c | 34 +++-- trace2/tr2_tls.h | 55 ++++--- trace2/tr2_tmr.c | 182 +++++++++++++++++++++++ trace2/tr2_tmr.h | 140 ++++++++++++++++++ 17 files changed, 1359 insertions(+), 102 deletions(-) create mode 100644 trace2/tr2_ctr.c create mode 100644 trace2/tr2_ctr.h create mode 100644 trace2/tr2_tmr.c create mode 100644 trace2/tr2_tmr.h base-commit: 3dcec76d9df911ed8321007b1d197c1a206dc164 Published-As: https://github.com/gitgitgadget/git/releases/tag/pr-1373%2Fjeffhostetler%2Ftrace2-stopwatch-v4-v2 Fetch-It-Via: git fetch https://github.com/gitgitgadget/git pr-1373/jeffhostetler/trace2-stopwatch-v4-v2 Pull-Request: https://github.com/gitgitgadget/git/pull/1373 Range-diff vs v1: 1: 870f29166ea < -: ----------- builtin/merge-file: fix compiler warning on MacOS with clang 11.0.0 2: 43c41f7035d < -: ----------- builtin/unpack-objects.c: fix compiler warning on MacOS with clang 11.0.0 3: 73704b6f660 = 1: 6e7e4f3187e trace2: use size_t alloc,nr_open_regions in tr2tls_thread_ctx 4: 7123886a804 = 2: 9dee7a75903 tr2tls: clarify TLS terminology 7: 77a4daf9a4b ! 3: 804dab9e1a7 api-trace2.txt: elminate section describing the public trace2 API @@ Documentation/technical/api-trace2.txt: take a `va_list` argument. - -These messages are concerned with Git thread usage. - --e.g: `void trace2_thread_start(const char *name_hint)`. +-e.g: `void trace2_thread_start(const char *thread_name)`. - -=== Region and Data Messages - 5: 82f1672e180 ! 4: 637b422b860 trace2: rename trace2 thread_name argument as name_hint @@ Metadata Author: Jeff Hostetler ## Commit message ## - trace2: rename trace2 thread_name argument as name_hint + trace2: rename the thread_name argument to trace2_thread_start - Rename the `thread_name` argument in `tr2tls_create_self()` - and `trace2_thread_start()` to be `name_hint` to make it clear - that the passed argument is a hint that will be used to create + Rename the `thread_name` argument in `tr2tls_create_self()` and + `trace2_thread_start()` to be `thread_base_name` to make it clearer + that the passed argument is a component used in the construction of the actual `struct tr2tls_thread_ctx.thread_name` variable. - This should make it clearer in the API that the trace2 layer - does not borrow the caller's string pointer/buffer, but rather - that it will use that hint in formatting the actual thread's - name. Previous discussion on the mailing list indicated that - there was confusion about this point. + The base name will be used along with the thread id to create a + unique thread name. This commit does not change how the `thread_name` field is allocated or stored within the `tr2tls_thread_ctx` structure. Signed-off-by: Jeff Hostetler - ## Documentation/technical/api-trace2.txt ## -@@ Documentation/technical/api-trace2.txt: e.g: `void trace2_child_start(struct child_process *cmd)`. - - These messages are concerned with Git thread usage. - --e.g: `void trace2_thread_start(const char *thread_name)`. -+e.g: `void trace2_thread_start(const char *name_hint)`. - - === Region and Data Messages - - ## trace2.c ## @@ trace2.c: void trace2_exec_result_fl(const char *file, int line, int exec_id, int code) file, line, us_elapsed_absolute, exec_id, code); } -void trace2_thread_start_fl(const char *file, int line, const char *thread_name) -+void trace2_thread_start_fl(const char *file, int line, const char *name_hint) ++void trace2_thread_start_fl(const char *file, int line, const char *thread_base_name) { struct tr2_tgt *tgt_j; int j; @@ trace2.c: void trace2_thread_start_fl(const char *file, int line, const char *th trace2_region_enter_printf_fl(file, line, NULL, NULL, NULL, "thread-proc on main: %s", - thread_name); -+ name_hint); ++ thread_base_name); return; } @@ trace2.c: void trace2_thread_start_fl(const char *file, int line, const char *th us_elapsed_absolute = tr2tls_absolute_elapsed(us_now); - tr2tls_create_self(thread_name, us_now); -+ tr2tls_create_self(name_hint, us_now); ++ tr2tls_create_self(thread_base_name, us_now); for_each_wanted_builtin (j, tgt_j) if (tgt_j->pfn_thread_start_fl) @@ trace2.h: void trace2_exec_result_fl(const char *file, int line, int exec_id, in * - * Thread names should be descriptive, like "preload_index". - * Thread names will be decorated with an instance number automatically. -+ * The thread name hint should be descriptive, like "preload_index" or ++ * The thread base name should be descriptive, like "preload_index" or + * taken from the thread-proc function. A unique thread name will be -+ * created from the hint and the thread id automatically. ++ * created from the given base name and the thread id automatically. */ void trace2_thread_start_fl(const char *file, int line, - const char *thread_name); -+ const char *name_hint); ++ const char *thread_base_name); -#define trace2_thread_start(thread_name) \ - trace2_thread_start_fl(__FILE__, __LINE__, (thread_name)) -+#define trace2_thread_start(name_hint) \ -+ trace2_thread_start_fl(__FILE__, __LINE__, (name_hint)) ++#define trace2_thread_start(thread_base_name) \ ++ trace2_thread_start_fl(__FILE__, __LINE__, (thread_base_name)) /* * Emit a 'thread_exit' event. This must be called from inside the @@ trace2/tr2_tls.c: void tr2tls_start_process_clock(void) } -struct tr2tls_thread_ctx *tr2tls_create_self(const char *thread_name, -+struct tr2tls_thread_ctx *tr2tls_create_self(const char *name_hint, ++struct tr2tls_thread_ctx *tr2tls_create_self(const char *thread_base_name, uint64_t us_thread_start) { struct tr2tls_thread_ctx *ctx = xcalloc(1, sizeof(*ctx)); @@ trace2/tr2_tls.c: struct tr2tls_thread_ctx *tr2tls_create_self(const char *threa if (ctx->thread_id) strbuf_addf(&ctx->thread_name, "th%02d:", ctx->thread_id); - strbuf_addstr(&ctx->thread_name, thread_name); -+ strbuf_addstr(&ctx->thread_name, name_hint); ++ strbuf_addstr(&ctx->thread_name, thread_base_name); if (ctx->thread_name.len > TR2_MAX_THREAD_NAME) strbuf_setlen(&ctx->thread_name, TR2_MAX_THREAD_NAME); @@ trace2/tr2_tls.h: struct tr2tls_thread_ctx { + * The first thread in the process will have: + * { .thread_id=0, .thread_name="main" } + * Subsequent threads are given a non-zero thread_id and a thread_name -+ * constructed from the id and a "name hint" (which is usually based -+ * upon the name of the thread-proc function). For example: ++ * constructed from the id and a thread base name (which is usually just ++ * the name of the thread-proc function). For example: + * { .thread_id=10, .thread_name="th10fsm-listen" } + * This helps to identify and distinguish messages from concurrent threads. + * The ctx.thread_name field is truncated if necessary to help with column @@ trace2/tr2_tls.h: struct tr2tls_thread_ctx { * current thread. */ -struct tr2tls_thread_ctx *tr2tls_create_self(const char *thread_name, -+struct tr2tls_thread_ctx *tr2tls_create_self(const char *name_hint, ++struct tr2tls_thread_ctx *tr2tls_create_self(const char *thread_base_name, uint64_t us_thread_start); /* 6: 6492b6d2b98 ! 5: 4bf78e356e2 trace2: convert ctx.thread_name to flex array @@ Metadata Author: Jeff Hostetler ## Commit message ## - trace2: convert ctx.thread_name to flex array + trace2: convert ctx.thread_name from strbuf to pointer Convert the `tr2tls_thread_ctx.thread_name` field from a `strbuf` - to a "flex array" at the end of the context structure. + to a "const char*" pointer. The `thread_name` field is a constant string that is constructed when the context is created. Using a (non-const) `strbuf` structure for it caused some confusion in the past because it implied that someone could rename a thread after it was created. That usage was not - intended. Changing it to a "flex array" will hopefully make the - intent more clear. - - Also, move the maximum thread_name truncation to tr2_tgt_perf.c - because it is the only target that needs to worry about output column - alignment. + intended. Change it to a const pointer to make the intent more clear. Signed-off-by: Jeff Hostetler @@ trace2/tr2_tgt_event.c: static void event_fmt_prepare(const char *event_name, co * In brief mode, only emit