Search Results

Search found 21759 results on 871 pages for 'int'.

Page 165/871 | < Previous Page | 161 162 163 164 165 166 167 168 169 170 171 172  | Next Page >

  • Creating and using a static lib in xcode

    - by Alasdair Morrison
    I am trying to create a static library in xcode and link to that static library from another program. So as a test i have created a BSD static C library project and just added the following code: //Test.h int testFunction(); //Test.cpp #include "Test.h" int testFunction() { return 12; } This compiles fine and create a .a file (libTest.a). Now i want to use it in another program so I create a new xcode project (cocoa application) Have the following code: //main.cpp #include <iostream> #include "Testlib.h" int main (int argc, char * const argv[]) { // insert code here... std::cout << "Result:\n" <<testFunction(); return 0; } //Testlib.h extern int testFunction(); I right clicked on the project - add - existing framework - add other Selected the .a file and it added it into the project view. I always get this linker error: Build TestUselibrary of project TestUselibrary with configuration Debug Ld build/Debug/TestUselibrary normal x86_64 cd /Users/myname/location/TestUselibrary setenv MACOSX_DEPLOYMENT_TARGET 10.6 /Developer/usr/bin/g++-4.2 -arch x86_64 -isysroot /Developer/SDKs/MacOSX10.6.sdk -L/Users/myname/location/TestUselibrary/build/Debug -L/Users/myname/location/TestUselibrary/../Test/build/Debug -F/Users/myname/location/TestUselibrary/build/Debug -filelist /Users/myname/location/TestUselibrary/build/TestUselibrary.build/Debug/TestUselibrary.build/Objects-normal/x86_64/TestUselibrary.LinkFileList -mmacosx-version-min=10.6 -lTest -o /Users/myname/location/TestUselibrary/build/Debug/TestUselibrary Undefined symbols: "testFunction()", referenced from: _main in main.o ld: symbol(s) not found collect2: ld returned 1 exit status I am new to macosx development and fairly new to c++. I am probably missing something fairly obvious, all my experience comes from creating dlls on the windows platform. I really appreciate any help.

