--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/mupdf-source/thirdparty/openjpeg/src/lib/openjp2/thread.c	Mon Sep 15 11:43:07 2025 +0200
@@ -0,0 +1,954 @@
+/*
+ * The copyright in this software is being made available under the 2-clauses
+ * BSD License, included below. This software may be subject to other third
+ * party and contributor rights, including patent rights, and no such rights
+ * are granted under this license.
+ *
+ * Copyright (c) 2016, Even Rouault
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS `AS IS'
+ * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
+ * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+ * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+ * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+ * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+ * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#include <assert.h>
+
+#ifdef MUTEX_win32
+
+/* Some versions of x86_64-w64-mingw32-gc -m32 resolve InterlockedCompareExchange() */
+/* as __sync_val_compare_and_swap_4 but fails to link it. As this protects against */
+/* a rather unlikely race, skip it */
+#if !(defined(__MINGW32__) && defined(__i386__))
+#define HAVE_INTERLOCKED_COMPARE_EXCHANGE 1
+#endif
+
+#include <windows.h>
+#include <process.h>
+
+#include "opj_includes.h"
+
+OPJ_BOOL OPJ_CALLCONV opj_has_thread_support(void)
+{
+    return OPJ_TRUE;
+}
+
+int OPJ_CALLCONV opj_get_num_cpus(void)
+{
+    SYSTEM_INFO info;
+    DWORD dwNum;
+    GetSystemInfo(&info);
+    dwNum = info.dwNumberOfProcessors;
+    if (dwNum < 1) {
+        return 1;
+    }
+    return (int)dwNum;
+}
+
+struct opj_mutex_t {
+    CRITICAL_SECTION cs;
+};
+
+opj_mutex_t* opj_mutex_create(void)
+{
+    opj_mutex_t* mutex = (opj_mutex_t*) opj_malloc(sizeof(opj_mutex_t));
+    if (!mutex) {
+        return NULL;
+    }
+    InitializeCriticalSectionAndSpinCount(&(mutex->cs), 4000);
+    return mutex;
+}
+
+void opj_mutex_lock(opj_mutex_t* mutex)
+{
+    EnterCriticalSection(&(mutex->cs));
+}
+
+void opj_mutex_unlock(opj_mutex_t* mutex)
+{
+    LeaveCriticalSection(&(mutex->cs));
+}
+
+void opj_mutex_destroy(opj_mutex_t* mutex)
+{
+    if (!mutex) {
+        return;
+    }
+    DeleteCriticalSection(&(mutex->cs));
+    opj_free(mutex);
+}
+
+struct opj_cond_waiter_list_t {
+    HANDLE hEvent;
+    struct opj_cond_waiter_list_t* next;
+};
+typedef struct opj_cond_waiter_list_t opj_cond_waiter_list_t;
+
+struct opj_cond_t {
+    opj_mutex_t             *internal_mutex;
+    opj_cond_waiter_list_t  *waiter_list;
+};
+
+static DWORD TLSKey = 0;
+static volatile LONG inTLSLockedSection = 0;
+static volatile int TLSKeyInit = OPJ_FALSE;
+
+opj_cond_t* opj_cond_create(void)
+{
+    opj_cond_t* cond = (opj_cond_t*) opj_malloc(sizeof(opj_cond_t));
+    if (!cond) {
+        return NULL;
+    }
+
+    /* Make sure that the TLS key is allocated in a thread-safe way */
+    /* We cannot use a global mutex/critical section since its creation itself would not be */
+    /* thread-safe, so use InterlockedCompareExchange trick */
+    while (OPJ_TRUE) {
+
+#if HAVE_INTERLOCKED_COMPARE_EXCHANGE
+        if (InterlockedCompareExchange(&inTLSLockedSection, 1, 0) == 0)
+#endif
+        {
+            if (!TLSKeyInit) {
+                TLSKey = TlsAlloc();
+                TLSKeyInit = OPJ_TRUE;
+            }
+#if HAVE_INTERLOCKED_COMPARE_EXCHANGE
+            InterlockedCompareExchange(&inTLSLockedSection, 0, 1);
+#endif
+            break;
+        }
+    }
+
+    if (TLSKey == TLS_OUT_OF_INDEXES) {
