added POOL_tryAdd()

lib/common/pool.h

@@ -17,7 +17,8 @@ extern "C" {
 
 
 #include <stddef.h>   /* size_t */
-#include "zstd_internal.h"   /* ZSTD_customMem */
+#define ZSTD_STATIC_LINKING_ONLY   /* ZSTD_customMem */
+#include "zstd.h"
 
 typedef struct POOL_ctx_s POOL_ctx;
 
@@ -27,35 +28,43 @@ typedef struct POOL_ctx_s POOL_ctx;
  *  The maximum number of queued jobs before blocking is `queueSize`.
  * @return : POOL_ctx pointer on success, else NULL.
 */
-POOL_ctx *POOL_create(size_t numThreads, size_t queueSize);
+POOL_ctx* POOL_create(size_t numThreads, size_t queueSize);
 
-POOL_ctx *POOL_create_advanced(size_t numThreads, size_t queueSize, ZSTD_customMem customMem);
+POOL_ctx* POOL_create_advanced(size_t numThreads, size_t queueSize, ZSTD_customMem customMem);
 
 /*! POOL_free() :
     Free a thread pool returned by POOL_create().
 */
-void POOL_free(POOL_ctx *ctx);
+void POOL_free(POOL_ctx* ctx);
 
 /*! POOL_sizeof() :
     return memory usage of pool returned by POOL_create().
 */
-size_t POOL_sizeof(POOL_ctx *ctx);
+size_t POOL_sizeof(POOL_ctx* ctx);
 
 /*! POOL_function :
     The function type that can be added to a thread pool.
 */
-typedef void (*POOL_function)(void *);
+typedef void (*POOL_function)(void*);
 /*! POOL_add_function :
     The function type for a generic thread pool add function.
 */
-typedef void (*POOL_add_function)(void *, POOL_function, void *);
+typedef void (*POOL_add_function)(void*, POOL_function, void*);
 
 /*! POOL_add() :
-    Add the job `function(opaque)` to the thread pool.
+    Add the job `function(opaque)` to the thread pool. `ctx` must be valid.
     Possibly blocks until there is room in the queue.
     Note : The function may be executed asynchronously, so `opaque` must live until the function has been completed.
 */
-void POOL_add(void *ctx, POOL_function function, void *opaque);
+void POOL_add(POOL_ctx* ctx, POOL_function function, void* opaque);
+
+
+/*! POOL_tryAdd() :
+    Add the job `function(opaque)` to the thread pool if a worker is available.
+    return immediately otherwise.
+   @return : 1 if successful, 0 if not.
+*/
+int POOL_tryAdd(POOL_ctx* ctx, POOL_function function, void* opaque);
 
 
 #if defined (__cplusplus)