library: recycle the QUICK_THREADS #define, <PIDS> api

That #define QUICK_THREADS was impossible to implement
under the new <pids> interface. Plus it was also found
to distort some thread information (referenced below).

So, it's always been inactive under the newlib branch.

However, it will (with small changes) still serve some
useful purpose in our library. Now, when the redefined
FALSE_THREADS is active, those special strings showing
"[ duplicate ENUM ]" will appear for any child thread.

Note: the real reason for such strings appearing isn't
being exercised, only their mechanics. In actual usage
they are substituted when a user duplicates such items
in a results stack & only the 1st instance can own it.

With this patch, we are simply fooling the <pids> code
into thinking an item was duplicated via a NULL value.

Reference(s):
. from master branch
commit 25a6ecdbfb3262261465ce1dd0e0e758cf3ac497

Signed-off-by: Jim Warner <james.warner@comcast.net>

diff --git a/proc/readproc.c b/proc/readproc.c
index a434be03fec7e2b566706523eb67a80827e941d9..d06d024fb1773b78dfe4e4335db069768308c0fa 100644 (file)
--- a/proc/readproc.c
+++ b/proc/readproc.c
@@ -52,7 +52,7 @@ extern void __cyg_profile_func_enter(void*,void*);
 #define LEAVE(x)
 #endif
 
-#ifdef QUICK_THREADS
+#ifdef FALSE_THREADS
 // used when multi-threaded and some memory must not be freed
 #define MK_THREAD(q)   q->pad_1 =  '\xee'
 #define IS_THREAD(q) ( q->pad_1 == '\xee' )
@@ -88,29 +88,24 @@ static int task_dir_missing;
 // free any additional dynamically acquired storage associated with a proc_t
 // ( and if it's to be reused, refresh it otherwise destroy it )
 static inline void free_acquired (proc_t *p, int reuse) {
-#ifdef QUICK_THREADS
-    if (!IS_THREAD(p)) {
-#endif
-        if (p->environ)   free((void*)p->environ);
-        if (p->cmdline)   free((void*)p->cmdline);
-        if (p->cgname)    free((void*)p->cgname);
-        if (p->cgroup)    free((void*)p->cgroup);
-        if (p->environ_v) free((void*)*p->environ_v);
-        if (p->cmdline_v) free((void*)*p->cmdline_v);
-        if (p->cgroup_v)  free((void*)*p->cgroup_v);
-        if (p->supgid)    free(p->supgid);
-        if (p->supgrp)    free(p->supgrp);
-        if (p->cmd)       free(p->cmd);
-        if (p->sd_mach)   free(p->sd_mach);
-        if (p->sd_ouid)   free(p->sd_ouid);
-        if (p->sd_seat)   free(p->sd_seat);
-        if (p->sd_sess)   free(p->sd_sess);
-        if (p->sd_slice)  free(p->sd_slice);
-        if (p->sd_unit)   free(p->sd_unit);
-        if (p->sd_uunit)  free(p->sd_uunit);
-#ifdef QUICK_THREADS
-    }
-#endif
+    if (p->environ)   free((void*)p->environ);
+    if (p->cmdline)   free((void*)p->cmdline);
+    if (p->cgname)    free((void*)p->cgname);
+    if (p->cgroup)    free((void*)p->cgroup);
+    if (p->environ_v) free((void*)*p->environ_v);
+    if (p->cmdline_v) free((void*)*p->cmdline_v);
+    if (p->cgroup_v)  free((void*)*p->cgroup_v);
+    if (p->supgid)    free(p->supgid);
+    if (p->supgrp)    free(p->supgrp);
+    if (p->cmd)       free(p->cmd);
+    if (p->sd_mach)   free(p->sd_mach);
+    if (p->sd_ouid)   free(p->sd_ouid);
+    if (p->sd_seat)   free(p->sd_seat);
+    if (p->sd_sess)   free(p->sd_sess);
+    if (p->sd_slice)  free(p->sd_slice);
+    if (p->sd_unit)   free(p->sd_unit);
+    if (p->sd_uunit)  free(p->sd_uunit);
+
     memset(p, reuse ? '\0' : '\xff', sizeof(*p));
 }
 
@@ -391,7 +386,11 @@ ENTER(0x220);
     {   char *nl = strchr(S, '\n');
         int j = nl ? (nl - S) : strlen(S);
 
+#ifdef FALSE_THREADS
+        if (j && !IS_THREAD(P)) {
+#else
         if (j) {
+#endif
             P->supgid = xmalloc(j+1);       // +1 in case space disappears
             memcpy(P->supgid, S, j);
             if (' ' != P->supgid[--j]) ++j;
@@ -448,7 +447,11 @@ ENTER(0x220);
         P->tid  = Pid;
     }
 
+#ifdef FALSE_THREADS
+    if (!P->supgid && !IS_THREAD(P))
+#else
     if (!P->supgid)
+#endif
         P->supgid = xstrdup("-");
 
 LEAVE(0x220);
@@ -954,7 +957,7 @@ next_proc:
 
 //////////////////////////////////////////////////////////////////////////////////
 // This reads /proc/*/task/* data, for one task.
-#ifdef QUICK_THREADS
+#ifdef FALSE_THREADS
 // p is the POSIX process (task group summary) & source for some copies if !NULL
 #else
 // p is the POSIX process (task group summary) (not needed by THIS implementation)
@@ -981,7 +984,12 @@ static proc_t* simple_readtask(PROCTAB *restrict const PT, const proc_t *restric
         stat2proc(ub.buf, t);
     }
 
