Performance improvement hackathon: improve process comparison routines,

disable useless code in release builds such as runtime type-checking on
dynamic data structures and process fields that are not being computed,
faster(?) method for verifying the process owner (still need to ensure
correctness), don't destroy and create process objects for hidden kernel
threads over and over. Phew. I shouldn't be doing all this today, but I
could not resist.

1 files changed, 88 insertions, 52 deletions

diff --git a/ProcessList.c b/ProcessList.c
index fb7f8e9d..d6984568 100644
--- a/ProcessList.c
+++ b/ProcessList.c
@@ -15,6 +15,7 @@ in the source distribution for its full text.
 #include "Vector.h"
 #include "UsersTable.h"
 #include "Hashtable.h"
+#include "String.h"
 
 #include <sys/types.h>
 #include <sys/stat.h>
@@ -48,13 +49,17 @@ in the source distribution for its full text.
 #endif
 
 #ifndef MAX_READ
-#define MAX_READ 8192
+#define MAX_READ 2048
 #endif
 
 }*/
 
 /*{
 
+#ifdef DEBUG
+typedef int(*vxscanf)(void*, const char*, va_list);
+#endif
+
 typedef struct ProcessList_ {
    Vector* processes;
    Vector* processes2;
@@ -108,8 +113,6 @@ static ProcessField defaultHeaders[] = { PID, USER, PRIORITY, NICE, M_SIZE, M_RE
 
 #ifdef DEBUG
 
-typedef int(*vxscanf)(void*, const char*, va_list);
-
 #define ProcessList_read(this, buffer, format, ...) ProcessList_xread(this, (vxscanf) vsscanf, buffer, format, ## __VA_ARGS__ )
 #define ProcessList_fread(this, file, format, ...)  ProcessList_xread(this, (vxscanf) vfscanf, file, format, ## __VA_ARGS__ )
 
@@ -173,13 +176,13 @@ static inline int ProcessList_xread(ProcessList* this, vxscanf fn, void* buffer,
 ProcessList* ProcessList_new(UsersTable* usersTable) {
    ProcessList* this;
    this = malloc(sizeof(ProcessList));
-   this->processes = Vector_new(PROCESS_CLASS, true, DEFAULT_SIZE);
+   this->processes = Vector_new(PROCESS_CLASS, true, DEFAULT_SIZE, Process_compare);
    this->processTable = Hashtable_new(20, false);
    this->prototype = Process_new(this);
    this->usersTable = usersTable;
    
    /* tree-view auxiliary buffers */
-   this->processes2 = Vector_new(PROCESS_CLASS, true, DEFAULT_SIZE);
+   this->processes2 = Vector_new(PROCESS_CLASS, true, DEFAULT_SIZE, Process_compare);
    
    #ifdef DEBUG
    this->traceFile = fopen("/tmp/htop-proc-trace", "w");
@@ -286,11 +289,8 @@ void ProcessList_add(ProcessList* this, Process* p) {
 
 void ProcessList_remove(ProcessList* this, Process* p) {
    Hashtable_remove(this->processTable, p->pid);
-   ProcessField pf = this->sortKey;
-   this->sortKey = PID;
-   int index = Vector_indexOf(this->processes, p);
+   int index = Vector_indexOf(this->processes, p, Process_pidCompare);
    Vector_remove(this->processes, index);
-   this->sortKey = pf;
 }
 
 Process* ProcessList_get(ProcessList* this, int index) {
@@ -302,7 +302,7 @@ int ProcessList_size(ProcessList* this) {
 }
 
 static void ProcessList_buildTree(ProcessList* this, int pid, int level, int indent, int direction) {
-   Vector* children = Vector_new(PROCESS_CLASS, false, DEFAULT_SIZE);
+   Vector* children = Vector_new(PROCESS_CLASS, false, DEFAULT_SIZE, Process_compare);
 
    for (int i = 0; i < Vector_size(this->processes); i++) {
       Process* process = (Process*) (Vector_get(this->processes, i));
@@ -352,7 +352,7 @@ void ProcessList_sort(ProcessList* this) {
 
 static int ProcessList_readStatFile(ProcessList* this, Process *proc, FILE *f, char *command) {
    static char buf[MAX_READ];
-   long int zero;
+   unsigned long int zero;
 
    int size = fread(buf, 1, MAX_READ, f);
    if(!size) return 0;
@@ -370,6 +370,7 @@ static int ProcessList_readStatFile(ProcessList* this, Process *proc, FILE *f, c
    command[commsize] = '\0';
    location = end + 2;
    
