source: flair-src/branches/sanscv/lib/FlairCore/src/SharedMem_impl.cpp@ 326

Last change on this file since 326 was 324, checked in by Sanahuja Guillaume, 2 years ago

removing opencv dependency

File size: 4.4 KB
Line 
1// %flair:license{
2// This file is part of the Flair framework distributed under the
3// CECILL-C License, Version 1.0.
4// %flair:license}
5// created: 2014/02/10
6// filename: SharedMem_impl.cpp
7//
8// author: Guillaume Sanahuja
9// Copyright Heudiasyc UMR UTC/CNRS 7253
10//
11// version: $Id: $
12//
13// purpose: Class defining a shared memory
14//
15//
16/*********************************************************************/
17
18#include "SharedMem_impl.h"
19#include "SharedMem.h"
20#include <fcntl.h>
21#include <unistd.h>
22#include <sys/mman.h>
23#include <string.h>
24
25using std::string;
26using namespace flair::core;
27
28SharedMem_impl::SharedMem_impl(const SharedMem *self, string name, size_t size, SharedMem::Type &type):self(self),type(type),size(size) {
29#ifdef __XENO__
30 heap_binded = false;
31 int status = rt_heap_create(&heap, name.c_str(), size,
32 H_SHARED | H_FIFO | H_NONCACHED);
33 if (status == -EEXIST) {
34 heap_binded = true;
35 status = rt_heap_bind(&heap, name.c_str(), TM_INFINITE);
36 }
37 if (status != 0) {
38 char errorMsg[256];
39 self->Err("rt_heap_create error (%s)\n", strerror_r(-status, errorMsg, sizeof(errorMsg)));
40 return;
41 }
42
43 void *ptr;
44 status = rt_heap_alloc(&heap, 0, TM_NONBLOCK, &ptr);
45 if (status != 0) {
46 char errorMsg[256];
47 self->Err("rt_heap_alloc error (%s)\n", strerror_r(-status, errorMsg, sizeof(errorMsg)));
48 }
49 mem_segment = (char *)ptr;
50
51#else
52 if (type==SharedMem::Type::mutex) {
53 sem = new Semaphore(self,1,"/" + name + "_mutex",Semaphore::Type::named);
54 } else { //producerConsumer
55 sem_producer=new Semaphore(self,0,"/" + name + "_producer", Semaphore::Type::named);
56 sem_consumer=new Semaphore(self,0,"/" + name + "_consumer", Semaphore::Type::named);
57 }
58 shm_name = "/" + name;
59 fd = shm_open(shm_name.c_str(), O_RDWR | O_CREAT, 0666);
60 if (fd == -1) {
61 self->Err("Error creating shared memory\n");
62 }
63 ftruncate(fd, size);
64
65 mem_segment = (char *)mmap(NULL, size, PROT_READ | PROT_WRITE, MAP_SHARED, fd, 0);
66 if (mem_segment == MAP_FAILED) {
67 self->Err("Failed to map memory\n");
68 }
69#endif
70}
71
72SharedMem_impl::~SharedMem_impl() {
73 int status;
74
75#ifdef __XENO__
76
77 if (heap_binded == false) {
78 status = rt_heap_delete(&heap);
79 if (status != 0) {
80 char errorMsg[256];
81 self->Err("rt_heap_delete error (%s)\n", strerror_r(-status, errorMsg, sizeof(errorMsg)));
82 }
83 }
84
85#else
86 status = munmap(mem_segment, size);
87 if (status != 0) {
88 char errorMsg[256];
89 self->Err("Failed to unmap memory (%s)\n", strerror_r(-status, errorMsg, sizeof(errorMsg)));
90 }
91
92 status = close(fd);
93 if (status != 0) {
94 char errorMsg[256];
95 self->Err("Failed to close file (%s)\n", strerror_r(-status, errorMsg, sizeof(errorMsg)));
96 }
97
98 // do not check errors as it can be done by another process
99 status = shm_unlink(shm_name.c_str()); /*
100 if(status!=0)
101 {
102 char errorMsg[256];
103 self->Err("Failed to unlink memory (%s)\n",strerror_r(-status, errorMsg, sizeof(errorMsg)));
104 }
105*/
106 if (type==SharedMem::Type::mutex) {
107 delete sem;
108 } else {
109 delete sem_producer;
110 delete sem_consumer;
111 }
112#endif
113}
114
115void SharedMem_impl::ReaderReady() {
116 if (type==SharedMem::Type::producerConsumer) {
117 sem_consumer->ReleaseSemaphore();
118 } else {
119 self->Warn("Called on a non producerConsumer type of shared memory! (this is seriously wrong)");
120 }
121}
122
123void SharedMem_impl::Write(const char *buf, size_t size) {
124 if (type==SharedMem::Type::mutex) {
125 sem->GetSemaphore();
126 memcpy(mem_segment, buf, size);
127 sem->ReleaseSemaphore();
128 } else if (type==SharedMem::Type::producerConsumer) {
129 //wait until consumer took the data away before writing a new one
130 //but should not block if nobody's there to read
131 if (sem_consumer->TryGetSemaphore()) {
132 memcpy(mem_segment, buf, size);
133 sem_producer->ReleaseSemaphore();
134 }
135 }
136}
137
138bool SharedMem_impl::Read(char *buf, size_t size, Time nsTimeout) {
139 if (type==SharedMem::Type::mutex) {
140 if (sem->GetSemaphore()) { //may block for ever
141 memcpy(buf, mem_segment, size);
142 sem->ReleaseSemaphore();
143 return true;
144 }
145 } else if (type==SharedMem::Type::producerConsumer) {
146 if (sem_producer->GetSemaphore(nsTimeout)) { //if nobody ever writes we need to exit this after a while
147 memcpy(buf, mem_segment, size);
148 sem_consumer->ReleaseSemaphore();
149 return true;
150 };
151 }
152 return false;
153}
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