-#ifndef QUICK_THREADS
+#ifdef FALSE_THREADS
+    if (p)
+        MK_THREAD(t);
+#endif
+
+#ifndef FALSE_THREADS
     if (flags & PROC_FILLMEM)                           // read /proc/#/task/#statm
         if (file2str(path, "statm", &ub) != -1)
             statm2proc(ub.buf, t);
@@ -990,7 +998,7 @@ static proc_t* simple_readtask(PROCTAB *restrict const PT, const proc_t *restric
     if (flags & PROC_FILLSTATUS) {                      // read /proc/#/task/#/status
         if (file2str(path, "status", &ub) != -1) {
             status2proc(ub.buf, t, 0);
-#ifndef QUICK_THREADS
+#ifndef FALSE_THREADS
             if (flags & PROC_FILLSUPGRP)
                 supgrps_from_supgids(t);
 #endif
@@ -1019,7 +1027,7 @@ static proc_t* simple_readtask(PROCTAB *restrict const PT, const proc_t *restric
         }
     }
 
-#ifdef QUICK_THREADS
+#ifdef FALSE_THREADS
     if (!p) {
         if (flags & PROC_FILLMEM)
             if (file2str(path, "statm", &ub) != -1)
@@ -1046,36 +1054,33 @@ static proc_t* simple_readtask(PROCTAB *restrict const PT, const proc_t *restric
         if (flags & PROC_FILLSYSTEMD)                   // get sd-login.h stuff
             sd2proc(t);
 
-        if (flags & PROC_FILL_LXC)                      // value the lxc name
-            t->lxcname = lxc_containers(path);
-
-#ifdef QUICK_THREADS
+#ifdef FALSE_THREADS
     } else {
-        t->size      = p->size;
-        t->resident  = p->resident;
-        t->share     = p->share;
-        t->trs       = p->trs;
-        t->lrs       = p->lrs;
-        t->drs       = p->drs;
-        t->dt        = p->dt;
-        t->cmdline   = p->cmdline;     // better not free these until done with all threads!
-        t->cmdline_v = p->cmdline_v;
-        t->environ   = p->environ;
-        t->environ_v = p->environ_v;
-        t->cgname    = p->cgname;
-        t->cgroup    = p->cgroup;
-        t->cgroup_v  = p->cgroup_v;
-        t->supgid    = p->supgid;
-        t->supgrp    = p->supgrp;
-        t->sd_mach   = p->sd_mach;
-        t->sd_ouid   = p->sd_ouid;
-        t->sd_seat   = p->sd_seat;
-        t->sd_sess   = p->sd_sess;
-        t->sd_slice  = p->sd_slice;
-        t->sd_unit   = p->sd_unit;
-        t->sd_uunit  = p->sd_uunit;
-        t->lxcname   = p->lxcname;
-        MK_THREAD(t);
+        if (t != p) {
+            t->size      = p->size;
+            t->resident  = p->resident;
+            t->share     = p->share;
+            t->trs       = p->trs;
+            t->lrs       = p->lrs;
+            t->drs       = p->drs;
+            t->dt        = p->dt;
+            t->cmdline   = NULL;
+            t->cmdline_v = NULL;
+            t->environ   = NULL;
+            t->environ_v = NULL;
+            t->cgname    = NULL;
+            t->cgroup    = NULL;
+            t->cgroup_v  = NULL;
+            t->supgid    = NULL;
+            t->supgrp    = NULL;
+            t->sd_mach   = NULL;
+            t->sd_ouid   = NULL;
+            t->sd_seat   = NULL;
+            t->sd_sess   = NULL;
+            t->sd_slice  = NULL;
+            t->sd_unit   = NULL;
+            t->sd_uunit  = NULL;
+        }
     }
 #endif
 
@@ -1089,9 +1094,12 @@ static proc_t* simple_readtask(PROCTAB *restrict const PT, const proc_t *restric
     if (flags & PROC_FILLNS)                            // read /proc/#/task/#/ns/*
         procps_ns_read_pid(t->tid, &(t->ns));
 
+    if (flags & PROC_FILL_LXC)
+        t->lxcname = lxc_containers(path);
+
     return t;
 next_task:
-#ifndef QUICK_THREADS
+#ifndef FALSE_THREADS
     (void)p;
 #endif
     return NULL;

diff --git a/proc/readproc.h b/proc/readproc.h
index 647c8578920ea4bf7162595a4283c60c0246b537..5e3b906d1dd08eaa0a90fecb89754cbad0711260 100644 (file)
--- a/proc/readproc.h
+++ b/proc/readproc.h
@@ -16,7 +16,8 @@
 #include <proc/namespace.h>
 
 #define SIGNAL_STRING
-//#define QUICK_THREADS        /* copy (vs. read) some thread info from parent proc_t */
+// the following is development only, forcing display of "[ duplicate ENUM ]" strings
+// #define FALSE_THREADS        /* set most child string fields to NULL */
 
 __BEGIN_DECLS
 
@@ -50,7 +51,7 @@ typedef struct proc_t {
         pcpu;           // stat (special)  %CPU usage (is not filled in by readproc!!!)
     char
        state,          // stat,status     single-char code for process state (S=sleeping)
-#ifdef QUICK_THREADS
+#ifdef FALSE_THREADS
         pad_1,          // n/a             padding (psst, also used if multi-threaded)
 #else
         pad_1,          // n/a             padding