    Read the article

  • Thread scheduling C

    - by MRP
    include <pthread.h> include <stdio.h> include <stdlib.h> #define NUM_THREADS 4 #define TCOUNT 5 #define COUNT_LIMIT 13 int done = 0; int count = 0; int thread_ids[4] = {0,1,2,3}; int thread_runtime[4] = {0,5,4,1}; pthread_mutex_t count_mutex; pthread_cond_t count_threshold_cv; void *inc_count(void *t) { int i; long my_id = (long)t; long run_time = thread_runtime[my_id]; if (my_id==2 && done ==0) { for(i=0; i< 5 ; i++) { if( i==4 ){done =1;} pthread_mutex_lock(&count_mutex); count++; if (count == COUNT_LIMIT) { pthread_cond_signal(&count_threshold_cv); printf("inc_count(): thread %ld, count = %d Threshold reached.\n", my_id, count); } printf("inc_count(): thread %ld, count = %d, unlocking mutex\n", my_id, count); pthread_mutex_unlock(&count_mutex); } } if (my_id==3 && done==1) { for(i=0; i< 4 ; i++) { if(i == 3 ){ done = 2;} pthread_mutex_lock(&count_mutex); count++; if (count == COUNT_LIMIT) { pthread_cond_signal(&count_threshold_cv); printf("inc_count(): thread %ld, count = %d Threshold reached.\n", my_id, count); } printf("inc_count(): thread %ld, count = %d, unlocking mutex\n", my_id, count); pthread_mutex_unlock(&count_mutex); } } if (my_id==4&& done == 2) { for(i=0; i< 8 ; i++) { pthread_mutex_lock(&count_mutex); count++; if (count == COUNT_LIMIT) { pthread_cond_signal(&count_threshold_cv); printf("inc_count(): thread %ld, count = %d Threshold reached.\n",my_id, count); } printf("inc_count(): thread %ld, count = %d, unlocking mutex\n", my_id, count); pthread_mutex_unlock(&count_mutex); } } pthread_exit(NULL); } void *watch_count(void *t) { long my_id = (long)t; printf("Starting watch_count(): thread %ld\n", my_id); pthread_mutex_lock(&count_mutex); if (count<COUNT_LIMIT) { pthread_cond_wait(&count_threshold_cv, &count_mutex); printf("watch_count(): thread %ld Condition signal received.\n", my_id); count += 125; printf("watch_count(): thread %ld count now = %d.\n", my_id, count); } pthread_mutex_unlock(&count_mutex); pthread_exit(NULL); } int main (int argc, char *argv[]) { int i, rc; long t1=1, t2=2, t3=3, t4=4; pthread_t threads[4]; pthread_attr_t attr; pthread_mutex_init(&count_mutex, NULL); pthread_cond_init (&count_threshold_cv, NULL); pthread_attr_init(&attr); pthread_attr_setdetachstate(&attr,PTHREAD_CREATE_JOINABLE); pthread_create(&threads[0], &attr, watch_count, (void *)t1); pthread_create(&threads[1], &attr, inc_count, (void *)t2); pthread_create(&threads[2], &attr, inc_count, (void *)t3); pthread_create(&threads[3], &attr, inc_count, (void *)t4); for (i=0; i<NUM_THREADS; i++) { pthread_join(threads[i], NULL); } printf ("Main(): Waited on %d threads. Done.\n", NUM_THREADS); pthread_attr_destroy(&attr); pthread_mutex_destroy(&count_mutex); pthread_cond_destroy(&count_threshold_cv); pthread_exit(NULL); } so this code creates 4 threads. thread 1 keeps track of the count value while the other 3 increment the count value. the run time is the number of times the thread will increment the count value. I have a done value that allows the first thread to increment the count value first until its run time is up.. so its like a First Come First Serve. my question is, is there a better way of implementing this? I have read about SCHED_FIFO or SCHED_RR.. I guess I dont know how to implement them into this code or if it can be.

    Read the article

  • What's the deal with Java's public fields?

    - by Annan
    I've been reading two articles (1)(2) on javaworld.com about how all class fields should be private and getter/setter methods are just as bad. An object should act on the data it has rather than allowing access to it. I'm currently working on a University assignment for Connect Four. In designing the program the Agents playing the Game need access to the Board's state (so they can decide what to move). They also need to pass this move to the Game so it can validate it as a legal move. And during deciding what to move pieces are grouped into Threats with a start and end Points. Board, Threat and Point objects don't really do anything. They are just there to store related data that can be accessed in a human readable way. At the start of design I was representing Points on the board as two element int arrays, however that got annoying when creating points or referencing components of them. So, the class: public class Point { public int x; public int y; public Point(int x, int y){ this.x = x; this.y = y; } } Perfect in every way I can think of. Except it breaks every rule I've learned. Have I sinned?

    Read the article

  • undefined symbols when compiling libjingle for Mac OS X

    - by wwh37
    Compiling libjinge-0.4.0 on my Leopard returned the following errors: /bin/sh ../../../libtool --silent --tag=CXX --mode=link g++ -g -o login login-login_main.o login-xmppsocket.o login-xmppthread.o login-xmpppump.o login-xmppauth.o ../../../talk/xmpp/libcricketxmpp.la ../../../talk/xmllite/libcricketxmllite.la ../../../talk/base/libcricketbase.la -lexpat -lpthread -lssl -lcrypto Undefined symbols: "_BIO_clear_flags", referenced from: socket_read(bio_st*, char*, int)in libcricketbase.a(openssladapter.o) socket_write(bio_st*, char const*, int)in libcricketbase.a(openssladapter.o) "_BIO_set_flags", referenced from: socket_read(bio_st*, char*, int)in libcricketbase.a(openssladapter.o) socket_write(bio_st*, char const*, int)in libcricketbase.a(openssladapter.o) Any ideas? I couldn't find an answer... Thanks!

