htop/TraceScreen.c

/*
htop - TraceScreen.c
(C) 2005-2006 Hisham H. Muhammad
Released under the GNU GPLv2, see the COPYING file
in the source distribution for its full text.
*/

#include "TraceScreen.h"

#include "CRT.h"
#include "ProcessList.h"
#include "ListItem.h"
#include "IncSet.h"
#include "StringUtils.h"
#include "FunctionBar.h"

#include <stdio.h>
#include <unistd.h>
#include <string.h>
#include <stdlib.h>
#include <stdbool.h>
#include <unistd.h>
#include <fcntl.h>
#include <sys/time.h>
#include <sys/types.h>
#include <sys/wait.h>
#include <signal.h>


static const char* const TraceScreenFunctions[] = {"Search ", "Filter ", "AutoScroll ", "Stop Tracing   ", "Done   ", NULL};

static const char* const TraceScreenKeys[] = {"F3", "F4", "F8", "F9", "Esc"};

static int TraceScreenEvents[] = {KEY_F(3), KEY_F(4), KEY_F(8), KEY_F(9), 27};

const InfoScreenClass TraceScreen_class = {
   .super = {
      .extends = Class(Object),
      .delete = TraceScreen_delete
   },
   .draw = TraceScreen_draw,
   .onErr = TraceScreen_updateTrace,
   .onKey = TraceScreen_onKey,
};

TraceScreen* TraceScreen_new(Process* process) {
   TraceScreen* this = xMalloc(sizeof(TraceScreen));
   Object_setClass(this, Class(TraceScreen));
   this->tracing = true;
   this->contLine = false;
   this->follow = false;
   FunctionBar* fuBar = FunctionBar_new(TraceScreenFunctions, TraceScreenKeys, TraceScreenEvents);
   CRT_disableDelay();
   return (TraceScreen*) InfoScreen_init(&this->super, process, fuBar, LINES-2, "");
}

void TraceScreen_delete(Object* cast) {
   TraceScreen* this = (TraceScreen*) cast;
   if (this->child > 0) {
      kill(this->child, SIGTERM);
      waitpid(this->child, NULL, 0);
      fclose(this->strace);
   }
   CRT_enableDelay();
   free(InfoScreen_done((InfoScreen*)cast));
}

void TraceScreen_draw(InfoScreen* this) {
   attrset(CRT_colors[PANEL_HEADER_FOCUS]);
   mvhline(0, 0, ' ', COLS);
   mvprintw(0, 0, "Trace of process %d - %s", this->process->pid, this->process->comm);
   attrset(CRT_colors[DEFAULT_COLOR]);
   IncSet_drawBar(this->inc);
}

bool TraceScreen_forkTracer(TraceScreen* this) {
   int error = pipe(this->fdpair);
   if (error == -1) return false;
   this->child = fork();
   if (this->child == -1) return false;
   if (this->child == 0) {
      CRT_dropPrivileges();
      dup2(this->fdpair[1], STDERR_FILENO);
      int ok = fcntl(this->fdpair[1], F_SETFL, O_NONBLOCK);
      if (ok != -1) {
         char buffer[32] = {0};
         xSnprintf(buffer, sizeof(buffer), "%d", this->super.process->pid);
         execlp("strace", "strace", "-T", "-tt", "-s", "512", "-p", buffer, NULL);
      }
      const char* message = "Could not execute 'strace'. Please make sure it is available in your $PATH.";
      ssize_t written = write(this->fdpair[1], message, strlen(message));
      (void) written;
      exit(1);
   }
   int ok = fcntl(this->fdpair[0], F_SETFL, O_NONBLOCK);
   if (ok == -1) return false;
   this->strace = fdopen(this->fdpair[0], "r");
   this->fd_strace = fileno(this->strace);
   return true;
}

void TraceScreen_updateTrace(InfoScreen* super) {
   TraceScreen* this = (TraceScreen*) super;
   char buffer[1025];
   fd_set fds;
   FD_ZERO(&fds);
// FD_SET(STDIN_FILENO, &fds);
   FD_SET(this->fd_strace, &fds);
   struct timeval tv;
   tv.tv_sec = 0; tv.tv_usec = 500;
   int ready = select(this->fd_strace+1, &fds, NULL, NULL, &tv);
   size_t nread = 0;
   if (ready > 0 && FD_ISSET(this->fd_strace, &fds))
      nread = fread(buffer, 1, sizeof(buffer) - 1, this->strace);
   if (nread && this->tracing) {
      const char* line = buffer;
      buffer[nread] = '\0';
      for (size_t i = 0; i < nread; i++) {
         if (buffer[i] == '\n') {
            buffer[i] = '\0';
            if (this->contLine) {
               InfoScreen_appendLine(&this->super, line);
               this->contLine = false;
            } else {
               InfoScreen_addLine(&this->super, line);
            }
            line = buffer+i+1;
         }
      }
      if (line < buffer+nread) {
         InfoScreen_addLine(&this->super, line);
         buffer[nread] = '\0';
         this->contLine = true;
      }
      if (this->follow)
         Panel_setSelected(this->super.display, Panel_size(this->super.display)-1);
   }
}

bool TraceScreen_onKey(InfoScreen* super, int ch) {
   TraceScreen* this = (TraceScreen*) super;
   switch(ch) {
      case 'f':
      case KEY_F(8):
         this->follow = !(this->follow);
         if (this->follow)
            Panel_setSelected(super->display, Panel_size(super->display)-1);
         return true;
      case 't':
      case KEY_F(9):
         this->tracing = !this->tracing;
         FunctionBar_setLabel(super->display->defaultBar, KEY_F(9), this->tracing?"Stop Tracing   ":"Resume Tracing ");
         InfoScreen_draw(this);
         return true;
   }
   this->follow = false;
   return false;
}