Author: wyoung
Date: Thu Jan 3 18:14:44 2008
New Revision: 2081
URL: http://svn.gna.org/viewcvs/mysqlpp?rev=2081&view=rev
Log:
Initial version of cpoolp example completed
Modified:
trunk/README-examples.txt
trunk/examples/cpoolp.cpp
Modified: trunk/README-examples.txt
URL:
http://svn.gna.org/viewcvs/mysqlpp/trunk/README-examples.txt?rev=2081&r1=2080&r2=2081&view=diff
==============================================================================
--- trunk/README-examples.txt (original)
+++ trunk/README-examples.txt Thu Jan 3 18:14:44 2008
@@ -105,6 +105,9 @@
returned row. This example uses this to gather statistics
on the sample table's contents.
+ cpoolp, cpoolw: Respectively, the POSIX and Windows threads
+ variants of the ConnectionPool class demonstration.
+
load_jpeg: Inserts a JPEG file into the sample database,
for use by the cgi_jpeg example. (See below.) Unlike the
other examples, this one takes anything given on the
Modified: trunk/examples/cpoolp.cpp
URL:
http://svn.gna.org/viewcvs/mysqlpp/trunk/examples/cpoolp.cpp?rev=2081&r1=2080&r2=2081&view=diff
==============================================================================
--- trunk/examples/cpoolp.cpp (original)
+++ trunk/examples/cpoolp.cpp Thu Jan 3 18:14:44 2008
@@ -25,11 +25,12 @@
***********************************************************************/
#include "cmdline.h"
-#include "printdata.h"
#include <mysql++.h>
#include <iostream>
+
+#include "../config.h"
using namespace std;
@@ -67,7 +68,7 @@
// Create connection using the parameters we were passed upon
// creation. This could be something much more complex, but for
// the purposes of the example, this suffices.
- cout << "Creating new pooled connection..." << endl;
+ cout << endl << "Creating new pooled connection!" << endl;
return new mysqlpp::Connection(
db_.empty() ? 0 : db_.c_str(),
server_.empty() ? 0 : server_.c_str(),
@@ -79,7 +80,7 @@
{
// Our superclass can't know how we created the Connection, so
// it delegates destruction to us, to be safe.
- cout << "Destroying pooled connection..." << endl;
+ cout << endl << "Destroying pooled connection!" << endl;
delete cp;
}
@@ -98,9 +99,51 @@
*poolptr = 0;
+#if defined(HAVE_PTHREAD)
+static void*
+worker_thread(void* running_flag)
+{
+ // Pull data from the sample table a bunch of times, releasing the
+ // connection we use each time.
+ for (int i = 0; i < 6; ++i) {
+ // Go get a free connection from the pool, or create a new one
+ // if there are no free conns yet.
+ mysqlpp::Connection* cp = poolptr->grab();
+ if (!cp) {
+ cerr << "Failed to get a connection from the pool!" <<
endl;
+ break;
+ }
+
+ // Pull a copy of the sample stock table and print a dot for
+ // each row in the result set.
+ mysqlpp::Query query(cp->query("select * from stock"));
+ mysqlpp::StoreQueryResult res = query.store();
+ for (int j = 0; j < res.num_rows(); ++j) {
+ cout.put('.');
+ }
+
+ // Immediately release the connection once we're done using it.
+ // If we don't, the pool can't detect idle connections reliably.
+ poolptr->release(cp);
+
+ // Delay 1-4 seconds before doing it again. Because this can
+ // delay longer than the idle timeout, we'll occasionally force
+ // the creation of a new connection on the next loop.
+ sleep(rand() % 4 + 1);
+ }
+
+ // Tell main() that this thread is no longer running
+ *reinterpret_cast<bool*>(running_flag) = false;
+
+ return 0;
+}
+#endif // defined(HAVE_PTHREAD)
+
+
int
main(int argc, char *argv[])
{
+#if defined(HAVE_PTHREAD)
// Get database access parameters from command line
const char* db = 0, *server = 0, *user = 0, *pass = "";
if (!parse_command_line(argc, argv, &db, &server, &user, &pass)) {
@@ -130,9 +173,38 @@
// Setup complete. Now let's spin some threads...
cout << "Pool created and working correctly. Now to do some "
"real work..." << endl;
+ srand(time(0));
+ bool running[] = {
+ true, true, true, true, true, true, true,
+ true, true, true, true, true, true, true };
+ const int num_threads = sizeof(running) / sizeof(running[0]);
+ int i;
+ for (i = 0; i < num_threads; ++i) {
+ pthread_t pt;
+ int err = pthread_create(&pt, 0, worker_thread, running + i);
+ if (err != 0) {
+ cerr << "Failed to create thread " << i <<
+ ": error code " << err << endl;
+ return 1;
+ }
+ }
+
+ // Test the 'running' flags every second until we find that they're
+ // all turned off, indicating that all threads are stopped.
+ cout << endl << "Waiting for threads to complete..." << endl;
+ do {
+ sleep(1);
+ i = 0;
+ while (i < num_threads && !running[i]) ++i;
+ }
+ while (i < num_threads);
+ cout << endl << "All threads stopped!" << endl;
// Shut it all down...
delete poolptr;
+#else
+ cout << argv[0] << " requires pthreads to function!" << endl;
+#endif
return 0;
}
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