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root/radiance/ray/src/common/rtprocess.h
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Comparing ray/src/common/rtprocess.h (file contents):
Revision 3.4 by schorsch, Mon Jul 14 22:23:59 2003 UTC vs.
Revision 3.19 by greg, Fri Feb 28 16:23:47 2020 UTC

# Line 9 | Line 9
9   #define _RAD_PROCESS_H_
10  
11   #include  <errno.h>
12 < #ifdef _WIN32
12 > #include <stdio.h>
13 > #if defined(_WIN32) || defined(_WIN64)
14    #include <windows.h> /* DWORD etc. */
15 <  typedef DWORD pid_t;
15 >  typedef DWORD RT_PID;
16    #include <process.h> /* getpid() and others */
17 +  #define getpid _getpid
18 +  #define execv _execv
19 +  #define execvp _execvp
20   #else
21    #include <sys/param.h>
22 +  #include <sys/types.h>
23 +  typedef pid_t RT_PID;
24   #endif
25  
26   #include "paths.h"
# Line 28 | Line 34 | extern "C" {
34  
35     This means that we shouldn't rely on PIDs and file descriptors
36     being the same type, so we have to describe processes with a struct,
37 <   instead of the original int[3]. To keep things simple, we typedef
38 <   the posix pid_t on those systems that don't have it already.
37 >   instead of the original int[3]. For that purpose, we typedef a
38 >   platform independent RT_PID.
39 > */
40  
41 <   Some older Windows systems use negative PIDs. Open_process() and
42 <   close_process() will convert those to positive values during
43 <   runtime, so that client modules can still use -1 as invalid PID.
41 > /* On Unix, we can set flags and assign descriptors before opening a
42 >   process, coupling an existing input or output to the new process rather
43 >   than opening both pipes.  If PF_FILT_INP is passed in the flags member of
44 >   SUBPROC, then the given r stream will be attached to the standard input
45 >   of the child process, and subsequent reads from that descriptor in the
46 >   parent get data from the standard output of the child, instead.  The
47 >   returned w descriptor is set to -1, since there is no longer any way
48 >   to write to the input of the child.  The default r descriptor of 0 will
49 >   compel the child to act as a filter on the standard input of the parent.
50 >   Whatever r handle you specify, the child will filter its read operations.
51 >   Note that this should be called before anything has been buffered using r.
52 >   If PF_FILT_OUT is set in flags, then the given w stream will be
53 >   attached to the standard output of the child, and subsequent writes
54 >   to that descriptor in the parent send data to the standard input
55 >   of the child. The returned r descriptor is set to -1, since
56 >   there is no output to read from any longer in the child.  The
57 >   default w descriptor of 1 will cause the child to act as a filter
58 >   on the output of the parent.  Make sure to call fflush(stdout) first
59 >   if any data was buffered.  It is illegal to set both PF_FILT_INP and
60 >   PF_FILT_OUT, as a circular process is guaranteed to hang.
61 >  
62 >   If you want behavior similar to popen(cmd, "w") (again Unix-only),
63 >   keeping stdout open in parent, use a duplicate descriptor like so:
64 >   {
65 >        SUBPROC rtp = sp_inactive;
66 >        FILE    *fout;
67 >        fflush(stdout);
68 >        rtp.w = dup(fileno(stdout));
69 >        rtp.flags |= PF_FILT_OUT;
70 >        if (open_process(&rtp, cmd_argv) <= 0) {
71 >                perror(cmd_argv[0]); exit(1);
72 >        }
73 >        fout = fdopen(rtp.w, "w");
74 >        ...write data to filter using fout until finished...
75 >        fclose(fout);
76 >        if (close_process(&rtp)) {
77 >                perror(cmd_argv[0]); exit(1);
78 >        }
79 >        ...can continue sending data directly to stdout...
80 >    }
81 >    We could also have called open_process() after fdopen() above, or after
82 >    using fopen() on a file if we wanted to insert our filter before it.
83 >    A similar sequence may be used to filter from stdin without closing
84 >    it, though process termination becomes more difficult with two readers.
85 >    Filtering input from a file works better, since the file is then read by
86 >    the child only, as in:
87 >    {
88 >        SUBPROC rtp = sp_inactive;
89 >        FILE    *fin = fopen(fname, "r");
90 >        if (fin == NULL) {
91 >                open_error(fname); exit(1);
92 >        }
93 >        rtp.r = fileno(fin);
94 >        rtp.flags |= PF_FILT_INP;
95 >        if (open_process(&rtp, cmd_argv) <= 0) {
96 >                perror(cmd_argv[0]); fclose(fin); exit(1);
97 >        }
98 >        ...read filtered file data from fin until EOF...
99 >        fclose(fin);
100 >        if (close_process(&rtp)) {
101 >                perror(cmd_argv[0]); exit(1);
102 >        }
103 >    }
104   */
105  
106  
# Line 48 | Line 115 | extern "C" {
115      #endif
116    #endif
117   #endif
118 +                                /* process flags */
119 + #define PF_RUNNING      1               /* process is running */
120 + #define PF_FILT_INP     2               /* use assigned read descriptor */
121 + #define PF_FILT_OUT     4               /* use assigned write descriptor */
122  
123   typedef struct {
124 <        int r; /* read handle */
125 <        int w; /* write handle */
126 <        int running; /* doing something */
127 <        pid_t pid; /* process ID */
124 >        int     flags;          /* what is being done */
125 >        int     r;              /* read handle */
126 >        int     w;              /* write handle */
127 >        RT_PID  pid;            /* process ID */
128   } SUBPROC;
129  
130 < #define SP_INACTIVE {-1,-1,0,0} /* for static initializations */
130 > #define SP_INACTIVE {0,0,1,-1}  /* for static initializations */
131  
132 + #define close_process(pd)       close_processes(pd,1)
133 +
134   extern int open_process(SUBPROC *pd, char *av[]);
135 < extern int close_process(SUBPROC *pd);
135 > extern int close_processes(SUBPROC pd[], int nproc);
136   extern int process(SUBPROC *pd, char *recvbuf, char *sendbuf, int nbr, int nbs);
137   extern int readbuf(int fd, char *bpos, int siz);
138   extern int writebuf(int fd, char *bpos, int siz);
139  
140 + #if defined(_WIN32) || defined(_WIN64)
141 + /* any non-negative increment will send the process to IDLE_PRIORITY_CLASS. */
142 + extern int win_kill(RT_PID pid, int sig /* ignored */);
143 + extern int win_nice(int inc);
144 + #endif
145 +
146 + extern SUBPROC  sp_inactive;
147  
148   #ifdef __cplusplus
149   }

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