1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
|
/*
#include "thread.h"
// constants
#define GPIO_FN_MAXLEN 32
#define POLL_TIMEOUT 10000
#define RDBUF_LEN 5
// monitoring thread data structure
struct monitor_data{
int thread_id;
int pin;
int edgePin;
int lastKnownState;
int running;
};
struct monitor_data monitor_data_array[21];
pthread_t threads[21];
Thread::Thread()
{
}
Thread::~Thread()
{
}
void* Interrupt::monitorPinInterrupt(void *threadarg)
{
// obtain the monitoring data structure from the thread argument
struct monitor_data *monitorData;
monitorData = (struct monitor_data *) threadarg;
// cache a local pin value variabl
int pin = monitorData->pin;
int edgePin = monitorData->edgePin;
printf("\nNATIVE (GpioInterrupt) MONITORING PIN %d @ EDGE %d\n", pin, edgePin);
// monitoring instance variables
char fn[GPIO_FN_MAXLEN];
int fd,ret;
struct pollfd pfd;
char rdbuf[RDBUF_LEN];
// allocate memory
memset(rdbuf, 0x00, RDBUF_LEN);
memset(fn, 0x00, GPIO_FN_MAXLEN);
// attempt to access the pin state from the linux sysfs
// (each GPIO pin value is stored in file: '/sys/class/gpio/gpio#/value' )
snprintf(fn, GPIO_FN_MAXLEN-1, "/sys/class/gpio/gpio%d/value", edgePin);
fd=open(fn, O_RDONLY);
if(fd<0)
{
// return error; unable to get file descriptor
// (this is likely because the pin has not been exported)
perror(fn);
// return 2;
}
// set polling config structure
pfd.fd=fd;
pfd.events=POLLPRI; // High priority data may be read.
// attempt to read the pin state from the linux sysfs
ret=read(fd, rdbuf, RDBUF_LEN-1);
if(ret<0)
{
// return error; unable to read the data file
// (this is likely because the user has insufficient permissions)
perror("read()");
// return 4;
}
printf("value is: %s\n", rdbuf);
// set the running state of the instance monitor data structure
monitorData->running = 1;
// initialize last known value and cache the value as the last known state
int compareLastKnown = strncmp(rdbuf, "1", 1); // only compare the first character; rdbuff may have more junk chars
monitorData->lastKnownState = compareLastKnown;
// continuous thread loop
for(;;)
{
// clear/reset the data buffer
memset(rdbuf, 0x00, RDBUF_LEN);
// seek to the fist position in the data file
lseek(fd, 0, SEEK_SET);
// wait for data to be written to the GPIO value file
// (timeout every 10 seconds and restart)
ret=poll(&pfd, 1, POLL_TIMEOUT);
// if the return value is less than '0' then
// an error was thrown; bail out of the thread
if(ret<0)
{
perror("poll()");
close(fd);
// return 6;
}
// if the return value is equal to '0' then
// the polling simply timed out and we can restart
else if(ret==0)
{
printf("timeout\n");
continue;
}
// if the return value is greater than '0' then
// a change to the GPIO data file occurred
else
{
// read the data from the file into the data buffer
ret=read(fd, rdbuf, RDBUF_LEN-1);
if(ret<0)
{
// data read error
perror("read()");
continue;
}
printf("interrupt, value is: %s\n", rdbuf);
// compare the data in the data buffer with the last known value state
// (we do this to prevent double event invocation for the same value)
int compareResult = strncmp(rdbuf, "1", 1); // only compare the first character; rdbuff may have more junk chars
Thread* cptr = (Thread*)threadarg;
cptr->signaldata.emit();
}
}
// if we reached this code (unlikely),
// then close the data file and exit the thread
close(fd);
return 0;
}
int Thread::Thread_enableChangeCallback (int pin)
{
// get the index position for the requested pin number
int index = pin;
int edgePin = pin;
// ensure that the requested pin index is valid
if(index >= 0 && edgePin >= 0)
{
// only start this thread monitor if it has not already been started
if(monitor_data_array[index].running <= 0)
{
// configure the monitor instance data
monitor_data_array[index].thread_id = index;
monitor_data_array[index].pin = pin;
monitor_data_array[index].edgePin = edgePin;
// create monitoring instance thread
pthread_create(&threads[index], NULL,monitorPinInterrupt,static_cast<void*>(&monitor_data_array[index]));
return 1;
}
// return '0' when no action was taken;
// (monitor already running)
return 0;
}
// return '-1' on error; not a valid pin
return -1;
}
int Thread::Thread_disableChangeCallback (int pin)
{
// get the index position for the requested pin number
int index = pin;
// ensure that the requested pin index is valid
if(index >= 0)
{
// kill the monitoring thread
if(monitor_data_array[index].running > 0)
{;
pthread_cancel(threads[index]);
// return '1' when a thread was actively killed
return 1;
}
// return '0' when no action was taken
// (monitor is not currently active/running)
return 0;
}
// return '-1' on error; not a valid pin
return -1;
} |
Pb d'uilisation de libsigc++ et pthread
Répondre avec citation
Partager