[2] | 1 | // %flair:license{
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[15] | 2 | // This file is part of the Flair framework distributed under the
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| 3 | // CECILL-C License, Version 1.0.
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[2] | 4 | // %flair:license}
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| 5 | // created: 2014/02/10
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| 6 | // filename: SharedMem_impl.cpp
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| 7 | //
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| 8 | // author: Guillaume Sanahuja
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| 9 | // Copyright Heudiasyc UMR UTC/CNRS 7253
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| 10 | //
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| 11 | // version: $Id: $
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| 12 | //
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| 13 | // purpose: Class defining a shared memory
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| 14 | //
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| 15 | //
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| 16 | /*********************************************************************/
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| 17 |
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| 18 | #include "SharedMem_impl.h"
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| 19 | #include "SharedMem.h"
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| 20 | #include <fcntl.h>
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| 21 | #include <unistd.h>
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| 22 | #include <sys/mman.h>
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| 23 | #include <string.h>
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| 24 |
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| 25 | using std::string;
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| 26 | using namespace flair::core;
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| 27 |
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[238] | 28 | SharedMem_impl::SharedMem_impl(const SharedMem *self, string name, size_t size, SharedMem::Type &type):self(self),type(type),size(size) {
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[2] | 29 | #ifdef __XENO__
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[15] | 30 | heap_binded = false;
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| 31 | int status = rt_heap_create(&heap, name.c_str(), size,
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| 32 | H_SHARED | H_FIFO | H_NONCACHED);
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| 33 | if (status == -EEXIST) {
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| 34 | heap_binded = true;
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| 35 | status = rt_heap_bind(&heap, name.c_str(), TM_INFINITE);
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| 36 | }
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| 37 | if (status != 0) {
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[213] | 38 | char errorMsg[256];
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[133] | 39 | self->Err("rt_heap_create error (%s)\n", strerror_r(-status, errorMsg, sizeof(errorMsg)));
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[15] | 40 | return;
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| 41 | }
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[2] | 42 |
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[15] | 43 | void *ptr;
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| 44 | status = rt_heap_alloc(&heap, 0, TM_NONBLOCK, &ptr);
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| 45 | if (status != 0) {
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[213] | 46 | char errorMsg[256];
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[133] | 47 | self->Err("rt_heap_alloc error (%s)\n", strerror_r(-status, errorMsg, sizeof(errorMsg)));
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[15] | 48 | }
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| 49 | mem_segment = (char *)ptr;
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[2] | 50 |
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| 51 | #else
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[238] | 52 | if (type==SharedMem::Type::mutex) {
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| 53 | sem = new Semaphore(self,1,"/" + name + "_mutex",Semaphore::Type::named);
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| 54 | } else { //producerConsumer
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| 55 | sem_producer=new Semaphore(self,0,"/" + name + "_producer", Semaphore::Type::named);
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| 56 | sem_consumer=new Semaphore(self,0,"/" + name + "_consumer", Semaphore::Type::named);
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| 57 | }
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[15] | 58 | shm_name = "/" + name;
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| 59 | fd = shm_open(shm_name.c_str(), O_RDWR | O_CREAT, 0666);
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| 60 | if (fd == -1) {
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| 61 | self->Err("Error creating shared memory\n");
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| 62 | }
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| 63 | ftruncate(fd, size);
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[2] | 64 |
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[203] | 65 | mem_segment = (char *)mmap(NULL, size, PROT_READ | PROT_WRITE, MAP_SHARED, fd, 0);
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[15] | 66 | if (mem_segment == MAP_FAILED) {
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| 67 | self->Err("Failed to map memory\n");
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| 68 | }
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[2] | 69 | #endif
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| 70 | }
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| 71 |
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[15] | 72 | SharedMem_impl::~SharedMem_impl() {
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| 73 | int status;
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[133] | 74 |
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[2] | 75 | #ifdef __XENO__
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| 76 |
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[15] | 77 | if (heap_binded == false) {
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| 78 | status = rt_heap_delete(&heap);
