aboutsummaryrefslogtreecommitdiff
path: root/gold/workqueue-internal.h
diff options
context:
space:
mode:
authorIan Lance Taylor <iant@google.com>2007-12-14 19:00:21 +0000
committerIan Lance Taylor <iant@google.com>2007-12-14 19:00:21 +0000
commit17a1d0a9b26ce8f4f71073c41483baa0c10ed83b (patch)
tree3cdd95751145e2cf1cbcaedee2df8790c86b935d /gold/workqueue-internal.h
parent7004837e8d2e02ee35c50d236681e9c30a283619 (diff)
downloadgdb-17a1d0a9b26ce8f4f71073c41483baa0c10ed83b.zip
gdb-17a1d0a9b26ce8f4f71073c41483baa0c10ed83b.tar.gz
gdb-17a1d0a9b26ce8f4f71073c41483baa0c10ed83b.tar.bz2
Rewrite workqueue. This version eliminates the master thread, and
reduces the amount of locking required to find a new thread to run.
Diffstat (limited to 'gold/workqueue-internal.h')
-rw-r--r--gold/workqueue-internal.h86
1 files changed, 33 insertions, 53 deletions
diff --git a/gold/workqueue-internal.h b/gold/workqueue-internal.h
index d9fd160..201caa4 100644
--- a/gold/workqueue-internal.h
+++ b/gold/workqueue-internal.h
@@ -24,6 +24,7 @@
#define GOLD_WORKQUEUE_INTERNAL_H
#include <queue>
+#include <csignal>
#include "gold-threads.h"
#include "workqueue.h"
@@ -36,92 +37,71 @@ namespace gold
class Workqueue_thread;
-// The Workqueue_runner abstract class. This is the interface used by
-// the general workqueue code to actually run a task.
+// The Workqueue_threader abstract class. This is the interface used
+// by the general workqueue code to manage threads.
-class Workqueue_runner
+class Workqueue_threader
{
public:
- Workqueue_runner(Workqueue* workqueue)
+ Workqueue_threader(Workqueue* workqueue)
: workqueue_(workqueue)
{ }
- virtual ~Workqueue_runner()
+ virtual ~Workqueue_threader()
{ }
- // Run a task. This is always called in the main thread.
- virtual void
- run(Task*, Task_locker*) = 0;
-
// Set the number of threads to use. This is ignored when not using
// threads.
virtual void
set_thread_count(int) = 0;
- protected:
- // This is called by an implementation when a task is completed.
- void completed(Task* t, Task_locker* tl)
- { this->workqueue_->completed(t, tl); }
+ // Return whether to cancel the current thread.
+ virtual bool
+ should_cancel_thread() = 0;
- Workqueue* get_workqueue() const
+ protected:
+ // Get the Workqueue.
+ Workqueue*
+ get_workqueue()
{ return this->workqueue_; }
private:
+ // The Workqueue.
Workqueue* workqueue_;
};
-// The threaded instantiation of Workqueue_runner.
+// The threaded instantiation of Workqueue_threader.
-class Workqueue_runner_threadpool : public Workqueue_runner
+class Workqueue_threader_threadpool : public Workqueue_threader
{
public:
- Workqueue_runner_threadpool(Workqueue* workqueue);
+ Workqueue_threader_threadpool(Workqueue*);
- ~Workqueue_runner_threadpool();
-
- void
- run(Task*, Task_locker*);
+ ~Workqueue_threader_threadpool();
+ // Set the thread count.
void
set_thread_count(int);
- private:
- // This class can not be copied.
- Workqueue_runner_threadpool(const Workqueue_runner_threadpool&);
- Workqueue_runner_threadpool& operator=(const Workqueue_runner_threadpool&);
-
- // Return the next Task and Task_locker to run. This returns false
- // if the calling thread should simply exit.
+ // Return whether to cancel a thread.
bool
- get_next(Task**, Task_locker**);
+ should_cancel_thread();
- // This is called when the thread completes a task.
+ // Process all tasks. This keeps running until told to cancel.
void
- thread_completed(Task*, Task_locker*);
-
- // The Workqueue_thread class calls functions from this and from the
- // parent Workqueue_runner.
- friend class Workqueue_thread;
-
- // An entry on the queue of tasks to run.
- typedef std::pair<Task*, Task_locker*> Task_queue_entry;
+ process(int thread_number)
+ { this->get_workqueue()->process(thread_number); }
- // A queue of tasks to run.
- typedef std::queue<Task_queue_entry> Task_queue;
+ private:
+ // This is set if we need to check the thread count.
+ volatile sig_atomic_t check_thread_count_;
- // The number of threads we want to create. This is only changed in
- // the main thread or when only one thread is running. This is set
- // to zero when all threads should exit.
- int desired_thread_count_;
- // A lock controlling access to the remaining fields.
+ // Lock for the remaining members.
Lock lock_;
- // The number of threads we have created.
- int actual_thread_count_;
- // The number of threads which are running a task.
- int running_thread_count_;
- // A queue of tasks to run.
- Task_queue task_queue_;
- // A condition variable which signals when the task_queue_ changed.
- Condvar task_queue_condvar_;
+ // The number of threads we want to create. This is set to zero
+ // when all threads should exit.
+ int desired_thread_count_;
+ // The number of threads currently running.
+ int threads_;
};
} // End namespace gold.