Separate out comm registry from app and library

The way the comm and pids are associated may be different with different
apps. Let the app decide how it will register a mapping of comm and
pid.

Created trace-util.c file to hold the app side of comms.

Create pevent_register_comm to implement the library register routine.

Signed-off-by: Steven Rostedt <rostedt@goodmis.org>

4 files changed, 60 insertions, 25 deletions

diff --git a/Makefile b/Makefile
index 7472c11..473682d 100644
--- a/Makefile
+++ b/Makefile
@@ -18,7 +18,7 @@ LIB_FILE = libparsevent.a
 trace-read.o::          parse-events.h
 trace-cmd.o::           parse-events.h $(LIB_FILE)
 
-trace-cmd:: trace-cmd.o trace-read.o
+trace-cmd:: trace-cmd.o trace-read.o trace-util.o
         $(CC) $^ $(LIBS) -o $@
 
 parse-events.o: parse-events.c parse-events.h
diff --git a/parse-events.c b/parse-events.c
index 46eaf08..c03dc08 100644
--- a/parse-events.c
+++ b/parse-events.c
@@ -84,41 +84,32 @@ static int cmdline_cmp(const void *a, const void *b)
         return 0;
 }
 
-void parse_cmdlines(char *file, int size __unused)
+static struct cmdline_list {
+        struct cmdline_list     *next;
+        char                    *comm;
+        int                     pid;
+} *cmdlist = NULL;
+
+static int cmdline_init(void)
 {
-        struct cmdline_list {
-                struct cmdline_list     *next;
-                char                    *comm;
-                int                     pid;
-        } *list = NULL, *item;
-        char *line;
-        char *next = NULL;
+        struct cmdline_list *item;
         int i;
 
-        line = strtok_r(file, "\n", &next);
-        while (line) {
-                item = malloc_or_die(sizeof(*item));
-                sscanf(line, "%d %as", &item->pid,
-                       (float *)(void *)&item->comm); /* workaround gcc warning */
-                item->next = list;
-                list = item;
-                line = strtok_r(NULL, "\n", &next);
-                cmdline_count++;
-        }
-
         cmdlines = malloc_or_die(sizeof(*cmdlines) * cmdline_count);
 
         i = 0;
-        while (list) {
-                cmdlines[i].pid = list->pid;
-                cmdlines[i].comm = list->comm;
+        while (cmdlist) {
+                cmdlines[i].pid = cmdlist->pid;
+                cmdlines[i].comm = cmdlist->comm;
                 i++;
-                item = list;
-                list = list->next;
+                item = cmdlist;
+                cmdlist = cmdlist->next;
                 free(item);
         }
 
         qsort(cmdlines, cmdline_count, sizeof(*cmdlines), cmdline_cmp);
+
+        return 0;
 }
 
 static char *find_cmdline(int pid)
@@ -129,6 +120,9 @@ static char *find_cmdline(int pid)
         if (!pid)
                 return "<idle>";
 
+        if (!cmdlines)
+                cmdline_init();
+
         key.pid = pid;
 
         comm = bsearch(&key, cmdlines, cmdline_count, sizeof(*cmdlines),
@@ -139,6 +133,21 @@ static char *find_cmdline(int pid)
         return "<...>";
 }
 
+int pevent_register_comm(char *comm, int pid)
+{
+        struct cmdline_list *item;
+
+        item = malloc_or_die(sizeof(*item));
+        item->comm = comm;
+        item->pid = pid;
+        item->next = cmdlist;
+
+        cmdlist = item;
+        cmdline_count++;
+
+        return 0;
+}
+
 static struct func_map {
         unsigned long long              addr;
         char                            *func;
diff --git a/parse-events.h b/parse-events.h
index 8516672..41a57cc 100644
--- a/parse-events.h
+++ b/parse-events.h
@@ -306,4 +306,6 @@ enum trace_flag_type {
         TRACE_FLAG_SOFTIRQ              = 0x10,
 };
 
+int pevent_register_comm(char *comm, int pid);
+
 #endif /* _PARSE_EVENTS_H */
diff --git a/trace-util.c b/trace-util.c
new file mode 100644
index 0000000..563a75e
--- /dev/null
+++ b/trace-util.c
@@ -0,0 +1,24 @@
+#define _GNU_SOURCE
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <ctype.h>
+#include <errno.h>
+
+#include "parse-events.h"
+
+void parse_cmdlines(char *file, int size __unused)
+{
+        char *comm;
+        char *line;
+        char *next = NULL;
+        int pid;
+
+        line = strtok_r(file, "\n", &next);
+        while (line) {
+                sscanf(line, "%d %as", &pid,
+                       (float *)(void *)&comm); /* workaround gcc warning */
+                pevent_register_comm(comm, pid);
+                line = strtok_r(NULL, "\n", &next);
+        }
+}