+   #ifdef DEBUG
    int num = ProcessList_read(this, location, 
       "%c %d %d %d %d %d %lu %lu %lu %lu "
       "%lu %lu %lu %ld %ld %ld %ld %ld %ld "
@@ -377,14 +378,34 @@ static int ProcessList_readStatFile(ProcessList* this, Process *proc, FILE *f, c
       "%lu %lu %lu %lu %lu %lu %lu %lu "
       "%d %d",
       &proc->state, &proc->ppid, &proc->pgrp, &proc->session, &proc->tty_nr, 
-      &proc->tpgid, &proc->flags, &proc->minflt, &proc->cminflt, &proc->majflt, 
-      &proc->cmajflt, &proc->utime, &proc->stime, &proc->cutime, &proc->cstime, 
+      &proc->tpgid, &proc->flags,
+      &proc->minflt, &proc->cminflt, &proc->majflt, &proc->cmajflt,
+      &proc->utime, &proc->stime, &proc->cutime, &proc->cstime, 
       &proc->priority, &proc->nice, &zero, &proc->itrealvalue, 
       &proc->starttime, &proc->vsize, &proc->rss, &proc->rlim, 
       &proc->startcode, &proc->endcode, &proc->startstack, &proc->kstkesp, 
       &proc->kstkeip, &proc->signal, &proc->blocked, &proc->sigignore, 
       &proc->sigcatch, &proc->wchan, &proc->nswap, &proc->cnswap, 
       &proc->exit_signal, &proc->processor);
+   #else
+   long int uzero;
+   int num = ProcessList_read(this, location, 
+      "%c %d %d %d %d %d %lu %lu %lu %lu "
+      "%lu %lu %lu %ld %ld %ld %ld %ld %ld "
+      "%lu %lu %ld %lu %lu %lu %lu %lu "
+      "%lu %lu %lu %lu %lu %lu %lu %lu "
+      "%d %d",
+      &proc->state, &proc->ppid, &proc->pgrp, &proc->session, &proc->tty_nr, 
+      &proc->tpgid, &proc->flags,
+      &zero, &zero, &zero, &zero,
+      &proc->utime, &proc->stime, &proc->cutime, &proc->cstime, 
+      &proc->priority, &proc->nice, &uzero, &uzero, 
+      &zero, &zero, &uzero, &zero, 
+      &zero, &zero, &zero, &zero, 
+      &zero, &zero, &zero, &zero, 
+      &zero, &zero, &zero, &zero, 
+      &proc->exit_signal, &proc->processor);
+   #endif
    
    // This assert is always valid on 2.4, but reportedly not always valid on 2.6.
    // TODO: Check if the semantics of this field has changed.
@@ -397,14 +418,15 @@ static int ProcessList_readStatFile(ProcessList* this, Process *proc, FILE *f, c
 bool ProcessList_readStatusFile(ProcessList* this, Process* proc, char* dirname, char* name) {
    char statusfilename[MAX_NAME+1];
    statusfilename[MAX_NAME] = '\0';
+   /*
+   bool success = false;
+   char buffer[256];
+   buffer[255] = '\0';
    snprintf(statusfilename, MAX_NAME, "%s/%s/status", dirname, name);
    FILE* status = ProcessList_fopen(this, statusfilename, "r");
-   bool success = false;
    if (status) {
-      char buffer[1024];
-      buffer[1023] = '\0';
       while (!feof(status)) {
-         char* ok = fgets(buffer, 1023, status);
+         char* ok = fgets(buffer, 255, status);
          if (!ok)
             break;
          if (String_startsWith(buffer, "Uid:")) {
@@ -421,14 +443,18 @@ bool ProcessList_readStatusFile(ProcessList* this, Process* proc, char* dirname,
       fclose(status);
    }
    if (!success) {
-      snprintf(statusfilename, MAX_NAME, "%s/%s/stat", dirname, name);
+   */
+      snprintf(statusfilename, MAX_NAME, "%s/%s", dirname, name);
       struct stat sstat;
       int statok = stat(statusfilename, &sstat);
       if (statok == -1)
          return false;
       proc->st_uid = sstat.st_uid;
-   }
-   return success;
+      return true;
+   /*
+   } else
+      return true;
+   */
 }
 
 void ProcessList_processEntries(ProcessList* this, char* dirname, int parent, float period) {
@@ -469,25 +495,25 @@ void ProcessList_processEntries(ProcessList* this, char* dirname, int parent, fl
          char command[PROCESS_COMM_LEN + 1];
 
