Fennel: /home/pub/open/dev/fennel/device/AioLinuxScheduler.cpp Source File (original) (raw)
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00023 #include "fennel/common/CommonPreamble.h"
00024
00025 #ifdef USE_LIBAIO_H
00026
00027 #include "fennel/device/AioLinuxScheduler.h"
00028 #include "fennel/device/RandomAccessDevice.h"
00029 #include "fennel/device/DeviceAccessSchedulerParams.h"
00030 #include "fennel/common/SysCallExcn.h"
00031 #include <errno.h>
00032
00033 FENNEL_BEGIN_CPPFILE("$Id: //open/dev/fennel/device/AioLinuxScheduler.cpp#9 $");
00034
00035 extern "C"
00036 DeviceAccessScheduler *newAioLinuxScheduler(
00037 DeviceAccessSchedulerParams const ¶ms)
00038 {
00039 return new AioLinuxScheduler(params);
00040 }
00041
00042 AioLinuxScheduler::AioLinuxScheduler(
00043 DeviceAccessSchedulerParams const ¶ms)
00044 {
00045 quit = false;
00046 nRequestsOutstanding.clear();
00047 context = NULL;
00048 int rc = io_queue_init(params.maxRequests, &context);
00049 if (rc) {
00050 throw SysCallExcn("io_queue_init failed");
00051 }
00052
00053
00054
00055 Thread::start();
00056 }
00057
00058 inline bool AioLinuxScheduler::isStarted() const
00059 {
00060 return Thread::isStarted();
00061 }
00062
00063 AioLinuxScheduler::~AioLinuxScheduler()
00064 {
00065 assert(());
00066 assert(
);
00067 int rc = io_queue_release(context);
00068 if (rc) {
00069 throw SysCallExcn("io_queue_release failed");
00070 }
00071 }
00072
00073 void AioLinuxScheduler::registerDevice(
00074 SharedRandomAccessDevice pDevice)
00075 {
00076 int hFile = pDevice->getHandle();
00077
00078
00079
00080 int flags = fcntl(hFile, F_GETFL);
00081 fcntl(hFile, F_SETFL, flags | O_DIRECT);
00082 }
00083
00084 bool AioLinuxScheduler::schedule(RandomAccessRequest &request)
00085 {
00086 assert(isStarted());
00087 request.pDevice->prepareTransfer(request);
00088 return submitRequests(request.bindingList);
00089 }
00090
00091 bool AioLinuxScheduler::submitRequests(
00092 RandomAccessRequest::BindingList &bindingList)
00093 {
00094 iocb *requestsArray[bindingList.size()];
00095 iocb **requests = requestsArray;
00096
00097
00098 int n = 0;
00099 RandomAccessRequest::BindingListMutator bindingMutator(bindingList);
00100 for (; bindingMutator; ++n) {
00101 RandomAccessRequestBinding *pBinding = bindingMutator.detach();
00102 requests[n] = pBinding;
00103 }
00104
00105 if (n == 0) {
00106
00107 return true;
00108 }
00109
00110
00111 int rc = io_submit(context, n, requests);
00112 if (rc == -EAGAIN) {
00113 rc = 0;
00114 }
00115
00116 if (rc < 0) {
00117
00118 throw SysCallExcn("io_submit failed");
00119 }
00120
00121
00122
00123
00124 for (int i = 0; i < rc; ++i) {
00125 ++nRequestsOutstanding;
00126 }
00127
00128 if (rc == n) {
00129
00130 return true;
00131 } else {
00132
00133
00134 requests += rc;
00135 n -= rc;
00136 deferLeftoverRequests(requests, n);
00137 return false;
00138 }
00139 }
00140
00141 void AioLinuxScheduler::deferLeftoverRequests(
00142 iocb **ppLeftovers,
00143 uint nLeftovers)
00144 {
00145 assert(nLeftovers > 0);
00146
00147
00148 RandomAccessRequest::BindingList bindingList;
00149
00150 for (uint i = 0; i < nLeftovers; ++i) {
00151 RandomAccessRequestBinding *pBinding =
00152 static_cast<RandomAccessRequestBinding *>(ppLeftovers[i]);
00153 bindingList.push_back(*pBinding);
00154 }
00155
00156 StrictMutexGuard deferredQueueGuard(deferredQueueMutex);
00157 deferredQueue.push_back(bindingList);
00158 }
00159
00160 bool AioLinuxScheduler::retryDeferredRequests()
00161 {
00162 for (;;) {
00163 StrictMutexGuard deferredQueueGuard(deferredQueueMutex);
00164 if (deferredQueue.empty()) {
00165
00166 return true;
00167 }
00168 RandomAccessRequest::BindingList bindingList = deferredQueue.front();
00169 deferredQueue.pop_front();
00170
00171 deferredQueueGuard.unlock();
00172
00173 bool success = submitRequests(bindingList);
00174 if (!success) {
00175
00176 return false;
00177 }
00178 }
00179 }
00180
00181 void AioLinuxScheduler::stop()
00182 {
00183 assert(isStarted());
00184 quit = true;
00185
00186 Thread::join();
00187 }
00188
00189 void AioLinuxScheduler::run()
00190 {
00191 while (nRequestsOutstanding || ) {
00192 io_event event;
00193 timespec ts;
00194
00195
00196 if (retryDeferredRequests()) {
00197
00198
00199 ts.tv_sec = 1;
00200 ts.tv_nsec = 0;
00201 } else {
00202
00203
00204 ts.tv_sec = 0;
00205 ts.tv_nsec = 1000000;
00206 }
00207
00208 long rc = io_getevents(context, 1, 1, &event, &ts);
00209
00210
00211
00212
00213 if ((rc == 0) || (rc == -EINTR)) {
00214
00215 continue;
00216 }
00217
00218 if (rc != 1) {
00219 throw SysCallExcn("io_getevents failed");
00220 }
00221 RandomAccessRequestBinding *pBinding =
00222 static_cast<RandomAccessRequestBinding *>(event.obj);
00223 bool success = (pBinding->getBufferSize() == event.res)
00224 && !event.res2;
00225 pBinding->notifyTransferCompletion(success);
00226 --nRequestsOutstanding;
00227 }
00228 }
00229
00230 FENNEL_END_CPPFILE("$Id: //open/dev/fennel/device/AioLinuxScheduler.cpp#9 $");
00231
00232 #endif
00233
00234