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root/radiance/ray/src/common/rtprocess.h
Revision: 3.18
Committed: Fri Feb 28 05:18:49 2020 UTC (4 years, 2 months ago) by greg
Content type: text/plain
Branch: MAIN
Changes since 3.17: +33 -6 lines
Log Message:
Added filtering capabilities to Unix version of open_process()

File Contents

# User Rev Content
1 greg 3.18 /* RCSid $Id: rtprocess.h,v 3.17 2018/03/20 17:45:07 greg Exp $ */
2 schorsch 3.1 /*
3     * rtprocess.h
4     * Routines to communicate with separate process via dual pipes
5     *
6     * WARNING: On Windows, there's a system header named <process.h>.
7     */
8     #ifndef _RAD_PROCESS_H_
9     #define _RAD_PROCESS_H_
10    
11 schorsch 3.3 #include <errno.h>
12 greg 3.13 #include <stdio.h>
13 schorsch 3.16 #if defined(_WIN32) || defined(_WIN64)
14 schorsch 3.3 #include <windows.h> /* DWORD etc. */
15 schorsch 3.10 typedef DWORD RT_PID;
16 schorsch 3.3 #include <process.h> /* getpid() and others */
17 schorsch 3.16 #define getpid _getpid
18     #define execv _execv
19 greg 3.17 #define execvp _execvp
20 schorsch 3.1 #else
21     #include <sys/param.h>
22 schorsch 3.10 #include <sys/types.h>
23     typedef pid_t RT_PID;
24 schorsch 3.1 #endif
25    
26     #include "paths.h"
27    
28 schorsch 3.4 #ifdef __cplusplus
29     extern "C" {
30     #endif
31 schorsch 3.1
32     /* On Windows, a process ID is a DWORD. That might actually be the
33     same thing as an int, but it's better not to assume anything.
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 schorsch 3.10 instead of the original int[3]. For that purpose, we typedef a
38     platform independent RT_PID.
39 schorsch 3.1 */
40    
41 greg 3.18 /* 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    
63 schorsch 3.1
64     #ifndef PIPE_BUF
65     #ifdef PIPSIZ
66     #define PIPE_BUF PIPSIZ
67     #else
68     #ifdef PIPE_MAX
69     #define PIPE_BUF PIPE_MAX
70     #else
71     #define PIPE_BUF 512 /* hyperconservative */
72     #endif
73     #endif
74     #endif
75 greg 3.18 /* process flags */
76     #define PF_RUNNING 1 /* process is running */
77     #define PF_FILT_INP 2 /* use assigned read descriptor */
78     #define PF_FILT_OUT 4 /* use assigned write descriptor */
79 schorsch 3.1
80     typedef struct {
81 greg 3.18 int flags; /* what is being done */
82     int r; /* read handle */
83     int w; /* write handle */
84     RT_PID pid; /* process ID */
85 schorsch 3.1 } SUBPROC;
86    
87 greg 3.18 #define SP_INACTIVE {0,0,1,-1} /* for static initializations */
88 schorsch 3.1
89 greg 3.15 #define close_process(pd) close_processes(pd,1)
90    
91 schorsch 3.1 extern int open_process(SUBPROC *pd, char *av[]);
92 greg 3.15 extern int close_processes(SUBPROC pd[], int nproc);
93 schorsch 3.1 extern int process(SUBPROC *pd, char *recvbuf, char *sendbuf, int nbr, int nbs);
94     extern int readbuf(int fd, char *bpos, int siz);
95     extern int writebuf(int fd, char *bpos, int siz);
96 schorsch 3.5
97 schorsch 3.16 #if defined(_WIN32) || defined(_WIN64)
98 schorsch 3.5 /* any non-negative increment will send the process to IDLE_PRIORITY_CLASS. */
99 greg 3.14 extern int win_kill(RT_PID pid, int sig /* ignored */);
100 schorsch 3.5 extern int win_nice(int inc);
101     #endif
102 schorsch 3.1
103 greg 3.18 extern SUBPROC sp_inactive;
104 schorsch 3.1
105     #ifdef __cplusplus
106     }
107     #endif
108     #endif /* _RAD_PROCESS_H_ */
109