    Read the article

  • Creating java class with annotated fields in runtime

    - by Sarmun
    The problem is that I need to create in runtime a class like this: public class Foo { @Bar int value0; @Bar int value1; @Bar int value2; .... } with number of fields being decided at runtime. I was looking at Javassist, and there you can create a new class, and add fields to it, but I haven't found a way to annotate those fields.

    Read the article

  • LINQ dynamic query

    - by ile
    How to dynamically generate LINQ query: int[] IDArray = {55, 36}; public IQueryable<ContactListView> FindAllContacts(int loggedUserID, int[] IDArray) { var result = ( from contact in db.Contacts //Start of dynamic part... where contact.UserID == loggedUserID foreach (var id in IDArray) { where contact.UserID == id } // End of dynamic part orderby contact.ContactID descending select new ContactListView { ContactID = contact.ContactID, FirstName = contact.FirstName, LastName = contact.LastName }); return result; } Thanks, Ile

    Read the article

  • exchanging 2 memory positions

    - by Jordi
    I am working with OpenCV and Qt, Opencv use BGR while Qt uses RGB , so I have to swap those 2 bytes for very big images. There is a better way of doing the following? I can not think of anything faster but looks so simple and lame... int width = iplImage->width; int height = iplImage->height; uchar *iplImagePtr = (uchar *) iplImage->imageData; uchar buf; int limit = height * width; for (int y = 0; y < limit; ++y) { buf = iplImagePtr[2]; iplImagePtr[2] = iplImagePtr[0]; iplImagePtr[0] = buf; iplImagePtr += 3; } QImage img((uchar *) iplImage->imageData, width, height, QImage::Format_RGB888);

    Read the article

  • C variable declarations after function heading in definition

    - by Yktula
    When reading some FreeBSD source code (See: radix.h lines 158-173), I found variable declarations that followed the "function heading" in the definition. Is this valid in ISO C (C99)? when should this be done in production code instead of just declaring the variables within the "function heading?" Why is it being done here? I refer to the function heading the string that looks like this: int someFunction(int i, int b) {

    Read the article

  • qtableview (libqt) how do I correctly create a QModelIndex

    - by Chris Camacho
    I'm trying to enter edit mode on a specific cell like this void MainWindow::on_addButton_released(void) { tm->addRow(); tableView->scrollToBottom(); int ec=tm->firstWritableColumn(); int r=tm->rowCount(QModelIndex()); QModelIndex id = tm->index(r, ec, QModelIndex()); tableView->setCurrentIndex(id); tableView->edit(id); qDebug() << "row:" << r << " col:" << ec << "index:" << id; } my model creates an index like this QModelIndex TableModel::index(int row,int column,QModelIndex parent) const { Q_UNUSED(parent); return createIndex(row,column,0); } the debug output looks like this row: 9 col: 1 index: QModelIndex(9,1,0x0,TableModel(0xbf3f50) ) I'm fairly sure that the index is somehow invalid as setCurrentIndex doesn't seem to be working

    Read the article

  • Several numpy arrays with SWIG

    - by Petter
    I am using SWIG to pass numpy arrays from Python to C++ code: %include "numpy.i" %init %{ import_array(); %} %apply (float* INPLACE_ARRAY1, int DIM1) {(float* data, int n)}; class Class { public: void test(float* data, int n) { //... } }; and in Python: c = Class() a = zeros(5) c.test(a) This works, but how can I pass multiple numpy arrays to the same function?

    Read the article

  • MYSQL in PHPMYADMIN - create table relationship from one table

    - by Stanley DecoWood
    I want to create a table relationship with MYSQL PHPMYADMIN. I have this Create table: CREATE TABLE students(code_students int(8)not null AUTO_INCREMENT, name_students varchar(25), age_students int(3), degree_program varchar(25), code_advisor int(8)not null, primary key(code_students, code_advisor) ); and i want to make a create table named advise relationship between code_students, code_advisor.

