qemu/trace/simple.c

2  * Simple trace backend
7  * the COPYING file in the top-level directory.
16 #include "trace/control.h"
17 #include "trace/simple.h"
18 #include "qemu/error-report.h"
19 #include "qemu/qemu-print.h"
21 /** Trace file header event ID, picked to avoid conflict with real event IDs */
24 /** Trace file magic number */
27 /** Trace file version number, bump if format changes */
31 #define DROPPED_EVENT_ID (~(uint64_t)0 - 1)
33 /** Trace record is valid */
37  * Trace records are written out by a dedicated thread.  The thread waits for
63 /* * Trace buffer entry */
94  * Read a trace record from the trace buffer
96  * @idx         Trace buffer index
97  * @record      Trace record to fill
119     (*recordptr)->event &= ~TRACE_RECORD_VALID;  in get_trace_record()
120     /* clear the trace buffer range for consumed record otherwise any byte  in get_trace_record()
188             unused = fwrite(recordptr, recordptr->length, 1, trace_fp);  in writeout_thread()
189             writeout_idx += recordptr->length;  in writeout_thread()
201     rec->rec_off = write_to_buffer(rec->rec_off, &val, sizeof(uint64_t));  in trace_record_write_u64()
207     rec->rec_off = write_to_buffer(rec->rec_off, &slen, sizeof(slen));  in trace_record_write_str()
209     rec->rec_off = write_to_buffer(rec->rec_off, (void*)s, slen);  in trace_record_write_str()
224         if (new_idx - writeout_idx > TRACE_BUF_LEN) {  in trace_record_start()
225             /* Trace Buffer Full, Event dropped ! */  in trace_record_start()
227             return -ENOSPC;  in trace_record_start()
239     rec->tbuf_idx = idx;  in trace_record_start()
240     rec->rec_off  = (idx + sizeof(TraceRecord)) % TRACE_BUF_LEN;  in trace_record_start()
272     read_from_buffer(rec->tbuf_idx, &record, sizeof(TraceRecord));  in trace_record_finish()
275     write_to_buffer(rec->tbuf_idx, &record, sizeof(TraceRecord));  in trace_record_finish()
277     if (((unsigned int)g_atomic_int_get(&trace_idx) - writeout_idx)  in trace_record_finish()
296             return -1;  in st_write_event_mapping()
304  * Enable / disable tracing, return whether it was enabled.
306  * @enable: enable if %true, else disable.
308 bool st_set_trace_file_enabled(bool enable)  in st_set_trace_file_enabled()  argument
313     if (enable == !!trace_fp) {  in st_set_trace_file_enabled()
317     /* Halt trace writeout */  in st_set_trace_file_enabled()
322     if (enable) {  in st_set_trace_file_enabled()
343         /* Resume trace writeout */  in st_set_trace_file_enabled()
354  * Set the name of a trace file
356  * @file        The trace file name or NULL for the default name-<pid> set at
367         trace_file_name = g_strdup_printf(CONFIG_TRACE_FILE "-" FMT_pid, (pid_t)getpid());  in st_set_trace_file()
377     qemu_printf("Trace file \"%s\" %s.\n",  in st_print_trace_file_status()
401     thread = g_thread_new("trace-thread", fn, NULL);  in trace_thread_create()
418         warn_report("unable to initialize simple trace backend");  in st_init()