          Process* process;
+
          Process* existingProcess = (Process*) Hashtable_get(this->processTable, pid);
-         if (!existingProcess) {
-            process = Process_clone(prototype);
+         if (existingProcess) {
+            process = existingProcess;
+         } else {
+            process = prototype;
+            process->comm = NULL;
             process->pid = pid;
-            ProcessList_add(this, process);
             if (! ProcessList_readStatusFile(this, process, dirname, name))
                goto errorReadingProcess;
-         } else {
-            process = existingProcess;
+            char* username = UsersTable_getRef(this->usersTable, process->st_uid);
+            if (username) {
+               strncpy(process->user, username, PROCESS_USER_LEN);
+            } else {
+               snprintf(process->user, PROCESS_USER_LEN, "%d", process->st_uid);
+            }
          }
          process->updated = true;
 
-         char* username = UsersTable_getRef(this->usersTable, process->st_uid);
-         if (username) {
-            strncpy(process->user, username, PROCESS_USER_LEN);
-         } else {
-            snprintf(process->user, PROCESS_USER_LEN, "%d", process->st_uid);
-         }
-
          int lasttimes = (process->utime + process->stime);
 
          snprintf(statusfilename, MAX_NAME, "%s/%s/stat", dirname, name);
@@ -498,13 +524,30 @@ void ProcessList_processEntries(ProcessList* this, char* dirname, int parent, fl
 
          int success = ProcessList_readStatFile(this, process, status, command);
          fclose(status);
-         if(!success) {
+         if(!success)
             goto errorReadingProcess;
-         }
 
          process->percent_cpu = (process->utime + process->stime - lasttimes) / 
             period * 100.0;
 
+         snprintf(statusfilename, MAX_NAME, "%s/%s/statm", dirname, name);
+         status = ProcessList_fopen(this, statusfilename, "r");
+
+         if(!status) {
+            goto errorReadingProcess;
+         }
+         int num = ProcessList_fread(this, status, "%d %d %d %d %d %d %d",
+             &process->m_size, &process->m_resident, &process->m_share, 
+             &process->m_trs, &process->m_drs, &process->m_lrs, 
+             &process->m_dt);
+
+         fclose(status);
+         if(num != 7)
+            goto errorReadingProcess;
+
+         if (this->hideKernelThreads && process->m_size == 0)
+            goto errorReadingProcess;
+
          if(!existingProcess) {
             snprintf(statusfilename, MAX_NAME, "%s/%s/cmdline", dirname, name);
             status = ProcessList_fopen(this, statusfilename, "r");
@@ -524,21 +567,6 @@ void ProcessList_processEntries(ProcessList* this, char* dirname, int parent, fl
             fclose(status);
          }
 
-         snprintf(statusfilename, MAX_NAME, "%s/%s/statm", dirname, name);
-         status = ProcessList_fopen(this, statusfilename, "r");
-
-         if(!status) {
-            goto errorReadingProcess;
-         }
-         int num = ProcessList_fread(this, status, "%d %d %d %d %d %d %d",
-             &process->m_size, &process->m_resident, &process->m_share, 
-             &process->m_trs, &process->m_drs, &process->m_lrs, 
-             &process->m_dt);
-
-         fclose(status);
-         if(num != 7)
-            goto errorReadingProcess;
-
          process->percent_mem = process->m_resident / 
             (float)(this->usedMem - this->cachedMem - this->buffersMem) * 
             100.0;
@@ -548,17 +576,25 @@ void ProcessList_processEntries(ProcessList* this, char* dirname, int parent, fl
             this->runningTasks++;
          }
 
-         if (this->hideKernelThreads && process->m_size == 0)
-            ProcessList_remove(this, process);
+         if (!existingProcess) {
+            process = Process_clone(process);
+            ProcessList_add(this, process);
+         }
 
          continue;
 
          // Exception handler.
          errorReadingProcess: {
-            ProcessList_remove(this, process);
+            if (existingProcess)
+               ProcessList_remove(this, process);
+            else {
+               if (process->comm)
+                  free(process->comm);
+            }
          }
       }
    }
+   prototype->comm = NULL;
    closedir(dir);
 }