    Read the article

  • Invalid argument when calling linux splice()

    - by benny wallace
    Hi I wanted to try out the splice syscall. I have this function - it should copy content of one file to another: static void test_splice( int in, int out ) { int i = 0, rcvd = 0; int filedes[2]; off_t off = 0; if ( pipe( filedes ) < 0 ) { perror( "Kicha pipe" ); exit( EXIT_FAILURE ); } for ( i = 0; i < NUMLOOPS; ++i ) { if ( ( rcvd = splice( in, NULL, filedes[1], NULL, BUFSIZE, SPLICE_F_MORE | SPLICE_F_MOVE ) ) < 0 ) { perror( "splice" ); exit( EXIT_FAILURE ); } if ( splice( filedes[0], NULL, out, NULL, rcvd, SPLICE_F_MORE | SPLICE_F_MOVE ) < 0 ) { perror( "splice" ); exit( EXIT_FAILURE ); } } } The second call to splice in first iteration returns EINVAL ( invalid argument from perror ) everytime - what could be the reason?

    Read the article

  • Strange things appear on running the program

    - by FILIaS
    Hey! I'm fixing a program but I'm facing a problem and I cant really realize what's the wrong on the code. I would appreciate any help. I didnt post all the code...but i think with this part you can get an idea of it. With the following function enter() I wanna add user commands' datas to a list. eg. user give the command: "enter james bond 007 gun" 'james' is supposed to be the name, 'bond' the surname, 007 the amount and the rest is the description. I use strtok in order to 'cut' the command,then i put each name on a temp array. Then i call InsertSort in order to put the datas on a linked list but in alphabetical order depending on the surname that users give. I wanna keep the list on order and put each time the elements on the right position. /* struct for all the datas that user enters on file*/ typedef struct catalog { char short_name[50]; char surname[50]; signed int amount; char description[1000]; struct catalog *next; }catalog,*catalogPointer; catalogPointer current; catalogPointer head = NULL; void enter(void)//user command: enter <name> <surname> <amount> <description> { int n,j=2,k=0; char temp[1500]; char command[1500]; while (command[j]!=' ' && command[j]!='\0') { temp[k]=command[j]; j++; k++; } temp[k]='\0'; char *curToken = strtok(temp," "); printf("temp is:%s \n",temp); char short_name[50],surname[50],description[1000]; signed int amount; //short_name=(char *)malloc(sizeof (char *)); //surname=(char *)malloc(sizeof (char *)); //description=(char *)malloc(sizeof (char *)); //amount=(int *)malloc(sizeof (int *)); printf("\nWhat you entered for saving:\n"); for (n = 0; curToken !='\0'; ++n) { if (curToken) { strncpy(short_name, curToken, sizeof (char *)); / } printf("Short Name: %s \n",short_name); curToken = strtok(NULL," "); if (curToken) strncpy(surname, curToken, sizeof (char *)); / printf("SurName: %s \n",surname); curToken = strtok(NULL," "); if (curToken) { char *chk; amount = (int) strtol(curToken, &chk, 10); if (!isspace(*chk) && *chk != 0) fprintf(stderr,"Warning: expected integer value for amount, received %s instead\n",curToken); } printf("Amount: %d \n",amount); curToken = strtok(NULL,"\0"); if (curToken) { strncpy(description, curToken, sizeof (char *)); } printf("Description: %s \n",description); break; } if (findEntryExists(head, surname) != NULL) printf("\nAn entry for <%s %s> is already in the catalog!\nNew entry not entered.\n",short_name,surname); else { printf("\nTry to entry <%s %s %d %s> in the catalog list!\n",short_name,surname,amount,description); InsertSort(&head,short_name, surname, amount, description); printf("\n**Entry done!**\n"); } // Maintain the list in alphabetical order by surname. } /********Uses special case code for the head end********/ void SortedInsert(catalog** headRef, catalogPointer newNode,char short_name[],char surname[],signed int amount,char description[]) { strcpy(newNode->short_name, short_name); strcpy(newNode->surname, surname); newNode->amount=amount; strcpy(newNode->description, description); // Special case for the head end if (*headRef == NULL||(*headRef)->surname >= newNode->surname) { newNode->next = *headRef; *headRef = newNode; } else { // Locate the node before the point of insertion catalogPointer current = *headRef; catalogPointer temp=current->next; while ( temp!=NULL ) { if(strcmp(temp->surname,newNode->surname)<0 ) current = temp; } newNode->next = temp; temp = newNode; } } // Given a list, change it to be in sorted order (using SortedInsert()). void InsertSort(catalog** headRef,char short_name[],char surname[],signed int amount,char description[]) { catalogPointer result = NULL; // build the answer here catalogPointer current = *headRef; // iterate over the original list catalogPointer next; while (current!=NULL) { next = current->next; // tricky - note the next pointer before we change it SortedInsert(&result,current,short_name,surname,amount,description); current = next; } *headRef = result; } Running the program I get these strange things (garbage?)... Choose your selection: enter james bond 007 gun Your command is: enter james bond 007 gun temp is:james What you entered for saving: Short Name: james SurName: Amount: 0 Description: 0T?? Try to entry james 0 0T?? in the catalog list! Entry done! Also I'm facing a problem on how to use the 'malloc' on this program. Thanks in advance. . .

