diff options
author | Lluís <xscript@gmx.net> | 2011-08-31 20:30:57 +0200 |
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committer | Stefan Hajnoczi <stefanha@linux.vnet.ibm.com> | 2011-09-01 10:34:53 +0100 |
commit | edb47ec498a5c00607e8d428668d5141822a9eac (patch) | |
tree | 3e1e9edc6ddfae6e34c132f16ec04fe32eb5335d /simpletrace.c | |
parent | 09001ee7b27b9b5f049362efc427d03e2186a431 (diff) |
trace: move backend-specific code into the trace/ directory
Signed-off-by: Lluís Vilanova <vilanova@ac.upc.edu>
Diffstat (limited to 'simpletrace.c')
-rw-r--r-- | simpletrace.c | 355 |
1 files changed, 0 insertions, 355 deletions
diff --git a/simpletrace.c b/simpletrace.c deleted file mode 100644 index de355e9675..0000000000 --- a/simpletrace.c +++ /dev/null @@ -1,355 +0,0 @@ -/* - * Simple trace backend - * - * Copyright IBM, Corp. 2010 - * - * This work is licensed under the terms of the GNU GPL, version 2. See - * the COPYING file in the top-level directory. - * - */ - -#include <stdlib.h> -#include <stdint.h> -#include <stdio.h> -#include <time.h> -#include <signal.h> -#include <pthread.h> -#include "qemu-timer.h" -#include "trace.h" - -/** Trace file header event ID */ -#define HEADER_EVENT_ID (~(uint64_t)0) /* avoids conflicting with TraceEventIDs */ - -/** Trace file magic number */ -#define HEADER_MAGIC 0xf2b177cb0aa429b4ULL - -/** Trace file version number, bump if format changes */ -#define HEADER_VERSION 0 - -/** Records were dropped event ID */ -#define DROPPED_EVENT_ID (~(uint64_t)0 - 1) - -/** Trace record is valid */ -#define TRACE_RECORD_VALID ((uint64_t)1 << 63) - -/** Trace buffer entry */ -typedef struct { - uint64_t event; - uint64_t timestamp_ns; - uint64_t x1; - uint64_t x2; - uint64_t x3; - uint64_t x4; - uint64_t x5; - uint64_t x6; -} TraceRecord; - -enum { - TRACE_BUF_LEN = 4096, - TRACE_BUF_FLUSH_THRESHOLD = TRACE_BUF_LEN / 4, -}; - -/* - * Trace records are written out by a dedicated thread. The thread waits for - * records to become available, writes them out, and then waits again. - */ -static pthread_mutex_t trace_lock = PTHREAD_MUTEX_INITIALIZER; -static pthread_cond_t trace_available_cond = PTHREAD_COND_INITIALIZER; -static pthread_cond_t trace_empty_cond = PTHREAD_COND_INITIALIZER; -static bool trace_available; -static bool trace_writeout_enabled; - -static TraceRecord trace_buf[TRACE_BUF_LEN]; -static unsigned int trace_idx; -static FILE *trace_fp; -static char *trace_file_name = NULL; - -/** - * Read a trace record from the trace buffer - * - * @idx Trace buffer index - * @record Trace record to fill - * - * Returns false if the record is not valid. - */ -static bool get_trace_record(unsigned int idx, TraceRecord *record) -{ - if (!(trace_buf[idx].event & TRACE_RECORD_VALID)) { - return false; - } - - __sync_synchronize(); /* read memory barrier before accessing record */ - - *record = trace_buf[idx]; - record->event &= ~TRACE_RECORD_VALID; - return true; -} - -/** - * Kick writeout thread - * - * @wait Whether to wait for writeout thread to complete - */ -static void flush_trace_file(bool wait) -{ - pthread_mutex_lock(&trace_lock); - trace_available = true; - pthread_cond_signal(&trace_available_cond); - - if (wait) { - pthread_cond_wait(&trace_empty_cond, &trace_lock); - } - - pthread_mutex_unlock(&trace_lock); -} - -static void wait_for_trace_records_available(void) -{ - pthread_mutex_lock(&trace_lock); - while (!(trace_available && trace_writeout_enabled)) { - pthread_cond_signal(&trace_empty_cond); - pthread_cond_wait(&trace_available_cond, &trace_lock); - } - trace_available = false; - pthread_mutex_unlock(&trace_lock); -} - -static void *writeout_thread(void *opaque) -{ - TraceRecord record; - unsigned int writeout_idx = 0; - unsigned int num_available, idx; - size_t unused __attribute__ ((unused)); - - for (;;) { - wait_for_trace_records_available(); - - num_available = trace_idx - writeout_idx; - if (num_available > TRACE_BUF_LEN) { - record = (TraceRecord){ - .event = DROPPED_EVENT_ID, - .x1 = num_available, - }; - unused = fwrite(&record, sizeof(record), 1, trace_fp); - writeout_idx += num_available; - } - - idx = writeout_idx % TRACE_BUF_LEN; - while (get_trace_record(idx, &record)) { - trace_buf[idx].event = 0; /* clear valid bit */ - unused = fwrite(&record, sizeof(record), 1, trace_fp); - idx = ++writeout_idx % TRACE_BUF_LEN; - } - - fflush(trace_fp); - } - return NULL; -} - -static void trace(TraceEventID event, uint64_t x1, uint64_t