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| 79 | if (status != 0) {
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[213] | 80 | char errorMsg[256];
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[133] | 81 | self->Err("rt_heap_delete error (%s)\n", strerror_r(-status, errorMsg, sizeof(errorMsg)));
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[2] | 82 | }
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[15] | 83 | }
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[2] | 84 |
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| 85 | #else
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[15] | 86 | status = munmap(mem_segment, size);
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| 87 | if (status != 0) {
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[213] | 88 | char errorMsg[256];
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[133] | 89 | self->Err("Failed to unmap memory (%s)\n", strerror_r(-status, errorMsg, sizeof(errorMsg)));
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[15] | 90 | }
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[2] | 91 |
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[15] | 92 | status = close(fd);
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| 93 | if (status != 0) {
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[213] | 94 | char errorMsg[256];
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[133] | 95 | self->Err("Failed to close file (%s)\n", strerror_r(-status, errorMsg, sizeof(errorMsg)));
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[15] | 96 | }
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[2] | 97 |
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[149] | 98 | // do not check errors as it can be done by another process
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[15] | 99 | status = shm_unlink(shm_name.c_str()); /*
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| 100 | if(status!=0)
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| 101 | {
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[213] | 102 | char errorMsg[256];
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[133] | 103 | self->Err("Failed to unlink memory (%s)\n",strerror_r(-status, errorMsg, sizeof(errorMsg)));
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[15] | 104 | }
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[2] | 105 | */
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[238] | 106 | if (type==SharedMem::Type::mutex) {
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| 107 | delete sem;
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| 108 | } else {
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| 109 | delete sem_producer;
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| 110 | delete sem_consumer;
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| 111 | }
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[2] | 112 | #endif
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| 113 | }
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| 114 |
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[149] | 115 | void SharedMem_impl::ReaderReady() {
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[238] | 116 | if (type==SharedMem::Type::producerConsumer) {
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| 117 | sem_consumer->ReleaseSemaphore();
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| 118 | } else {
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| 119 | self->Warn("Called on a non producerConsumer type of shared memory! (this is seriously wrong)");
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| 120 | }
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[149] | 121 | }
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| 122 |
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[15] | 123 | void SharedMem_impl::Write(const char *buf, size_t size) {
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[149] | 124 | if (type==SharedMem::Type::mutex) {
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[238] | 125 | sem->GetSemaphore();
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[149] | 126 | memcpy(mem_segment, buf, size);
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[238] | 127 | sem->ReleaseSemaphore();
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[149] | 128 | } else if (type==SharedMem::Type::producerConsumer) {
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[238] | 129 | //wait until consumer took the data away before writing a new one
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[149] | 130 | //but should not block if nobody's there to read
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[238] | 131 | if (sem_consumer->TryGetSemaphore()) {
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[149] | 132 | memcpy(mem_segment, buf, size);
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[238] | 133 | sem_producer->ReleaseSemaphore();
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[149] | 134 | }
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| 135 | }
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[2] | 136 | }
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| 137 |
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[203] | 138 | bool SharedMem_impl::Read(char *buf, size_t size, Time nsTimeout) {
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[149] | 139 | if (type==SharedMem::Type::mutex) {
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[238] | 140 | if (sem->GetSemaphore()) { //may block for ever
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[203] | 141 | memcpy(buf, mem_segment, size);
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[238] | 142 | sem->ReleaseSemaphore();
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[203] | 143 | return true;
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| 144 | }
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[149] | 145 | } else if (type==SharedMem::Type::producerConsumer) {
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[238] | 146 | if (sem_producer->GetSemaphore(nsTimeout)) { //if nobody ever writes we need to exit this after a while
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[206] | 147 | memcpy(buf, mem_segment, size);
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[238] | 148 | sem_consumer->ReleaseSemaphore();
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[203] | 149 | return true;
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[238] | 150 | };
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[149] | 151 | }
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[203] | 152 | return false;
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[2] | 153 | }
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