diff mbox

[ovs-dev,v2,2/6] process: Retrieve process status.

Message ID 1493247595-79635-3-git-send-email-bhanuprakash.bodireddy@intel.com
State Deferred
Headers show

Commit Message

Bodireddy, Bhanuprakash April 26, 2017, 10:59 p.m. UTC 
Implement function to retrieve the process status. This will be used by
Keepalive monitoring thread for detecting false alarms.

Signed-off-by: Bhanuprakash Bodireddy <bhanuprakash.bodireddy@intel.com>
---
 lib/process.c | 60 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 lib/process.h | 10 ++++++++++
 2 files changed, 70 insertions(+)
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Patch

diff --git a/lib/process.c b/lib/process.c
index e9d0ba9..e35e643 100644
--- a/lib/process.c
+++ b/lib/process.c
@@ -50,6 +50,20 @@  struct process {
     int status;
 };
 
+struct pstate2Num {
+    char *tidState;
+    int num;
+};
+
+const struct pstate2Num pstate_map[] = {
+    { "S", STOPPED_STATE },
+    { "R", ACTIVE_STATE },
+    { "t", TRACED_STATE },
+    { "Z", DEFUNC_STATE },
+    { "D", UNINTERRUPTIBLE_SLEEP_STATE },
+    { "NULL", UNUSED_STATE },
+};
+
 /* Pipe used to signal child termination. */
 static int fds[2];
 
@@ -390,6 +404,52 @@  process_run(void)
 #endif
 }
 
+int
+get_process_status(int tid, int *pstate)
+{
+#ifdef __linux__
+    static char process_name[20];
+    FILE *stream;
+    char line[75];
+    char Name[15], value[5], status[20];
+    int i, ln;
+
+    snprintf(process_name, sizeof(process_name),
+             "/proc/%d/status", tid);
+    stream = fopen(process_name, "r");
+    if (stream == NULL) {
+        VLOG_WARN_ONCE("%s: open failed: %s", process_name,
+            ovs_strerror(errno));
+        return errno;
+    }
+
+    ln=0;
+    while (fgets(line, sizeof line, stream)) {
+        if (!ovs_scan(line,
+                      "%6s %2s %14s\n",
+                       Name, value, status)) {
+            VLOG_WARN_ONCE("%s: could not parse line %d: %s",
+                    process_name, ln, line);
+            continue;
+        }
+        if (!strcmp(Name, "State:")) {
+            for (i=0; pstate_map[i].tidState != NULL; i++) {
+                if (strcmp(pstate_map[i].tidState, value) == 0) {
+                    VLOG_INFO("The state is %s, status is %d\n",
+                        pstate_map[i].tidState, pstate_map[i].num);
+                    *pstate = pstate_map[i].num;
+                    break;
+                }
+            }
+            break;
+        }
+        ln++;
+   }
+   return 0;
+#else
+   return ENOSYS;
+#endif
+}
 
 /* Causes the next call to poll_block() to wake up when process 'p' has
  * exited. */
diff --git a/lib/process.h b/lib/process.h
index 3feac7e..8a5513e 100644
--- a/lib/process.h
+++ b/lib/process.h
@@ -20,6 +20,15 @@ 
 #include <stdbool.h>
 #include <sys/types.h>
 
+enum process_states {
+    UNUSED_STATE,
+    STOPPED_STATE,
+    ACTIVE_STATE,
+    TRACED_STATE,
+    DEFUNC_STATE,
+    UNINTERRUPTIBLE_SLEEP_STATE
+};
+
 struct process;
 
 /* Starting and monitoring subprocesses.
@@ -38,6 +47,7 @@  bool process_exited(struct process *);
 int process_status(const struct process *);
 void process_run(void);
 void process_wait(struct process *);
+int get_process_status(int, int *);
 
 /* These functions are thread-safe. */
 char *process_status_msg(int);