    Read the article

  • ASP.net MVC 2 EditorFor Dictionary Bind

    - by user307540
    Hi! I try this, but don't work. bemutatkozas@Modify = null all the time. public class Iroda { public Dictionary<int,string> bemutatkozas { get; set; } } public ActionResult Index() { var dct = new Dictionary<int, string>(); dct.Add(1, "magyar"); dct.Add(2, "angol"); dct.Add(3, "olasz"); return View(new Iroda { bemutatkozas = dct }); } [HttpPost] public ActionResult Modify(Dictionary<int,string> bemutatkozas) { return View(); } <% using (Html.BeginForm("Modify","Iroda")) {%> <%= Html.ValidationSummary(true) %> <fieldset> <legend>Fields</legend> <%= Html.EditorFor(o=>o.bemutatkozas,"MultiLanguageEditor") %> <p> <input type="submit" value="Save" /> </p> </fieldset> <% } %> <%@ Control Language="C#" Inherits="System.Web.Mvc.ViewUserControl<Dictionary<int, string>>" %> <% int i = 0; %> <% foreach (var s in Model) { %> <%= Html.Hidden(Html.ViewContext.ViewData.TemplateInfo.HtmlFieldPrefix+"["+i+"].key", s.Key) %> <%= Html.TextBox(Html.ViewContext.ViewData.TemplateInfo.HtmlFieldPrefix+"["+i+"].value",s.Value) %> <% i++; %> <% }%> Whats the solution? Thx!

    Read the article

  • Returning an anonymous class that uses a final primitive. How does it work?

    - by Tim P
    Hi, I was wondering if someone could explain how the following code works: public interface Result { public int getCount(); public List<Thing> getThings(); } class SomeClass { ... public Result getThingResult() { final List<Thing> things = .. populated from something. final int count = 5; return new Result { @Override public int getCount() { return count; } @Override public List<Thing> getThings(); return things; } } } ... } Where do the primitive int , List reference and List instance get stored in memory? It can't be on the stack.. so where? Is there a difference between how references and primitives are handled in this situation? Thanks a bunch, Tim P.

    Read the article

  • overloading friend operator<< for template class

    - by starcorn
    Hello, I have read couple of the question regarding my problem on stackoverflow now, and none of it seems to solve my problem. Or I maybe have done it wrong... The overloaded << if I make it into an inline function. But how do I make it work in my case? warning: friend declaration std::ostream& operator<<(std::ostream&, const D<classT>&)' declares a non-template function warning: (if this is not what you intended, make sure the function template has already been declared and add <> after the function name here) -Wno-non-template-friend disables this warning /tmp/cc6VTWdv.o:uppgift4.cc:(.text+0x180): undefined reference to operator<<(std::basic_ostream<char, std::char_traits<char> >&, D<int> const&)' collect2: ld returned 1 exit status template <class T> T my_max(T a, T b) { if(a > b) return a; else return b; } template <class classT> class D { public: D(classT in) : d(in) {}; bool operator>(const D& rhs) const; classT operator=(const D<classT>& rhs); friend ostream& operator<< (ostream & os, const D<classT>& rhs); private: classT d; }; int main() { int i1 = 1; int i2 = 2; D<int> d1(i1); D<int> d2(i2); cout << my_max(d1,d2) << endl; return 0; } template <class classT> ostream& operator<<(ostream &os, const D<classT>& rhs) { os << rhs.d; return os; }