+        opj_free(cond);
+        return NULL;
+    }
+    cond->internal_mutex = opj_mutex_create();
+    if (cond->internal_mutex == NULL) {
+        opj_free(cond);
+        return NULL;
+    }
+    cond->waiter_list = NULL;
+    return cond;
+}
+
+void opj_cond_wait(opj_cond_t* cond, opj_mutex_t* mutex)
+{
+    opj_cond_waiter_list_t* item;
+    HANDLE hEvent = (HANDLE) TlsGetValue(TLSKey);
+    if (hEvent == NULL) {
+        hEvent = CreateEvent(NULL, /* security attributes */
+                             0,    /* manual reset = no */
+                             0,    /* initial state = unsignaled */
+                             NULL  /* no name */);
+        assert(hEvent);
+
+        TlsSetValue(TLSKey, hEvent);
+    }
+
+    /* Insert the waiter into the waiter list of the condition */
+    opj_mutex_lock(cond->internal_mutex);
+
+    item = (opj_cond_waiter_list_t*)opj_malloc(sizeof(opj_cond_waiter_list_t));
+    assert(item != NULL);
+
+    item->hEvent = hEvent;
+    item->next = cond->waiter_list;
+
+    cond->waiter_list = item;
+
+    opj_mutex_unlock(cond->internal_mutex);
+
+    /* Release the client mutex before waiting for the event being signaled */
+    opj_mutex_unlock(mutex);
+
+    /* Ideally we would check that we do not get WAIT_FAILED but it is hard */
+    /* to report a failure. */
+    WaitForSingleObject(hEvent, INFINITE);
+
+    /* Reacquire the client mutex */
+    opj_mutex_lock(mutex);
+}
+
+void opj_cond_signal(opj_cond_t* cond)
+{
+    opj_cond_waiter_list_t* psIter;
+
+    /* Signal the first registered event, and remove it from the list */
+    opj_mutex_lock(cond->internal_mutex);
+
+    psIter = cond->waiter_list;
+    if (psIter != NULL) {
+        SetEvent(psIter->hEvent);
+        cond->waiter_list = psIter->next;
+        opj_free(psIter);
+    }
+
+    opj_mutex_unlock(cond->internal_mutex);
+}
+
+void opj_cond_destroy(opj_cond_t* cond)
+{
+    if (!cond) {
+        return;
+    }
+    opj_mutex_destroy(cond->internal_mutex);
+    assert(cond->waiter_list == NULL);
+    opj_free(cond);
+}
+
+struct opj_thread_t {
+    opj_thread_fn thread_fn;
+    void* user_data;
+    HANDLE hThread;
+};
+
+static unsigned int __stdcall opj_thread_callback_adapter(void *info)
+{
+    opj_thread_t* thread = (opj_thread_t*) info;
+    HANDLE hEvent = NULL;
+
+    thread->thread_fn(thread->user_data);
+
+    /* Free the handle possible allocated by a cond */
+    while (OPJ_TRUE) {
+        /* Make sure TLSKey is not being created just at that moment... */
+#if HAVE_INTERLOCKED_COMPARE_EXCHANGE
+        if (InterlockedCompareExchange(&inTLSLockedSection, 1, 0) == 0)
+#endif
+        {
+            if (TLSKeyInit) {
+                hEvent = (HANDLE) TlsGetValue(TLSKey);
+            }
+#if HAVE_INTERLOCKED_COMPARE_EXCHANGE
+            InterlockedCompareExchange(&inTLSLockedSection, 0, 1);
+#endif
+            break;
+        }
+    }
+    if (hEvent) {
+        CloseHandle(hEvent);
+    }
+
+    return 0;
+}
+
+opj_thread_t* opj_thread_create(opj_thread_fn thread_fn, void* user_data)
+{
+    opj_thread_t* thread;
+
+    assert(thread_fn);
+
+    thread = (opj_thread_t*) opj_malloc(sizeof(opj_thread_t));
+    if (!thread) {
+        return NULL;
+    }
+    thread->thread_fn = thread_fn;
+    thread->user_data = user_data;
+
+    thread->hThread = (HANDLE)_beginthreadex(NULL, 0,
+                      opj_thread_callback_adapter, thread, 0, NULL);
+
+    if (thread->hThread == NULL) {
+        opj_free(thread);
+        return NULL;
