xref: /linux/tools/lib/api/fd/array.c (revision efc7d01a9ecdc59946fad1743d96a0db9925064c)
1  // SPDX-License-Identifier: GPL-2.0-only
2  /*
3   * Copyright (C) 2014, Red Hat Inc, Arnaldo Carvalho de Melo <acme@redhat.com>
4   */
5  #include "array.h"
6  #include <errno.h>
7  #include <fcntl.h>
8  #include <poll.h>
9  #include <stdlib.h>
10  #include <unistd.h>
11  #include <string.h>
12  
13  void fdarray__init(struct fdarray *fda, int nr_autogrow)
14  {
15  	fda->entries	 = NULL;
16  	fda->priv	 = NULL;
17  	fda->nr		 = fda->nr_alloc = 0;
18  	fda->nr_autogrow = nr_autogrow;
19  }
20  
21  int fdarray__grow(struct fdarray *fda, int nr)
22  {
23  	struct priv *priv;
24  	int nr_alloc = fda->nr_alloc + nr;
25  	size_t psize = sizeof(fda->priv[0]) * nr_alloc;
26  	size_t size  = sizeof(struct pollfd) * nr_alloc;
27  	struct pollfd *entries = realloc(fda->entries, size);
28  
29  	if (entries == NULL)
30  		return -ENOMEM;
31  
32  	priv = realloc(fda->priv, psize);
33  	if (priv == NULL) {
34  		free(entries);
35  		return -ENOMEM;
36  	}
37  
38  	memset(&entries[fda->nr_alloc], 0, sizeof(struct pollfd) * nr);
39  	memset(&priv[fda->nr_alloc], 0, sizeof(fda->priv[0]) * nr);
40  
41  	fda->nr_alloc = nr_alloc;
42  	fda->entries  = entries;
43  	fda->priv     = priv;
44  	return 0;
45  }
46  
47  struct fdarray *fdarray__new(int nr_alloc, int nr_autogrow)
48  {
49  	struct fdarray *fda = calloc(1, sizeof(*fda));
50  
51  	if (fda != NULL) {
52  		if (fdarray__grow(fda, nr_alloc)) {
53  			free(fda);
54  			fda = NULL;
55  		} else {
56  			fda->nr_autogrow = nr_autogrow;
57  		}
58  	}
59  
60  	return fda;
61  }
62  
63  void fdarray__exit(struct fdarray *fda)
64  {
65  	free(fda->entries);
66  	free(fda->priv);
67  	fdarray__init(fda, 0);
68  }
69  
70  void fdarray__delete(struct fdarray *fda)
71  {
72  	fdarray__exit(fda);
73  	free(fda);
74  }
75  
76  int fdarray__add(struct fdarray *fda, int fd, short revents, enum fdarray_flags flags)
77  {
78  	int pos = fda->nr;
79  
80  	if (fda->nr == fda->nr_alloc &&
81  	    fdarray__grow(fda, fda->nr_autogrow) < 0)
82  		return -ENOMEM;
83  
84  	fda->entries[fda->nr].fd     = fd;
85  	fda->entries[fda->nr].events = revents;
86  	fda->priv[fda->nr].flags = flags;
87  	fda->nr++;
88  	return pos;
89  }
90  
91  int fdarray__filter(struct fdarray *fda, short revents,
92  		    void (*entry_destructor)(struct fdarray *fda, int fd, void *arg),
93  		    void *arg)
94  {
95  	int fd, nr = 0;
96  
97  	if (fda->nr == 0)
98  		return 0;
99  
100  	for (fd = 0; fd < fda->nr; ++fd) {
101  		if (!fda->entries[fd].events)
102  			continue;
103  
104  		if (fda->entries[fd].revents & revents) {
105  			if (entry_destructor)
106  				entry_destructor(fda, fd, arg);
107  
108  			fda->entries[fd].revents = fda->entries[fd].events = 0;
109  			continue;
110  		}
111  
112  		if (!(fda->priv[fd].flags & fdarray_flag__nonfilterable))
113  			++nr;
114  	}
115  
116  	return nr;
117  }
118  
119  int fdarray__poll(struct fdarray *fda, int timeout)
120  {
121  	return poll(fda->entries, fda->nr, timeout);
122  }
123  
124  int fdarray__fprintf(struct fdarray *fda, FILE *fp)
125  {
126  	int fd, printed = fprintf(fp, "%d [ ", fda->nr);
127  
128  	for (fd = 0; fd < fda->nr; ++fd)
129  		printed += fprintf(fp, "%s%d", fd ? ", " : "", fda->entries[fd].fd);
130  
131  	return printed + fprintf(fp, " ]");
132  }
133