    Read the article

  • How can I make Swig correctly wrap a char* buffer that is modified in C as a Java Something-or-other

    - by Ukko
    I am trying to wrap some legacy code for use in Java and I was quite happy to see that Swig was able to handle the header file and it generate a great wrapper that almost works. Now I am looking for the deep magic that will make it really work. In C I have a function that looks like this DLL_IMPORT int DustyVoodoo(char *buff, int len, char *curse); This integer returned by this function is an error code in case it fails. The arguments are buff is a character buffer len is the length of the data in the buffer curse the another character buffer that contains the result of calling DustyVoodoo So, you can see where this is going, the result is actually coming back via the third argument. Also len is confusing since it may be the length of both buffers, they are always allocated as being the same size in calling code but given what DustyVoodoo does I don't think that they need be the same. To be safe both buffers should be the same size in practice, say 512 chars. The C code generated for the binding is as follows: SWIGEXPORT jint JNICALL Java_pemapiJNI_DustyVoodoo(JNIEnv *jenv, jclass jcls, jstring jarg1, jint jarg2, jstring jarg3) { jint jresult = 0 ; char *arg1 = (char *) 0 ; int arg2 ; char *arg3 = (char *) 0 ; int result; (void)jenv; (void)jcls; arg1 = 0; if (jarg1) { arg1 = (char *)(*jenv)->GetStringUTFChars(jenv, jarg1, 0); if (!arg1) return 0; } arg2 = (int)jarg2; arg3 = 0; if (jarg3) { arg3 = (char *)(*jenv)->GetStringUTFChars(jenv, jarg3, 0); if (!arg3) return 0; } result = (int)PemnEncrypt(arg1,arg2,arg3); jresult = (jint)result; if (arg1) (*jenv)->ReleaseStringUTFChars(jenv, jarg1, (const char *)arg1); if (arg3) (*jenv)->ReleaseStringUTFChars(jenv, jarg3, (const char *)arg3); return jresult; } It is correct for what it does; however, it misses the fact that cursed is not just an input, it is altered by the function and should be returned as an output. It also does not know that the java Strings are really buffers and should be backed by a suitably sized array. I think that Swig can do the right thing here, I just can't figure out from the documentation how to tell Swig what it needs to know. Any typemap masers in the house?

    Read the article

  • How this is code is getting compiled even though we are using a constant which is defined later?

    - by GK
    In the following code DEFAULT_CACHE_SIZE is declared later, but it is used to assign a value to String variable before than that, so was curious how is it possible? public class Test { public String getName() { return this.name; } public int getCacheSize() { return this.cacheSize; } public synchronized void setCacheSize(int size) { this.cacheSize = size; System.out.println("Cache size now " + this.cacheSize); } private final String name = "Reginald"; private int cacheSize = DEFAULT_CACHE_SIZE; private static final int DEFAULT_CACHE_SIZE = 200; }

    Read the article

  • C/C++: Passing a structure by value, with another structure as one of its members, changes values of

