source/gldbg.cpp

   1 /* $Id$
   2
   3 This file is part of gldbg
   4 Copyright © 2009  Mikko Rasa, Mikkosoft Productions
   5 Distributed under the GPL
   6 */
   7
   8 #include <cstdlib>
   9 #include <cerrno>
  10 #include <cstring>
  11 #include <sys/poll.h>
  12 #include <sys/socket.h>
  13 #include <sys/wait.h>
  14 #include <msp/core/except.h>
  15 #include <msp/fs/dir.h>
  16 #include <msp/io/print.h>
  17 #include <msp/strings/lexicalcast.h>
  18 #include "gldbg.h"
  19 #include "glprint.h"
  20
  21 using namespace std;
  22 using namespace Msp;
  23
  24 Application::RegApp<GlDbg> GlDbg::reg;
  25
  26 GlDbg::GlDbg(int argc, char **argv):
  27         pid(0),
  28         sock_fd(-1),
  29         glprint(glprint_new(0, 16384))
  30 {
  31         libdir = FS::get_sys_lib_dir(argv[0], "gldbg");
  32         args.assign(argv+1, argv+argc);
  33 }
  34
  35 int GlDbg::main()
  36 {
  37         catch_signal(SIGINT);
  38         launch();
  39
  40         Application::main();
  41 }
  42
  43 void GlDbg::tick()
  44 {
  45         int status;
  46         int ret = waitpid(pid, &status, WNOHANG);
  47         if(ret==pid)
  48         {
  49                 if(WIFEXITED(status) || WIFSIGNALED(status))
  50                 {
  51                         IO::print("Target process exited\n");
  52                         exit(0);
  53                 }
  54         }
  55
  56         pollfd pfd = { sock_fd, POLLIN, 0 };
  57         ret = poll(&pfd, 1, -1);
  58         if(ret>0)
  59         {
  60                 char rbuf[1024];
  61                 ret = read(sock_fd, rbuf, 1024);
  62                 if(ret>0)
  63                 {
  64                         buffer.append(rbuf, ret);
  65                         while(buffer.size()>buf_offset)
  66                         {
  67                                 int ret = gldecoder_decode(glprint, buffer.data()+buf_offset, buffer.size()-buf_offset);
  68                                 if(ret<0)
  69                                         break;
  70                                 buf_offset += ret;
  71                                 IO::print("%s\n", glprint_get_buffer(glprint));
  72                         }
  73                         if(buf_offset>8192)
  74                         {
  75                                 buffer.erase(0, buf_offset);
  76                                 buf_offset=0;
  77                         }
  78                 }
  79         }
  80 }
  81
  82 void GlDbg::launch()
  83 {
  84         int fds[2];
  85         socketpair(AF_UNIX, SOCK_STREAM, 0, fds);
  86         sock_fd = fds[0];
  87
  88         pid = fork();
  89         if(pid==0)
  90         {
  91                 string fd_str = lexical_cast(fds[1]);
  92                 setenv("LD_PRELOAD", (libdir/"glwrap.so").str().c_str(), true);
  93                 setenv("GLWRAP_FD", fd_str.c_str(), true);
  94                 close(fds[0]);
  95                 std::vector<char *> argv(args.size()+1);
  96                 for(unsigned i=0; i<args.size(); ++i)
  97                         argv[i] = strdup(args[i].c_str());
  98                 argv[args.size()] = 0;
  99                 execvp(argv[0], &argv[0]);
 100                 ::exit(127);
 101         }
 102         else if(pid>0)
 103         {
 104                 close(fds[1]);
 105         }
 106         else
 107         {
 108                 throw SystemError("Could not launch process", errno);
 109         }
 110 }