--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/lib/ctx.h	Thu Dec 31 16:40:13 2009 +0200
@@ -0,0 +1,75 @@
+#ifndef PNGTILE_CTX_H
+#define PNGTILE_CTX_H
+
+/**
+ * Shared context between images, used to provide a threadpool for parralelizing tile operations
+ */
+#include "pngtile.h"
+
+#include <pthread.h>
+#include <sys/queue.h>
+#include <stdbool.h>
+
+/**
+ * Worker thread
+ */
+struct pt_thread {
+    /** Shared context */
+    struct pt_ctx *ctx;
+
+    /** Thread handle */
+    pthread_t tid;
+
+    /** @see pt_ctx::threads */
+    TAILQ_ENTRY(pt_thread) ctx_threads;
+};
+
+/**
+ * Work function
+ */
+typedef void (*pt_work_func) (void *arg);
+
+/**
+ * Work that needs to be done
+ */
+struct pt_work {
+    /** Work func */
+    pt_work_func func;
+
+    /** Work info */
+    void *arg;
+    
+    /** @see pt_ctx::work */
+    TAILQ_ENTRY(pt_work) ctx_work;
+};
+
+/**
+ * Shared context
+ */
+struct pt_ctx {
+    /** Accepting new work */
+    bool running;
+
+    /** Threadpool */
+    TAILQ_HEAD(pt_ctx_threads, pt_thread) threads;
+
+    /** Pending work */
+    TAILQ_HEAD(pt_ctx_work, pt_work) work;
+
+    /** Control access to ::work */
+    pthread_mutex_t work_mutex;
+
+    /** Wait for work to become available */
+    pthread_cond_t work_cond;
+
+    /** Thread is idle */
+    pthread_cond_t idle_cond;
+};
+
+/**
+ * Enqueue a work unit
+ */
+int pt_ctx_work (struct pt_ctx *ctx, pt_work_func func, void *arg);
+
+
+#endif