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POnaming threads, using typedef/struct
 

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  1. POnaming threads, using typedef/struct
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    <p>I am creating a program to practice using threads. I am trying to name them so that when the program is run, you can clearly see "Flight 1 is taking off..." or "Flight 6 is landing..." and so on. I would like every thread to have a flyTime (so I know what order they will use the runway in) which will be randomly generated. I have tried and am having difficulty using struct/typedef to give each pthread these characteristics so i can say for example flight.flyTime and use it throughout the program. Here is the relevant part of my code without my landing/takeoff functions:</p> <pre><code>#include &lt;pthread.h&gt; #include &lt;stdio.h&gt; #include &lt;cstdlib&gt; #include &lt;iostream&gt; #include &lt;queue&gt; #define NUM_THREADS 8 //8 flights pthread_mutex_t runway1lock; void *FlightID(void *flightid){ long fid; fid = (long)flightid; pthread_exit(NULL); } typedef struct{ //each plane has these characteristics long fid; int StartState; // if start=1 ==&gt; taking off:::if start=2 ==&gt; landing int flyTime; //fly == randomly generated time (order) }FLIGHTS; FLIGHTS flights[NUM_THREADS]; int StartState(flights[NUM_THREADS]){ int startState; for (int i=0; i&lt;=NUM_THREADS; i++){ startState = rand() % 1+2; } std::string start; if(startState == 1){ start = "Taking off"; } if(startState == 2){ start = "Landing"; } for (int t=0; t&lt;NUM_THREADS; t++){ std::cout &lt;&lt; "Start State for Flight# " &lt;&lt; FlightID &lt;&lt; " is " &lt;&lt; start &lt;&lt; std::endl; } return startState; } int main(int argc, char *argv[]){ // pthread_t flights[NUM_THREADS]; //pthread_t keeps a thread ID after the thread is created with pthread_create() //it's like an index on a vector of threads int rc; long t; for (t=1; t&lt;=NUM_THREADS; t++){ //loop creates threads(flights) printf("In main: Creating flight %1d\n", t); rc = pthread_create(&amp;flights[t], NULL, FlightID, (void *)t); if (rc){ printf("ERROR: return code from pthread_create() is %d\n", rc); return (-1); } printf("Created flight %1d\n", t); StartState(flights[t]); //gives every flight a start state if(StartState(flights[t])==1){ std::cout &lt;&lt; "Flight # " &lt;&lt; &amp;flights[t] &lt;&lt; " is listed as waiting at the gate." &lt;&lt; std::endl; //go to takeoff function and go through switch case } if(StartState(flights[t])==2){`enter code here` std::cout &lt;&lt; "Flight # " &lt;&lt; &amp;flights[t] &lt;&lt; " is listed as waiting to land." &lt;&lt; std::endl; //go to landing function and go through switch case } } pthread_exit(NULL); } </code></pre>
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    1. COwhy don't you use C++ threads? Your code looks very much like C with some C++ extensions ...
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    2. COTo be honest I'm not familiar with C or C++ so I wouldn't be sure how to use threads any differently than above. I can successfully print out "Creating flight 1, Created flight 1, creating flight 2, created flight 2" and so on, but that uses %1d -- when I get down to the use of FlightID... "Flight #1 is listed as waiting to land" prints several times, which means FlightID didn't get assigned to each thread (rather than &flights[t]) as I had intended it to
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      1. USAnna
    3. COit's still unclear what you're actually trying to achieve. Perhaps you can generate a SSCCE?
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      1. USWalter
 

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