+    }
+    return thread;
+}
+
+void opj_thread_join(opj_thread_t* thread)
+{
+    WaitForSingleObject(thread->hThread, INFINITE);
+    CloseHandle(thread->hThread);
+
+    opj_free(thread);
+}
+
+#elif MUTEX_pthread
+
+#include <pthread.h>
+#include <stdlib.h>
+#include <unistd.h>
+
+/* Moved after all system includes, and in particular pthread.h, so as to */
+/* avoid poisoning issuing with malloc() use in pthread.h with ulibc (#1013) */
+#include "opj_includes.h"
+
+OPJ_BOOL OPJ_CALLCONV opj_has_thread_support(void)
+{
+    return OPJ_TRUE;
+}
+
+int OPJ_CALLCONV opj_get_num_cpus(void)
+{
+#ifdef _SC_NPROCESSORS_ONLN
+    return (int)sysconf(_SC_NPROCESSORS_ONLN);
+#else
+    return 1;
+#endif
+}
+
+struct opj_mutex_t {
+    pthread_mutex_t mutex;
+};
+
+opj_mutex_t* opj_mutex_create(void)
+{
+    opj_mutex_t* mutex = (opj_mutex_t*) opj_calloc(1U, sizeof(opj_mutex_t));
+    if (mutex != NULL) {
+        if (pthread_mutex_init(&mutex->mutex, NULL) != 0) {
+            opj_free(mutex);
+            mutex = NULL;
+        }
+    }
+    return mutex;
+}
+
+void opj_mutex_lock(opj_mutex_t* mutex)
+{
+    pthread_mutex_lock(&(mutex->mutex));
+}
+
+void opj_mutex_unlock(opj_mutex_t* mutex)
+{
+    pthread_mutex_unlock(&(mutex->mutex));
+}
+
+void opj_mutex_destroy(opj_mutex_t* mutex)
+{
+    if (!mutex) {
+        return;
+    }
+    pthread_mutex_destroy(&(mutex->mutex));
+    opj_free(mutex);
+}
+
+struct opj_cond_t {
+    pthread_cond_t cond;
+};
+
+opj_cond_t* opj_cond_create(void)
+{
+    opj_cond_t* cond = (opj_cond_t*) opj_malloc(sizeof(opj_cond_t));
+    if (!cond) {
+        return NULL;
+    }
+    if (pthread_cond_init(&(cond->cond), NULL) != 0) {
+        opj_free(cond);
+        return NULL;
+    }
+    return cond;
+}
+
+void opj_cond_wait(opj_cond_t* cond, opj_mutex_t* mutex)
+{
+    pthread_cond_wait(&(cond->cond), &(mutex->mutex));
+}
+
+void opj_cond_signal(opj_cond_t* cond)
+{
+    int ret = pthread_cond_signal(&(cond->cond));
+    (void)ret;
+    assert(ret == 0);
+}
+
+void opj_cond_destroy(opj_cond_t* cond)
+{
+    if (!cond) {
+        return;
+    }
+    pthread_cond_destroy(&(cond->cond));
+    opj_free(cond);
+}
+
+
+struct opj_thread_t {
+    opj_thread_fn thread_fn;
+    void* user_data;
+    pthread_t thread;
+};
+
+static void* opj_thread_callback_adapter(void* info)
+{
+    opj_thread_t* thread = (opj_thread_t*) info;
+    thread->thread_fn(thread->user_data);
+    return NULL;
+}
+
+opj_thread_t* opj_thread_create(opj_thread_fn thread_fn, void* user_data)
+{
+    pthread_attr_t attr;
+    opj_thread_t* thread;
+
+    assert(thread_fn);
+
+    thread = (opj_thread_t*) opj_malloc(sizeof(opj_thread_t));
+    if (!thread) {
+        return NULL;
+    }
+    thread->thread_fn = thread_fn;
+    thread->user_data = user_data;
+
+    pthread_attr_init(&attr);
+    pthread_attr_setdetachstate(&attr, PTHREAD_CREATE_JOINABLE);
+    if (pthread_create(&(thread->thread), &attr,
+                       opj_thread_callback_adapter, (void *) thread) != 0) {
+        opj_free(thread);
+        return NULL;
+    }
+    return thread;
+}
+
+void opj_thread_join(opj_thread_t* thread)
+{
+    void* status;
+    pthread_join(thread->thread, &status);
+
+    opj_free(thread);
+}
+
+#else
+/* Stub implementation */
+
+#include "opj_includes.h"
+
+OPJ_BOOL OPJ_CALLCONV opj_has_thread_support(void)
+{
+    return OPJ_FALSE;
+}
+
+int OPJ_CALLCONV opj_get_num_cpus(void)
+{
+    return 1;
+}
+
+opj_mutex_t* opj_mutex_create(void)
+{
+    return NULL;
+}