    - by jellyfisharepretty
    Sorry for the confusing title, but it basically says it all. Here's the structures I'm using (found in OpenCV) : struct CV_EXPORTS CvRTParams : public CvDTreeParams { bool calc_var_importance; int nactive_vars; CvTermCriteria term_crit; CvRTParams() : CvDTreeParams( 5, 10, 0, false, 10, 0, false, false, 0 ), calc_var_importance(false), nactive_vars(0) { term_crit = cvTermCriteria( CV_TERMCRIT_ITER+CV_TERMCRIT_EPS, 50, 0.1 ); } } and typedef struct CvTermCriteria { int type; int max_iter; double epsilon; } CvTermCriteria; CV_INLINE CvTermCriteria cvTermCriteria( int type, int max_iter, double epsilon ) { CvTermCriteria t; t.type = type; t.max_iter = max_iter; t.epsilon = (float)epsilon; return t; } Now, I initialize a CvRTParams structure and set values for its members : CvRTParams params; params.max_depth = 8; params.min_sample_count = 10; params.regression_accuracy = 0; params.use_surrogates = false; params.max_categories = 10; params.priors = priors; params.calc_var_importance = true; params.nactive_vars = 9; params.term_crit.max_iter = 33; params.term_crit.epsilon = 0.1; params.term_crit.type = 3; Then call a function of an object, taking params in as a parameter : CvRTrees* rt = new CvRTrees; rt->train(t, CV_ROW_SAMPLE, r, 0, 0, var_type, 0, params) What happens now ? Values of... params.term_crit.max_iter params.term_crit.epsilon params.term_crit.type have changed ! They are no longer 33, 0.1 and 3, but something along the lines of 3, 7.05541e-313 and 4, and this, for the whole duration of the CvRtrees::train() function...

    Read the article

  • mysql query performance help

    - by Stefano
    Hi I have a quite large table storing words contained in email messages mysql> explain t_message_words; +----------------+---------+------+-----+---------+----------------+ | Field | Type | Null | Key | Default | Extra | +----------------+---------+------+-----+---------+----------------+ | mwr_key | int(11) | NO | PRI | NULL | auto_increment | | mwr_message_id | int(11) | NO | MUL | NULL | | | mwr_word_id | int(11) | NO | MUL | NULL | | | mwr_count | int(11) | NO | | 0 | | +----------------+---------+------+-----+---------+----------------+ table contains about 100M rows mwr_message_id is a FK to messages table mwr_word_id is a FK to words table mwr_count is the number of occurrencies of word mwr_word_id in message mwr_message_id To calculate most used words, I use the following query SELECT SUM(mwr_count) AS word_count, mwr_word_id FROM t_message_words GROUP BY mwr_word_id ORDER BY word_count DESC LIMIT 100; that runs almost forever (more than half an hour on the test server) mysql> show processlist; +----+------+----------------+--------+---------+------+----------------------+----------------------------------------------------- | Id | User | Host | db | Command | Time | State | Info +----+------+----------------+--------+---------+------+----------------------+----------------------------------------------------- processlist | 41 | root | localhost:3148 | tst_db | Query | 1955 | Copying to tmp table | SELECT SUM(mwr_count) AS word_count, mwr_word_id FROM t_message_words GROUP BY mwr_word_id | +----+------+----------------+--------+---------+------+----------------------+----------------------------------------------------- 3 rows in set (0.00 sec) Is there anything I can do to "speed up" the query (apart from adding more ram, more cpu, faster disks)? thank you in advance stefano

    Read the article

  • Java Arrays.equals() returns false for two dimensional arrays.

    - by Achilles
    Hi there, I was just curious to know - why does Arrays.equals(double[][], double[][]) return false? when in fact the arrays have the same number of elements and each element is the same? For example I performed the following test. ` [java] double[][] a, b; int size =5; a=new double[size][size]; b=new double[size][size]; for( int i = 0; i < size; i++ ) for( int j = 0; j < size; j++ ){ a[i][j]=1.0; b[i][j]=1.0; } if(Arrays.equals(a, b)) System.out.println("Equal"); else System.out.println("Not-equal"); [/java] ` Returns false and prints "Not-equal. on the other hand, if I have something like this: [java] double[] a, b; int size =5; a=new double[size]; b=new double[size]; for( int i = 0; i < size; i++ ){ a[i]=1.0; b[i]=1.0; } if(Arrays.equals(a, b)) System.out.println("Equal"); else System.out.println("Not-equal"); } [/java] returns true and prints "Equal". Does the method only work with single dimensions? if so, is there something similar for multi-dimensional arrays in Java?

