57 lines
1.5 KiB
C++
57 lines
1.5 KiB
C++
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A shared resource example.
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#include <iostream>
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#include <cstring>
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using namespace std;
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class output {
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static char sharedResource[255]; // this is the shared resource
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static int inuse; // buffer available if 0; in use otherwise
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static int oindex; // index of sharedResource
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char str[80];
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int i; // index of next char in str
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int who; // identifies the object, must be > 0
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public:
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output(int w, char *s) {
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strcpy(str, s);
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i = 0;
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who = w;
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}
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int putbuf()
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{
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if(!str[ i ]) { // done outputting
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inuse = 0; // release buffer
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return 0; // signal termination
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}
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if(!inuse) // get buffer
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inuse = who;
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if(inuse != who) // in use by someone else
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return -1;
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if(str[ i ]) { // still chars to output
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sharedResource[oindex] = str[ i ];
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i++; oindex++;
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sharedResource[oindex] = '\0';// always keep null-terminated
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return 1;
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}
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return 0;
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}
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void show() {
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cout << sharedResource << '\n';
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}
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};
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char output::sharedResource[255]; // this is the shared resource
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int output::inuse = 0; // buffer available if 0; in use otherwise
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int output::oindex = 0; // index of sharedResource
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int main()
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{
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output object1(1, "This is a test"), object2(2, " of statics");
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while(object1.putbuf() | object2.putbuf()) ; // output chars
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object1.show();
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return 0;
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}
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