+
+void opj_mutex_lock(opj_mutex_t* mutex)
+{
+    (void) mutex;
+}
+
+void opj_mutex_unlock(opj_mutex_t* mutex)
+{
+    (void) mutex;
+}
+
+void opj_mutex_destroy(opj_mutex_t* mutex)
+{
+    (void) mutex;
+}
+
+opj_cond_t* opj_cond_create(void)
+{
+    return NULL;
+}
+
+void opj_cond_wait(opj_cond_t* cond, opj_mutex_t* mutex)
+{
+    (void) cond;
+    (void) mutex;
+}
+
+void opj_cond_signal(opj_cond_t* cond)
+{
+    (void) cond;
+}
+
+void opj_cond_destroy(opj_cond_t* cond)
+{
+    (void) cond;
+}
+
+opj_thread_t* opj_thread_create(opj_thread_fn thread_fn, void* user_data)
+{
+    (void) thread_fn;
+    (void) user_data;
+    return NULL;
+}
+
+void opj_thread_join(opj_thread_t* thread)
+{
+    (void) thread;
+}
+
+#endif
+
+typedef struct {
+    int key;
+    void* value;
+    opj_tls_free_func opj_free_func;
+} opj_tls_key_val_t;
+
+struct opj_tls_t {
+    opj_tls_key_val_t* key_val;
+    int                key_val_count;
+};
+
+static opj_tls_t* opj_tls_new(void)
+{
+    return (opj_tls_t*) opj_calloc(1, sizeof(opj_tls_t));
+}
+
+static void opj_tls_destroy(opj_tls_t* tls)
+{
+    int i;
+    if (!tls) {
+        return;
+    }
+    for (i = 0; i < tls->key_val_count; i++) {
+        if (tls->key_val[i].opj_free_func) {
+            tls->key_val[i].opj_free_func(tls->key_val[i].value);
+        }
+    }
+    opj_free(tls->key_val);
+    opj_free(tls);
+}
+
+void* opj_tls_get(opj_tls_t* tls, int key)
+{
+    int i;
+    for (i = 0; i < tls->key_val_count; i++) {
+        if (tls->key_val[i].key == key) {
+            return tls->key_val[i].value;
+        }
+    }
+    return NULL;
+}
+
+OPJ_BOOL opj_tls_set(opj_tls_t* tls, int key, void* value,
+                     opj_tls_free_func opj_free_func)
+{
+    opj_tls_key_val_t* new_key_val;
+    int i;
+
+    if (tls->key_val_count == INT_MAX) {
+        return OPJ_FALSE;
+    }
+    for (i = 0; i < tls->key_val_count; i++) {
+        if (tls->key_val[i].key == key) {
+            if (tls->key_val[i].opj_free_func) {
+                tls->key_val[i].opj_free_func(tls->key_val[i].value);
+            }
+            tls->key_val[i].value = value;
+            tls->key_val[i].opj_free_func = opj_free_func;
+            return OPJ_TRUE;
+        }
+    }
+    new_key_val = (opj_tls_key_val_t*) opj_realloc(tls->key_val,
+                  ((size_t)tls->key_val_count + 1U) * sizeof(opj_tls_key_val_t));
+    if (!new_key_val) {
+        return OPJ_FALSE;
+    }
+    tls->key_val = new_key_val;
+    new_key_val[tls->key_val_count].key = key;
+    new_key_val[tls->key_val_count].value = value;
+    new_key_val[tls->key_val_count].opj_free_func = opj_free_func;
+    tls->key_val_count ++;
+    return OPJ_TRUE;
+}
+
+
+typedef struct {
+    opj_job_fn          job_fn;
+    void               *user_data;
+} opj_worker_thread_job_t;
+
+typedef struct {
+    opj_thread_pool_t   *tp;
+    opj_thread_t        *thread;
+    int                  marked_as_waiting;
+
+    opj_mutex_t         *mutex;
+    opj_cond_t          *cond;
+} opj_worker_thread_t;
+
+typedef enum {
+    OPJWTS_OK,
+    OPJWTS_STOP,
+    OPJWTS_ERROR
+} opj_worker_thread_state;
+
+struct opj_job_list_t {
+    opj_worker_thread_job_t* job;
+    struct opj_job_list_t* next;
+};
+typedef struct opj_job_list_t opj_job_list_t;
+
+struct opj_worker_thread_list_t {
+    opj_worker_thread_t* worker_thread;
+    struct opj_worker_thread_list_t* next;
+};
+typedef struct opj_worker_thread_list_t opj_worker_thread_list_t;
+
+struct opj_thread_pool_t {