x2, uint64_t x3, - uint64_t x4, uint64_t x5, uint64_t x6) -{ - unsigned int idx; - uint64_t timestamp; - - if (!trace_list[event].state) { - return; - } - - timestamp = get_clock(); - - idx = __sync_fetch_and_add(&trace_idx, 1) % TRACE_BUF_LEN; - trace_buf[idx] = (TraceRecord){ - .event = event, - .timestamp_ns = timestamp, - .x1 = x1, - .x2 = x2, - .x3 = x3, - .x4 = x4, - .x5 = x5, - .x6 = x6, - }; - __sync_synchronize(); /* write barrier before marking as valid */ - trace_buf[idx].event |= TRACE_RECORD_VALID; - - if ((idx + 1) % TRACE_BUF_FLUSH_THRESHOLD == 0) { - flush_trace_file(false); - } -} - -void trace0(TraceEventID event) -{ - trace(event, 0, 0, 0, 0, 0, 0); -} - -void trace1(TraceEventID event, uint64_t x1) -{ - trace(event, x1, 0, 0, 0, 0, 0); -} - -void trace2(TraceEventID event, uint64_t x1, uint64_t x2) -{ - trace(event, x1, x2, 0, 0, 0, 0); -} - -void trace3(TraceEventID event, uint64_t x1, uint64_t x2, uint64_t x3) -{ - trace(event, x1, x2, x3, 0, 0, 0); -} - -void trace4(TraceEventID event, uint64_t x1, uint64_t x2, uint64_t x3, uint64_t x4) -{ - trace(event, x1, x2, x3, x4, 0, 0); -} - -void trace5(TraceEventID event, uint64_t x1, uint64_t x2, uint64_t x3, uint64_t x4, uint64_t x5) -{ - trace(event, x1, x2, x3, x4, x5, 0); -} - -void trace6(TraceEventID event, uint64_t x1, uint64_t x2, uint64_t x3, uint64_t x4, uint64_t x5, uint64_t x6) -{ - trace(event, x1, x2, x3, x4, x5, x6); -} - -void st_set_trace_file_enabled(bool enable) -{ - if (enable == !!trace_fp) { - return; /* no change */ - } - - /* Halt trace writeout */ - flush_trace_file(true); - trace_writeout_enabled = false; - flush_trace_file(true); - - if (enable) { - static const TraceRecord header = { - .event = HEADER_EVENT_ID, - .timestamp_ns = HEADER_MAGIC, - .x1 = HEADER_VERSION, - }; - - trace_fp = fopen(trace_file_name, "w"); - if (!trace_fp) { - return; - } - - if (fwrite(&header, sizeof header, 1, trace_fp) != 1) { - fclose(trace_fp); - trace_fp = NULL; - return; - } - - /* Resume trace writeout */ - trace_writeout_enabled = true; - flush_trace_file(false); - } else { - fclose(trace_fp); - trace_fp = NULL; - } -} - -/** - * Set the name of a trace file - * - * @file The trace file name or NULL for the default name-<pid> set at - * config time - */ -bool st_set_trace_file(const char *file) -{ - st_set_trace_file_enabled(false); - - free(trace_file_name); - - if (!file) { - if (asprintf(&trace_file_name, CONFIG_TRACE_FILE, getpid()) < 0) { - trace_file_name = NULL; - return false; - } - } else { - if (asprintf(&trace_file_name, "%s", file) < 0) { - trace_file_name = NULL; - return false; - } - } - - st_set_trace_file_enabled(true); - return true; -} - -void st_print_trace_file_status(FILE *stream, int (*stream_printf)(FILE *stream, const char *fmt, ...)) -{ - stream_printf(stream, "Trace file \"%s\" %s.\n", - trace_file_name, trace_fp ? "on" : "off"); -} - -void st_print_trace(FILE *stream, int (*stream_printf)(FILE *stream, const char *fmt, ...)) -{ - unsigned int i; - - for (i = 0; i < TRACE_BUF_LEN; i++) { - TraceRecord record; - - if (!get_trace_record(i, &record)) { - continue; - } - stream_printf(stream, "Event %" PRIu64 " : %" PRIx64 " %" PRIx64 - " %" PRIx64 " %" PRIx64 " %" PRIx64 " %" PRIx64 "\n", - record.event, record.x1, record.x2, - record.x3, record.x4, record.x5, - record.x6); - } -} - -void st_print_trace_events(FILE *stream, int (*stream_printf)(FILE *stream, const char *fmt, ...)) -{ - unsigned int i; - - for (i = 0; i < NR_TRACE_EVENTS; i++) { - stream_printf(stream, "%s [Event ID %u] : state %u\n", - trace_list[i].tp_name, i, trace_list[i].state); - } -} - -bool st_change_trace_event_state(const char *name, bool enabled) -{ - unsigned int i; - - for (i = 0; i < NR_TRACE_EVENTS; i++) { - if (!strcmp(trace_list[i].tp_name, name)) { - trace_list[i].state = enabled; - return true; - } - } - return false; -} - -void st_flush_trace_buffer(void) -{ - flush_trace_file(true); -} - -bool st_init(const char *file) -{ - pthread_t thread; - pthread_attr_t attr; - sigset_t set, oldset; - int ret; - - pthread_attr_init(&attr); - pthread_attr_setdetachstate(&attr, PTHREAD_CREATE_DETACHED); - - sigfillset(&set); - pthread_sigmask(SIG_SETMASK, &set, &oldset); - ret = pthread_create(&thread, &attr, writeout_thread, NULL); - pthread_sigmask(SIG_SETMASK, &oldset, NULL); - - if (ret != 0) { - return false; - } - - atexit(st_flush_trace_buffer); - st_set_trace_file(file); - return true; -} |