    Read the article

  • Strcpy and malloc issues

    - by mrblippy
    Hi, i am having trouble getting a method relating to a linked list working, i get the errors: assignment makes pointer from integer without a cast and passing argument 1 of âstrcpyâ makes pointer from integer without a cast. i have tried to include all the relevant code, but let me know if you need more info. thanks. struct unit { char code[5]; char *name; node_ptr students; }; typedef struct node *node_ptr; struct node { int student_id; char *studentname; node_ptr next; }; void enrol_student(struct unit u[], int n) { int i, p; int student_id = 0; char code_to_enrol[7]; char buffer[100]; node_ptr studentslist; scanf("%s\n", code_to_enrol); for(i=0; i <= n; i++) { studentslist = u[i].students; if(strcmp(u[i].code ,code_to_enrol)<=0) { scanf("enter student details %d %s\n", &studentID, buffer); p = (char *) malloc (strlen(buffer)+1); strcpy(p, buffer); insert_in_order(student_id, buffer, studentslist); } } } void insert_in_order(int n, char *i, node_ptr list) { node_ptr before = list; node_ptr students = (node_ptr) malloc(sizeof(struct node)); students->ID = n; students->name = *i; while(before->next && (before->next->ID < n)) { before = before->next; } students->next = before->next; before->next = students; }

    Read the article

  • how is data stored at bit level according to "Endianness" ?

    - by bakra
    I read about Endianness and understood squat... so I wrote this main() { int k = 0xA5B9BF9F; BYTE *b = (BYTE*)&k; //value at *b is 9f b++; //value at *b is BF b++; //value at *b is B9 b++; //value at *b is A5 } k was equal to "A5 B9 BF 9F" and (byte)pointer "walk" o/p was "9F BF b9 A5" so I get it bytes are stored backwards...ok. ~ so now I thought how is it stored at BIT level... I means is "9f"(1001 1111) stored as "f9"(1111 1001)? so I wrote this int _tmain(int argc, _TCHAR* argv[]) { int k = 0xA5B9BF9F; void *ptr = &k; bool temp= TRUE; cout<<"ready or not here I come \n"< for(int i=0;i<32;i++) { temp = *( (bool*)ptr + i ); if( temp ) cout<<"1 "; if( !temp) cout<<"0 "; if(i==7||i==15||i==23) cout<<" - "; } } I get some random output even for nos. like "32" I dont get anything sensible. why ?

    Read the article

  • Illegal instruction in Assembly

    - by Natasha
    I really do not understand why this simple code works fine in the first attempt but when putting it in a procedure an error shows: NTVDM CPU has encountered an illegal instruction CS:db22 IP:4de4 OP:f0 ff ff ff ff The first code segment works just fine: .model small .stack 100h .code start: mov ax,@data mov ds,ax mov es,ax MOV AH,02H ;sets cursor up MOV BH,00H MOV DH,02 MOV DL,00 INT 10H EXIT: MOV AH,4CH INT 21H END However This generates an error: .model small .stack 100h .code start: mov ax,@data mov ds,ax mov es,ax call set_cursor PROC set_cursor near MOV AH,02H ;sets cursor up MOV BH,00H MOV DH,02 MOV DL,00 INT 10H RET set_cursor ENDP EXIT: MOV AH,4CH INT 21H END Note: Nothing is wrong with windows config. I have tried many sample codes that work fine Thanks

    Read the article

  • How *restrict / *__restrict__ works in C / C++?

    - by Moraru Lilian
    Here is some code I wrote: #include <iostream> using namespace std; int main(void) { int i = 7; int *__restrict__ a = &i; *a = 5; int *b = &i, *c = &i; *b = 8; *c = 9; cout << **&a << endl; //*a return 0; } From what I've read, if I do " *a = 5 ", it changes the value of the memory he, "a", is pointing to, after that the memory to which he is pointing to should not be modified by anyone else except "a", which means that these program is wrong because "b" and "c" modify it after that. Or, even if "b" modifies "i" first, after that only "a" should have access to that memory( "i" ). Am I getting it correctly?

    Read the article

< Previous Page | 161 162 163 164 165 166 167 168 169 170 171 172  | Next Page >