+    opj_worker_thread_t*             worker_threads;
+    int                              worker_threads_count;
+    opj_cond_t*                      cond;
+    opj_mutex_t*                     mutex;
+    volatile opj_worker_thread_state state;
+    opj_job_list_t*                  job_queue;
+    volatile int                     pending_jobs_count;
+    opj_worker_thread_list_t*        waiting_worker_thread_list;
+    int                              waiting_worker_thread_count;
+    opj_tls_t*                       tls;
+    int                              signaling_threshold;
+};
+
+static OPJ_BOOL opj_thread_pool_setup(opj_thread_pool_t* tp, int num_threads);
+static opj_worker_thread_job_t* opj_thread_pool_get_next_job(
+    opj_thread_pool_t* tp,
+    opj_worker_thread_t* worker_thread,
+    OPJ_BOOL signal_job_finished);
+
+opj_thread_pool_t* opj_thread_pool_create(int num_threads)
+{
+    opj_thread_pool_t* tp;
+
+    tp = (opj_thread_pool_t*) opj_calloc(1, sizeof(opj_thread_pool_t));
+    if (!tp) {
+        return NULL;
+    }
+    tp->state = OPJWTS_OK;
+
+    if (num_threads <= 0) {
+        tp->tls = opj_tls_new();
+        if (!tp->tls) {
+            opj_free(tp);
+            tp = NULL;
+        }
+        return tp;
+    }
+
+    tp->mutex = opj_mutex_create();
+    if (!tp->mutex) {
+        opj_free(tp);
+        return NULL;
+    }
+    if (!opj_thread_pool_setup(tp, num_threads)) {
+        opj_thread_pool_destroy(tp);
+        return NULL;
+    }
+    return tp;
+}
+
+static void opj_worker_thread_function(void* user_data)
+{
+    opj_worker_thread_t* worker_thread;
+    opj_thread_pool_t* tp;
+    opj_tls_t* tls;
+    OPJ_BOOL job_finished = OPJ_FALSE;
+
+    worker_thread = (opj_worker_thread_t*) user_data;
+    tp = worker_thread->tp;
+    tls = opj_tls_new();
+
+    while (OPJ_TRUE) {
+        opj_worker_thread_job_t* job = opj_thread_pool_get_next_job(tp, worker_thread,
+                                       job_finished);
+        if (job == NULL) {
+            break;
+        }
+
+        if (job->job_fn) {
+            job->job_fn(job->user_data, tls);
+        }
+        opj_free(job);
+        job_finished = OPJ_TRUE;
+    }
+
+    opj_tls_destroy(tls);
+}
+
+static OPJ_BOOL opj_thread_pool_setup(opj_thread_pool_t* tp, int num_threads)
+{
+    int i;
+    OPJ_BOOL bRet = OPJ_TRUE;
+
+    assert(num_threads > 0);
+
+    tp->cond = opj_cond_create();
+    if (tp->cond == NULL) {
+        return OPJ_FALSE;
+    }
+
+    tp->worker_threads = (opj_worker_thread_t*) opj_calloc((size_t)num_threads,
+                         sizeof(opj_worker_thread_t));
+    if (tp->worker_threads == NULL) {
+        return OPJ_FALSE;
+    }
+    tp->worker_threads_count = num_threads;
+
+    for (i = 0; i < num_threads; i++) {
+        tp->worker_threads[i].tp = tp;
+
+        tp->worker_threads[i].mutex = opj_mutex_create();
+        if (tp->worker_threads[i].mutex == NULL) {
+            tp->worker_threads_count = i;
+            bRet = OPJ_FALSE;
+            break;
+        }
+
+        tp->worker_threads[i].cond = opj_cond_create();
+        if (tp->worker_threads[i].cond == NULL) {
+            opj_mutex_destroy(tp->worker_threads[i].mutex);
+            tp->worker_threads_count = i;
+            bRet = OPJ_FALSE;
+            break;
+        }
+
+        tp->worker_threads[i].marked_as_waiting = OPJ_FALSE;
+
+        tp->worker_threads[i].thread = opj_thread_create(opj_worker_thread_function,
+                                       &(tp->worker_threads[i]));
+        if (tp->worker_threads[i].thread == NULL) {
+            opj_mutex_destroy(tp->worker_threads[i].mutex);
+            opj_cond_destroy(tp->worker_threads[i].cond);
+            tp->worker_threads_count = i;
+            bRet = OPJ_FALSE;
+            break;
+        }
+    }
+
+    /* Wait all threads to be started */
+    /* printf("waiting for all threads to be started\n"); */
+    opj_mutex_lock(tp->mutex);
+    while (tp->waiting_worker_thread_count < tp->worker_threads_count) {
+        opj_cond_wait(tp->cond, tp->mutex);
+    }
+    opj_mutex_unlock(tp->mutex);
+    /* printf("all threads started\n"); */
+
+    if (tp->state == OPJWTS_ERROR) {
+        bRet = OPJ_FALSE;
+    }
+
+    return bRet;
+}
+
+/*
+void opj_waiting()
+{
+    printf("waiting!\n");
+}
+*/
+
+static opj_worker_thread_job_t* opj_thread_pool_get_next_job(
+    opj_thread_pool_t* tp,
+    opj_worker_thread_t* worker_thread,
+    OPJ_BOOL signal_job_finished)
+{
+    while (OPJ_TRUE) {
+        opj_job_list_t* top_job_iter;
+
+        opj_mutex_lock(tp->mutex);
+
+        if (signal_job_finished) {
+            signal_job_finished = OPJ_FALSE;
+            tp->pending_jobs_count --;
+            /*printf("tp=%p, remaining jobs: %d\n", tp, tp->pending_jobs_count);*/
+            if (tp->pending_jobs_count <= tp->signaling_threshold) {
+                opj_cond_signal(tp->cond);
+            }
+        }
+
+        if (tp->state == OPJWTS_STOP) {
+            opj_mutex_unlock(tp->mutex);
+            return NULL;
+        }
+        top_job_iter = tp->job_queue;
+        if (top_job_iter) {
+            opj_worker_thread_job_t* job;
+            tp->job_queue = top_job_iter->next;
+
+            job = top_job_iter->job;
+            opj_mutex_unlock(tp->mutex);
+            opj_free(top_job_iter);
+            return job;
+        }
+
+        /* opj_waiting(); */
+        if (!worker_thread->marked_as_waiting) {
+            opj_worker_thread_list_t* item;
+
+            worker_thread->marked_as_waiting = OPJ_TRUE;
+            tp->waiting_worker_thread_count ++;
+            assert(tp->waiting_worker_thread_count <= tp->worker_threads_count);
+
+            item = (opj_worker_thread_list_t*) opj_malloc(sizeof(opj_worker_thread_list_t));
+            if (item == NULL) {
+                tp->state = OPJWTS_ERROR;
+                opj_cond_signal(tp->cond);
+
+                opj_mutex_unlock(tp->mutex);
+                return NULL;
+            }
+
+            item->worker_thread = worker_thread;
+            item->next = tp->waiting_worker_thread_list;
+            tp->waiting_worker_thread_list = item;
+        }
+
+        /* printf("signaling that worker thread is ready\n"); */
+        opj_cond_signal(tp->cond);
+
+        opj_mutex_lock(worker_thread->mutex);
+        opj_mutex_unlock(tp->mutex);
+
+        /* printf("waiting for job\n"); */
+        opj_cond_wait(worker_thread->cond, worker_thread->mutex);
+
+        opj_mutex_unlock(worker_thread->mutex);
+        /* printf("got job\n"); */
+    }
+}
+
+OPJ_BOOL opj_thread_pool_submit_job(opj_thread_pool_t* tp,
+                                    opj_job_fn job_fn,
+                                    void* user_data)
+{
+    opj_worker_thread_job_t* job;
+    opj_job_list_t* item;
+
+    if (tp->mutex == NULL) {
+        job_fn(user_data, tp->tls);
+        return OPJ_TRUE;
+    }
+
+    job = (opj_worker_thread_job_t*)opj_malloc(sizeof(opj_worker_thread_job_t));
+    if (job == NULL) {
+        return OPJ_FALSE;
+    }
+    job->job_fn = job_fn;
+    job->user_data = user_data;
+
+    item = (opj_job_list_t*) opj_malloc(sizeof(opj_job_list_t));
+    if (item == NULL) {
+        opj_free(job);
+        return OPJ_FALSE;
+    }
+    item->job = job;
+
+    opj_mutex_lock(tp->mutex);
+
+    tp->signaling_threshold = 100 * tp->worker_threads_count;
+    while (tp->pending_jobs_count > tp->signaling_threshold) {
+        /* printf("%d jobs enqueued. Waiting\n", tp->pending_jobs_count); */
+        opj_cond_wait(tp->cond, tp->mutex);
+        /* printf("...%d jobs enqueued.\n", tp->pending_jobs_count); */
+    }
+
+    item->next = tp->job_queue;
+    tp->job_queue = item;
+    tp->pending_jobs_count ++;
+
+    if (tp->waiting_worker_thread_list) {
+        opj_worker_thread_t* worker_thread;
+        opj_worker_thread_list_t* next;
+        opj_worker_thread_list_t* to_opj_free;
+
+        worker_thread = tp->waiting_worker_thread_list->worker_thread;
+
+        assert(worker_thread->marked_as_waiting);
+        worker_thread->marked_as_waiting = OPJ_FALSE;
+
+        next = tp->waiting_worker_thread_list->next;
+        to_opj_free = tp->waiting_worker_thread_list;
+        tp->waiting_worker_thread_list = next;
+        tp->waiting_worker_thread_count --;
+
+        opj_mutex_lock(worker_thread->mutex);
+        opj_mutex_unlock(tp->mutex);
+        opj_cond_signal(worker_thread->cond);
+        opj_mutex_unlock(worker_thread->mutex);
+
+        opj_free(to_opj_free);
+    } else {
+        opj_mutex_unlock(tp->mutex);
+    }
+
+    return OPJ_TRUE;
+}
+
+void opj_thread_pool_wait_completion(opj_thread_pool_t* tp,
+                                     int max_remaining_jobs)
+{
+    if (tp->mutex == NULL) {
+        return;
+    }
+
+    if (max_remaining_jobs < 0) {
+        max_remaining_jobs = 0;
+    }
+    opj_mutex_lock(tp->mutex);
+    tp->signaling_threshold = max_remaining_jobs;
+    while (tp->pending_jobs_count > max_remaining_jobs) {
+        /*printf("tp=%p, jobs before wait = %d, max_remaining_jobs = %d\n", tp, tp->pending_jobs_count, max_remaining_jobs);*/
+        opj_cond_wait(tp->cond, tp->mutex);
+        /*printf("tp=%p, jobs after wait = %d\n", tp, tp->pending_jobs_count);*/
+    }
+    opj_mutex_unlock(tp->mutex);
+}
+
+int opj_thread_pool_get_thread_count(opj_thread_pool_t* tp)
+{
+    return tp->worker_threads_count;
+}
+
+void opj_thread_pool_destroy(opj_thread_pool_t* tp)
+{
+    if (!tp) {
+        return;
+    }
+    if (tp->cond) {
+        int i;
+        opj_thread_pool_wait_completion(tp, 0);
+
+        opj_mutex_lock(tp->mutex);
+        tp->state = OPJWTS_STOP;
+        opj_mutex_unlock(tp->mutex);
+
+        for (i = 0; i < tp->worker_threads_count; i++) {
+            opj_mutex_lock(tp->worker_threads[i].mutex);
+            opj_cond_signal(tp->worker_threads[i].cond);
+            opj_mutex_unlock(tp->worker_threads[i].mutex);
+            opj_thread_join(tp->worker_threads[i].thread);
+            opj_cond_destroy(tp->worker_threads[i].cond);
+            opj_mutex_destroy(tp->worker_threads[i].mutex);
+        }
+
+        opj_free(tp->worker_threads);
+
+        while (tp->waiting_worker_thread_list != NULL) {
+            opj_worker_thread_list_t* next = tp->waiting_worker_thread_list->next;
+            opj_free(tp->waiting_worker_thread_list);
+            tp->waiting_worker_thread_list = next;
+        }
+
+        opj_cond_destroy(tp->cond);
+    }
+    opj_mutex_destroy(tp->mutex);
+    opj_tls_destroy(tp->tls);
+    opj_free(tp);
+}